Abstract:

Pure PA 6 membranes and inorganic particle PA 6 composite membranes were prepared through non-solvent induced phase separation (NIPS) method by using formic acid as solvent, poly(caprolactam) (PA 6) as polymer matrix and inorganic nanoparticles as filler. The structures and optical-thermal properties of these membranes were characterized. The results showed that the higher the concentration of the coagulation bath, the more surface pores in the PA 6 membrane and the higher the solar spectral reflectance values. The concentration of the coagulation bath had no significant effect on the pore size and distribution of the cross-section pores of PA 6 membrane. Also, the infrared transmittance in the range of human body thermal radiation (7—14μm) did not change significantly. Compared with pure PA 6 membrane, the addition of inorganic particles could make the surface of the membrane rougher. The visible light spectral reflectance increased and transmittance decreased corresponding to mid- and far-bands. Especially, the number of interface nanopores in the membrane increased after doped with nano SiO₂ particles. Moreover, the thermal stability of the membrane material integrated with 50nm SiO₂ nanoparticles was significantly reduced.

Key words: infrared-transparency, nylon, porous membrane, optical-thermal performance, inorganic particles

摘要：

以甲酸为溶剂、聚己内酰胺（PA 6）为高分子聚合物基体、无机纳米粒子为填料，通过非溶剂相分离（NIPS）方法分别制备纯PA 6膜及无机粒子-PA 6复合膜，并对膜的结构和光热性能进行表征。结果表明，在实验所选的凝固浴质量分数范围内，凝固浴质量分数越大，PA 6膜的表层孔隙数量越多，太阳光谱反射率越大，但凝固浴质量分数对PA 6膜总体孔隙的孔径及分布影响不明显，人体热辐射波段范围内（7~14μm）的红外透过率变化不大。与纯PA 6膜相比，添加无机粒子后可使膜的表层变得更粗糙，可见光谱反射率提高，中远红外波段透过率下降；掺杂纳米SiO₂粒子后，膜的界面纳米尺度孔数量增多，且50nm粒径的SiO₂粒子明显降低了膜材料的热稳定性。

关键词: 红外透过, 尼龙, 多孔膜, 光热性能, 无机粒子