超声强制浸润法制备碳纳米纸/聚合物导热复合材料

为实现聚合物基导热复合材料的高效制备,提出了一种利用超声焊接设备实施的超声强制浸润方法。采用真空抽滤方法制备出由碳纳米管(Carbon nanotubes, CNTs)堆叠而成的碳纳米纸(Carbon nanopapers, CNPs), 将CNPs放置在未固化的聚二甲基硅氧烷(Polydimethylsiloxane, PDMS)中,利用超声焊接设备的高频率、高功率超声源进行震荡,凭借超声波的能量传递作用,使液态PDMS逐步浸润到CNPs中。在100℃加热30 min固化后,即得到兼具高柔性和优良导热性能的CNPs/PDMS复合材料。结果表明,相同振幅条件下,CNPs/PDMS复合材料的导热性能随超声处理时长的增加而先上升后下降,并在超声时长为1.9 s时达到最优,热导率达5.781 W/(m·K)。验证了超声强制浸润法高效的制备柔性导热复合材料的可行性。 

Preparation of carbon nanopapers/polymer thermal conductive composite by ultrasonic forced infiltration

An ultrasonic-assisted forced infiltration method using plastic welding equipment was proposed to realize the efficient preparation of polymer-based thermal conductive composites. The carbon nanopapers (CNPs) consisted by pure carbon nanotubes (CNTs) were prepared using the method of vacuum filtration. The CNPs were placed into uncured polydimethylsiloxane (PDMS) viscous resin. The plastic welding equipment with high frequency and high power ultrasonic source was applied for the ultrasonic treatment, and the liquid PDMS would gradually infiltrated into CNPs depending on the energy transfer effect of ultrasonic wave. The CNPs/PDMS composites with high flexibility and excellent thermal conductivity could be obtained after CNPs/PDMS being cured at 100℃ for 30 min. The experimental results show that under the same amplitude condition, the thermal conductivity of CNPs/PDMS composites would increase first and then decrease with the increase of ultrasonic duration. The thermal conductivity reaches the peak value of 5.781 W/(m·K) when the ultrasonic duration is 1.9 s. The applicability of ultrasonic-assisted forced infiltration method for the preparation of flexible thermal conductive composites is verified in this research work.