Preparation of Dually, pH- and Thermo-Responsive Nanocapsules in Inverse Miniemulsion

详细信息    查看全文

• 作者：Zhihai Cao ; Katharina Landfester ; Ulrich Ziener
• 刊名：Langmuir
• 出版年：2012
• 出版时间：January 17, 2012
• 年：2012
• 卷：28
• 期：2
• 页码：1163-1168
• 全文大小：389K
• 年卷期：v.28,no.2(January 17, 2012)
• ISSN：1520-5827

文摘

pH- and thermo-sensitive nanocapsules were successfully synthesized via inverse miniemulsion copolymerization of N-isopropyl acrylamide (NIPAM), N,N鈥?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鈥搃norganic nanocapsules were prepared by coating a layer of silica particles on the surface of the sensitive nanocapsules.