Dunphy Darren R, Alam Todd M, Tate Michael P, Hillhouse Hugh W, Smarsly Bernd, Collord Andrew D, Carnes Eric, Baca Helen K, Köhn Ralf, Sprung Michael, Wang Jin, Brinker C Jeffrey
University of New Mexico/NSF Center for Micro-Engineered Materials, Department of Chemical and Nuclear Engineering, Albuquerque, New Mexico 87131, USA.
Langmuir. 2009 Aug 18;25(16):9500-9. doi: 10.1021/la900748r.
The nanostructure of silica and hybrid thin film mesophases templated by phospholipids via an evaporation-induced self-assembly (EISA) process was investigated by grazing-incidence small-angle X-ray scattering (GISAXS). Diacyl phosphatidylcholines with two tails of 6 or 8 carbons were found to template 2D hexagonal mesophases, with the removal of lipid from these lipid/silica films by thermal or UV/O3 processing resulting in a complete collapse of the pore volume. Monoacyl phosphatidylcholines with single tails of 10-14 carbons formed 3D micellular mesophases; the lipid was found to be extractable from these 3D materials, yielding a porous material. In contrast to pure lipid/silica thin film mesophases, films formed from the hybrid bridged silsesquioxane precursor bis(triethoxysilyl)ethane exhibited greater stability toward (both diacyl and monoacyl) lipid removal. Ellipsometric, FTIR, and NMR studies show that the presence of phospholipid suppresses siloxane network formation, while actually promoting condensation reactions in the hybrid material. 1D X-ray scattering and FTIR data were found to be consistent with strong interactions between lipid headgroups and the silica framework.
通过掠入射小角X射线散射（GISAXS）研究了磷脂通过蒸发诱导自组装（EISA）过程模板化的二氧化硅和混合薄膜中间相的纳米结构。发现具有6个或8个碳的两条尾巴的二酰基磷脂酰胆碱可模板化二维六方中间相，通过热或紫外线/臭氧处理从这些脂质/二氧化硅薄膜中去除脂质会导致孔体积完全塌陷。具有10 - 14个碳的单条尾巴的单酰基磷脂酰胆碱形成三维微胞中间相；发现脂质可从这些三维材料中提取，从而得到一种多孔材料。与纯脂质/二氧化硅薄膜中间相相比，由杂化桥联倍半硅氧烷前体双（三乙氧基硅基）乙烷形成的薄膜对（二酰基和单酰基）脂质去除表现出更高的稳定性。椭圆偏振、傅里叶变换红外光谱（FTIR）和核磁共振（NMR）研究表明，磷脂的存在会抑制硅氧烷网络的形成，而实际上会促进杂化材料中的缩合反应。发现一维X射线散射和FTIR数据与脂质头基和二氧化硅骨架之间的强相互作用一致。
