氟化PVA-SiO2薄膜单面疏水性的研究与表征

Research and Characterization of Single-sided Hydrophobicity of Fluorinated PVA-SiO2 Films

目的研究开发一种具有单面疏水性能的聚乙烯醇薄膜材料作为包装材料。方法将质量分数为12%、醇解度为88%的PVA溶液与质量分数为5%的纳米SiO2溶液按体积比为1∶1混合并加热搅拌,通过流延干燥的方式制备PVA-SiO2薄膜。然后分别用体积分数为2.5%,5%,7.5%的十七氟癸基三甲氧基硅烷(FAS)-乙醇溶液以浸泡方式修饰薄膜的其中一面,并通过溶解性测试、接触角测试、场发射扫描电子显微镜(FE-SEM)、傅里叶变换衰减全反射红外光谱测试(ATR-FTIR)等方法表征改性结果。结果结果表明薄膜单面疏水性得到改善,改性后的薄膜在水中的溶解时间增加,且接触角均在120°以上,表明FAS起到了降低表面能的作用;FE-SEM结果显示,Si元素含量对薄膜的疏水性能有着重要影响;ATR-FTIR显示,FAS改性成功将氟原子引入到薄膜表面,且增加了硅原子的数量。其中用质量分数为5%的FAS-乙醇溶液修饰后的薄膜疏水性最好,接触角达到了126.21°。结论与未改性薄膜相比,经FAS单面疏水改性的PVA-SiO2薄膜疏水性能得到大大提高,拓宽了PVA薄膜材料的应用领域。

The work aims to study and develop a kind of polyvinyl alcohol(PVA)film material with single-sided hydrophobic property as packaging material.PVA-SiO2 films were prepared by tape-casting drying with 12%(mass fraction)PVA solution with 88%alcoholysis degree and 5%(mass fraction)nano-SiO2 solution heated and stirred at 1:1 volume ratio.Then,one side of the film was modified by 2.5%,5%and 7.5%heptafluorodecyl trimethoxysilane(FAS)-ethanol solution,and the modified results were characterized by solubility test,contact angle test,field emission scanning electron microscopy(FE-SEM)and Fourier transform attenuated total reflection infrared spectroscopy(ATR-FTIR).The results indicated that,the one-sided hydrophobicity of the films was improved.The dissolution time of modified film in water increased and the contact angles of all kinds of modified films were above 120°,which meant that FAS did play a role in lowering the surface energy.FE-SEM results showed that,the content of Si element had an important influence on the hydrophobicity of the films.ATR-FTIR showed that,fluorine atoms were successfully introduced into the film surface after FAS modification,and the number of silicon atoms was increased.The hydrophobicity of the film modified by 5%(mass fraction)FAS-ethanol solution was the best,and the contact angle reached 126.21°.The hydrophobic properties of PVA-SiO2 films after single-sided modification by FAS are much better than those of unmodified ones,which widen the application field of PVA film materials.