Flame retardant and superhydrophobic composites via oriented arrangement of boron nitride nanosheets

In this work, cobalt ferrite (CoFe2O4) was used to modify self-lubricating boron nitride nanosheets (BNNs), followed by the treatments of stearic acid to fabricate a superhydrophobic and magnetic composite fillers: STA-CoFe2O4-BNNs. Under a magnetic field, the STA-CoFe2O4-BNNs fillers can be well-aligned to form a denser arrangement in the polydimethylsiloxane (PDMS) matrix, which prevented heat transfer to underlying materials, and prepared hydrophobic and flame retardant composite materials (i.e., STA-CoFe2O4-BNNs/PDMS). The peak smoke production release and the total smoke rate of the oriented STA-CoFe2O4-BNNs/PDMS were reduced by 35.8% and 44.7%, respectively, compared with those of the pure PDMS. The obtained STA-CoFe2O4-BNNs/PDMS shows exceptional superhydrophobic durability under knife-scratch, high temperature, corrosive liquids, and UV irradiation.