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  • ISSN 1008-9357
  • CN 31-1633/O6
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Theoretical Studies on the Thermal Stability of New Types of High Temperature Resistant Resins
WU Xiaowei, ZHU Weihua
 doi: 10.14133/j.cnki.1008-9357.20210804001
[Abstract](0) [FullText HTML](0) x[PDF 4929KB](0)
The development of new resins with high heat resistance and excellent processing properties is of great significance to aerospace, communications, and electronics fields. In this work, density functional theory (DFT) was used to systematically study the bond dissociation energies (BDEs) of main bonds in a series of new heat-resistant silane-arylacetylene resin, aromatic heterocyclic-containing resin, and cyano-containing resin molecules. The DFT-B3LYP functional and 6-31g(d,p) basis set were adopted to make all resin molecules relax fully. The vibrational analysis results show that all resin molecules have no imaginary frequency, indicating that they correspond to the stable configuration on their potential energy surfaces. Then, we calculated the BDEs of the main chemical bonds in all resin molecules. This article mainly studies the thermal stability of resin monomer molecules, so the thermal stability of the monomer molecules can be measured by calculating the BDEs of the main bonds in the resin monomer molecules. In fact, the curing reaction of the resin monomer molecules at high temperatures usually occurs on the branches, while the ring remains unchanged. The heterocyclic ring is aromatic, and the BDE value of the bond on the ring is higher than that of the non-cyclic bond. Therefore, the BDE value of the bond on the heterocyclic ring and the benzene ring in the resin monomer molecule is not considered in this work. At the same time, the reactants and free radical products were optimized and the vibrational analysis was performed. The results show that the cyano-containing resin molecules have higher thermal stability than the silane-aryne-containing resin molecules and aromatic heterocyclic-containing resin molecules, indicating that the introduction of cyano groups into the resin molecules is more helpful for improving their thermal stability than the introduction of silane-arylalkynyl and aromatic heterocycles groups. Our studies found the weakest bond in each resin molecule and revealed the essence of its thermal stability at the microscopic level. This provides a theoretical basis for the design, synthesis, and application of new high temperature resistant resins.
Preparation and Properties of Polybutyrolactam/Chitosan Electrospun Composite Fiber Membranes with Nano-cobweb Structure
ZENG Beidi, CHEN Tao, ZHAO Liming
 doi: 10.14133/j.cnki.1008-9357.20210603001
[Abstract](0) [FullText HTML](0) x[PDF 5323KB](0)
Nano-cobweb fibers supported by conventional electrospun fibers are 2D membranes with structure similar to spider webs, for which the average diameter is less than 50 nm and can be potentially applied in the fields of fine filter, sensor, tissue engineering, high performance protective clothing etc. Herein, polybutyrolactamide (PBL) and chitosan (CS), both derived from biomass and are biodegradable, were applied to construct the electrospun composite fiber membranes with nano-cobweb structure. The effects of blending ratio of PBL to CS and the solution concentration on solution properties as well as the fiber morphology and membrane structure were investigated. The cell compatibility of the electrospun composite fiber membranes was also discussed. It is found that the addition of polycationic CS improved the spinnability of PBL/FA solutions and the composite fibers could be continually electrospun. As the proportion of CS was increased, the conductivity and viscosity of the solutions both increased. Varying CS mass fraction in PBL/CS blend from 10% to 30% at fixed solution mass fraction of 8.0%, the solution viscosity increased even more than the conductivity did, and only fiber membranes without nano- cobweb structure were obtained. Increasing solution concentration also increased the solution conductivity and viscosity, but the increase in conductivity was more significant, which proved to be beneficial to electrospinning composite fiber membranes with nano-cobweb structure. When CS mass fraction in PBL/CS blend was 10, increasing solution mass fraction from 8.0% to 9.0% didn’t help to get nano-cobweb structure. The nano-cobweb structure with breakages was obtained when CS mass fraction was 20% at the solution mass fraction of 10.0. The composite fiber membranes with perfect nano-cobweb structure and 100% coverage could be electrospun by further increasing CS content and solution mass fraction to 30% and 11.0%, respectively. The results of Fourier Transform infrared spectroscopy (FI-IR) and X-ray diffraction (XRD) indicate that the addition of CS inhibited the crystallization of PBL and the composite fibers were of low crystallinity and even amorphous. The results of MTT assay confirmed that PBL/CS electrospun composite fiber membranes were noncytotoxic and could promote cell proliferation, especially for those with nano-cobweb structures. Such biobased and biodegradable composite fiber membranes are promising materials in the field of wound-dressing, nerve repairing and regenerative tissue engineering.
Curing Behavior of Poly(silicon alkyne imide) (PSI) Resin
GUO Yalin, CUI Hong, SONG Shuang, GAO Liang, LIN Jiaping, LIU Yijia, YU Huiqin, LIU Xiaohong
 doi: 10.14133/j.cnki.1008-9357.2021080900
[Abstract](9) [FullText HTML](8) x[PDF 5476KB](4)
The curing behavior of poly(silicon-alkyne imide) (PSI) resin, which is copolymerized by the polyimide (ATPI) designed by a materials genome approach and the silicon-containing arylacetylene (PSA), has been studied in this paper to meet the need of application study and property assessment of PSI resin. The characterization of PSI resin molecular structure, the DSC test of PSI resin, the analysis of the cure kinetics and rheological behavior for PSI resin were carried out and the curing processing of PSI resin was determined. The results indicated that PSI resin is cured by the reaction of alkynyl groups at the molecular of the copolymer according to Infrared spectroscopy (IR) analysis and thermogravimetric analysis (TGA) of PSI resin prior to and after curing. The initial reaction temperature and reaction enthalpy are relatively high when PSI resin is cured and the reaction heat is released at a relatively small temperature range. The activation energy, frequency factor and reaction order from analysis of the cure kinetics for the PSI resin curing reaction are 83.2kJ/mol, 5.0×1012s−1, and 0.93 respectively. The curing processing of the PSI resin is initially determined to be 160℃, 3 h→190℃, 2 h→220℃, 2 h→250℃, 4 h.
Structures of Hierarchical Nanowires Analyzed by Static Light Scattering Characterization and Dissipative Particle Dynamics Simulation
YANG Wenyi, WU Fangsheng, WANG Liquan, LIN Jiaping
 doi: 10.14133/j.cnki.1008-9357.20210610002
[Abstract](20) [FullText HTML](28) x[PDF 5370KB](4)
The micelles self-assembled from poly (γ-benzyl L-glutamate)-g-polyethylene glycol (PBLG-g-PEG) can further assemble into hierarchical nanowires under low-temperature conditions. To obtain the structure information of nanowires in solution, we combined the static light scattering characterization and dissipative particle dynamics simulation to study and analyze the state of hierarchical nanowires in solution and further discussed the effects of initial mixed solvent and growth time on nanowires. The results showed that the dependence of the shape factor on scattering wave vectors is closely related to the length scale, which reveals the structure of nanowires with various degrees of polymerization. The nanowires formed by hierarchical self-assembly can be comparable with polymers, which shows the characteristics of rigid polymers, which are closely related to the ordered arrangement of the PBLG chain. The research work clarifies the state of hierarchical nanowires in solutions and provides a means for analyzing assembly structure in solutions.
Lateral Size Dependence of Graphene Oxide in Modifying Shape Memory Polymer Fibers
XUE Sutong, WANG Xianliu, YI Bingcheng, GUO Xuran, TANG Han, SHEN Yanbing, ZHANG Yanzhong
 doi: 10.14133/j.cnki.1008-9357.20210411001
[Abstract](136) [FullText HTML](70) x[PDF 1598KB](45)
Graphene oxide (GO) with different lateral sizes was doped into the shape memory capable fibers of poly(L-lactic acid)/poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PLLA/PHBV) via electrospinning. A series of characterizing techniques such as Raman spectroscopy (Raman), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and differential scanning calorimetry (DSC) were employed to characterize the structure and thermal properties of the composite fibers. Thereafter, shape memory properties were determined by performing dynamic mechanical analysis (DMA), shape recovery stress, and photothermal effect tests. Lastly, the effect of GO lateral sizes on the osteodifferentiation capacity of bone marrow stromal cells (BMSCs) cultured on the fibrous PLLA/PHBV mats was examined by conducting cell proliferation and osteodifferentiation relevant assays. It was found that incorporation of small-sized GO (sGO) into the fiber matrix gave rise to the most significant reinforcing effects on the mechanical strengthening and shape recovery capability of the fibrous PLLA/PHBV mats, with the tensile Young's modulus increased by about 124%, the shape recovery stress increased by about 29%, the shape recovery rate increased by about 47%, and the thermal responsive rate increased by about 30-fold. In terms of osteogenic performance, the PLLA/PHBV fibers doped with large-sized GO (lGO) demonstrated the best osteogenic induction capacity in BMSCs, with the secreted alkaline phosphatase (ALP) increased by 92% and the calcium deposits by 133%.
