研究了3-氨丙基三乙氧基硅烷(APTES)和非离子表面活性剂十二烷基聚氧乙烯(C12EO4)水溶液的相行为、溶液自聚集作用和流变性,小角度X-射线散射(SAXS)、低温透射电子显微镜(cryo-TEM)和氘谱核磁共振(2H NMR)测定确定了溶液中聚集体结构,测定了聚集体混合物溶液的流变性质.结果表明:随着溶液混合物组分的变化,溶液聚集体结构发生了改变,在Lα相区内,恒定C12EO4浓度,随着APTES浓度增加聚集体结构由高曲率聚集体转变为低曲率的层状结构;而在恒定APTES浓度时,随着C12EO4增加,Lα相由低粘弹性的囊泡溶液转变为粘弹性极高的密堆积囊泡和平面层状结构共存的类凝胶相,溶液聚集体结构和结构转变是由于APTES水解产物插入至C12EO4胶束引起的.非离子表面活性剂和氨基硅烷混合物溶液相结构及结构转变的新结果对于完全理解该类混合物的实际应用,特别是作为模板合成硅材料的应用具有重要理论意义.
Phase behavior, self-assembly, and theological properties of 3-aminopropyltriethoxysilane (APTES) and nonionic surfactant, CH3(CH2)ll(OCHECHE)4OH (C12EO4), in water were studied. The self-assembled structures were determined by means of small angle X-ray scattering (SAXS), cryo-transmission electron microscopy (cryo-TEM), freeze-fracture TEM (FF-TEM), and 2H nuclear magnetic resonance (2H NMR) measurements and the properties of self-assembled mixtures were obtained by rheological measurements. With a variation of the composition, different self-assembled structures were ob- tained. In the L~ phase region, a phase structural transition from an aggregate with high curvatures to the lamellar structures with low curvatures is observed with an increase of APTES concentration at a constant concentration of C12EO4. At constant APTES concentration, with an increase of C12EO4 concentration, densely packed vesicles and planarly lamellar structures which behave the properties as gel-like solutions having the rather high viscosity coexist. The phase structural transition was considered to be induced by the insertion of the hydrolytic products of APTES into the palisade of the micelles of C12EO4. These new observations on phase structural transition and self-assembly of nonionic surfactant and aminosilane mixtures could be very important for the full understanding for their applications, especially as templates in the synthesis of silica ma- terials, etc.