Enhanced through-thickness thermal conductivity of epoxy with cellulose-supported boron nitride nanosheets

Thermal management is an important application of nanocomposites. To effectively enhance the through-thickness thermal conductivity, we report a strategy by preparing cellulose-supported boron nitride nanosheets (BNNSs) aerogel and then impregnating with epoxy matrix. Two environmentally friendly approaches, i.e., the urea-NaOH aqueous solution and an ionic liquid 1-butyl-3-methylimidazolium acetate (BmimAc) with dimethyl sulfoxide (DMSO), were investigated to prepare cellulose-supported 3D BNNS network. The nanocomposites prepared by BmimAc-DMSO with supernatant BNNSs showed the highest through-thickness thermal conductivity enhancement, i.e. approximately three times at a low BNNS loading of 8 wt% than the neat epoxy (0.2 W/mK). The structure of cellulose-supported network and BNNS size have shown noticeable effects on thermal conductivity improvement. The infrared thermal images suggest that such epoxy nanocomposites responded more rapidly to heating and cooling.