Design and Preparation of pH/Temperature Stimulated Responsive Core-Shell Mesoporous Silica Nanoparticles
CHEN Haowen, CHEN Miaoxin, LIU Yehong, ZHANG Yuhua, XU Shouhong
 doi: 10.14133/j.cnki.1008-9357.20210402001
[Abstract](171) [FullText HTML](95) x[PDF 1252KB](41)
Premature leakage of drugs into the bloodstream remains a problem in the process of drug delivery, resulting in higher toxic and side effects on normal tissue cells. Novel drug carriers enabling effective drug accumulation in the tumor site have got much attention of researchers. Poly (methyl acrylic acid diisopropyl amino ethyl ester) (PDPA) is a polymer with pH-sensitive response, the diisopropylamine in the side chains are protonated in an acidic environment, resulting in its changing from hydrophobic to hydrophilic. PDPA was grafted onto the surface of mesoporous silica nanoparticles (MSNs) by atom transfer radical polymerization (ATRP) reaction. Then folic acid (FA) was introduced onto PDPA as a targeting ligand for enabling the drug carrier to enter tumor cells effectively. Simultaneously P(MEO2MA90-co-OEGMA10)-b-PDPA10 (poly [di (ethylene glycol) methyl ether methacrylate-co-oligo (ethylene glycol) methacrylate]-b-poly[methyl acrylic acid diisopropyl amino ethyl ester]) with dual sensitivity of temperature and pH was synthesized and the lower critical solution temperatures (LCST) of the polymer was adjusted to 44 ℃ by adjusting the proportion of three monomers. A drug carrier with a core-shell structure was self-assembled through hydrophobic force by covering the later polymer on the surface of MSNs-PDPA-FA. Finally, the drug release kinetics of the carrier was studied by using doxorubicin(DOX) as a model drug, and the result showed that the total leakage of the model drug DOX was less than 10% after 48 h in normal physiological environment (pH=7.4, 37 ℃). However, when the pH was changed to 5.0 at 44 ℃, the shell was dissociated from the core and the drug was released. Then, the drug was released rapidly within 5 h and the cumulative drug release could reach to 65% in 48 h. Therefore, this research was expected to construct a shielding system based on the pH/temperature dual-responsive polymer, which could be used to avoid premature exposure of certain functional groups or molecules to the normal physiological environment, and it could also prevent the premature release of drugs in the normal tissues.
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Infection Behavior During Ageing of Polymers: A Review
LIU Xuan, YANG Rui
 doi: 10.14133/j.cnki.1008-9357.20210903001
[Abstract](7) [FullText HTML](8) [PDF 5653KB](3)
When polymers are in blends or used together, the ageing process of polymer components or polymers affects each other, which is called infection behavior of ageing. Due to the infection behavior of polymer ageing, the research results of an individual polymer cannot be used to predict the life of this polymer material in blends or used with other polymers. Therefore, infection behavior is an important topic in the field of ageing study. This article mainly features the research progress towards infection behavior of polymer ageing. Firstly, the "contacting" and "non-contacting" behaviors are emphatically illustrated, which are the two typical patterns of infection behavior of ageing. Ageing spreads via infection agents within a polymer or polymer blend, and between different polymers separated from each other. Infection agents play an important role in infection behavior. Then the source and effects of infection agents are analyzed. Infection agents include radicals, volatile organic small molecules, gases, volatile additives and so on. All these infection agents work in "contacting" behavior, while volatile and gaseous matter are more important in "non-contacting" behavior. Benzoyl peroxide (BPO), formaldehyde and acetic acid are found to accelerate the thermo-oxidative ageing of polypropylene (PP). Eighteen volatile organic small molecules including acids, esters, aldehydes, ketones and alcohols are demonstrated to accelerate the photo-oxidative ageing of PP to different extents. Finally, the applications of infection behavior in the field of environmental protection and heritage protection are introduced and the challenges and prospects are proposed. The characterization of infection agents and their mechanism of action remained to be clarified systematically.
Polytriazole Elastomers Based on Akyne-Terminated Polyethylene Glycol
WANG Linxiao, BIE Ruye, FANG Jianwei, ZHANG Yu, WAN Liqiang, HUANG Farong
 doi: 10.14133/j.cnki.1008-9357.20210809001
[Abstract](8) [FullText HTML](2) [PDF 5411KB](1)
Elastomer had a wide range of applications and a large market capacity, but general-purpose elastomer had the disadvantages of poor heat resistance and complex synthesis processes. Compared with traditional elastomer, polytriazole elastomer (PTAE) had the advantages of good heat resistance and simple synthesis, but the existed PTAE has poor mechanical properties (tensile strength <10 MPa).In order to obtain PTAE with excellent mechanical properties, a series of novel PTAE with soft segments and hard segments alternately distributed along the main chain were synthesized via a metal-free 1,3-dipolar cycloaddition reaction. Based on the structural characteristics, alkynyl-terminated polyethylene glycol (DPPEG) with amount of polyether segments, biphenyl dibenzyl azide (BPDBA) with rigid aromatic rings and diethynylbenzene (m-DEB) were employed as soft segments, hard segments, and chain extender, respectively. The PTAEs possess good mechanical properties and thermal stability. With the increases of the DPPEG molar content, the tensile strength decreases from 16.27 MPa to 1.70 MPa, the elongation at break first increases and then drops, ranging from 249% to 990%. And with the increases of the molecular weight of the DPPEG, the tensile strength first increases and then decreases, ranging from 0.80 MPa to 22.5 MPa, the elongation at break first decreases and then increases, ranging from 196% to 325%. Although the thermal stability of PTAEs decreases with the increase of molar content and molecular weight of DPPEG, the 5 % mass loss temperature still exceed 335 ℃, which proves that the structure has good thermal stability. The glass transition temperature of PTAE is less than 10 ℃ which can maintain elasticity at room temperature.
Preparation and Performance of Poly(silicon-alkyne imide) Resins and their composites
SONG Shuang, ZHANG Songqi, CAI Chunhua, LIN Jiaping, DU Lei
 doi: 10.14133/j.cnki.1008-9357.20210918001
[Abstract](6) [FullText HTML](2) [PDF 5456KB](2)
Silicon-containing arylacetylene resin has excellent heat resistance and low-temperature curing properties. Its main defects are the brittleness of the cured resin and poor interface adhesion with the reinforcement. Polyimide resin (PI) has good thermal and mechanical properties, and excellent interfacial adhesion with reinforcement. The idea of copolymerizing PI and silicon-containing arylacetylene resin is proposed aiming to develop a high-temperature resistant composite matrix resin with excellent heat resistance and low temperature curing properties, and good adhesive property with the reinforcement. First, a highly heat-resistant acetylene-terminated polyimide (ATPI) was designed and screened by a material genome approach (MGA). And then the ATPI was synthesized with 3,4'-Oxydiphthalic anhydride, 3,4-oxydianiline and 3-ethynylaniline. The chemical structure was investigated by means of Fourier transform infrared spectrometer (FT-IR) and hydrogen nuclear magnetic resonance (1H-NMR). Then, by copolymerizing ATPI and poly(vinylsilylene ethynylenephenylenethynylene) resin(PSA), poly(silicon-alkyne imide) resin (PSI) was prepared. The thermal curing behavior of PSI was investigated by means of differential scanning calorimetry (DSC), and the curing process was designed based on the result of DSC. The thermal stability of the cured PSI resin was analyzed by thermogravimetric analysis (TGA). The results showed that the decomposition temperature of 5% mass loss (Td5) and the char yield at 800 °C (Yr800) of the cured PSI were 573 °C and 85.9% in nitrogen. The mechanical property of cured PSI was characterized by universal testing instruments. The flexural strength of cured PSI resin was up to 49.8 MPa, which was 2.5 times higher than that of PSA resin. Next, quartz and T800 carbon fiber reinforced PSI composites were prepared by compression molding or heat pressure tank molding process. Flexural strength and interlaminar shear strength (ILSS) of reinforced composites were measured by universal testing instruments. The flexural strength and ILSS of T800 carbon fiber reinforced composite reached 1 553 MPa and 84.1 MPa. After 350 °C treated for 100 h, the ILSS could remain basically unchanged. The T800 carbon fiber composite material had good heat resistance and mechanical stability. The flexural strength and ILSS of quartz fiber reinforced composite were 539 MPa and 37.6 MPa, respectively. The dielectric property of quartz fiber reinforced composite was also studied. After 500 °C treated for 5 min, the dielectric constant of the material was basically unchanged compared with that at room temperature. The dielectric property of the quartz fiber composite material was stable at high temperatures.
