PVDF/多巴胺改性二氧化钛复合膜光阻隔性研究

Study on UV-Vis Light Shielding Performance of PVDF Based Dopamine Coated Titanium Dioxide Composite Films

制备了表面包覆聚多巴胺层的二氧化钛(TiO_2@PDA)复合粒子,并采用溶液刮涂法制备了聚偏氟乙烯(PVDF)/TiO_2和PVDF/TiO_2@PDA复合膜。利用傅立叶变换红外光谱仪、X射线光电子能谱仪、透射电子显微镜表征了复合粒子的结构,利用紫外–可见光分光光度计、对比率仪表征了复合膜的紫外–可见光阻隔性。结果表明,PVDF/TiO_2复合膜对紫外光具有优异的阻隔性,但对可见光的阻隔性(即不透明度)随TiO_2含量增加而先增加后不变,PVDF/TiO_2@PDA复合膜的不透明度则随TiO_2@PDA含量的增加而单调增大。当薄膜厚度为20μm,TiO_2体积分数为10%时,PVDF/TiO_2复合膜对比率(CR)值为92.8%,小于完全不透明临界值98%,而PVDF/TiO_2@PDA(多巴胺处理20 min)复合膜CR值为98.39%。一定TiO_2浓度下,随着多巴胺处理TiO_2时间的增大,复合膜达到完全不透明所需的薄膜厚度逐渐减小。

Poly(dopamine) coated titanium dioxide (TiO2@PDA) hybrid particles and PVDF/TiO2,PVDF/TiO2@PDA composite films were prepared by casting method. The structure,morphology,and properties of TiO2@PDA hybrid particles and composite films were investigated by FTIR,XPS,TEM,UV/VIS spectrophotometer and covering power meter. The results showed that the UV screen property of both kinds of composite film was excellent. As to the visible light blocking properties,for the PVDF/TiO2 composite films,the opacity increased first and kept unchanged as the TiO2 concentration increased,however, the opacity of PVDF/TiO2@PDA composite films increased monotonically as the fraction of TiO2@PDA increased. The contrast ratio(CR) of the PVDF/TiO2 film with 20μm thickness and 10vol% TiO2 was 92.8%,lower than the critical CR 98% for a complete opacity,however,the CR of PVDF/TiO2@PDA composite films was 98.39% as the reaction time between TiO2 and dopamine was 20 min. At a fixed TiO2 concentration,as the thickness of PDA coating layer increased,the film thickness of the composite film necessary to achieve completely opaque decreased.