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, Available online ,
doi: 10.14133/j.cnki.1008-9357.20220520001
Abstract:
Electrospun polycaprolactone (PCL) nanofibers are often used as biomedical materials for drug release systems and tissue engineering scaffolds due to their biodegradability, but the hydrophobicity and mechanical defects limit the wider applications. Here, polybutyrolactam (PBL), a biodegradable polyamide with excellent mechanical properties and high moisture regain, was blended with PCL in co-solvent to electrospin fiber membranes with improved mechanical properties and hydrophilicity. Scanning electron microscope (SEM), water contact angle measuring instrument, atomic force microscope (AFM), energy dispersive spectroscopy (EDS), transmission electron microscope (TEM), X-ray diffraction (XRD), thermogravimetric analyzer (TGA), differential scanning calorimetry (DSC), electronic universal tension machine were used to investigate the morphology, diameter and distribution of fibers, and hydrophilicity, crystallinity, thermal and mechanical properties of the fiber membranes. It was found that increasing PBL content increased the fiber diameter, narrowed the diameter distribution and significantly improved the hydrophilicity of the fiber membranes. PBL proved to be compatible with PCL and the crystallinity of PCL/PBL electrospun fiber membranes that increased with the increase in PBL content was higher than that of monocomponent fiber membranes. Increasing PBL content also slightly raised the melting point of PCL component in fiber membranes, while that of PBL kept unchanged. The crystallization temperatures of PBL and PCL, and the thermal stability of fiber membranes decreased with the increase of PBL content. The addition in PBL significantly improved the mechanical properties of electrospun fiber membranes The more PBL content was, the better the mechanical properties of the fiber membranes was.
Electrospun polycaprolactone (PCL) nanofibers are often used as biomedical materials for drug release systems and tissue engineering scaffolds due to their biodegradability, but the hydrophobicity and mechanical defects limit the wider applications. Here, polybutyrolactam (PBL), a biodegradable polyamide with excellent mechanical properties and high moisture regain, was blended with PCL in co-solvent to electrospin fiber membranes with improved mechanical properties and hydrophilicity. Scanning electron microscope (SEM), water contact angle measuring instrument, atomic force microscope (AFM), energy dispersive spectroscopy (EDS), transmission electron microscope (TEM), X-ray diffraction (XRD), thermogravimetric analyzer (TGA), differential scanning calorimetry (DSC), electronic universal tension machine were used to investigate the morphology, diameter and distribution of fibers, and hydrophilicity, crystallinity, thermal and mechanical properties of the fiber membranes. It was found that increasing PBL content increased the fiber diameter, narrowed the diameter distribution and significantly improved the hydrophilicity of the fiber membranes. PBL proved to be compatible with PCL and the crystallinity of PCL/PBL electrospun fiber membranes that increased with the increase in PBL content was higher than that of monocomponent fiber membranes. Increasing PBL content also slightly raised the melting point of PCL component in fiber membranes, while that of PBL kept unchanged. The crystallization temperatures of PBL and PCL, and the thermal stability of fiber membranes decreased with the increase of PBL content. The addition in PBL significantly improved the mechanical properties of electrospun fiber membranes The more PBL content was, the better the mechanical properties of the fiber membranes was.
, Available online ,
doi: 10.14133/j.cnki.1008-9357.20221029001
Abstract:
Wearable devices have attracted tremendous interest in recent decades, but the rigidity of traditional battery components limited its development. To power up the wearable devices, is urgent to develop a new type of stretchable energy storage devices. A series of representative stretchable battery preparation methods have been reported. This review summarizes the related works in this field, divides the strategies to achieve stretchability into two categories: device-level and component-level. We focus on the structural design in different dimensions and the preparation methods of each stretchable component to achieve stretchability, analyzes the advantages and shortcomings of both ways. The general issues such as energy density , interface degradation, encapsulation process and device integration of the stretchable battery are pointed out, and the future development trend is also foreseen.
Wearable devices have attracted tremendous interest in recent decades, but the rigidity of traditional battery components limited its development. To power up the wearable devices, is urgent to develop a new type of stretchable energy storage devices. A series of representative stretchable battery preparation methods have been reported. This review summarizes the related works in this field, divides the strategies to achieve stretchability into two categories: device-level and component-level. We focus on the structural design in different dimensions and the preparation methods of each stretchable component to achieve stretchability, analyzes the advantages and shortcomings of both ways. The general issues such as energy density , interface degradation, encapsulation process and device integration of the stretchable battery are pointed out, and the future development trend is also foreseen.
Articles in press have been peer-reviewed and accepted, which are not yet assigned to volumes /issues, but are citable by Digital Object Identifier (DOI).
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, Available online ,
doi: 10.14133/j.cnki.1008-9357.20220322001
Abstract:
Poly(ethylene glycol) monomethyl ether-poly(2-diisopropylaminoethyl methacry-late)-poly(acrylamide-co-acrylonitrile) (mPEG-PDPA-P(AAm-co-AN)), a novel amphiphilic triblock ABC polymer, was designed and synthesized. This polymer was prepared by atom transfer radical polymerization (ATRP) and reversible addition-fragmentation chain transfer polymerization (RAFT). When pH changes, PDPA undergoes a hydrophilic-hydrophobic transition. Therefore, the polymer has pH-responsivity with a pH-sensitive point at pH 6.53. The P(AAm-co-AN) fragment forms hydrogen bonds at low temperature. At high temperature, hydrogen bonds are formed between the polymer chains and water molecules so that the polymer mPEG-PDPA-P(AAm-co-AN) has a high critical solution temperature (UCST). By varying the monomer ratios of acrylamide (AAm) to acrylonitrile (AN) and the concentration of the solution, polymers with different UCSTs can be obtained. In a neutral environment at room temperature, the polymer solution forms micelles by self-assembly with mPEG as the shell and PDPA and P(AAm-co-AN) as the core. The particle size, potential and morphology of the micelles in various external environments were studied by dynamic light scattering (DLS) and transmission electron microscopy (TEM). An increase in temperature induces a transition from micelles to asymmetric vesicles. The lower pH encourages the polymer to form looser micelles. Simultaneously changing the pH and temperature, the hydrophilicity of each block of the polymer increases, the micelles dissolve sufficiently, and the particle size increases. In an in vitro drug release investigation, polymeric micelles show good drug delivery for both the hydrophilic drug doxorubicin (DOX) and the hydrophobic drug quercetin. The micelles show low leakage at 37 ℃ and pH 7.4. The release rate of drug from the micelles increases significantly with the increasing of temperature and the decreasing of pH. It is demonstrated that the polymeric micelles have good environmental stimulus sensing ability and controlled drug release.
Poly(ethylene glycol) monomethyl ether-poly(2-diisopropylaminoethyl methacry-late)-poly(acrylamide-co-acrylonitrile) (mPEG-PDPA-P(AAm-co-AN)), a novel amphiphilic triblock ABC polymer, was designed and synthesized. This polymer was prepared by atom transfer radical polymerization (ATRP) and reversible addition-fragmentation chain transfer polymerization (RAFT). When pH changes, PDPA undergoes a hydrophilic-hydrophobic transition. Therefore, the polymer has pH-responsivity with a pH-sensitive point at pH 6.53. The P(AAm-co-AN) fragment forms hydrogen bonds at low temperature. At high temperature, hydrogen bonds are formed between the polymer chains and water molecules so that the polymer mPEG-PDPA-P(AAm-co-AN) has a high critical solution temperature (UCST). By varying the monomer ratios of acrylamide (AAm) to acrylonitrile (AN) and the concentration of the solution, polymers with different UCSTs can be obtained. In a neutral environment at room temperature, the polymer solution forms micelles by self-assembly with mPEG as the shell and PDPA and P(AAm-co-AN) as the core. The particle size, potential and morphology of the micelles in various external environments were studied by dynamic light scattering (DLS) and transmission electron microscopy (TEM). An increase in temperature induces a transition from micelles to asymmetric vesicles. The lower pH encourages the polymer to form looser micelles. Simultaneously changing the pH and temperature, the hydrophilicity of each block of the polymer increases, the micelles dissolve sufficiently, and the particle size increases. In an in vitro drug release investigation, polymeric micelles show good drug delivery for both the hydrophilic drug doxorubicin (DOX) and the hydrophobic drug quercetin. The micelles show low leakage at 37 ℃ and pH 7.4. The release rate of drug from the micelles increases significantly with the increasing of temperature and the decreasing of pH. It is demonstrated that the polymeric micelles have good environmental stimulus sensing ability and controlled drug release.
