School of Chemistry and Chemical Engineering, Sun Yat-sen University, Guangzhou, Guangdong 510275, People's Republic of China.
J Colloid Interface Sci. 2010 Mar 1;343(1):141-8. doi: 10.1016/j.jcis.2009.11.005. Epub 2009 Nov 6.
Inorganic/polymer nanocomposite silica-poly(N-isopropylacrylamide) (SiO(2)-PNIPA) was successfully synthesized through a one-pot approach in supercritical carbon dioxide (scCO(2)). All raw materials, N-isopropylacrylamide (NIPA), vinyltriethoxysilane (VTEO), tetraethoxysilane (TEOS), initiator 2,2'-azobisisobutyronitrile (AIBN), crosslinker N,N'-methylenebisacrylamide (MBAM) and hydrolysis agent acetic acid (AA) were introduced into one autoclave and the parallel reactions of free radical polymerization and hydrolysis/condensation occurred simultaneously in the reaction mixture with scCO(2) as solvent. The obtained novel composite particles were characterized by Fourier transform infrared spectroscopy (FTIR), scanning electronic microscopy (SEM), transmission electron microscopy (TEM) and energy dispersive X-ray spectroscopy (EDS). The swelling ratios (SR) and lower critical solution temperatures (LCSTs) of the prepared thermoresponsive microspheres were investigated by swelling tests and ultraviolet-visible (UV) spectrophotometry, respectively. TEM images demonstrated that well-dispersed particles with diameter less than 100 nm were formed. The composite microgels exhibited higher LCSTs than poly(N-isopropylacrylamide) (PNIPA) microgels did. The in vitro release simulation of the particles in situ impregnated with ibuprofen indicated that SiO(2)-PNIPA composites could improve the drug releasing effect of the microgels as controlled drug delivery systems.
无机/聚合物纳米复合材料二氧化硅-聚(N-异丙基丙烯酰胺)(SiO2-PNIPA)通过在超临界二氧化碳(scCO2)中的一锅法成功合成。所有原料,N-异丙基丙烯酰胺(NIPA)、乙烯三乙氧基硅烷(VTEO)、四乙氧基硅烷(TEOS)、引发剂 2,2'-偶氮二异丁腈(AIBN)、交联剂 N,N'-亚甲基双丙烯酰胺(MBAM)和水解剂乙酸(AA)都被引入到一个高压釜中,在反应混合物中,自由基聚合和水解/缩合的平行反应同时在 scCO2 作为溶剂的情况下发生。通过傅里叶变换红外光谱(FTIR)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)和能量色散 X 射线光谱(EDS)对得到的新型复合颗粒进行了表征。通过溶胀实验和紫外-可见(UV)分光光度法分别研究了制备的温敏微球的溶胀比(SR)和低临界溶液温度(LCST)。TEM 图像表明形成了直径小于 100nm 的分散良好的颗粒。复合微凝胶的 LCST 高于聚(N-异丙基丙烯酰胺)(PNIPA)微凝胶。布洛芬原位浸渍颗粒的体外释放模拟表明,SiO2-PNIPA 复合材料可以改善微凝胶作为控制药物释放系统的药物释放效果。