Prepared of Self-Healing and Anti-Corrosion Dual-Function Microcapsules via Emulsion Template Method
ZHANG Lichang, WU Kaiyun, DONG Jiahao, LUO Jing, LIU Ren
 doi: 10.14133/j.cnki.1008-9357.20210502001
[Abstract](27) [FullText HTML](12) [PDF 5551KB](1)
A new type of microcapsule with self-healing and anti-corrosion function was prepared by emulsion template combined with photopolymerization and in-situ polymerization. Then the dual-functional microcapsules were dispersed in water-based epoxy resin to fabricate smart anti-corrosion coatings. In our strategy, lignosulfonate was used as an emulsifier to stabilize the oil phase composed of tung oil, glycidyl methacrylate (GMA) and 1, 6-hexanediol diacrylate (HDDA). GMA and HDDA underwent crosslinking and formed the shell of microcapsule initiated by UV light. Aniline monomer was added to the water phase subsequently and adsorbed on the outer surface of the microcapsules through the electrostatic interaction between lignosulfonate and aniline. Then the polyaniline (PANI) shell was synthesized subsequently via chemical oxidative polymerization of aniline initiated by ammonium persulfate in the water phase. The polyaniline microcapsules (Tung oil-PGMA@PANI) loaded with tung oil were prepared. The microcapsule has a composite shell structure, in which the PGMA shell layer can stabilize the emulsion droplet and improve the toughness of the microcapsule, the PANI shell layer gives the microcapsule anti-corrosion performance, and the loaded tung oil can give the microcapsule self-healing performance.The FT-IR, TGA and SEM tests proved the successful preparation of the microcapsules, and the tung oil loading in the microcapsules reached 55.1% (mass fraction). The solvent resistance result showed that the microcapsules had strong resistance to water and common non-polar solvents. The self-healing and corrosion inhibition properties of coatings were tested by microscope and salt spray test. As the mass fraction of microcapsules were 7.5%, the defects of coating could be completely repaired after 3 days, and the salt spray test results proved that the microcapsules could significantly improve the anti-corrosion performance of the smart coatings.
Synthesis and Characterization of Poly(arylene ether phosphine oxide)s with Pendent Sulfonated Fluorenyl as Proton Exchange Membranes
FU Zhinan, TAN Yunlong, XAIO Guyu, YAN Deyue
 doi: 10.14133/j.cnki.1008-9357.20210216001
[Abstract](31) [FullText HTML](23) [PDF 5549KB](20)
The preparation of non-fluorinated proton exchange membranes (PEMs) include post-sulfonation and direct polycondensation methods. The latter method involves the synthesis of sulfonated monomers, but the purification of sulfonated monomers is generally time-consuming. Herein, poly(arylene ether phosphine oxide)s (PAEPO) with pendant fluorenyl groups are synthesized by polycondensation of 9,9-bis(4-hydroxyphenyl) fluorene and bis(4-fluorophenyl) phenyl phosphine oxide, then the side-chain type sulfonated poly(arylene ether phosphine oxide)s (sPAEPO) are prepared by post-sulfonation as proton exchange membranes. NMR and FT-IR are used to determine the chemical structure of PAEPO and sPAEPO, and AFM is employed to characterize the microstructure of the sPAEPO PEMs. The dimensional stability and proton conductivity of the sPAEPO PEMs are also investigated. The results illustrate that the sulfonic acid groups in the side benzene rings facilitate the resultant membranes to form the microphase separation structures with well-connected hydrophilic phases, achieving high proton conductivity, low swelling, and excellent overall properties. At 80 °C, the as-made PEMs exhibit a swelling of 30%, less than that of most non-fluorinated PEMs, whereas their proton conductivity is 0.075 S/cm, close to that of Nafion 117. Besides, they also display excellent thermal stability and oxidation resistance. Therefore, the as-made PEMs show promising application prospects.
Preparation and Characterization of Acrylic Quaternary Ammonium Salt Copolymer Films
WANG Youchang, LIANG Wencheng, FAN Yao, GONG Chenyu, LANG Meidong
 doi: 10.14133/j.cnki.1008-9357.20210322001
[Abstract](128) [FullText HTML](107) [PDF 5637KB](38)
Quaternary ammonium salts as a kind of typical antibacterial materials, possess excellent bactericidal properties. However, most quaternary ammonium salts have the defects of low plasticity and poor film forming performance. Based on this, P(BA-co-DMAEMA) was prepared by free radical polymerization with n-butyl acrylate (BA) and 2-(diethylamino) ethyl methacrylate (DMAEMA). Then, a series of acrylic P(BA-co-DMAEMA)-R (R: bromine butane (BB), bromo hexane (HB) and bromine octane (OB) ) copolymers with different length alkanes were obtained by using BB, HB, OB as quaternization agents. Finally, P(BA-co-DMAEMA)-R films were prepared by tape casting method. The chemical structures of P(BA-co-DMAEMA) and P(BA-co-DMAEMA)-R were characterized by H-nuclear magnetic resonance (1H-NMR), Fourier transform infrared spectroscopy (FT-IR) and gel permeation chromatography (GPC). The mechanical properties, hydrophilicity, light transmittance of P(BA-co-DMAEMA)-R films were tested by universal mechanical testing machine, contact angle tester, UV spectrophotometer. The results show that the introduction of brominated alkanes (BB, HB, OB) could effectively improve the mechanical properties, hydrophilicity, light transmittance of the films. The elongation at break of P(BA-co-DMAEMA)-R films increases with the increase of alkane chain, the surface of the films changes from hydrophilic to hydrophobic. The transmittance of P(BA-co-DMAEMA)-R films increases with the increase of alkane chain, and the maximum transmittance is over 80%. The antibacterial properties of P(BA-co-DMAEMA)-R films are assessed by agar plate colony counting assay and zone of inhibition test. When n(BA)/n(DMAEMA) = 23/77, the quaternization degree of P(BA-co-DMAEMA)-R are 58% (BB), 45% (HB) and 39% (OB), respectively. It is observed that P(BA-co-DMAEMA)-R films exhibite outstanding broad-spectrum antimicrobial activity against S. aureus and E. coli. The antimicrobial activity is based on contact-killing of P(BA-co-DMAEMA)-R film surface, without releasing bactericidal agents, as demonstrated by the zone of inhibition test. Meanwhile, P(BA-co-DMAEMA)-R films also possess excellent antifogging performance, and its preparation process is simple and controllable, which would be used in packaging materials in the future.
Development and Applications of UV-Curing 3D Printing and Photosensitive Resin
WANG Shichong, ZHU Yuwei, WU Yao, XIANG Hongping, LIU Xiaoxuan, PENG Zhongquan, RONG Minzhi, ZHANG Mingqiu
 doi: 10.14133/j.cnki.1008-9357.20210510001
[Abstract](98) [FullText HTML](48) [PDF 6439KB](71)
UV-curing 3D printing, one of the rapid prototyping technologies, can manufacture various complex objects by the layer-by-layer UV-curing of photosensitive resin. Comparing with other additive manufacturing technologies, it has already become one of the popular ones, due to its advantages of fast curing rate, high precision, eco-friendliness, excellent surface quality, low cost, and so on. Photosensitive resin is the preferred 3D printing main materials for high-precision products, owing to the excellent rheology properties and instant UV-curing characteristics. Generally, photosensitive resin used for 3D printing mainly consists of photosensitive prepolymers, reactive diluents, photo-initiators and a handful of additives. With the wider applications of UV-curing 3D printing, the consumption of photosensitive resin is rapidly increasing. However, there are some urgent problems to photosensitive resin, such as surface oxygen inhibition, high volume shrinkage and unsatisfactory mechanical properties. In view of the lack of systematic discussion on the latest research progress of UV-curing 3D printing and its photosensitive resin, this review focuses on the research advances and development prospect of UV-curing 3D printing and its photosensitive resin accordingly. Firstly, the printing principles and advantages and disadvantages of the universally available and newly-developed UV-curing 3D printing technologies are introduced detailly. Then, the effects of the basic compositions and molecular structures of photosensitive resins on the performances of 3D printed devices are emphatically discussed. The practical applications of UV-curing 3D printing and its photosensitive resins are also presented by living examples, including model making, industrial manufacturing and biomedical devices. Finally, the present status and future development of UV-curing 3D printing and its photosensitive resins are analyzed and prospected. This review will effectively contribute the technological progress and widen applications of UV-curing 3D printing and photosensitive resins.
Combination of Host Defense Peptide Mimicking Peptide Polymer and Proteinase K against Biofilms
BI Yufang, WU Yueming, LIU Shiqi, QIAN Yuxin, LIU Runhui
 doi: 10.14133/j.cnki.1008-9357.20210523001
[Abstract](38) [FullText HTML](23) [PDF 5498KB](11)
Staphylococcus aureus (S. aureus) is one of the main pathogens causing urinary catheter-related infections, and its biofilm has strong resistance to immune clearance and antibiotics. Effective measures should be taken to solve catheter biofilm-related infections fundamentally. In this study, the host defense peptide mimicking peptide polymer was synthesized by rapid ring-opening polymerization of α-amino acid N-carboxyanhydride (NCA), which was initiated by lithium bis(trimethylsilyl)amide (LiHMDS). The resulting polymer showed a narrow molecular weight distribution. Antimicrobial experiment showed that this peptide polymer had a high bactericidal activity against the planktonic and persister cells of methicillin-resistant Staphylococcus aureus (MRSA). Bactericidal mechanism showed that this peptide polymer killed MRSA by destroying the integrity of bacterial cell membrane. Protein is one of the basic components of extracellular polymeric matrix (EPS), which plays an important role in bacterial colonization and biofilm development. The dispersing effect of protease K on EPS is beneficial to the penetration of antimicrobial agents into biofilms. 1.25 U/mL proteinase K dispersed mature MRSA biofilms in artificial urine, and the remaining cell viability was about 55% of the control group. The combination of proteinase K and polymer further eradicated mature MRSA biofilms in artificial urine, which confirmed the potential of synergism in eradicating the biofilms inside urinary catheter. The optimal combination reduced the cell viability within biofilms to about 10% of the control group.
