一种利用梯度光掩模制备梯度表面的简便方法

A FACILE METHOD FOR PREPARING POLYMER GRADIENT SURFACES WITH A PRINTED GRADATION PHOTOMASK

以自制杂化双向拉伸聚丙烯/氧化硅(BOPP/SiOx)有机/无机杂化膜为基材,由喷墨打印机直接在杂化膜表面打印色阶图案,制备出对紫外光强度呈梯度透过的梯度光掩模;通过此掩模控制,在双向拉伸聚丙烯(BOPP)和聚对苯二甲酸乙二醇酯(PET)表面实施受限光催化氧化(CPO)光感应羟基化反应、受限光接枝丙烯酸(AA)以及表面沉淀紫外光接枝丙烯酰胺(AM)聚合反应.全反射红外光谱(ATR-FTIR)、X射线光电子能谱(XPS)、水接触角、荧光显微镜及扫描电镜(SEM)分析表明,分别得到表面能、接枝层厚度及接枝链密度呈梯度分布的功能性梯度表面.

A novel and facile method using a printed gradation photomask combined with photoreactions for preparing polymer surfaces with gradient distribution of surface energy,grafting layer thickness and grafting chain density was developed.The gradation photomask with gradient change of photo transmittance intensity,almost in the range of 0～100% at both 254 nm and 365 nm,has been successfully prepared by direct printing black ink onto the biaxially oriented polypropylene and silica（BOPP/SiOx） hybrid film.The applications of the gradient photomask in photo-induced reactions,such as confined photo-catalytic oxidation（CPO） and photografting polymerizations,have been exploited.In CPO reaction with a printed gradient photomask,the static water contact angles（CAs） of modified surfaces of BOPP and PET films exhibited the surface energy gradient properties,for example,the CAs of BOPP decreased almost linearly from about 103°（unmodified） to about 39° and PET film from about 78°（unmodified） to less than 10° respectively.In UV induced surface grafting polymerization of acrylic acid（AA）,the dry thickness of PAA brushes showed a gradient change from about several nanometers to bout 750 nm on the BOPP film substrate.While in precipitation-photografting polymerization of acrylamide（AM）,ATR-FTIR,X-ray photoelectron spectroscopy（XPS）,fluorescence microscopy and scanning electron microscopy（SEM） demonstrated the existence of the gradient grafting chain density on the polymer surfaces,i.e,the content of Nitrogen determined by XPS increased from about 0 wt% of pristine BOPP film to about 11.28%.So far,this is one of the most convenient methods reported for preparation of polymer gradient surfaces,and it is a versatile facile method in preparation of a gradient surface controlled by the gradation photomask.