纳秒激光诱导热解碳表面周期结构及参量优化

摘要

为了寻求激光加工的最佳工艺参量，采用纳秒激光在人工心脏瓣膜材料热解碳的表面加工微细结构，分析脉冲能量、激光扫描次数、脉宽、扫描速率、扫描间距对热解碳消熔规律的影响。根据热解碳的消熔规律构建了3种微结构模型；根据经典超疏水Cassie理论，分析了热解碳表面发生超疏水的条件，计算出在单位面积上，经硅烷化的热解碳表面微结构占总面积的百分数小于20％，表面就可产生超疏水性。以表面接触角值为实验指标，采用正交实验法优化出了激光诱导热解碳表面周期性结构的最佳实验方案，设计了6组实验参量，成功地在热解碳表面构建了凹坑阵列、平行光栅、乳突阵列微结构。结果表明，6种微结构表面硅烷化后都具备超疏水性。这对制备具有抗凝血性的人工心脏瓣膜表面具有很大帮助。%In order to find the optimal parameters of laser processing ,the micro-structures were fabricated on pyrolytic carbon of the artificial heart valves with nanosecond laser .Effects of pulse energy, scanning times, pulse width, scanning speed and scanning gap on the melt rules of the pyrolytic carbon were analyzed .Three kinds of micro-structures were fabricated according to the melt rules of pyrolytic carbon .The conditions of superhydrophobicity were analyzed according to Cassie theory.When the percentage of pyrolytic carbon surface micro-structures to the total area in the unit area is less than 20%, the surface becomes superhydrophobic .Choosing contact angle as test index , the experimental program was optimized according to orthogonal design .Micro-structures of pit array, parallel grating and mastoid were fabricated successfully on the surface of pyrolytic carbon under six kinds of experimental programs .The testing results of contact angle show that the six kinds of micro-structures surfaces have the superhydrophobicity after silanization .The results are helpful for the fabrication of the artifical heart valves of anticooagulant property .