Department of Chemistry, Key Laboratory of Advanced Textile Materials and Manufacturing Technology of Ministry of Education, Zhejiang Sci-Tech University, Hangzhou 310018, China.
J Colloid Interface Sci. 2011 Jul 1;359(1):269-78. doi: 10.1016/j.jcis.2011.03.011. Epub 2011 Mar 10.
The effects of the alkyl group on the surface segregation of poly(n-alkyl methacrylate) end-capped with various numbers of units of 2-perfluorooctylethyl methacrylate (FMA) (PnAMA-ec-PFMA) were investigated by differential scanning calorimetry, angle-resolved XPS analysis, contact angle measurements, and X-ray diffraction (XRD). The results show that with similar numbers of FMA units at the polymer chain end the extent of fluorine segregation (Q) increased with increasing the number of carbon atoms in the side n-alkyl chains of poly(n-alkyl methacrylate). The surface fluorine content within 5 nm deep of the film of poly(n-octadecyl methacrylate) end-capped with one FMA unit (PODMA(160)-ec-PFMA(1.0)) was 208-fold higher than that of the bulk level. These observed differences in Q values were found due to the aggregate structure of the end-capped polymers in the solution, the flexibility, and the crystallinity of the n-alkyl side chains. When the nonfluorinated block was completely amorphous, the molecular aggregate structure of the end-capped polymers in the solution played an important role in the surface segregation of the fluorinated moieties on the resulting film. However, when the nonfluorinated block was crystalline, crystallinity would enhance greatly the segregation of the fluorinated moieties.
通过差示扫描量热法、角分辨 X 射线光电子能谱分析、接触角测量和 X 射线衍射（XRD）研究了具有不同数量的 2-全氟辛基乙基甲基丙烯酸酯（FMA）单元的聚（n-烷基甲基丙烯酸酯）封端的聚（n-烷基甲基丙烯酸酯）的烷基对表面偏析的影响（PnAMA-ec-PFMA）。结果表明，在聚合物链末端具有相似数量的 FMA 单元时，氟的偏析程度（Q）随聚（n-烷基甲基丙烯酸酯）侧链中碳原子数的增加而增加。在一个 FMA 单元（PODMA（160）-ec-PFMA（1.0））封端的聚（十八烷基甲基丙烯酸酯）的膜中，深度为 5nm 以内的表面氟含量比体相水平高 208 倍。观察到 Q 值的这些差异是由于末端封端聚合物在溶液中的聚集结构、侧链的柔韧性和结晶性。当非氟化嵌段完全无定形时，末端封端聚合物在溶液中的分子聚集结构在所得膜中氟化物部分的表面偏析中起重要作用。然而，当非氟化嵌段结晶时，结晶度会大大增强氟化物部分的偏析。
