高级检索

    温敏性异丙基丙烯酰胺-二氧化硅透明质酸核壳型杂化微凝胶的合成和体积相变行为

    Synthesis and Volume Phase Behaviors of TemperatureSensitive PNIPAMHAMSiO2 CoreShell Hybride Microgels

    • 摘要: 通过溶胶凝胶法,利用硅烷偶联剂(KH550)对纳米SiO2颗粒进行原位改性,使其表面带正电。改性后的SiO2颗粒(MSiO2)通过静电作用吸附带负电的透明质酸(HA)形成核壳颗粒(HAMSiO2)。进一步在壳层HA链上接枝聚合N异丙基丙烯酰胺(NIPAM)制得核壳结构温敏性杂化微凝胶(PNIPAMHAMSiO2),并用AFM和SEM表征其在云母表面的成膜性能。结果表明:HAMSiO2核壳颗粒平均粒径约为182 nm,壳层厚度15 nm,其粒径或壳层厚度可以通过改变MSiO2溶液或HA溶液的浓度来调节;温敏性PNIPAMHAMSiO2微凝胶的体积相变温度为32 °C,与PNIPAM溶液的最低临界溶解温度(LCST)一致,在体积相变温度以下旋涂于云母表面的微凝胶呈现球形颗粒,体积相变温度以上旋涂膜可以转变为致密的膜。

       

      Abstract: 3Aminopropyl triethoxysilane KH550 was used to modify SiO2 nanoparticles through in situ solgel method. Then, the positively charged SiO2 molecules were covered by negatively charged HA molecules through electrostatic force to form coreshell nanoparticles (HAMSiO2). Furthermore, Nisopropylacylamide (NIPAM) was grafted onto the chain of HA to form temperaturesensitive hybride microgels (PNIPAMHAMSiO2), whose properties of filmforming were characterized by AFM and SEM. Results show that the average diameter and shell thickness of HAMSiO2 particles are 182 nm and 15 nm, respectively. The volume phase transition temperature of temperaturesensitive PNIPAMHAMSiO2 microgels is 32 °C, which is consistent with the lower critical solution temperature (LCST) of PNIPAM solutions. The microgels are spherical on the mica surface under volume phase transition temperature, and the compact film forms on the mica above volume phase transition temperature.

       

    /

    返回文章
    返回