, Available online ,
doi: 10.14133/j.cnki.1008-9357.20220809001
Abstract:
Poly(3,4-ethylenedioxythiophene) (PEDOT) is used in organic-inorganic heterojunction based ultraviolet (uv) photodetector (UV PD) due to its good environmental stability, high conductivity and special photoelectric characteristics. The commonly used methods for depositing PEDOT films include solution spin coating, electrochemical polymerization, vacuum evaporation and immersion. In this paper, PEDOT film on the surface of fluorine doped tin oxide (FTO) coated glass conductive glass is obtained by solid-state polymerization, using 2,5-dibromo-3,4-ethylenedioxythiophene (DBEDOT) as monomer. The PEDOT film modified FTO was combined with zinc oxide nano arrays (ZnO NRs) modified FTO to fabricate the organic-inorganic heterojunction based UV PD, and the performance of UV photodetection ability was studied. The materials were characterized by ultraviolet-visible spectroscopy (UV-Vis), Fourier-transfer infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and X-ray powder diffractometry (XRD). The photo-responsivity, response speed and stability of the UV photodetector were examined in detail through current-voltag (I-V), current-time (I-t) and Tafel curves at zero bias voltage under UV irradiation (365 nm, 0.32 mW/cm2). Results showed that the PEDOT film had large flake structure, which was conducive to the good contact of ZnO NRs to build a better p-n heterojunction. Furthermore, the introduction of PEDOT film effectively solved the problems of short carrier life, high recombination rate of hole-electrons and slow light response speed of ZnO NRs. In a word, the PEDOT film enhanced the optoelectronic performance of ZnO NRs, which possessed high responsivity of 15.34 mA/W, fast response time of 0.159 s/0.162 s (rise time/fall time) under UV irradiation (365 nm, 0.32 mW/cm2) and good stability.
Poly(3,4-ethylenedioxythiophene) (PEDOT) is used in organic-inorganic heterojunction based ultraviolet (uv) photodetector (UV PD) due to its good environmental stability, high conductivity and special photoelectric characteristics. The commonly used methods for depositing PEDOT films include solution spin coating, electrochemical polymerization, vacuum evaporation and immersion. In this paper, PEDOT film on the surface of fluorine doped tin oxide (FTO) coated glass conductive glass is obtained by solid-state polymerization, using 2,5-dibromo-3,4-ethylenedioxythiophene (DBEDOT) as monomer. The PEDOT film modified FTO was combined with zinc oxide nano arrays (ZnO NRs) modified FTO to fabricate the organic-inorganic heterojunction based UV PD, and the performance of UV photodetection ability was studied. The materials were characterized by ultraviolet-visible spectroscopy (UV-Vis), Fourier-transfer infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and X-ray powder diffractometry (XRD). The photo-responsivity, response speed and stability of the UV photodetector were examined in detail through current-voltag (I-V), current-time (I-t) and Tafel curves at zero bias voltage under UV irradiation (365 nm, 0.32 mW/cm2). Results showed that the PEDOT film had large flake structure, which was conducive to the good contact of ZnO NRs to build a better p-n heterojunction. Furthermore, the introduction of PEDOT film effectively solved the problems of short carrier life, high recombination rate of hole-electrons and slow light response speed of ZnO NRs. In a word, the PEDOT film enhanced the optoelectronic performance of ZnO NRs, which possessed high responsivity of 15.34 mA/W, fast response time of 0.159 s/0.162 s (rise time/fall time) under UV irradiation (365 nm, 0.32 mW/cm2) and good stability.
, Available online ,
doi: 10.14133/j.cnki.1008-9357.20220723001
Abstract:
Supramolecular chirality usually plays an important role in biological processes and living systems. A novel achiral liquid crystalline polymer where the molecular chirality can be transferred is described, which provides a simple method to realize the chiral selfassembly in achiral polymer systems. However, the supramolecular chiral structures are often easily destroyed by external stimulus due to the weak non-covalent interactions between building blocks, which limits the application of the chiral supramolecular materials to a large extent. In the most systems composed of achiral precursors, the destroyed chiral ordered structures cannot be recovered in the absence of the pre-chiral resource. In order to improve the stability of supramolecular chiral structure and overcome its strong dependence on the chiral resource, a series of achiral liquid crystalline polymers containing phenyl benzoate groups as the mesogens and cinnamic acid groups as the cross-linkable center in the polymer side-chains are designed and synthesized. Combining with the induction of chiral limonene and photo-crosslinking, the supramolecular chirality constructed from achiral polymers can be permanently memorized in a simple way. Even when the helical structure is destroyed by polar solvent or high temperature, the memorized chiral information enables the complete self-recovery behavior without any pre-chiral resource. The current research will provide a new strategy for the preparation of chiral supramolecular materials with stored chiral information.
Supramolecular chirality usually plays an important role in biological processes and living systems. A novel achiral liquid crystalline polymer where the molecular chirality can be transferred is described, which provides a simple method to realize the chiral selfassembly in achiral polymer systems. However, the supramolecular chiral structures are often easily destroyed by external stimulus due to the weak non-covalent interactions between building blocks, which limits the application of the chiral supramolecular materials to a large extent. In the most systems composed of achiral precursors, the destroyed chiral ordered structures cannot be recovered in the absence of the pre-chiral resource. In order to improve the stability of supramolecular chiral structure and overcome its strong dependence on the chiral resource, a series of achiral liquid crystalline polymers containing phenyl benzoate groups as the mesogens and cinnamic acid groups as the cross-linkable center in the polymer side-chains are designed and synthesized. Combining with the induction of chiral limonene and photo-crosslinking, the supramolecular chirality constructed from achiral polymers can be permanently memorized in a simple way. Even when the helical structure is destroyed by polar solvent or high temperature, the memorized chiral information enables the complete self-recovery behavior without any pre-chiral resource. The current research will provide a new strategy for the preparation of chiral supramolecular materials with stored chiral information.
, Available online ,
doi: 10.14133/j.cnki.1008-9357.20220421001
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Molybdenum disulfide (MoS2) was introduced into the polyacrylamide/chitosan (PAM/CS) hydrogel system by free radical polymerization, and the PAM/CS/MoS2 composite polymer hydrogel with interpenetrating network structure was prepared. The composition and morphology of the hydrogels were analyzed by Fourier transform infrared spectroscopy, Raman spectroscopy, scanning electron microscopy, and laser scanning confocal microscopy. The mechanical properties and hydrophilic properties were tested by a universal testing machine and a contact angle measuring instrument. Finally, the application of the composite hydrogel film in the field of humidity sensing was explored by a quartz crystal microbalance (QCM). The PAM/CS/MoS2-0.4 (mass of MoS2 in this system is 0.4 mg) composite hydrogel has a maximum compressive stress of 584.6 kPa and a maximum compressive strain of 83.8%; The introduction of MoS2 improves the hydrophilicity of the composite hydrogel; As the relative humidity of the environment increases from 11% to 95%, the frequency response of the QCM humidity sensor modified by the composite hydrogel film reaches a maximum of 2642 Hz, and its sensitivity of 1% change of relative humidity is 31.45 Hz, which is expected to be applied in the field of humidity sensing.
Molybdenum disulfide (MoS2) was introduced into the polyacrylamide/chitosan (PAM/CS) hydrogel system by free radical polymerization, and the PAM/CS/MoS2 composite polymer hydrogel with interpenetrating network structure was prepared. The composition and morphology of the hydrogels were analyzed by Fourier transform infrared spectroscopy, Raman spectroscopy, scanning electron microscopy, and laser scanning confocal microscopy. The mechanical properties and hydrophilic properties were tested by a universal testing machine and a contact angle measuring instrument. Finally, the application of the composite hydrogel film in the field of humidity sensing was explored by a quartz crystal microbalance (QCM). The PAM/CS/MoS2-0.4 (mass of MoS2 in this system is 0.4 mg) composite hydrogel has a maximum compressive stress of 584.6 kPa and a maximum compressive strain of 83.8%; The introduction of MoS2 improves the hydrophilicity of the composite hydrogel; As the relative humidity of the environment increases from 11% to 95%, the frequency response of the QCM humidity sensor modified by the composite hydrogel film reaches a maximum of 2642 Hz, and its sensitivity of 1% change of relative humidity is 31.45 Hz, which is expected to be applied in the field of humidity sensing.
