疏油/疏水-亲水转换涂层的制备及其转换机理

Preparation of Oleophobic/Hydrophobic-Hydrophilic Smart Surface and Its Switching Mechanism

采用乳液聚合的方法,将溶解性差异较大的两种单体全氟烷基丙烯酸酯(PFAA)和丙烯酸(AA)进行共聚,得到聚(全氟烷基丙烯酸酯-丙烯酸)(P(PFAA-AA)),并用红外光谱(IR)、差示扫描量热法(DSC)和热重分析法(TG)对聚合物的结构和性能进行了表征和分析.将聚合物乳液整理到棉织物上,发现该聚合物涂层具有疏油/疏水-亲水转换功能.正十六烷在织物上的接触角为122°,水在织物上的接触角在30min内从127°减小到33°.对疏油/疏水-亲水转换机理进行了推测,并利用X-射线光电子能谱仪(XPS),通过测试润湿前后织物上涂层不同深度化学元素组成变化,证明转换机理的推测是正确的.

Poly（perfluoroalkylated acrylate-acrylic acid） （P（PFAA - AA） ） copolymer was prepared by the emulsion copolymerization of perfluoroalkylated acrylate and acrylic acid with quite different solubility behaviors. The structure and properties of the copolymers were characterized by infrared spectrometer （IR）, differential scanning calorimetry（DSC）and thermogravimetry （TG）. The copolymer emulsion was applied to a piece of cotton fabric to form a smart surface which exhibited oleophobicity and hydrophobicity in air, the contact angles of water and hexadecane on the treated fabric were 127° and 122° respectively. While contacted with water, the surface was switched to hydrophilic in a few minutes, a significant decrease of water contact angles from 127° to 33° within 30 rain was observed. The mechanism for this surface switching was proposed and confirmed by the surface compositions changes at different depths on dry and wet cotton fabric determined by X-ray photoelectron spectroscopy （XPS）.