Functionalization of boron nitride nanosheets by diazonium salt for preparation of nanocomposites with high‐density polyethylene

Abstract

Functionalization of boron nitride nanosheets (BNNSs)has always been a challenge due to its chemical inertness and anti-oxidative properties. In a concentrated base environment, the B-N bonds on the surface of BNNSs were broken to produce a large number of B-OH and N-H functional groups. Afterwards, aniline carbocation produced by decomposition of the diazonium salt was utilized to achieve high grafting content of Ph-NH 2 groups onto the surface of BNNSs. Further, the amide reaction between amino and stearyl chloride verified the reactivity of Ph-NH 2 groups on the surface of BNNSs, with the result that BNNSs were abundantly decorated by aliphatic chains at 22.9 wt% grafting yield. The surface aliphatic chains of BNNSs strongly improved the interfacial adhesion between the High-density polyethylene (HDPE) matrix and the filler and provided an excellent dispersion of SC-BNNSs in the HDPE matrix. Therefore, HDPE/SC-BNNSs nanocomposites showed improved thermal stability, thermal conductivity, neutron shielding property and flexural modulus with no apparent reduction in tensile strength. When filler content exceeded 5 wt%, the HDPE/SC-BNNSs nanocomposites showed a higher thermal decomposition temperature than the composites with pristine BNNSs fillers. POLYM.

Thermally Conductive but Electrically Insulating Polybenzazole Nanofiber/Boron Nitride Nanosheets Nanocomposite Paper for Heat Dissipation of 5G Base Stations and Transformers

“…24 In addition, the extra absorption peaks of BNNS-M at 1631 and 1107 cm −1 could be assigned to C�O and C�O, respectively, also confirming the existence of the oxalic groups. 23,25 Moreover, the significant decrease of ζ potential after being modified proves that BNNS-M has been negatively charged (Figure 2f). In summary, these characterizations and analyses prove that BNNS-M was successfully prepared.…”

Recent advances in precursor-derived ceramics integrated with two-dimensional materials

“…The oxidized h-BNs can be used directly in many applications. 77,78 Second, further modification of oxidized h-BNs by grafting with complex molecules could tune their surface properties for specific application environments. 79,80 A sheet-like SiCN/BN composite was synthesised via the pyrolysis of polyureasilazane-functionalized h-BN sheets (Fig.…”

Molecular Functionalization of 2d Materials

“…Raman spectroscopy has been chosen in most of the cases as a sensitive technique to detect the functionalization of graphene due to the characteristic D band in the Raman spectra when the modification takes place. Given their success for the functionalization of graphene, the use of aryl diazonium salts has been extended for the functionalization of other 2D materials such as MoS2, WS2, MoSe2, WSe2 98 , black phosporous (BP) 99 or hexagonal boron nitride (h-BN) 100 The molecular functionalization of MoS2 using diazonium salts emerges as an alternative that does not require the presence of defects on the surface and can be used, as a consequence, to modify pristine surfaces of MoS2. Initial studies were done using chemically exfoliated MoS2 by intercalation of n-butyl lithium, dispersion in water and ultrasonication.…”