, Available online ,
doi: 10.14133/j.cnki.1008-9357.20221109001
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Tumor blockade therapy is a promising penetration-independent antitumor modality through inhibiting the substance exchange between the tumor and surrounding microenvironments. However, the strategies of vessel-targeted blockade, construction of an artificial extracellular matrix, and so forth are limited by possible side effects, inadequate tumor obstruction, and short duration. Inspired by the biomineralization in living organisms, artificially induced biomineralization in the tumor tissues has been emerging as an unconventional therapeutic modality characterized by long duration and satisfying biocompatibility. On this basis, our group reacted alendronate (ALN) with 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-poly(ethylene glycol)-hydroxysuccinimide eater (DSPE-PEG-NHS) to synthesize DSPE-PEG-ALN (DPA), in which the DSPE group was able to insert into cytomembrane, and bisphosphonic group attracted positive ions, mainly calcium ion, to initiate the chain reaction of biomineral deposition. Ultimately, an intense physical barrier was constructed in the periphery of tumor tissue, leading to effective tumor inhibition. To realize selective biomineralization around the tumor tissue, we designed a polypeptide-based biomineralization-inducing nanoparticle (BINP) equipped with the tumor microenvironment-responsiveness. Because of the hydrophobicity of long aliphatic chains, they were assembled in the interior of nanostructures at normal physiological conditions, while tending to expose at acidic microenvironments to selectively insert in the tumor cytomembrane. Then BINP initiated a biomineralized layer right there to achieve effective suppression of osteosarcoma progression. The design and application of in situ biomineralization-inducing functional polymers provide promising alternatives for clinical malignancy therapy.
Tumor blockade therapy is a promising penetration-independent antitumor modality through inhibiting the substance exchange between the tumor and surrounding microenvironments. However, the strategies of vessel-targeted blockade, construction of an artificial extracellular matrix, and so forth are limited by possible side effects, inadequate tumor obstruction, and short duration. Inspired by the biomineralization in living organisms, artificially induced biomineralization in the tumor tissues has been emerging as an unconventional therapeutic modality characterized by long duration and satisfying biocompatibility. On this basis, our group reacted alendronate (ALN) with 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-poly(ethylene glycol)-hydroxysuccinimide eater (DSPE-PEG-NHS) to synthesize DSPE-PEG-ALN (DPA), in which the DSPE group was able to insert into cytomembrane, and bisphosphonic group attracted positive ions, mainly calcium ion, to initiate the chain reaction of biomineral deposition. Ultimately, an intense physical barrier was constructed in the periphery of tumor tissue, leading to effective tumor inhibition. To realize selective biomineralization around the tumor tissue, we designed a polypeptide-based biomineralization-inducing nanoparticle (BINP) equipped with the tumor microenvironment-responsiveness. Because of the hydrophobicity of long aliphatic chains, they were assembled in the interior of nanostructures at normal physiological conditions, while tending to expose at acidic microenvironments to selectively insert in the tumor cytomembrane. Then BINP initiated a biomineralized layer right there to achieve effective suppression of osteosarcoma progression. The design and application of in situ biomineralization-inducing functional polymers provide promising alternatives for clinical malignancy therapy.
, Available online ,
doi: 10.14133/j.cnki.1008-9357.20220919001
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One of the most effective methods for improving the storage density of resistive random access memories (RRAMs) is to fabricate 3D vertical stacking devices. By using BP-DDAT(DDAT: S-1-dodecyl-S′-(α,α′-dimethyl-α′′-aceticacid)trithiocarbonate) as a key 2D template and reversible addition-fragmentation chain transfer (RAFT) reagent, a novel poly(N-vinylcarbazole) covalently functionalized black phosphorus derivative (BP-PVK) is successfully synthesized and well-characterized by Infrared spectroscopy, X-ray electron spectroscopy and UV-Vis absorption spectroscopy. The environmental stability and solubility of BP nanosheets are greatly improved. Using BP-PVK as active layer, a double-layer vertically stacked RRAM memory device (17×17 stripe array) with a configuration of Al/BP-PVK/Al/BP-PVK/Al is fabricated. The as-fabricated device shows good bistable electrical switching and non-volatile rewritable performance at room temperature, with an ON/OFF current ratio exceeding 103, higher production yield of the memory devices and structural uniformity.
One of the most effective methods for improving the storage density of resistive random access memories (RRAMs) is to fabricate 3D vertical stacking devices. By using BP-DDAT(DDAT: S-1-dodecyl-S′-(α,α′-dimethyl-α′′-aceticacid)trithiocarbonate) as a key 2D template and reversible addition-fragmentation chain transfer (RAFT) reagent, a novel poly(N-vinylcarbazole) covalently functionalized black phosphorus derivative (BP-PVK) is successfully synthesized and well-characterized by Infrared spectroscopy, X-ray electron spectroscopy and UV-Vis absorption spectroscopy. The environmental stability and solubility of BP nanosheets are greatly improved. Using BP-PVK as active layer, a double-layer vertically stacked RRAM memory device (17×17 stripe array) with a configuration of Al/BP-PVK/Al/BP-PVK/Al is fabricated. The as-fabricated device shows good bistable electrical switching and non-volatile rewritable performance at room temperature, with an ON/OFF current ratio exceeding 103, higher production yield of the memory devices and structural uniformity.
, Available online ,
doi: 10.14133/j.cnki.1008-9357.20220609001
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To improve the capacity of adhesion and migration in vascular smooth muscle cells (vSMCs), the fiber surface was modified by having the electrospun aligned poly(lactic-lactide) (PLLA) ultrafine fibers individually coated with hyaluronic acid (HA) biomacromolecules via stable jet coaxial electrospinning (SJCES). First of all, under the condition of serum-free starvation, the effect of HA presence in the culture medium on promoting vSMC migration was examined. Then, highly-aligned HA-coated PLLA composite fibers (HA-PLLA) in shell-core structure were produced by SJCES, and the morphology, shell-core structure and mechanical properties of the HA-PLLA fibers were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), polarized infrared spectroscopy (P-FTIR), X-ray diffraction (XRD), and a universal mechanical tester. Finally, the efficacy of HA-PLLA fiber arrays in supporting vSMC migration was detected based on an improved "wound" healing method. Results showed that the presence of HA was capable of promoting vSMC migration. HA-PLLA aligned fibers in shell-core structure were successfully fabricated using SJCES. Modification of HA significantly improved the cytocompatibility of the aligned PLLA fibers, and enhanced their efficiency in directing vSMC migration, thus, confirming the effectiveness of HA modification in promoting the migration of vSMCs on the aligned fibrous substrate of PLLA.
To improve the capacity of adhesion and migration in vascular smooth muscle cells (vSMCs), the fiber surface was modified by having the electrospun aligned poly(lactic-lactide) (PLLA) ultrafine fibers individually coated with hyaluronic acid (HA) biomacromolecules via stable jet coaxial electrospinning (SJCES). First of all, under the condition of serum-free starvation, the effect of HA presence in the culture medium on promoting vSMC migration was examined. Then, highly-aligned HA-coated PLLA composite fibers (HA-PLLA) in shell-core structure were produced by SJCES, and the morphology, shell-core structure and mechanical properties of the HA-PLLA fibers were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), polarized infrared spectroscopy (P-FTIR), X-ray diffraction (XRD), and a universal mechanical tester. Finally, the efficacy of HA-PLLA fiber arrays in supporting vSMC migration was detected based on an improved "wound" healing method. Results showed that the presence of HA was capable of promoting vSMC migration. HA-PLLA aligned fibers in shell-core structure were successfully fabricated using SJCES. Modification of HA significantly improved the cytocompatibility of the aligned PLLA fibers, and enhanced their efficiency in directing vSMC migration, thus, confirming the effectiveness of HA modification in promoting the migration of vSMCs on the aligned fibrous substrate of PLLA.
