Aggregation behavior of star-shaped fluoropolymers containing polyhedral oligomeric silsesquioxane (POSS) at the air–water interface

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• 作者：Zhiguang Li ; Xiaoyan Ma ; Xinghua Guan ; Xiu Qiang…
• 关键词：Star ; shaped fluoropolymers ; POSS ; Aggregation behavior ; At the air–water interface
• 刊名：Colloid and Polymer Science
• 出版年：2017
• 出版时间：January 2017
• 年：2017
• 卷：295
• 期：1
• 页码：157-170
• 全文大小：
• 刊物类别：Chemistry and Materials Science
• 刊物主题：Polymer Sciences; Soft and Granular Matter, Complex Fluids and Microfluidics; Characterization and Evaluation of Materials; Physical Chemistry; Food Science; Nanotechnology and Microengineering;
• 出版者：Springer Berlin Heidelberg
• ISSN：1435-1536
• 卷排序：295

文摘

Aggregation behavior of three star-shaped fluoropolymers containing polyhedral oligomeric silsesquioxane (POSS) and different monomers poly(methyl methacrylate) (PMMA), poly(trifluoroethyl methacrylate) (PTFEMA) and poly[poly(ethylene glycol)methyl ether methacrylate] (PMPEGMA), POSS-(PMMA-b-PTFEMA)₈, POSS-(PTFEMA-b-PMMA)₈, and POSS-(PTFEMA-b-PMPEGMA)₈) was investigated at the air–water interface. The interfacial rheology and surface morphology were studied through surface pressure and compression modulus measurements, hysteresis, relaxation, atomic force microscopy (AFM), and X-ray photoelectron spectroscopy (XPS). The surface pressure–mean molecular area (Π-MMA) isotherms exhibited four regions, and it was found that the pseudoplateau observed corresponds to a “pancake-to-brush” transition. The compression modulus isotherms showed two peak values which were related to the phase transition of the monolayer. The hysteresis behaviors were compared in two different regions during the compression–expansion process. In addition, the relaxation of the monolayer was discussed using the step compression method. The relaxation process was proposed that related to the adsorption–desorption exchange of molecules and polymer segments on the surface (fast relaxation process) and the reconformation of the adsorbed macromolecules inside the adsorption layer (slow relaxation process). Furthermore, the Langmuir–Blodgett (LB) films prepared at different surface pressures from the three copolymers were scanned by AFM and a variety of morphologies were observed. Finally, the structure evolutions for the three star-shaped copolymers that aggregate at the air–water interface were proposed.