Machine Learning on the Chemical Reaction of Organic Synthesis
ZHANG Liangshun
 doi: 10.14133/j.cnki.1008-9357.20210823002
[Abstract](23) [FullText HTML](7) [PDF 7757KB](7)
It is a challenging task to predict the outcome of chemical reaction and design the route of synthetic planes in the field of organic synthesis. As a novel strategy, the machine-learning approach has extended to study the task of organic synthesis. Focusing on the small organic molecules, we review the progress of organic synthesis by virtue of machine-learning approach, including the dataset collection of chemical reaction, the prediction of chemical reaction and the route of synthetic plane. With respect to the molecules of resin with complicated architecture, we comment on the challenging issues for organic synthesis based on machine learning, such as the deficiency and bias of dataset, the ill-defined representation of molecular structures and the machine-learning approach with small dataset.
Size-Tunable and Controlled Degradable Ultrathin Nanotubes Self-Assembled by Amphipathic Alternating Copolymer
SU Peng, CUI Chenhui, ZHANG Qiang, ZHANG Yanfeng
 doi: 10.14133/j.cnki.1008-9357.20210407001
[Abstract](9) [FullText HTML](33) [PDF 5314KB](0)
Polymeric nanotubes have great advantages in biological carrier applications due to their flexible structure design and large aspect ratio. The independence of self-assembly structure from molecular weight and molecular weight distribution is a major advantage of alternating polymers for self-assembly. In the present study, we synthesized a series of amphipathic alternating copolymers with hydrophobic sections of different lengths by thiol-halogen click chemistry reactions. The molecular weight and structure of three alternating copolymers are characterized by gel permeation chromatography (GPC) and nuclear magnetic resonance (NMR). These alternating copolymers self-assembled in water and dimethyl sulfoxide (DMSO) (Volume ratio 4∶1) and formed a series of ultrathin nanotubes with a wall thickness of only 1~2 nm. Through transmission electron microscope (TEM), we have observed that as the length of the carbon chains in the hydrophobic sections of the alternating copolymers increases, the diameters of the nanotubes increase from 19.61 nm to 26.24 nm. Besides, through the software simulation of Chem3D, we have verified the hypothesis that the alternating copolymer folds to form a sandwich structure and further self-assembles into nanotubes. The nanosheets assembled by alternating copolymers with longer hydrophobic sections are thicker, the bigger bending stress resulting in the formation of larger diameter nanotubes which was more thermodynamically stable. Biological carriers need on-demand release when they reach the target. Therefore, the carriers generally required to have the ability to controllable release or disintegrate. In this study, the hydrophobic thioether bonds in alternating copolymers were transformed to the sulfone bonds after oxidation. The better water solubility of sulfone bonds will enhance the hydrophilicity of the alternating copolymers, which caused the tubular structure of the nanotube to decompose after oxidation by H2O2 at 37 °C for 2 h. The large aspect ratio and controlled degradation of these nanotubes may have potential applications in biological delivery and controlled releasing.
Preparation and Properties of Polyvinyl Alcohol/ε-Polylysine Hydrogel Wound Dressing
FAN Yao, LIANG Wencheng, WANG Youchang, LANG Meidong
 doi: 10.14133/j.cnki.1008-9357.20210330002
[Abstract](72) [FullText HTML](64) [PDF 6057KB](20)
Composite hydrogels (PVCL) with antibacterial properties were prepared by freeze-thawing method by introducing ε-polylysine(ε-PL) and citric acid (CA) into polyvinyl alcohol (PVA) aqueous solution. The structure and properties of PVCL composite hydrogels were characterized by fourier transform infrared spectroscopy (FT-TR), scanning electron microscopy (SEM), differential scanning calorimetry (DSC), universal tensile testing machine and swelling capacity. The biological properties of the composite hydrogels were characterized by antibacterial test, hemolysis test and cytotoxicity test. Results showed that the mechanical properties of PVA hydrogels were improved by adding CA. Compared with pure PVA hydrogel, the tensile strength of hydrogel was increased by 66.7% from 1.8 MPa to 3.0 MPa, and the elongation at break increased by 19.8% from 355.9% to 426.5%. However, the addition of ε-PL could reduce the mechanical properties of the hydrogels. The highest swelling rate of the composite hydrogel was 293.7%. ε-PL provided excellent antimicrobial activity for composite hydrogels, the antibacterial rate increased with the increase of ε-PL, and the highest antibacterial rate against E.coli and S.aureus was close to 100%. In addition, PVCL composite hydrogels PVCL had excellent hemocompatibility and cytocompatibility.
Preparation of Stimulus-Responsive Copolymer-Decorated Gold Nanorods and Their Anti-tumor Effects
GUO Min, HOU Guanghui, XU Weijun, QIAN Junmin
 doi: 10.14133/j.cnki.1008-9357.20210323001
[Abstract](86) [FullText HTML](44) [PDF 5885KB](27)
A triblock copolymer with mussel-inspired adhesive ability, poly(acryl hydrazide)-b-poly(N-(3, 4-dihydroxyphenylethyl) acrylamide)-b-poly(monomethoxypolyethylene glycol acrylate) (HDP), was designed and synthesized via reversible addition fragmentation chain transfer polymerization process from three monomers, including 1-tert-butoxycarbonyl-2-acrylhydrazide(Boc-AH), N-(3, 4-dihydroxyphenylethyl) acrylamide and poly(ethylene glycol) methyl ether methacrylate (mPEGA). The copolymer was used for decorating gold nanorod (GNR) to obtain GNR-based nanocarrier. Chemotherapeutic drug doxorubicin (DOX) was conjugated onto the nanocarrier by an acid-labile hydrazone linkage, resulting in HDP-GNR-DOX nanodrug. The physicochemical properties of the nanocarrier, such as structure, stability, photothermal performance, and pH responsive drug release, were characterized. Moreover, the in vitro anti-tumor effect of the nanodrug towards breast cancer cells (MCF-7) was evaluated. Results showed that the DOX content of the nanodrug was as high as 8.1% and the nanodrug exhibited excellent photothermal conversion ability, favorable stability and pH-responsive drug release behavior. Importantly, cell experimental results demonstrated that the nanodrug could be effectively internalized by MCF-7 cells. In the case of near infrared irradiation, the nanodrug showed high apoptosis-inducing ability on MCF-7 cells, achieving highly efficient photothermal-chemotherapy of breast cancer.
Mussel-inspired Azo-Polydopamine Coating for Photoelectric Dual Response Memristive Device
GONG Ming-lei, LIU Minyang, WANG Xiao-yang, YANG Jin-bo, CHEN Yu, ZHANG Bin
 doi: 10.14133/j.cnki.1008-9357.20210701001
[Abstract](27) [FullText HTML](16) [PDF 5573KB](4)
The development of high-performance memristors meets the needs of the era of big data. In particular, memristors that use organic/polymer materials with flexibly adjustable structures as the active layer are becoming increasingly popular in the field of photoelectric sensing and artificial intelligence. Inspired by mussel-inspired chemistry, a polydopamine (PDA) film was self-assembled on Indium Tin Oxide(ITO)-coated glass substrate to form an active layer, and then grafted azobenzene (Azo) with photoisomerization properties through click chemistry to prepare the memristive device with the structure of Al/PDA-Azo/ITO, and its photoelectric performance have been studied. As a result, azo molecules are covalently grafted on the surface of polydopamine. The as-prepared device exhibits stable nonvolatile rewritable memory characteristics under applied voltage scanning. The conductivity of the device increases by 30 times after UV light irradiation, and it can be recovered after visible light irradiation, indicating that the fabricated memoristor achieves photoelectric dual response.