, Available online ,
doi: 10.14133/j.cnki.1008-9357.20220613001
Abstract:
Thermotropic liquid crystal copolyesters (TLCPs) with high melting point were synthesized by acetylation and melt polycondensation using p-hydroxybenzoic acid (HBA), terephthalic acid (PTA), and hydroquinone (HQ) as monomers. HBA and HQ were converted into 4-acetyloxybenzoic acid (ABA) and 1,4-diacetoxybenzoic (AHQ) respectively by acetylation to improve the reactivity.Zinc acetate was selected as the catalyst, and the mole ratio of monomers was n(ABA)∶n(PTA)∶n(AHQ)=60∶20∶20. The ternary copolyester shows excellent thermal stability and high melting point of 407 ℃. Furthermore, a series of new TLCPs (HBA/PTA/SuA/HQ) containing flexible segments were synthesized by incorporating the long-chain aliphatic 1,8-suberic acid (1,8-SuA), partially replacing PTA. The structure of the modified copolyesters were characterized by Fourier transform infrared spectrometer (FT-IR) and carbon-13 nuclear magnetic resonance (13C-NMR). The thermal properties and the liquid crystal texture of the copolyesters were analyzed using differential scanning calorimetry (DSC), thermal gravimetric analyzer (TGA), polarized optical microscope (POM) and X-ray diffraction (XRD). The results show that the melting point of the HBA/PTA/SuA/HQ copolyester decreases from 407 ℃ to 214 ℃ with the increasing of the 1,8-SuA content, but the crystallinity increases from 25.2% to 32.2%. The synthesized TLCPs show good thermal stability with the maximum decomposition temperature over 428 ℃. The decomposition temperature of the copolyesters decreases with the 1,8-SuA increases accordingly, and the char yield is between 22.1% and 31.3%, slightly lower than the initial ternary copolyester. All the synthesized copolyesters exhibit the similar textures of nematic liquid crystals. The results indicate that the combination property of the new copolyesters is little influenced by the introduction of long-chain aliphatic 1,8-SuA but the processability can be significantly improved.
Thermotropic liquid crystal copolyesters (TLCPs) with high melting point were synthesized by acetylation and melt polycondensation using p-hydroxybenzoic acid (HBA), terephthalic acid (PTA), and hydroquinone (HQ) as monomers. HBA and HQ were converted into 4-acetyloxybenzoic acid (ABA) and 1,4-diacetoxybenzoic (AHQ) respectively by acetylation to improve the reactivity.Zinc acetate was selected as the catalyst, and the mole ratio of monomers was n(ABA)∶n(PTA)∶n(AHQ)=60∶20∶20. The ternary copolyester shows excellent thermal stability and high melting point of 407 ℃. Furthermore, a series of new TLCPs (HBA/PTA/SuA/HQ) containing flexible segments were synthesized by incorporating the long-chain aliphatic 1,8-suberic acid (1,8-SuA), partially replacing PTA. The structure of the modified copolyesters were characterized by Fourier transform infrared spectrometer (FT-IR) and carbon-13 nuclear magnetic resonance (13C-NMR). The thermal properties and the liquid crystal texture of the copolyesters were analyzed using differential scanning calorimetry (DSC), thermal gravimetric analyzer (TGA), polarized optical microscope (POM) and X-ray diffraction (XRD). The results show that the melting point of the HBA/PTA/SuA/HQ copolyester decreases from 407 ℃ to 214 ℃ with the increasing of the 1,8-SuA content, but the crystallinity increases from 25.2% to 32.2%. The synthesized TLCPs show good thermal stability with the maximum decomposition temperature over 428 ℃. The decomposition temperature of the copolyesters decreases with the 1,8-SuA increases accordingly, and the char yield is between 22.1% and 31.3%, slightly lower than the initial ternary copolyester. All the synthesized copolyesters exhibit the similar textures of nematic liquid crystals. The results indicate that the combination property of the new copolyesters is little influenced by the introduction of long-chain aliphatic 1,8-SuA but the processability can be significantly improved.
, Available online ,
doi: 10.14133/j.cnki.1008-9357.20220726001
Abstract:
Organic memristors have the advantages of ultra-fast speed, ultra-low power consumption, non-volatile storage, and low manufacturing costs, which are expected to become key electronic components to break through the von Neumann bottleneck and the limit of Moore’s Law. However, the stability, homogeneity, and repeatability of memristors prepared by organic materials are poorer than inorganic memristors. Most of the current research addresses this problem from the aspect of morphology and crystalline control, while the research on optimization at the molecular level is relatively poor. The molecular coplanarity can be effectively improved by using conjugated donor-acceptor units with strong push-pull electronic effects, functional groups with small steric effects and shorter alkyl chains. In this work, two novel two-dimensional conjugated donor-acceptor polymers, pBDTT-PTQx and pBDTT-BBT, were synthesized by the Stille coupling method, and their resistive switching properties were studied by optimizing molecular coplanarity. Both materials have highly robust Flash-like resistive switching behaviors and can be written and erased for more than 100 cycles. The simulation calculation of density functional theory shows that the resistance change mechanism of the two materials is charge transfer. Compared with pBDTT-PTQx, the dihedral angle between the donor and the acceptor of pBDTT-BBT is only −179.27 °, and the mean square roughness of the device surface is only 1.71 nm. The ON/OFF ratio of pBDTT-BBT can still be maintained at around 10 and the disturbance is small after the 104 s read operation. What’s more, the disturbance coefficients of switching voltage are only 9.4% and 6.7%, and the disturbance coefficient of the resistance state is only 13.7% and 9.4%.
Organic memristors have the advantages of ultra-fast speed, ultra-low power consumption, non-volatile storage, and low manufacturing costs, which are expected to become key electronic components to break through the von Neumann bottleneck and the limit of Moore’s Law. However, the stability, homogeneity, and repeatability of memristors prepared by organic materials are poorer than inorganic memristors. Most of the current research addresses this problem from the aspect of morphology and crystalline control, while the research on optimization at the molecular level is relatively poor. The molecular coplanarity can be effectively improved by using conjugated donor-acceptor units with strong push-pull electronic effects, functional groups with small steric effects and shorter alkyl chains. In this work, two novel two-dimensional conjugated donor-acceptor polymers, pBDTT-PTQx and pBDTT-BBT, were synthesized by the Stille coupling method, and their resistive switching properties were studied by optimizing molecular coplanarity. Both materials have highly robust Flash-like resistive switching behaviors and can be written and erased for more than 100 cycles. The simulation calculation of density functional theory shows that the resistance change mechanism of the two materials is charge transfer. Compared with pBDTT-PTQx, the dihedral angle between the donor and the acceptor of pBDTT-BBT is only −179.27 °, and the mean square roughness of the device surface is only 1.71 nm. The ON/OFF ratio of pBDTT-BBT can still be maintained at around 10 and the disturbance is small after the 104 s read operation. What’s more, the disturbance coefficients of switching voltage are only 9.4% and 6.7%, and the disturbance coefficient of the resistance state is only 13.7% and 9.4%.
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2022, 35(6): 493-508.
doi: 10.14133/j.cnki.1008-9357.20220103001
Abstract:
Aqueous zinc ion batteries deliver the merits of high safety, abundant resources, low cost and environmental friendliness, thus exhibiting broad application prospects in large-scale energy storage system. However, serious dendrite growth and side reactions occur at the Zn anode/electrolyte interphase, giving rise to the poor cycling life and Coulombic efficiency. These problems severely hinder the practical applications of zinc ion batteries. Therefore, constructing of suitable protective layers is one of the most important pathways to inhibit zinc dendrite and side reactions like hydrogen evolution, benefiting from their ability to isolate the zinc anode from the electrolyte while allowing rapid Zn2+ migration and facilitating uniform electrodeposition. Functional polymers show potentials as promising Zn anode protective layers, owing to their adjustable functional groups, rapid Zn2+ conduction, excellent flexibility, good film-formation and adhesion. This review summarizes the progress of functional polymers serving as zinc protective layers, and finally presents a perspective on the future development in this field.
