THE ADSORPTION OF LINEAR POLY(N-ISOPROPYLACRYLAMIDE)CHAINS ON SURFACTANT-FREE POLYSTYRENE NANOPARTICLES

作     者：吴奇 

作者机构：Department of Chemistry The Chinese University of Hong Kong Shatin N T. Hong Kong China The Open Laboratory of Bond Selective Chemistry Department of Chemical Physics University of the Science and Technology of China Hefei 230026 China 

出 版 物：《Chinese Journal of Polymer Science》 (高分子科学（英文版）)

年 卷 期：1999年第17卷第6期

页      面：595-601页

核心收录：

学科分类：081704[工学-应用化学] 07[理学] 0817[工学-化学工程与技术] 070304[理学-物理化学(含∶化学物理)] 08[工学] 0805[工学-材料科学与工程（可授工学、理学学位）] 0703[理学-化学] 

主　　题：poly(N-isopropylacrylamide) polystyrene nanoparticles surface adsorption of polymers light scattering 

摘      要：The adsorption of linear poly(N-isopropylacrylamide) (PNIPAM) chains on surfactant-free polystyrene (PS) nanoparticles was used as a model system to study the hydrophobic adsorption of polymer on the surface, because the hydrophobility of PNIPAM can be continuously varied by a small temperature change. The adsorption was investigated by a combination of static and dynamic laser light scattering (LLS) measurements. In static LLS, the absolute excess scattered light intensity led to the amount of PNIPAM adsorbed on the surface. In dynamic LLS, the hydrodynamic thickness of the adsorbed PNIPAM layer was accurately measured. For a given particle concentration, the adsorption increases as the PNIPAM concentration and the incubation temperature increase. The average density of the adsorbed PNIPAM layer is reciprocally proportional to the number of the PNIPAM chains on the surface, revealing a simple scaling of the chain density distribution. The adsorption follows the Langmuir s isotherm. The enthalpy change estimated from the adsorption at 25 degrees C and 30 degrees C is slightly positive, indicating that the adsorption involves the coil-to-globule transition of the chains on the surface.