Self-Healing Vascularized Glass Fiber Reinforced Polymer Composites
ZHAO Dafang, LI Bintai, SHI Jiaqi, BAI Jinpeng
 doi: 10.14133/j.cnki.1008-9357.20210112003
[Abstract](95) [FullText HTML](64) [PDF 5711KB](8)
Inspired by natural healing processes, a variety of synthetic self-healing materials have been developed, including fiber reinforced polymer (FRP) composites. Therefore, self-healing FRP composites have recently become a focus in the fields. This paper considers the development of autonomic self-healing within a glass fiber-reinforced polymer (GFRP). Vascularised GFRP was prepared from glass fiber SW280A reinforced epoxy 3218 by removing polymer fibers after curing. A homemade ambient-curable healing resin formation (diglycidyl ether of bisphenol-A/aliphatic amine) epoxy system has been used as self-healing agent. It was demonstrated that the strength recovery possibility when with vessels distributed at specific interfaces within a laminate by ultrasonic C scan, micro-X-ray computer tomography (μ-CT) and recovery of post-impact compression strength. In this study, A autonomous, stimulus triggered, self-healing system in GFRP composites was established. Vascules are used as sensing pathway, which detect the introduction of ply delaminations and matrix microcracking following a 6.67 J-10 J low-velocity impact event. Once damage connectivity between the sensing vascule and those open to the ambient environment is established, the delivery of a healing agent to the damage zone is triggered. Two kinds samples with vascules orientation of parallel and transverse to the 0° was prepared. In both samples, the damage was connected with the vascules following a 6.67 J-10 J low-velocity impact event. The healing agents flowed into damage position and the sample can be healed. Using this autonomous healing approach, near full recovery of post-impact compression strength (211 MPa) was achieved compared with compression after impact (CAI, 202 MPa). The successful implementation of this bioinspired technology could substantially enhance the integrity and reliability of aerospace structures, whilst offering benefits through improved performance/weight ratios and extended lifetimes.
Electrochemical Immunosensor Based on Gold Nanoparticles/Polypyrrole-Polydopamine
QU Chunbo, ZHANG Jingyi, NA Lixin, LUO Jing
 doi: 10.14133/J.CNKI.1008-9357.20210411002
[Abstract](100) [FullText HTML](79) [PDF 0KB](49)
A novel ultrasensitive impedimetric immunosensor was constructed for the detection of carcino-embryonic antigen (CEA) using conductive and adhesive bio-inspired gold/polypyrrole-polydopamine nanocomposites as an immobilization matrix. A polypyrrole-polydopamine complex (PPy-PDA) was first prepared by the polymerization of pyrrole and dopamine, which was then blended with the chloroauric acid solution (HAuCl4). The in-situ reduction of \begin{document}${\rm AuCl}_4^- $\end{document} to gold nanoparticles (Au NPs) by polydopamine led to the successful preparation of gold/polypyrrole-polydopamine nanocomposites (Au/PPy-PDA). Au/PPy-PDA was characterized by Fourier transmission infrared (FTIR) spectroscopy, scanning electronic microscopy (SEM) coupled with energy dispersive X-ray spectroscopy (EDX) and electrical conductivity test. The dispersion test and adhesion test showed that PPy-PDA possessed good dispersibility in water and outstanding adhesion performance. The electrochemical measurement showed that Au/PPy-PDA not only provided a highly stable and biocompatible matrix for the convenient conjugation of antibody, but also accelerated the electron transfer process owing to the conductive PPy as well as encapsulated AuNPs, making it suitable to be applied as high-efficiency immunoassay platform. Under optimal conditions, a wide linear range from 10−12 ~5×10−7 g/mL and a detection limit of 0.2 pg/mL were demonstrated for the detection of CEA. Moreover, the proposed CEA immunosensor exhibited high specificity, excellent stability and reproducibility, providing an experimental evidence for early diagnosis and treatment of cancer.
Graphene/Azobenzene Photothermal Material Based on Zinc Coordination
GAO Wenchao, FENG Yiyu, FENG Wei
 doi: 10.14133/j.cnki.1008-9357.20210404001
[Abstract](99) [FullText HTML](49) [PDF 810KB](14)
Azobenzene has two configurations which are trans-configuration and cis-configuration. As a photo-isomerization molecule, azobenzene can transfer from trans-configuration in low energy state to cis-configuration in a high energy state under the irradiation of ultraviolet light (UV), which is the process of photo-isomerization. Herein, azobenzene and its derivatives are used in different industries and fields. However, due to their low energy density compared with other molecular solar thermal energy storage (MOST) like anthracene and norbornadiene, their applications in energy storage are influenced severely. The purpose of this paper is to find the method to solving the problem above. In this paper, 4-nitro-4'- aminoazobenzene (Azo) was grafted onto reduced graphene oxide (rGO) by the coupling reaction and then interacted with ZnCl2 to get the azobenzene graphene composite with zinc ion interaction (Zn-AGO). There are two mechanisms of energy storage/release in this method, photoisomerization of azobenzene onto graphene template, and ion interaction formation/destruction, which is a unige attempt to improve energy density through multiple mechanisms of heat release. It has been proved that the nanoscale templates have significant effect on improving the energy density of azobenzene derivatives. The FT-IR spectroscopy show that Zn-AGO is successfully prepared by this method. Moreover the maximum energy density of that is up to 504.2 J/g under the irradiation of UV (365 nm) for 4 h, which is about 1.69 times of the azobenzene graphene composite (AGO) without ion interaction. The results show that the introduction of zinc and graphene templates greatly improves the energy density of azobenzene, which provides a reference for the development and application of azobenzene composites with multiple mechanisms of energy storage in the future.
Organic Photoelectric Synaptic Materials, Devices and Applications
GUO Yanbo, LIU Gang
 doi: 10.14133/j.cnki.1008-9357.20210402002
[Abstract](204) [FullText HTML](101) [PDF 4158KB](62)
With the advent of big data and the Internet of Things (IoTs), artificial intelligence (AI) has received great attention from the global scientific and industrial communities. Photoelectric neuromorphic devices, which can overcome the Von Neumann bottleneck issue of conventional computer systems, are developing rapidly. The optical signal, which has the advantages of low power consumption, low crosstalk, high bandwidth and low computational requirements, can be regarded as an additional terminal to enrich the regulatory freedom of synaptic plasticity. The optoelectronic performance of optoelectronic devices largely depends on the design and preparation of optoelectronic materials. With the advantages of molecular diversity, low cost, easy processing, mechanical flexibility and compatibility with flexible substrates, organic materials are important materials platform for constructing high performance optoelectronic synaptic devices. In this review, the latest development of organic materials in optoelectronic devices and visual bionics is introduced, and the current application challenges and future prospects of organic materials are discussed.
Construction and Osteogenic Properties of Plasma-Assisted Nano-Coating
GUO Ximeng, JIN Lili, LI Chunwang, HE Hongyan, LIU Changsheng
 doi: 10.14133/j.cnki.1008-9357.20210330004
[Abstract](169) [FullText HTML](46) [PDF 1437KB](16)
In recent years, polyethylene terephthalate (PET) based LARS artificial ligaments have become popular in anterior cruciate ligament (ACL) reconstruction. However, due to its poor biological activity and high hydrophobicity, its application is limited for clinical uses. In order to improve the biological activity of materials and enhance the tendon-bone healing effect, oxygen plasma was used to introduce hydroxyl groups on the surface of PET in this study. It has been found that the surface physiochemical treatment and immobilization of bioactive molecules have great effects on the bioactivity improvement of the inert surfaces. Therefore, bone morphogenetic proteins (rhBMP-2) with typical osteoinducter and fibronectin (Fn) for enhancing the binding capacity of rhBMP-2 molecules were chosen as modifying molecules. The functional molecules such as epigallocatechin-3-gallate (EGCG) were coated on the PET surface first. There are six ortho phenolic hydroxyl groups in the molecular structure of EGCG, Fn molecules were then easily immobilized on the EGCG-PET surfaces. Since each subunit of Fn had a high-affinity binding site for rhBMP-2, rhBMP-2 molecules were biological anchored on the surface through long-chained Fn, which simulates the biomimetic design in the extracellular matrix. Thus, such molecules EGCG, Fn, and rhBMP-2 were sequentially immobilized on the PET surfaces. The nanocoating of rhBMP-2/EGCG/Fn was assembled to further enhance the loading efficiency of rhBMP-2 and control the release of rhBMP-2. Therefore, the surface-modified B/E-Fn-PET exhibits excellent cell compatibility. Moreover, effective loading, activity maintaining, and controlled release of rhBMP-2 give the implant surface high osteoinduction and better osteogenesis. Predictably, the integrated influences of these factors will provide the technical support for designing the insert implantable surface with high bioactivities.
