静电纺丝制备MWCNT_(s)/PVA定向导热复合纤维膜

Preparation of oriented MWCNT_(s)/PVA composite fiber membrane with high thermal conductivity via electrostatic spinning

将浓HNO_(3)和浓H_(2)SO_(4)酸化处理后的多壁碳纳米管(MWCNT_(s))加入聚乙烯醇(PVA)纺丝液中,通过静电纺丝法制备了不同MWCNT_(s)含量的MWCNT_(s)/PVA复合纤维膜。FT-IR分析表明,酸化后的MWCNT_(s)表面含有大量羟基和羧基。TEM分析表明,MWCNT_(s)在PVA内部呈定向线性排列。有效导热通道的形成,使得MWCNT_(s)/PVA复合纤维膜的水平导热系数显著增大,5%MWCNT_(s)/PVA的水平导热系数为1.32W/(m·K),为纯PVA纤维膜导热系数的6.6倍。同时,MWCNT_(s)的添加提高了复合纤维膜的热稳定性,5%MWCNT_(s)/PVA的热分解温度达到295.7℃,比纯PVA纤维膜提高了14.4℃。利用红外热像仪探测了MWCNT_(s)/PVA复合纤维膜应用于LED灯的散热效果,5%MWCNT_(s)/PVA纤维膜能有效降低LED灯珠的附近温度约11℃。

Multi-walled carbon nano-tubes(MWCNT_(s)) was treated with concentrated nitric acid and concentrated sulfuric acid, and then added into polyvinyl alcohol(PVA) solution as thermal conducting fillers to fabricate MWCNT_(s)/PVA nano-composite fiber membranes via electrostatic spinning.FT-IR results showed that acid-treated MWCNT_(s) contained large number of —OH and —COOH groups.TEM indicated that the acid treated MWCNT_(s) distributed evenly along the PVA fiber orientation and connected each other to form thermal conductive route effectively.Therefore, the horizontal thermal conductivity(λ//)of MWCNT_(s)/PVA composite fiber membranes increased remarkably, and λ//of 5wt% MWCNT_(s)/PVA fiber membrane was 1.32W(m·K)^(-1),which was 6.6 times of that of pure PVA fiber membrane.Meantime, with the loading of MWCNT_(s), the thermal stability of the composite fiber membrane was improved correspondingly.The degradation temperature of 5wt% MWCNT_(s)/PVA fiber membrane was 295.7℃,which was 14.4℃ higher than that of pure PVA fiber membrane.The heat dissipation effect of MWCNT_(s)/PVA nano-composite fiber membrane used in LED was evaluated via thermal infrared imager, and the results revealed that the temperature around LED decreased about 11℃ with the heat dissipating of 5wt% MWCNT_(s)/PVA composite fiber membrane.