Aqueous zinc ion batteries deliver the merits of high safety, abundant resources, low cost and environmental friendliness, thus exhibiting broad application prospects in large-scale energy storage system. However, serious dendrite growth and side reactions occur at the Zn anode/electrolyte interphase, giving rise to the poor cycling life and Coulombic efficiency. These problems severely hinder the practical applications of zinc ion batteries. Therefore, constructing of suitable protective layers is one of the most important pathways to inhibit zinc dendrite and side reactions like hydrogen evolution, benefiting from their ability to isolate the zinc anode from the electrolyte while allowing rapid Zn2+ migration and facilitating uniform electrodeposition. Functional polymers show potentials as promising Zn anode protective layers, owing to their adjustable functional groups, rapid Zn2+ conduction, excellent flexibility, good film-formation and adhesion. This review summarizes the progress of functional polymers serving as zinc protective layers, and finally presents a perspective on the future development in this field.
2022, 35(6): 509-516.
doi: 10.14133/j.cnki.1008-9357.20220506002
Abstract:
A novel kind of redox-responsive amphiphilic polyurethane triblock copolymer, PEG-PU(SS)-PEG, was designed and synthesized, in which PEG was the hydrophilic polyethylene glycol at both ends of the copolymer chain, and the middle hydrophobic polyurethane block PU(SS) was prepared from bis(2-hydroxyethyl) disulfide and hexamethylene diisocyanate (HDI) via step-growth polymerization. PEG-PU(SS)-PEG could self-assemble into stable micelles with the average diameter of about 100 nm through nano-precipitation method in aqueous solution, in which the hydrophilic corona and the hydrophobic cores were composed of PEG and PU(SS) blocks, respectively. Hydrophobic anti-cancer drugs, such as curcumin, could be loaded into the hydrophobic micellar cores to construct redox-responsive drug nanocarriers with the drug loading content and the drug loading efficiency as high as 22.2% and 71.3%, respectively. Due to the existence of the disulfide linkages in the hydrophobic PU(SS) blocks, in the presence of glutathione (GSH), the copolymer chains could be triggered to depolymerize, resulting in the disintegration of the nano-micelles and release of loaded curcumin. After being co-incubated with GSH for 6 h, the cumulative release amount of curcumin could reach about 90%. Therefore, PEG-PU(SS)-PEG was a potential candidate for the fabrication of drug nanocarriers.
A novel kind of redox-responsive amphiphilic polyurethane triblock copolymer, PEG-PU(SS)-PEG, was designed and synthesized, in which PEG was the hydrophilic polyethylene glycol at both ends of the copolymer chain, and the middle hydrophobic polyurethane block PU(SS) was prepared from bis(2-hydroxyethyl) disulfide and hexamethylene diisocyanate (HDI) via step-growth polymerization. PEG-PU(SS)-PEG could self-assemble into stable micelles with the average diameter of about 100 nm through nano-precipitation method in aqueous solution, in which the hydrophilic corona and the hydrophobic cores were composed of PEG and PU(SS) blocks, respectively. Hydrophobic anti-cancer drugs, such as curcumin, could be loaded into the hydrophobic micellar cores to construct redox-responsive drug nanocarriers with the drug loading content and the drug loading efficiency as high as 22.2% and 71.3%, respectively. Due to the existence of the disulfide linkages in the hydrophobic PU(SS) blocks, in the presence of glutathione (GSH), the copolymer chains could be triggered to depolymerize, resulting in the disintegration of the nano-micelles and release of loaded curcumin. After being co-incubated with GSH for 6 h, the cumulative release amount of curcumin could reach about 90%. Therefore, PEG-PU(SS)-PEG was a potential candidate for the fabrication of drug nanocarriers.
2022, 35(6): 517-523.
doi: 10.14133/j.cnki.1008-9357.20220531001
Abstract:
Hollow particles have attracted considerable attentions in recent years for their potential in diverse application fields. In this work, polypeptide-based hollow disk-like and conchoidal particles with surface nanostrips were prepared. For the poly(γ-benzyl-L-glutamate)-b-poly(ethylene glycol) (PBLG-b-PEG) block copolymer, through partial deprotection of the benzyl group of the PBLG block and esterification reaction between the carboxyl group and cinnamic alcohol, poly(γ-benzyl-L-glutamate-co-γ-cinnamyl-L-glutamate)-b-poly(ethylene glycol) (P(BLG/CLG)-b-PEG) block copolymers were obtained. The self-assemblies were prepared by a selective precipitation method. P(BLG/CLG)-b-PEG block copolymers and polystyrene (PS) homopolymers were first dissolved in THF-DMF mixture solvent; by adding water to the solution, core-shell particles with nanostrips on the surface were obtained, in which the hydrophobic PS homopolymer formed the spherical core and the P(BLG/CLG)-b-PEG block copolymers formed surface nanostrips. By changing the composition of THF-DMF mixture solvent, the surface patterns can be regulated. Spiral spheres were formed with V(THF)∶V(DMF) of 5∶5 as initial solvent, and meridian spheres were formed with V(THF)∶V(DMF) of 3∶7 as initial solvent. Under UV-irradiation at λ = 254 nm, a cycloaddition reaction can occur on the C=C double bond of the cinnamyl group. Therefore, the P(BLG/CLG) blocks in the shell of both the spiral spheres and the meridian spheres were cross-linked. To the solution of the shell-crosslinked spiral spheres and meridian spheres, 10-fold of THF was added to remove the PS homopolymers in the core. As a result, hollow nanodisks and hollow conchoidal particles were prepared, and the strip nanopatterns on the surface were retained. The morphology of the particles was characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and atomic force microscopy (AFM). It was found that the PS homopolymers were efficiently removed from the particles by THF solvent soaking, and the nanostrips prop up the hollow structure of the disk-like particles and conchoidal particles. The morphology and structure of these nanopatterned hollow particles are stable, and they maintain the three-dimensional features under microscopy observations. The inner space of the hollow disk can be refilled with hydrophobic polymers.
Hollow particles have attracted considerable attentions in recent years for their potential in diverse application fields. In this work, polypeptide-based hollow disk-like and conchoidal particles with surface nanostrips were prepared. For the poly(γ-benzyl-L-glutamate)-b-poly(ethylene glycol) (PBLG-b-PEG) block copolymer, through partial deprotection of the benzyl group of the PBLG block and esterification reaction between the carboxyl group and cinnamic alcohol, poly(γ-benzyl-L-glutamate-co-γ-cinnamyl-L-glutamate)-b-poly(ethylene glycol) (P(BLG/CLG)-b-PEG) block copolymers were obtained. The self-assemblies were prepared by a selective precipitation method. P(BLG/CLG)-b-PEG block copolymers and polystyrene (PS) homopolymers were first dissolved in THF-DMF mixture solvent; by adding water to the solution, core-shell particles with nanostrips on the surface were obtained, in which the hydrophobic PS homopolymer formed the spherical core and the P(BLG/CLG)-b-PEG block copolymers formed surface nanostrips. By changing the composition of THF-DMF mixture solvent, the surface patterns can be regulated. Spiral spheres were formed with V(THF)∶V(DMF) of 5∶5 as initial solvent, and meridian spheres were formed with V(THF)∶V(DMF) of 3∶7 as initial solvent. Under UV-irradiation at λ = 254 nm, a cycloaddition reaction can occur on the C=C double bond of the cinnamyl group. Therefore, the P(BLG/CLG) blocks in the shell of both the spiral spheres and the meridian spheres were cross-linked. To the solution of the shell-crosslinked spiral spheres and meridian spheres, 10-fold of THF was added to remove the PS homopolymers in the core. As a result, hollow nanodisks and hollow conchoidal particles were prepared, and the strip nanopatterns on the surface were retained. The morphology of the particles was characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and atomic force microscopy (AFM). It was found that the PS homopolymers were efficiently removed from the particles by THF solvent soaking, and the nanostrips prop up the hollow structure of the disk-like particles and conchoidal particles. The morphology and structure of these nanopatterned hollow particles are stable, and they maintain the three-dimensional features under microscopy observations. The inner space of the hollow disk can be refilled with hydrophobic polymers.