Tannic Acid-Assisted Rapid Deposition of Epsilon-Poly-L-Lysine Coating for Antibacterial Application
GUO Lingli, REN Xu, HE Xiaodong, ZHANG Kai, XU Liqun
 doi: 10.14133/j.cnki.1008-9357.20210321001
[Abstract](113) [FullText HTML](93) [PDF 1297KB](21)
Polydimethylsiloxane (PDMS) has good thermal stability, biocompatibility and corrosion resistance, and it has been widely used in the field of biomedical materials, i.e., medical catheters. However, the surface of PDMS is highly hydrophobic and susceptible to contamination by bacteria and plasma proteins. In this study, PDMS-TA-Ply surfaces were prepared by the rapid and successive deposition of tannic acid (TA) and ε-Poly-L-lysine (Ply) on the PDMS surface via the solution immersion method. The surface chemical elements and hydrophilic properties of PDMS-TA-Ply surfaces were evaluated by X-ray photoelectron spectroscopy (XPS) and contact angle measurement. The anti-protein adsorption, antibacterial adhesion, anti-biofilm formation and cytotoxicity of PDMS-TA-Ply surfaces were evaluated. The results showed that PDMS-TA-Ply surfaces exhibited good antifouling/antibacterial properties and low cytotoxicity toward L929 mouse fibroblasts. In addition, the PDMS-TA-Ply surface with higher content of Ply showed better antifouling/antibacterial performance.
Preparation and Properties of Temperature-Responsive Hydrogels Based on Acylhydrazone Reversible Covalent Bonds
HE Yuan, LUO Yuanyuan, LIU Tong, ZHANG Yinshan, GUO Zanru, ZHANG Jiali
 doi: 10.14133/j.cnki.1008-9357.20210322002
[Abstract](93) [FullText HTML](50) [PDF 1597KB](13)
A series of PAM-co-PDAAM-co-PNIPAM copolymers were synthesized by RAFT polymerization from acrylamide (AM), diacetone acrylamide (DAAM) and N-isopropylacrylamide (NIPAM). Their structure and composition were characterized by Nuclear Magnetic Resonance (1H-NMR) and Gel Permeation Chromatography (GPC). Hydrogel with pH and temperature dual-response formed by the acyl hydrazone dynamic bonds between ketocarbonyl in polymer and hydrazide in adipic dihydrazide (ADH). The dual-responsive behavior of hydrogels to temperature and pH was researched by rheological measurement, Scanning Electron Microscope (SEM) and Fourier Transform Infrared spectroscopy (FT-IR). At the same time, the hydrogel demonstrated temperature controlled self-healing properties. Besides, the hydrogels showed pH-and temperature-responsive controlled release behaviors for Dox.
Reversible Adsorption/Release for Anionic Dyes of Magnetic and CO2 Dual-Responsive Degradable Microgels
ZHANG Yinshan, MAO Xi, LIU Tong, GUO Zanru, XIONG Leyan, LIU Yongxin
 doi: 10.14133/j.cnki.1008-9357.20210322003
[Abstract](173) [FullText HTML](97) [PDF 1533KB](9)
Degradable magnetic and CO2 dual-responsive microgels were prepared by inverse suspension polymerization and in-situ synthesis of nanoparticles. The structure and morphology of microgels were characterized by Fourier-transformed infrared (FT-IR) spectroscopy, scanning electron microscope (SEM) and transmission electron microscope (TEM). The microgels exhibited magnetic and CO2 responsiveness, and could be degraded upon the treatment of DL-dithiothreitol (DTT). After treating with the stimulus of CO2, the microgels exhibited a selective adsorption for anionic dyes. The maximum adsorption capacity was up to 1413 mg g-1 for Alizarin red (AR). The microgels with adsorbates could be separated from solution under the help of an external magnetic field. Besides, the adsorbates could be desorbed by treating with solution of pH 12. Microgels regenerated with CO2 trigger exhibited high adsorption ability (>90%) after three consecutive recycling trials.
Preparation of Albumin/Hyaluronic Acid Composite Nanoparticles for Cisplatin Delivery
WANG Taibing, LI Ying, JIA Zhuohan, GUO Min, XU Weijun, QIAN Junmin, SUO Aili
 doi: 10.14133/j.cnki.1008-9357.20210318001
[Abstract](314) [FullText HTML](156) [PDF 1336KB](30)
Cisplatin is one of typical anti-tumor chemotherapeutic drugs, but its clinical application is restrained by serious toxic side effects and multidrug resistance. However, emerging nanotechnologies have great potential in overcoming the above problems. By means of albumin templating method, an albumin/hyaluronic acid composite nanocarrier was prepared from albumin, hydrazided hyaluronic acid and aldehyde hyaluronic acid. Cisplatin could be loaded into the nanocarrier via Pt-hydrazide coordination chemistry. Fourier transform infrared spectroscopy, proton nuclear magnetic resonance spectroscopy, transmission electron microscopy and inductively coupled plasma mass spectrometry were employed to characterize the chemical structure of nanocarrier and the physiochemical properties of nanodrug. The results showed that the nanodrug exhibited a subsphaeroidal morphology with an average size of about 150 nm and the loading content of cisplatin was as high as 10.8%. Moreover, the nanodrug displayed a reduction/acid dual responsive drug release behavior. In vitro cell experiments showed that the cytotoxicity of the nanocarrier was negligible and the nanodrug had good targeting ability towards hepatocellular carcinoma HepG2 cells. Importantly, the effect of the nanodrug in killing HepG2 cells was comparable to free cisplatin. It was found that inducing cell apoptosis was still major mechanism of killing HepG2 cells by the nanodrug. The albumin/hyaluronic acid composite nanoparticles are a promising carrier with excellent comprehensive performances for the targeting delivery of cisplatin, and might improve the therapeutic efficacy of cisplatin and reduce its toxic side effects in vivo.
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Invited Reviews
Glycopeptide-Based Polymers and Their Biomedical Applications
ZHANG Jingkai, LIU Xiaoxuan, LI Lili
2021, 34(5): 401-417.   doi: 10.14133/j.cnki.1008-9357.20210309001
[Abstract](300) [FullText HTML](179) [PDF 6781KB](53)
Glycopeptide-based polymers are a kind of biodegradable polymers composed of polypeptides and carbohydrates. Owing to their chemical similarity to natural glycopeptides and glycoproteins, they can mimic the structure and function of natural products. There are two main types of glycosides: N-glycosides and O-glycosides. Glycosides are coupled with amino acids in advance to form glycosylated amino acid building blocks, and then participate in the synthesis of glycopeptides together with amino acids in solid phase synthesis. Native chemical ligation is often used to synthesize longer glycopeptide that cannot be obtained by solid phase synthesis. Glycopeptides are designed to reflect multivalence, so the most common types include branched glycopeptides, self-assembled glycopeptides and polymer glycopeptides. Branched glycopeptides mainly include glycopeptide dendrimers. Self-assembled glycopeptides mainly consist of modifying various glycosyl groups on self-assembled polypeptides. Based on these self-assembled glycopeptides, glycopeptide materials can self-assemble into various nanostructures, such as micelles, vesicles, fibers and nanorods. As a kind of structural mimic of natural glycoproteins, synthetic glycopeptides can play a variety of biomedical roles. Synthetic glycopeptides are capable of binding to lectin or adhesive of bacteria or targeting intracellular bacteria of macrophages. Due to the overexpression of carbohydrate-binding proteins on tumor cells surfaces, glycopeptides have been widely investigated as an anti-tumor vaccine. In addition, glycopeptide-based hydrogels can be used as a biomimetic scaffold for mammalian cells growth due to their high-water content and similar structure, shape and composition to the extracellular matrix (ECM) in tissues. Glycopeptides can also simulate natural glycosaminoglycans to play a role in tissue and cartilage repair. We summarize the synthesis method, material design and biomedicine application of glycopeptides, focusing on the material design of glycopeptides in branched glycopeptides, self-assembled glycopeptides and polymer glycopeptides, and the applications of glycopeptides in antibacterial, anti-tumor vaccine, bionic scaffold, tissue and cartilage repair.
Properties of Poly(2-aminoazulene)-Based All-Solid-State Supercapacitors
JIN Xin, CHEN Zhian, SUN Sai, ZHUANG Xiaodong, CHEN Yu
2021, 34(5): 418-424.   doi: 10.14133/j.cnki.1008-9357.20210112002
[Abstract](886) [FullText HTML](564) [PDF 5609KB](49)
Conductive polymers with good intrinsic conductivity and high charge density are considered as potential electrode materials for supercapacitors. However, it has been reported that the chains of polypyrrole and polyaniline could expand and contract during the charging and discharging process, leading to structural de-conformation. Poly(2-aminoazulene) is lately reported to present large area film morphology and remarkable electrical conductivity at room temperature. Nevertheless, relevant studies based on azulene as supercapacitor electrode materials have rarely been reported. Here, we report an all-solid-state supercapacitor based on a conductive polymer, poly(2-aminoazulene), as the electrode material. According to conventional electrochemical measurement, poly(2-aminoazulene) film-based device exhibits promising capacitive performance in the operating voltage window of −0.2—0.8 V: maximum volumetric capacitance of 83 F/cm3 and maximum areal capacitance of 0.54 mF/cm2, maximum energy density of 11.6 mW·h/cm3 and maximum power density of 3304 W/cm3. In addition, the supercapacitor retains 95.1% of the initial capacitance after 1000 cycles, indicating good cycling stability which enables its reliability during practical applications. These results not only prove that poly(2-aminoazulene) could be next generation candidates of all-solid-state supercapacitor electrode materials but also provide a new strategy for exploration of intrinsic conductive polymers for energy storage.
