聚合物中纳米粒子气泡膨胀分散方法

提出了一种聚合物中纳米粒子气泡膨胀分散方法，并应用该方法制备了环氧树脂/SiO₂纳米复合材料。该方法将纳米粒子团聚体和压缩气体一同注射到聚合物熔体（溶液）中，形成内含纳米粒子的微气泡，并利用气泡急速膨胀时引起的高速拉伸作用实现纳米粒子在聚合物中的均匀分散。在对分散机理进行分析的基础上，通过数值仿真计算对其分散能力进行了分析。对气泡膨胀分散法制备的环氧树脂/SiO₂纳米复合材料进行了透射电镜（TEM）分析和DSC分析，结果表明，样品中SiO₂粒子粒径在15～30 nm之间，其玻璃化温度比高速搅拌法制备的对比样品高18℃。

Bubble inflation method for dispersing nanoparticles in polymers

A bubble inflation method for dispersing nanoparticles in polymers and its application in epoxy/nano-SiO₂ composite preparation were presented.The method injected nanopartciles into polymer melt（solution）by compressed gas in terms of particle-gas jet.Then，the particle-gas jet turned into particle included gas bubbles embedded in the melt（solution）.Nanoparticles were dispersed in polymers with the stretching effect induced by bubble inflation in polymer melt（solution）.Theoretical analysis and numerical simulation were carried out to enhance understanding of the dispersion mechanism.The effects of viscous drag caused by ultrahigh stretch and cohesive force of interaction，which comprised of short-range van der Waals attractive force and Born repulsive force，were considered in the analysis.According to theoretical analysis，when the bubble expands，the stretch rate of the epoxy resin solution on the bubble wall can reach 10⁵ s^-1.The viscous drag caused by ultrahigh stretch can destroy nanoparticles agglomerate and disperse nanoparticles in polymers uniformly.The epoxy/nano-SiO₂ composite prepared by the proposed method was investigated with transmission electron microscopy（TEM）and differential scanning calorimetry（DSC）.The result showed that the size of SiO₂ dispersed in epoxy resin was about 15—30 nm，and glass transition temperature was 18℃ higher than that of the epoxy/SiO₂ composite obtained by high speed stirring.