CAJ | 학술논문

以正硅酸甲酯(TMOS)为前驱体,0.01 mol·L-1盐酸(HCl)为催化剂,环氧丙烷(PO)为凝胶促进剂,粘均分子量(Mv)为10000的聚氧化乙烯(PEO)为相分离诱导剂,采用溶胶-凝胶伴随相分离制备SiO2多孔块体材料,利用差热分析(DTA)、傅里叶变换红外(FT-IR)光谱、扫描电镜(SEM)、X射线衍射(XRD)、汞压、N2吸附/脱附等测试技术对所制得的SiO2多孔块体进行了表征,探讨了环氧化物调控溶胶-凝胶以及PEO诱导相分离机理.结果表明,加入PEO能诱导SiO2凝胶发生相分离,当PEO/TMOS摩尔比为0.0018时,可以获得共连续多孔结构的SiO2块体材料,其大孔孔径分布在1-3μm之间,比表面积达719 m2·g-1,孔体积为0.48 m3·g-1.环氧丙烷因其环氧原子的强亲核性和不可逆的开环反应,促进溶胶-凝胶转换,同时借助吸附在SiO2低聚物上的PEO诱导SiO2凝胶相分离,从而制备共连续大孔及骨架结构的多孔块体.
이정규산갑지(TMOS)위전구체,0.01 mol·L-1염산(HCl)위최화제,배양병완(PO)위응효촉진제,점균분자량(Mv)위10000적취양화을희(PEO)위상분리유도제,채용용효-응효반수상분리제비SiO2다공괴체재료,이용차열분석(DTA)、부리협변환홍외(FT-IR)광보、소묘전경(SEM)、X사선연사(XRD)、홍압、N2흡부/탈부등측시기술대소제득적SiO2다공괴체진행료표정,탐토료배양화물조공용효-응효이급PEO유도상분리궤리.결과표명,가입PEO능유도SiO2응효발생상분리,당PEO/TMOS마이비위0.0018시,가이획득공련속다공결구적SiO2괴체재료,기대공공경분포재1-3μm지간,비표면적체719 m2·g-1,공체적위0.48 m3·g-1.배양병완인기배양원자적강친핵성화불가역적개배반응,촉진용효-응효전환,동시차조흡부재SiO2저취물상적PEO유도SiO2응효상분리,종이제비공련속대공급골가결구적다공괴체.
Macroporous SiO2 monoliths were prepared via a sol-gel process accompanied by phase separation using a tetramethoxysilane (TMOS) precursor, 0.01 mol·L-1 HCl catalyst, propylene oxide (PO) gelation agent, and poly(ethylene oxide) (PEO, viscosity-averaged molecular weight (Mv): 10000) phase separation inducer. Monoliths were characterized by differential thermal analysis/thermogravimetry (DTA/TG), Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), mercury porosimetry, and nitrogen adsorption/desorption analysis (BET). The mechanism of the epoxide-mediated sol-gel reaction and PEO induced phase separation was discussed. The addition of PEO induced phase separation, and monolithic SiO2 with a cocontinuous macroporous skeletal structure was obtained at PEO/TMOS molar ratio of 0.0018. Monoliths had a narrow pore size distribution of 1-3μm, surface area as high as 719 m2·g-1 and pore volume of 0.48 m3·g-1. This sol-gel transition is mediated by PO because of its strong nucleophilic properties and irreversible ring-opening reaction. Simultaneous phase separation is induced by PEO adsorbed on the SiO2 oligomers.