2022, 35(6): 524-531.
doi: 10.14133/j.cnki.1008-9357.20220524001
Abstract:
Due to the weak interaction between adjacent carbon nanotubes in vertical carbon nanotube arrays (VACNT), the horizontal thermal conductivity of VACNT is low. To solve this problem, the randomly oriented secondary carbon nanotube was grown inside the carbon nanotube array by chemical vapor deposition method. The secondary carbon nanotube formed a crosslinking network in VACNT, which enhanced the horizontal thermal conductivity of VACNT. Theoretical simulation analysis shows that the secondary carbon nanotubes are able to disperse the heat conduction to the concentrated heat, thus effectively modulating the thermal conductivity of the carbon nanotube arrays along the horizontal direction. The test results show that the carbon nanotube array with a secondary growth time of 30 min has a denser network structure and its density is 0.149 g/cm3, which is 26.3% higher than that of VACNT (0.118 g/cm3). Its vertical thermal conductivity and horizontal thermal conductivity are as high as 10.9 W/(m·K) and 7.8 W/(m·K), respectively, and the horizontal thermal conductivity is enhanced by 231.6% compared with that of VACNT.
Due to the weak interaction between adjacent carbon nanotubes in vertical carbon nanotube arrays (VACNT), the horizontal thermal conductivity of VACNT is low. To solve this problem, the randomly oriented secondary carbon nanotube was grown inside the carbon nanotube array by chemical vapor deposition method. The secondary carbon nanotube formed a crosslinking network in VACNT, which enhanced the horizontal thermal conductivity of VACNT. Theoretical simulation analysis shows that the secondary carbon nanotubes are able to disperse the heat conduction to the concentrated heat, thus effectively modulating the thermal conductivity of the carbon nanotube arrays along the horizontal direction. The test results show that the carbon nanotube array with a secondary growth time of 30 min has a denser network structure and its density is 0.149 g/cm3, which is 26.3% higher than that of VACNT (0.118 g/cm3). Its vertical thermal conductivity and horizontal thermal conductivity are as high as 10.9 W/(m·K) and 7.8 W/(m·K), respectively, and the horizontal thermal conductivity is enhanced by 231.6% compared with that of VACNT.
2022, 35(6): 532-539.
doi: 10.14133/j.cnki.1008-9357.20220403001
Abstract:
In this study, a series of β-amino acid polymers which have synergistic antifungal activity with itraconazole were designed and synthesized. The random copolymers (DAPxBuy)n were obtained by ring-opening polymerization of β-amino acid N-thiocarboxyanhydrides (β-NTA) under room temperature using 4-tert-Butylbenzylamine (tBuBz-NH2) as an initiator, with DL-β-norleucine N-thiocarboxyanhydrides as hydrophobic monomer and N(α)-Z-DL-2,3-diaminopropionic acid N-thiocarboxyanhydrides as cationic monomer. The effect of (DAPxBuy)n combined with itraconazole on C. albicans was evaluated by checkerboard antifungal test. The test showed that (DAPxBuy)n copolymers could effectively reverse itraconazole resistance in C. albicans through synergistic effect, while the minimum inhibitory concentration (MIC) of antifungal of itraconazole was reduced from more than 200 μg/mL to 3.1 μg/mL after exposure to (DAPxBuy)n, indicating that the antifungal activity of itraconazole reversed from ineffective to highly effective. In addition, most of (DAPxBuy)n copolymers did not cause significant hemolysis of human red blood cells and fibroblasts toxicity at a high concentration of 400 μg/mL. Our studies demonstrate that the (DAPxBuy)n copolymers can achieve efficient synergistic effect with itraconazole and reverse itraconazole resistance in C. albicans, showing broad potential in the treatment of fungal infections.
In this study, a series of β-amino acid polymers which have synergistic antifungal activity with itraconazole were designed and synthesized. The random copolymers (DAPxBuy)n were obtained by ring-opening polymerization of β-amino acid N-thiocarboxyanhydrides (β-NTA) under room temperature using 4-tert-Butylbenzylamine (tBuBz-NH2) as an initiator, with DL-β-norleucine N-thiocarboxyanhydrides as hydrophobic monomer and N(α)-Z-DL-2,3-diaminopropionic acid N-thiocarboxyanhydrides as cationic monomer. The effect of (DAPxBuy)n combined with itraconazole on C. albicans was evaluated by checkerboard antifungal test. The test showed that (DAPxBuy)n copolymers could effectively reverse itraconazole resistance in C. albicans through synergistic effect, while the minimum inhibitory concentration (MIC) of antifungal of itraconazole was reduced from more than 200 μg/mL to 3.1 μg/mL after exposure to (DAPxBuy)n, indicating that the antifungal activity of itraconazole reversed from ineffective to highly effective. In addition, most of (DAPxBuy)n copolymers did not cause significant hemolysis of human red blood cells and fibroblasts toxicity at a high concentration of 400 μg/mL. Our studies demonstrate that the (DAPxBuy)n copolymers can achieve efficient synergistic effect with itraconazole and reverse itraconazole resistance in C. albicans, showing broad potential in the treatment of fungal infections.
2022, 35(6): 540-547.
doi: 10.14133/j.cnki.1008-9357.20220417001
Abstract:
Developing an efficient adsorbent is of great importance for wastewater treatment. Despite many examples for their synthesis exist, it still remains a challenge to fabricate a versatile adsorbent to overcome the defects of their common forms (e.g., powder, pellet, bead and flake). Herein, a novel three-dimensional porous elastic adsorbent (3D-PE) was constructed by adhering porous carbon to polyurethane foam framework using ethylene-vinyl acetate copolymer. 3D-PE was characterized by scanning electron microscope (SEM), gas adsorption analyzer, electronic universal testing machine and UV-Vis spectrophotometer. Benefitting from the rational integration of the porous carbon, ethylene-vinyl acetate copolymer and polyurethane foam, 3D-PE exhibited high strength, excellent resilience and remarkable flexibility even under compression conditions. Inspired by these impressive characteristics, 3D-PE was potentially used as an adsorbent for wastewater purification, especially in a feasible application to be operated under harsh conditions. As a proof of concept, when the adsorbents were used towards methylene blue removal, 3D-PE exhibited high adsorption rate (96% removal efficiency within 5 min), stable recyclability even under a repeatedly compressed condition. In addition, kinetics and isotherm models were fitted. It was confirmed that the adsorption of methylene blue by 3D-PE was chemisorption and multi-molecular layer adsorption. 3D-PE may hold good promising applications in wastewater remediation, catalytic reactions, and environmental engineering.
Developing an efficient adsorbent is of great importance for wastewater treatment. Despite many examples for their synthesis exist, it still remains a challenge to fabricate a versatile adsorbent to overcome the defects of their common forms (e.g., powder, pellet, bead and flake). Herein, a novel three-dimensional porous elastic adsorbent (3D-PE) was constructed by adhering porous carbon to polyurethane foam framework using ethylene-vinyl acetate copolymer. 3D-PE was characterized by scanning electron microscope (SEM), gas adsorption analyzer, electronic universal testing machine and UV-Vis spectrophotometer. Benefitting from the rational integration of the porous carbon, ethylene-vinyl acetate copolymer and polyurethane foam, 3D-PE exhibited high strength, excellent resilience and remarkable flexibility even under compression conditions. Inspired by these impressive characteristics, 3D-PE was potentially used as an adsorbent for wastewater purification, especially in a feasible application to be operated under harsh conditions. As a proof of concept, when the adsorbents were used towards methylene blue removal, 3D-PE exhibited high adsorption rate (96% removal efficiency within 5 min), stable recyclability even under a repeatedly compressed condition. In addition, kinetics and isotherm models were fitted. It was confirmed that the adsorption of methylene blue by 3D-PE was chemisorption and multi-molecular layer adsorption. 3D-PE may hold good promising applications in wastewater remediation, catalytic reactions, and environmental engineering.
