LA/C14DMAO/H2O体系多结构自组装体及其模板金纳米材料制备与性能

Preparation and Property of Gold Nanoparticles from Muliple SelfAssembled Structures as Templates in LA/C_(14)DMAO/H_2O System

月桂酸（LA）与十四烷基二甲基氧化胺（C（14）DMAO）形成的无盐阴/阳离子表面活性剂混合体系表现出丰富的相行为。运用冷冻蚀刻透射电子显微镜（FF-TEM）和偏光显微镜（POM）、差示扫描量热（DSC）、流变和~2H NMR测定对体系相行为和微观结构进行了研究,发现水溶液中可自聚集形成胶束（L1）、层状（L（α1））、囊泡（Lav）和凝胶相。以胶束相和层状相为软模板制备了金纳米材料,运用透射电子显微镜（TEM）和能谱仪（EDS）表征了金纳米材料。与用传统阳离子表面活性剂溶液制备金纳米材料相比,该体系由于具有自身还原性而不需要加入还原剂NaBH4。实验证明：还原过程不会破坏模板溶液原有微观结构,且可通过调控聚集体结构实现控制制备金纳米材料形貌的目的。HK-2细胞的噻唑蓝（MTT）比色法实验进一步证明,本体系制备的球形金纳米材料作为基因载体具有高效和低毒的特点,在基因治疗中具有潜在的实际应用价值,可为寻求安全可靠的基因治疗途径提供实验数据和理论参考。

Rich phase behavior was observed in salt-free cationic/anionic （catanionic） surfactant mixtures of lauric acid （LA） with a nonionic surfactant, tetradecyldimethylamine oxide （C14DMAO）, in water. The phase behavior and microstructures of the LA/C14DMAO/H2O system were investigated by freeze-fracture transmission electron microscope （FF-TEM）, polarized optical microscope （POM）, differential scanning calorimetry （DSC）, rheological measurements, and 2H NMR. A variety of self-assembled microstructures were determined, including micelles （L, phase）, lamellae （Lo, phase）, vesicles （Lov phase） and gels. Using the L1 and Lo1 phases as the templates, gold nanoparticles could be produced, as confirmed by transmission electron microscope （TEM） and energy dispersive spectrometer （EDS）. Compared with the traditional method of preparing Au nanomaterials in aqueous solutions, this method can avoid the addition of NaBH, as a reducing agent. The sample solution plays roles as a template and a reductant and the reduction process does not destroy the original self-assembled microstructures in the solution. Hence, by controlling the aggregate structures of the template solution, one can achieve the goal of regulating the morphology of Au nanomatedals, which provides a new path for the preparation of noble metal nanostructured materials with different shapes and structures. The results of the methyl thiazolyl tetrazolium （MTT） assay with HK-2 cells show that, as a gene carrier, spherical Au-nanoparticles prepared in a micellar phase possess the characteristics of higher loading efficiency and lower toxicity than those obtained in traditional surfactant systems, demonstrating potential applications in gene therapy.