基于欠膨胀射流的SiO_2/环氧树脂纳米复合材料制备方法研究

Study on SiO_2 / Epoxy Nano-composites Preparation Method Based on Under-Expanding Jet

为实现在不添加分散剂的情况下将纳米粒子均匀分散在液相物料中,提出了一种基于欠膨胀射流的液相物料纳米粉添加分散方法.该方法利用欠膨胀射流将纳米粒子以气-粉微气泡的形式分散到液相物料内部,并利用微气泡受高频挤压爆破释放的能量,以及气泡膨胀过程产生的超声波效应和高拉伸场效应来实现纳米粉在液相物料中以纳米尺度粒子分散.设计了相应的分散系统,进行了无分散剂下纳米SiO2/环氧树脂添加分散实验.通过TEM和Tg测试对实验样品进行了表征,结果表明,分散相粒径在15～30nm之间,SiO2纳米颗粒均匀地分散在环氧树脂中.Tg温度比只经过一般高速机械搅拌得到的复合材料提高了约18℃.该方法解决了SiO2纳米粉颗粒在环氧树脂中的团聚问题.

In order to obtain suspended dispersion of nano-particles in liquid without the help of adding any dispersant, an under-expanded jet dispersion method for dispersing nano-particles in liquid was presented. In this method the nano-partailes are distributed into the liguid in terms of gas-particles diminutive bubbles with the help of under-expanded jet, and then dispersed into particles with nano-scale in the liquid. The process is supported by the energy released from the diminutive bubbles explosion under high frequency extrusion, the high stretching field and ultrasonic effect generated in the bubble inflation. Corresponding dispersion system was designed and non-dispersant dispersion experiment for SiO2 particles in epoxy resin was performed. The TEM image illustrates that the SiO2 particles disperse in epoxy resin in a homogenous fashion with SiO2 particles in the scale of 15-30nm. Tg testing result indicates the Tg temperature of the SiO2 /epoxy nano-composites prepared by this method is about 18℃ higher than that of prepared by conventional high speed mechanical agitation. The proposed method solves the problem of SiO2 nano-particles aggregation in epoxy resin.