2022, 35(6): 548-553.
doi: 10.14133/j.cnki.1008-9357.20220422002
Abstract:
Polybutyrolactam (PA4) was thermoplastic modified by melt blending extrusion with lithium chloride (LiCl) as the plasticizer. The thermodynamic, crystalline and mechanical properties of LiCl plasticized PA4（LiCl/PA4） were investigated by means of differential scanning calorimetry (DSC), wide-angle X-ray diffraction (WAXD), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FT-IR) and tensile test. XPS results showed that the O atom binding energy of unplasticized PA4 was 531.40 eV. Compared with the unplasticized sample, the binding energy of O atom in LiCl/PA4 system increased by 0.25 eV, while that of N atom was almost unchanged. Therefore, Li+ was mainly complexed with oxygen rather than N atomin in amide bond. Such complexation destroyed the intermolecular hydrogen bonds of PA4 and restrained the crystallization. With the increment of LiCl content, the melting point and crystallinity of PA4 gradually decreased. When m(LiCl)∶m(PA4) was 5%, the melting point of LiCl/PA4 decreased to 223.9 ℃ and was 41.6 ℃ lower than that of unplasticized sample. Meanwhile, the crystallinity of plasticized PA4 decreased to 37.88%. In addition, LiCl/PA4 still maintained good mechanical properties. The elongation at break of LiCl/PA4 increased with the addition of LiCl. The maximum elongation at break of LiCl/PA4 was 233% when m(LiCl)∶m(PA4) was 5%, which increased by 155% compared with that of the unplasticized sample. The tensile strength of plasticized PA4 was higher than that of the unplasticized sample, which increased first and then decreased with the increment of LiCl content. The maximum tensile strength reached 57.90 MPa when m(LiCl)∶m(PA4) was 1%.
Polybutyrolactam (PA4) was thermoplastic modified by melt blending extrusion with lithium chloride (LiCl) as the plasticizer. The thermodynamic, crystalline and mechanical properties of LiCl plasticized PA4（LiCl/PA4） were investigated by means of differential scanning calorimetry (DSC), wide-angle X-ray diffraction (WAXD), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FT-IR) and tensile test. XPS results showed that the O atom binding energy of unplasticized PA4 was 531.40 eV. Compared with the unplasticized sample, the binding energy of O atom in LiCl/PA4 system increased by 0.25 eV, while that of N atom was almost unchanged. Therefore, Li+ was mainly complexed with oxygen rather than N atomin in amide bond. Such complexation destroyed the intermolecular hydrogen bonds of PA4 and restrained the crystallization. With the increment of LiCl content, the melting point and crystallinity of PA4 gradually decreased. When m(LiCl)∶m(PA4) was 5%, the melting point of LiCl/PA4 decreased to 223.9 ℃ and was 41.6 ℃ lower than that of unplasticized sample. Meanwhile, the crystallinity of plasticized PA4 decreased to 37.88%. In addition, LiCl/PA4 still maintained good mechanical properties. The elongation at break of LiCl/PA4 increased with the addition of LiCl. The maximum elongation at break of LiCl/PA4 was 233% when m(LiCl)∶m(PA4) was 5%, which increased by 155% compared with that of the unplasticized sample. The tensile strength of plasticized PA4 was higher than that of the unplasticized sample, which increased first and then decreased with the increment of LiCl content. The maximum tensile strength reached 57.90 MPa when m(LiCl)∶m(PA4) was 1%.
2022, 35(6): 554-559.
doi: 10.14133/j.cnki.1008-9357.20220328001
Abstract:
The first technical obstacle encountered in the process of negative photoresist industrialization is that the lithographic pattern of the photoresist formula and lithography process optimized in the laboratory cannot be reproduced on the industrial production line. The reason for this could be the difference in exposure modes. A laboratory-prepared negative-tone photosensitive polyimide (n-PSPI) is used to prepare two polyimide photoresists with different photo-initiators. They were exposed under the same exposure energy in stepwise mode (high power, short time) and contact mode (low power, long time), respectively, being followed by solvent development for photolithography. Based on the resultant patterns, ideal lithography patterns can be obtained by stepper exposure with fast rate initiators or contact exposure with slow rate initiators. On the contrary, stepper exposure combined with slow rate initiators is prone to unclean development caused by free radical diffusion, while contact exposure combined with fast rate initiators results in low film retention rate caused by insufficient crosslinking. These undesirable graphics effects can not be improved by shortening or extending the exposure time. Therefore, the rational use of initiators is crucial for the formulation design of photoresists with different exposure modes. Combined with the theory of free radical formation and diffusion kinetics, the lithography pattern rule of n-PSPI photoresist under different exposure modes is explained. These conclusions can provide a theoretical guidance for formula modification when converting laboratory products to industrial applications.
The first technical obstacle encountered in the process of negative photoresist industrialization is that the lithographic pattern of the photoresist formula and lithography process optimized in the laboratory cannot be reproduced on the industrial production line. The reason for this could be the difference in exposure modes. A laboratory-prepared negative-tone photosensitive polyimide (n-PSPI) is used to prepare two polyimide photoresists with different photo-initiators. They were exposed under the same exposure energy in stepwise mode (high power, short time) and contact mode (low power, long time), respectively, being followed by solvent development for photolithography. Based on the resultant patterns, ideal lithography patterns can be obtained by stepper exposure with fast rate initiators or contact exposure with slow rate initiators. On the contrary, stepper exposure combined with slow rate initiators is prone to unclean development caused by free radical diffusion, while contact exposure combined with fast rate initiators results in low film retention rate caused by insufficient crosslinking. These undesirable graphics effects can not be improved by shortening or extending the exposure time. Therefore, the rational use of initiators is crucial for the formulation design of photoresists with different exposure modes. Combined with the theory of free radical formation and diffusion kinetics, the lithography pattern rule of n-PSPI photoresist under different exposure modes is explained. These conclusions can provide a theoretical guidance for formula modification when converting laboratory products to industrial applications.
2022, 35(6): 560-565.
doi: 10.14133/j.cnki.1008-9357.20220223001
Abstract:
Most of the traditional permanent hair dyes containing aniline molecules have the risk of carcinogenicity and sensitization. Since polydopamine has a similar molecular structure to eumelanin and good biocompatibility, the use of polydopamine in hair dyeing has become a hot research topic. However, due to the hydrophobic structure of the hair surface, the adhesion of dopamine in situ deposition on the hair surface is weak. Here, by taking advantage of the effect of hyaluronic acid (HA) to hair, dopamine (DA) was grafted onto HA via Schiff base reaction to strengthen the interactions between polydopamine and hair. The chemical structure of DA grafted hyaluronic acid (DAHA) was confirmed by Fourier Transform Infrared Spectrometer (FT-IR), Ultraviolet-Visible (UV-Vis) spectrophotometer, Proton Nuclear Magnetic Resonance (1H-NMR). The dyeing properties assisted by DAHA were characterized by Scanning Electron Microscope (SEM), single fiber strength tester and colorimeter. Results show that DA has been successfully grafted onto HA, and the grafting ratio for HA with a number average molecular weight of 0.2×104—1.0×104 was 34%. Compared with the hair samples dyeing without DAHA, the hair pretreated with DAHA has better color fastness after 30 washes. Moreover, with DAHA pretreatment, the tensile strength of hair improves, and the improvement rate is about 7.4%. SEM photos demonstrate that the polydopamine nanoparticles on the surface of hair dyed with DAHA were more uniform than those without DAHA.
Most of the traditional permanent hair dyes containing aniline molecules have the risk of carcinogenicity and sensitization. Since polydopamine has a similar molecular structure to eumelanin and good biocompatibility, the use of polydopamine in hair dyeing has become a hot research topic. However, due to the hydrophobic structure of the hair surface, the adhesion of dopamine in situ deposition on the hair surface is weak. Here, by taking advantage of the effect of hyaluronic acid (HA) to hair, dopamine (DA) was grafted onto HA via Schiff base reaction to strengthen the interactions between polydopamine and hair. The chemical structure of DA grafted hyaluronic acid (DAHA) was confirmed by Fourier Transform Infrared Spectrometer (FT-IR), Ultraviolet-Visible (UV-Vis) spectrophotometer, Proton Nuclear Magnetic Resonance (1H-NMR). The dyeing properties assisted by DAHA were characterized by Scanning Electron Microscope (SEM), single fiber strength tester and colorimeter. Results show that DA has been successfully grafted onto HA, and the grafting ratio for HA with a number average molecular weight of 0.2×104—1.0×104 was 34%. Compared with the hair samples dyeing without DAHA, the hair pretreated with DAHA has better color fastness after 30 washes. Moreover, with DAHA pretreatment, the tensile strength of hair improves, and the improvement rate is about 7.4%. SEM photos demonstrate that the polydopamine nanoparticles on the surface of hair dyed with DAHA were more uniform than those without DAHA.
