采用高压静电喷涂技术制备超疏水硅橡胶表面的应用研究

Research on Superhydrophobic Silicon Rubber Surface Made by High Voltage Electrospray

高压(HV)静电喷涂是1种简单有效的制备超疏水硅橡胶表面(SSRS)的方法,其原理是在静电力的作用下将电喷涂溶液雾化,在接收极固化成型。为此,在实验室中采用高压静电喷涂技术成功制备出超疏水硅橡胶表面,试验中所采用的电喷涂溶液是由AB组分的高温硫化(HTV)液体硅橡胶(LSR)、石油醚、N,N-二甲基甲酰胺(DMF)、纳米二氧化硅(Si O2)颗粒以及十七氟三甲氧基硅烷(FAS-17)组成的复合体系。试验结果表明:石油醚可起到对硅橡胶的稀释作用;DMF可用来提高溶液的极性,使溶液更易于喷涂,得到的喷涂颗粒尺寸减小;Si O2颗粒可用来构筑硅橡胶表面的复合微结构;FAS-17可在硅橡胶表面引入含氟基团、降低表面自由能,同时减小表面微结构尺寸(100 nm^1μm)。经过大量试验验证后提出在电喷涂溶液复合体系中电喷涂制备超疏水硅橡胶表面的最佳条件:石油醚、硅橡胶、DMF、Si O2、FAS-17的质量分数分别为41%、20%、30%、4%、5%。此时制备出的超疏水硅橡胶表面的静态接触角为163.4°,滚动角为4.3°。

For manufacturing superhydrophobic silicon rubber surface （SSRS） effcienfly and conveniently, we used the high voltage （HV） electrospray to prepare SSRS in laboratory and discussed some key issues in the process. The solution for electrospray is a composite system, which is comprised of AB component high-temperature vulcanization（HTV） liquid silicon rubber（LSR）, petroleum ether, N,N-dimethylformamide（DMF）, SiO2 nano-particles, and heptadecafluorodecyl trimethoxysilane （FAS-17）. According to the preparing process, several results were obtained. Conclusions can be drawn as follows： petroleum ether is effective to dilute HTV;DMF helps elevate the polarity of electrospray solution, which makes the solution easy to spray and reduces the scale length of spray particles;SiO2 nano-particles contribute to construct hierarchically micro-nano structures in the substrate;By adding FAS-17 into the solution, fluorine group will be intro- duced to HTV surfaces, which lowers the surface free energy and decreases the scale length of the surface morphology to 100 nm-1 μm. After a number of tests, we have proposed an optimized composition of the electrospray solution： the per- centages of petroleum ether, HTV, DMF, SiO2, and FAS-17 are about 41%, 20%, 30%, 4%, and 5%, respectively. With this composition, we can obtain SSRS with static contact angel of 163.4° and sliding angle of 4.3°.