Institute of Organic Chemistry III - Macromolecular Chemistry and Organic Materials, University of Ulm, Albert-Einstein-Allee 11, 89081 Ulm, Germany.
Langmuir. 2012 Jan 17;28(2):1163-8. doi: 10.1021/la2041357. Epub 2011 Dec 27.
pH- and thermo-sensitive nanocapsules were successfully synthesized via inverse miniemulsion copolymerization of N-isopropyl acrylamide (NIPAM), N,N'-methylene bisacrylamide (MBA), and a functional monomer, 4-vinyl pyridine (4-VP). The size and size distribution of nanocapsules were measured by dynamic light scattering (DLS). The particle morphology was observed by transmission electron microscopy (TEM). The final morphology of particles was strongly influenced by the hydrophobicity of functional monomers. The use of a hydrophilic functional monomer, acrylic acid, led to the formation of solid particles, while the use of the more hydrophobic functional monomer, 4-VP, resulted in the formation of nanocapsules. The particle morphology, size, and size distribution were investigated in terms of the content of 4-VP, MBA, and the type and content of surfactant. The pH- and thermo-sensitivities were characterized by measuring the size variation with the change of temperature and pH. The organic-inorganic nanocapsules were prepared by coating a layer of silica particles on the surface of the sensitive nanocapsules.
通过 N-异丙基丙烯酰胺（NIPAM）、N，N'-亚甲基双丙烯酰胺（MBA）和功能单体 4-乙烯基吡啶（4-VP）的反相细乳液共聚成功合成了 pH 和温度敏感的纳米胶囊。纳米胶囊的粒径和粒径分布通过动态光散射（DLS）进行测量。通过透射电子显微镜（TEM）观察颗粒形态。功能单体的疏水性强烈影响颗粒的最终形态。使用亲水性功能单体丙烯酸会导致形成固体颗粒，而使用疏水性更强的功能单体 4-VP 则会导致形成纳米胶囊。通过改变 4-VP、MBA 的含量以及表面活性剂的种类和含量，研究了颗粒形态、粒径和粒径分布。通过测量温度和 pH 变化时粒径的变化来表征 pH 和温度敏感性。通过在敏感纳米胶囊表面涂覆一层二氧化硅颗粒来制备有机-无机纳米胶囊。