2022, 35(6): 566-574.
doi: 10.14133/j.cnki.1008-9357.20220329001
Abstract:
Firstly, using hepta(6-azido-6-deoxy)-β-cyclodextrin and butyl-3-ynyl-β-d-galactoside as the raw material, galactose-β-cyclodextrin (Gal7-CD) with liver-targeting function was synthesized by Click reaction. Secondly, using cystamine dihydrochloride and octadecanoic acid as the raw material, cystamine octadecyl amide (NH2-SS-SA) was obtained through amino protection, acylation reaction and deprotection reaction. Next, adamantyl polyethylene glycol amine (Ad-PEG1000-NH2) was synthesized by using the acylation reaction of adamantanecarboxylic acid and amino polyethylene glycol, and then, which reacted with succinic anhydride to obtain adamantyl polyethylene glycol succinic acid (Ad-PEG1000-COOH). Then NH2-SS-SA reacted with Ad-PEG1000-COOH to obtain adamantyl polyethylene glycol amine octadecanamide (Ad-PEG1000-SS-C18). Finally, using dialysis method, Gal7-CD and Ad-PEG1000-SS-C18 self-assembled to form amphiphilic polymer through host-guest self-assembly, and then form polymer micelle (Gal7-SS-C18). Doxorubicin (DOX) was then used as a model drug to incorporate into Gal7-SS-C18 micelles. The particle size of polymer micelles and drug-loaded polymer micelles were determined by dynamic light scattering (DLS) to be (169.2±1.3) nm and (177.9±3.0) nm, respectively. The drug-loading capacity of the drug-loaded polymer micelles was measured by UV-Vis spectrophotometer to be (21.2±0.7)% and the encapsulation efficiency was (71.1±0.5)%. In the in vitro release experiment, the cumulative release of drug-loaded polymer micelles was lower in the simulated normal physiological environment of PBS, while the cumulative DOX release reached 82.38% within 48 h in the simulated tumor reduction microenvironment of PBS. The cytotoxicity and antitumor activity of polymer micelles were evaluated by using liver cancer cells (HepG2) and normal tissue cells (HEK-293) as cell models. The research results show that the polymer micelles have good biocompatibility. The drug-loaded polymer micelles show good targeting and controllable release properties, which have better tumor inhibition ability than free DOX.
Firstly, using hepta(6-azido-6-deoxy)-β-cyclodextrin and butyl-3-ynyl-β-d-galactoside as the raw material, galactose-β-cyclodextrin (Gal7-CD) with liver-targeting function was synthesized by Click reaction. Secondly, using cystamine dihydrochloride and octadecanoic acid as the raw material, cystamine octadecyl amide (NH2-SS-SA) was obtained through amino protection, acylation reaction and deprotection reaction. Next, adamantyl polyethylene glycol amine (Ad-PEG1000-NH2) was synthesized by using the acylation reaction of adamantanecarboxylic acid and amino polyethylene glycol, and then, which reacted with succinic anhydride to obtain adamantyl polyethylene glycol succinic acid (Ad-PEG1000-COOH). Then NH2-SS-SA reacted with Ad-PEG1000-COOH to obtain adamantyl polyethylene glycol amine octadecanamide (Ad-PEG1000-SS-C18). Finally, using dialysis method, Gal7-CD and Ad-PEG1000-SS-C18 self-assembled to form amphiphilic polymer through host-guest self-assembly, and then form polymer micelle (Gal7-SS-C18). Doxorubicin (DOX) was then used as a model drug to incorporate into Gal7-SS-C18 micelles. The particle size of polymer micelles and drug-loaded polymer micelles were determined by dynamic light scattering (DLS) to be (169.2±1.3) nm and (177.9±3.0) nm, respectively. The drug-loading capacity of the drug-loaded polymer micelles was measured by UV-Vis spectrophotometer to be (21.2±0.7)% and the encapsulation efficiency was (71.1±0.5)%. In the in vitro release experiment, the cumulative release of drug-loaded polymer micelles was lower in the simulated normal physiological environment of PBS, while the cumulative DOX release reached 82.38% within 48 h in the simulated tumor reduction microenvironment of PBS. The cytotoxicity and antitumor activity of polymer micelles were evaluated by using liver cancer cells (HepG2) and normal tissue cells (HEK-293) as cell models. The research results show that the polymer micelles have good biocompatibility. The drug-loaded polymer micelles show good targeting and controllable release properties, which have better tumor inhibition ability than free DOX.
2022, 35(6): 575-582.
doi: 10.14133/j.cnki.1008-9357.20220316001
Abstract:
Waterborne polyurethane (WPU) antibacterial film was prepared by UV curing after introducing hydrophilic quaternary ammonium salts to polyurethane (PU) molecular chains via quaternization reaction between different alkyl chain haloalkanes and tertiary amine groups. PUs were bonded with tertiary amine group and unsaturated group, using 3-dimethylamino-1,2-propanediol as the chain extender and hydroxyethyl methacrylate as the capping agent. The structure and properties of WPU dispersion and light cured films were characterized by FT-IR, particle size analyzer, optical contact angle instrument, etc. The antibacterial properties of the materials were tested by shaking-flask method and zone of inhibition. And the effects of tertiary amine compounds on the properties of WPU were investigated. When the mass fraction of tertiary amine compound was 9% and the alkyl long chain was 12, the antibacterial rates of WPU against Gram-negative E. coli and Gram-positive S. aureus were more than 99.5%. Meanwhile, the longer the alkyl chain was, the better the effect was. Through UV-curable crosslinking, it could still maintain excellent antibacterial performance and reflect positive durability after 96 h water washing. The zone of inhibition test showed that the prepared quaternary ammonium salts WPU antibacterial film belonged to contact-killing material which avoided the pollution and adverse effects on the environment, human beings and other materials. With the increase of tertiary amine content, the quaternization degree of WPU system first increased and then decreased, and the variation of quaternization degree affected the antibacterial properties. Moreover, polyurethane material also exhibited good mechanical properties. The increase of hard segment content of the system enhanced the tensile strength of polyurethane. And when the alkyl long chain was 12, the waterborne polyurethane material had better toughness.
Waterborne polyurethane (WPU) antibacterial film was prepared by UV curing after introducing hydrophilic quaternary ammonium salts to polyurethane (PU) molecular chains via quaternization reaction between different alkyl chain haloalkanes and tertiary amine groups. PUs were bonded with tertiary amine group and unsaturated group, using 3-dimethylamino-1,2-propanediol as the chain extender and hydroxyethyl methacrylate as the capping agent. The structure and properties of WPU dispersion and light cured films were characterized by FT-IR, particle size analyzer, optical contact angle instrument, etc. The antibacterial properties of the materials were tested by shaking-flask method and zone of inhibition. And the effects of tertiary amine compounds on the properties of WPU were investigated. When the mass fraction of tertiary amine compound was 9% and the alkyl long chain was 12, the antibacterial rates of WPU against Gram-negative E. coli and Gram-positive S. aureus were more than 99.5%. Meanwhile, the longer the alkyl chain was, the better the effect was. Through UV-curable crosslinking, it could still maintain excellent antibacterial performance and reflect positive durability after 96 h water washing. The zone of inhibition test showed that the prepared quaternary ammonium salts WPU antibacterial film belonged to contact-killing material which avoided the pollution and adverse effects on the environment, human beings and other materials. With the increase of tertiary amine content, the quaternization degree of WPU system first increased and then decreased, and the variation of quaternization degree affected the antibacterial properties. Moreover, polyurethane material also exhibited good mechanical properties. The increase of hard segment content of the system enhanced the tensile strength of polyurethane. And when the alkyl long chain was 12, the waterborne polyurethane material had better toughness.
Accepted
Chinese Library Classification 