Photoelectric Properties of Polythiophene Modified by Post-Polymerization Strategy
XIE Ziyi, SHAN Tong, WEI Qingyun, ZHONG Hongliang
2021, 34(5): 425-433.   doi: 10.14133/j.cnki.1008-9357.20210430001
[Abstract](96) [FullText HTML](45) [PDF 5608KB](18)
To optimize the structure and energy levels of polythiophene, a new type polymer namely of PtTSBO with thioalkyl side chains is successfully synthesized by Kumada catalyst transfer polycondensation (KCTP) with the monomer containing four thiophene units and thioalkyl sidechains, which broadens the scope of KTCP application. A post-polymerization strategy is also developed to functionally modify the side chains of PtTSBO. Polymers PtTSOBO and PtTSOOBO are prepared by controlling the amount of 3-chloroperbenzoic acid (m-CPBA) and the reaction temperature so that the sulfide in the side chains of PtTSBO can be efficiently and selectively oxidized to sulfoxide and sulfone. The chemical structure, light absorption and electrical properties are characterized by 1H-NMR, elemental analysis (EA), UV-Vis absorption spectroscopy and cyclic voltammetry (CV), and corresponding photovoltaic devices. After the post-polymerization modification, the HOMO energy levels of PtTSOBO and PtTSOOBO are significantly lower than that of PtTSBO, thus increasing the open-circuit voltage (Voc) of the corresponding photovoltaic devices. However, by introducing sulfoxide or sulfone groups, the planarity of the backbone in polythiophene is reduced, which is not conducive to their solid-state aggregation, consequently deteriorating the overall performance of photovoltaic devices fabricated. The photovoltaic devices based on PtTSOBO and PtTSOOBO need to be further studied and optimized, such as meticulous selection of acceptor materials with more suitable energy levels and miscibility. Meanwhile, the downshift energy levels of PtTSOBO and PtTSOOBO suggest they might be available for the application as electron-acceptor. This post-polymerization method paves a new way for modifying polythiophenes and promoting the low-cost production of functionalized polythiophenes.
Thieno[3,2-b]thiophene-Bridged Polypyrrole Film-Based Micro-Supercapacitors
HOU Pengxin, JIANG Kaiyue, ZHAI Guangqun, ZHUANG Xiaodong
2021, 34(5): 434-443.   doi: 10.14133/j.cnki.1008-9357.20210110001
[Abstract](548) [FullText HTML](365) [PDF 6402KB](40)
Polypyrrole, one of the famous conventional conductive polymers, has been well studied in the past decades. Due to the rational controlling methods of morphology and structure, polypyrrole-based materials have shown great potential in the field of energy conversion and storage. For example, polypyrrole could contribute excellent pseudocapacitance as electrode material for supercapacitors. However, synthesis of two-dimensional polypyrrole or ultra-thin films remains a challenge because of the easy aggregation and poor solubility features. In this work, the electron-rich thieno[3,2-b]thiophene unit is used to bridge pyrrole monomers to produce four-armed bipyrrole monomer. At liquid-liquid interface, conventional oxidative polymerization reaction can take place and uniform polypyrrole film with large area can be easily produced. Through directly laser scribing, interdigitated micro-supercapacitors based on Au layer supported polypyrrole film can be produced. After evaluation through cyclic voltammetry curves, impedance curves, etc., the micro-supercapacitors show areal specific capacitance of 1.10 mF/cm2, volumetric specific capacitance of 68.4 F/cm3, equivalent series resistance(ESR) of 4.2 Ω. The maximum energy density and power density of as-prepared micro-supercapacitors reach 9.50 mW·h/cm3 and 1 433 W/cm3, respectively.
Synthesis and Shape Memory Properties of POSS-Capped Poly(ethylene oxide) Telechelics
LI Lei, CAO Yuqin, CHANG Pengfei, ZHENG Sixun
2021, 34(5): 444-451.   doi: 10.14133/j.cnki.1008-9357.20210128001
[Abstract](61) [FullText HTML](49) [PDF 5933KB](26)
Polyhedral oligomeric silsesquioxane (POSS)-capped poly(ethylene oxide) (PEO) telechelics were synthesized via click chemistry approach between azidopropylheptaphenyl-POSS and alknyl-capped PEO. In these telechelics, POSS cages aggregated into microdomains via POSS-POSS interaction and dispersed in the continuous PEO matrix, which was observed by transmission electron microscope (TEM). Rheological measurements showed that values of loss modulus were lower than that of storage loss in the range of angular frequency from 0.01 to 100 rad/s (1 rad/s=\begin{document}$\dfrac {1} {2\text{π}} {\rm{Hz}}$\end{document}), indicating the formation of physical crosslinking network in POSS-PEO-POSS telechelics. The as-formed physical cross-linking sites endowed POSS-capped PEO telechelics with excellent thermal-induced shape recovery properties. Shape recovery rate was quite dependent on POSS content in the telechelics. The higher POSS content, the faster shape recovery rate. Moreover, the formation of physical crosslinking sites and hydrophilic features of PEO resulted in formation of hydrogels in water. These hydrogels displayed high swelling ratios and the swelling ratios increased with PEO lengths. More importantly, these hydrogels exhibited aqueously induced shape memory properties. This study prompted an innovative strategy to form physical crosslinking hydrogels via POSS-POSS interactions. The excellent thermally and aqueously induced shape memory properties make POSS-capped PEO telechelics promising as special biomedical devices.
High-Efficiency Organic Light-Emitting Diodes With D1-A-D2 Type Red Thermally Activated Delayed Fluorescence
HE Yihui, TANG Yanqing, XIE Fengming, ZHOU Jingxiong, ZENG Xinyi, TANG Jianxin
2021, 34(5): 452-459.   doi: 10.14133/j.cnki.1008-9357.20210204001
[Abstract](103) [FullText HTML](64) [PDF 7380KB](23)
At present, the development of novel high performance red thermally activated delayed fluorescence (TADF) materials still faces great challenges. In this work, the phenoxazin (PXZ) fragment was used as the strong electron donor with molecular rigidity (D1), the triphenylamine (TPA) fragment was used as the strong electron donor with large steric hindrance (D2), and the dibenzo[a, c]phenazine (BP) fragment composed of heterocyclic aromatic hydrocarbon was used as the strong electron acceptor (A). With the three fragments, a new high efficiency red TADF emitter with donor-receptor-donor (D1-A-D2) structure, 4, 4'-(3, 6-di (10H-phenoxazin-10-yl) dibenzo[a, c]phenazine-11, 12-diyl) bis (N, N-diphenylaniline) (2T-BP-2P), was designed. The photophysical, electrochemical and thermal properties of 2T-BP-2P were characterized by ultraviolet-visible (UV-Vis) absorption, photoluminescence (PL), thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC), respectively. At the same time, 2T-BP-2P was characterized and confirmed by nuclear magnetic resonance (NMR) and mass spectrometry (MS) technology. Results showed that 2T-BP-2P had a high photoluminescence quantum yield (ΦPL) of 78.5% in the 15% mass fraction doped films with 4,4′-bis(N-carbazolyl)-1,1′-biphenyl(CBP) as a host material. The device based on 2T-BP-2P achieved red emission at 614.5 nm, maximum external quantum efficiency (EQEmax) of 12.2%, and the Commission International de l'Eclairage (CIE) coordinate of (0.59, 0.40). What’s more, the lowest turn-on voltage (Von) was 2.9 eV, and the highest power efficiency (PE) and current efficiency (CE) of the device were 17.37 lm/W and 17.70 cd/A, respectively. The superior performance of this device is at the leading level among the known red-doped TADF-organic light-emitting diodes (OLEDs). A new strategy for the future development of high-performance red-emitting OLEDs is provided.
Synthesis and Photoluminescence Properties of Fluorescein-Based Poly(glycidyl methacrylate)
LIU Bin, WANG Yaling, CHU Bo, DUAN Hanyi, LI Yang, WANG Huiqi, HU Shengliang, ZHANG Xinghong
2021, 34(5): 460-467.   doi: 10.14133/j.cnki.1008-9357.20210409001
[Abstract](105) [FullText HTML](81) [PDF 5402KB](27)
Fluorescein(Flu)was introduced into poly(glycidyl methacrylate) (PGMA) chains by atomic transfer radical polymerization (ATRP) and fluorescein-based PGMA (Flu-PGMA) was prepared by using traditional fluorescein with aggregation induced quenching (ACQ) effect as initiator and glycidyl methacrylate (GMA) as monomer. The thermal and fluorescence properties of Flu-PGMA were characterized by differential scanning calorimetric, thermogravimetric analysis, steady-state and transient-state fluorescence spectrometers, and the device properties of white light-emitting diodes (LEDs) were investigated by PR655 spectrometer. The results showed that PGMA could overcome the ACQ effect of fluorescein, and the number-average molecular weight was 2.64×104 and polydispersity of Flu-PGMA was 1.5. The glass transition temperature and thermal decomposition temperature of Flu-PGMA could reach up to 79.8 °C and 280 °C, and its excellent thermal properties satisfy the needs of a phosphor. In addition, the Flu-PGMA presented excellent visible light transmittance of 64%–68% in a wavelength range of 400–800 nm. The solid-state fluorescence quantum yield of Flu-PGMA could reach up to 14.27%. The photoluminescence spectra exhibited excitation-independent characteristics and the strongest emission peak was located at 550 nm, which belongs to yellow emission. The average fluorescence decay lifetime fitted by biexponential function was 4.55 ns. When it was applied as a single-phase solid phosphor, a white LED with a color rendering index of 84 was fabricated under the excitation of 460 nm InGaN blue chip at a driving voltage of 2.7 V, which is higher than that of fluorescein-based LEDs reported at present. The correlated color temperature was 9 455 K and the color coordinates were located at (0.289, 0.282), which belongs to the white gamut.
