Similar with graphene, currently two dimensional (2D) boron nitride (BN) nanosheets, consisting of a few layers of hexagonal boron and nitride planes, are of particularly research interest. Since this nanomaterial possesses electrical-insulating property, good chemical inertness, high thermal conductivity and stability.1 So far, BN nanosheets have been widely applied to environmental, electronic packaging and lubrication industry.2,3,4 Nevertheless, as inorganic ceramic materials, pure BN nanosheets membrane is brittle and fragile, which limits their further applications. To satisfy the mechanical performance, BN nanosheets based composite membranes are therefore fabricated. For trapping the emulsified oils and organic molecules, novel porous BN nanosheets/ polyvinylidene fluoride (PVDF) ultrafiltration composite membranes are reported.5 The membranes are whitish and thin with porous BN network incorporating into the PVDF chains. Meanwhile, the PVDF serves as the binder and adheres the BN nanosheets firmly, thereby improving the mechanical performance. Owing to the hydrophobicity for both BN and PVDF, the membranes are efficient to separate organic moiety or oil from water. However, in most cases, the BN nanosheets could not be well dispersed in the polymer due to the poor affinity, which results in agglomeration and affects the final properties. In terms of that, amino group functionalized BN (FBN) nanosheets are rationally designed.6 The FBN is highly hydrophilic with impressive water concentration (30 mg ml-1). Moreover, it could be mixed with some water-soluble polymers such as polyvinyl alcohol (PVA) and poly (diallyl dimethyl ammonium chloride) (PDDA) at arbitrary ratios without precipitation, implying the super compatibility. By facile vacuum-assisted filtration of the aqueous mixture, the freestanding FBN based composite membranes are successfully weaved with layer by layer laminate nanostructures. The films show good flexibility and toughness, which could be folded and rolled for more than 100 times. More importantly, extra-high thermal conductivity (212.8 W m-1 K-1) and pronounced fire-retardancy capacity are obtained, which are promising for light-weight, soft thermal management materials.
1 W. Lei, D. Portehault, D. Liu, S. Qin, Y. Chen, Nat. Commun. 2013, 4, 1777.
2 D. Liu, W. Lei, S. Qin, Y. Chen, Sci. rep. 2014, 4, 4453.
3 W. Lei, D. Liu and Y. Chen, Adv. Mater. Interfaces 2015, 2, 1400529.
4 D. Liu, W. Lei, S. Qin, K. D. Klika,Y. Chen, Phys. Chem. Chem. Phys. 2016, 18, 84-88
5 D. Liu, L. He, W. Lei, K. D. Klika, L. Kong, Y. Chen, Adv. Mater. Interfaces 2015, 2, 1500228.
6 W. Lei, V. Mochalin, D. Liu, S. Qin, Y. Gogotsi, Y.Chen, Nat. Commun. 2015, 6, 8849.