Near-Infrared Light Induced Reverse Atom Transfer Radical Polymerization Assisted by Upconversion Particles
ZHANG Zhihui, ZHU Ye, LUO Jing, LIU Ren, LIU Xiaoya
2021, 34(5): 468-475.   doi: 10.14133/j.cnki.1008-9357.20210208001
[Abstract](205) [FullText HTML](148) [PDF 5409KB](32)
Near-infrared (NIR) light induced reverse atom transfer radical polymerization (ATRP) was achieved by using upconversion particle (UCP), which can convert the NIR light into light with ultraviolet-visible (UV-Vis) wavelength, as the internal light source, phenyl bis(2, 4, 6-trimethylbenzoyl)-phosphine oxide (BAPO) as the initiator, copper bromide (CuBr2)/N, N, N', N", N"-pentamethyldiethylenetriamine (PMDETA) as the catalyst, methyl methacrylate (MMA) as the main monomer, N, N-dimethylformamide (DMF) as the solvent, and the reaction condition of c(MMA)∶c(BAPO)∶c(CuBr2)∶c(PMDETA)=300∶1∶1∶3, VMMAVDMF=1∶1, and NIR laser power was 16.5 W/cm2. The UV-Vis spectrum of BAPO, the emission spectrum of UCP, and the photolysis of BAPO under irradiation of NIR light assisted by UCP indicated adaptability of BAPO and UCP. The process and reverse ATRP mechanism of this system were investigated by adjusting the conditions of polymerization, including whether UCP, BAPO or catalyst existed or not. In addition, the energy source of this polymerization was investigated by simulating the temperature of this system under NIR light irradiation. The results confirmed the photoluminescence of UCP under irradiation of 980 nm NIR light and the polymerization was initiated by fluorescence instead of thermal effect. UCP-assisted NIR induced reverse ATRP was capable of polymerization of various types of monomers, including MMA, methyl acrylate (MA) and styrene (St). The kinetics of MMA polymerization was investigated under UCP-assisted NIR induced reverse ATRP and a linear semilogarithmic plot of monomer concentration versus polymerization time was observed. The living character of the polymerization was confirmed by both the linear tendency of molecular weight evolution with monomer conversion and a chain extension experiment. The UCP-assisted NIR induced reverse ATRP provided well-defined polymer with relatively low polydispersity and excellent chain-end fidelity.
Synthesis of Pyrene-Based Two-Dimensional Polymer Film by Gas-Liquid Interface Strategy
HAN Xiangli, GUAN Jing, CHEN Le, ZHAO Pei, TAN Weiqiang, ZHENG Zhikun
2021, 34(5): 476-482.   doi: 10.14133/j.cnki.1008-9357.20210125001
[Abstract](538) [FullText HTML](266) [PDF 5741KB](42)
Two-dimensional (2D) material, such as 2D polymer (2DP) and 2D covalent organic framework (2D-COF), has arisen as promising materials because of their unique physicochemical properties and great potential in optoelectronics, sensing, catalysis, separation, and energy storage and conversion. The preparation of 2DP films with desirable structures is promising but remains a significant challenge. Recently, vigorous efforts have been devoted to synthesizing 2DP films through different methods, such as interfacial synthesis at gas-water or liquid-liquid. Herein, a fluorescent pyrene-based 2D polyimine (2D-PI) thin film was prepared via Schiff-base condensation between 4,4',4'',4'''-(pyrene-1,3,6,8-tetrayl)tetraaniline and 2,5-dihydroxyterephthalaldehyde with trifluoromethanesulfonic acid as a catalyst at room temperature by a surfactant-monolayer-assisted interfacial synthesis (SMAIS) approach. The morphology, structure, crystallinity, and fluorescence intensity of the film were characterized by scanning electron microscopy, atomic force microscopy, transmission electron microscopy, X-ray diffraction, fluorescence spectroscopy, Fourier transform infrared spectroscopy, and Raman spectroscopy. The results revealed that the film thickness was 70 nm, which could be controlled by changing the monomer concentration. The imine bond formation was confirmed by Fourier transform infrared spectroscopy and Raman spectroscopy. The film crystallinity depended on the diffusion rate of monomer and was significantly improved by adding trifluoromethanesulfonic acid and surfactant monolayer, which provided a confined 2D template for polymerization. In addition, the fluorescence strength of the film was enhanced by the existence of intramolecular hydrogen bonding in the framework structure. This study provided a unique idea for the preparation of 2DP films with solid luminescent properties, which may be potentially applied to detect water content in organic solvent.
Application of PVDF/TiO2 Electrospun Fiber Membrane in Photodegradation and Oil-Water Separation
GE Jun, FENG Yangyang, CHAI Peng, YAN Luke, CHEN Tao
2021, 34(5): 483-489.   doi: 10.14133/j.cnki.1008-9357.20210112001
[Abstract](668) [FullText HTML](258) [PDF 5529KB](35)
Polyvinylidene fluoride (PVDF) and tetrabutyl titanate (TBOT) are dissolved in a mixed solvent of N, N'-dimethylformamide (DMF) and acetone to electrospun into a fiber membrane. Then, TBOT contained in the electrospun fiber membrane was reduced to titanium dioxide (TiO2) by a one-step hydrothermal method at 150 °C. The PVDF fiber membrane material with TiO2 grown in situ on the surface and inside of the fiber was obtained. The morphology and structure of TiO2 grown on PVDF fibers in situ were determined by scanning electron microscopy (SEM), thermal gravity (TG), X-ray diffractometer (XRD) and Fourier infrared absorption spectroscopy (FT-IR). Then, the degradation effect of the composite film on the three organic dyes (rhodamine B, methyl orange and methylene blue) was tested by UV-visible spectroscopy. Finally, the gravity-driven method was used to separate the oil-water mixture, and the contact angle of the composite membrane to water and oil was tested to explore the oil-water separation effect of the composite membrane. Results show that the composite membrane has a good degradation effect on organic dyes such as rhodamine B, methyl orange, methylene blue. The composite membrane also has good lipophilic and hydrophobic properties. It is separated by a mixture of carbon tetrachloride and water. The composite membrane can effectively realize oil-water separation, and the oil-water separation efficiency can be as high as 98.2%.
Preparation of Polypyrrole/MnO2 Paper Electrode and Its Photothermal Effect to Enhanced Capacitor Performance
KANG Meng, WANG Pengfei, WANG Meng, WU Qiang, KE Xiaoling, ZHOU Jianhua
2021, 34(5): 490-496.   doi: 10.14133/j.cnki.1008-9357.20210131001
[Abstract](313) [FullText HTML](188) [PDF 5463KB](30)
The performance of supercapacitor degenerates at low temperature, even fails to work sometimes. Solar photothermal conversion provides a new direction for the performance improvement of supercapacitor. Manganese dioxide (MnO2) has a high specific capacity, while it should be compounded with other active materials due to its low electric conductivity. Therefore, this study aimed to improve the performance of MnO2-based supercapacitor using the photothermal effect of polypyrrole (PPy), which exhibited excellent light absorption ability and pseudocapacitance property. MnO2 and PPy were successively deposited on slow filter paper by wet chemistry method and low-temperature interfacial polymerization approach, and PPy/MnO2 paper-based composites with different PPy contents were prepared. The structures and properties of the composites were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, cyclic voltammetry, galvanostatic charge/discharge, and AC impedance spectroscopy. The results showed that the porous structure of filter paper was well preserved after PPy deposition, and MnO2 was covered to form a large active area. The specific capacitance of MnO2/PPy-400 single electrode reached 1 487.1 mF/cm2, 67% higher than that of pure PPy electrode. Under the simulated sunlight with the intensity of 1 kW/m2, the surface temperature of the assembled symmetrical supercapacitor increased from 21.2 °C to 46.7 °C after 10 min. The specific capacitance of the symmetrical supercapacitor assembled by the paper electrode with PPy of 400.0 μL was 52.9 mF/cm2 with illumination, five times that in dark, suggesting excellent photothermal effect to enhanced capacitor performance.