▎ 摘　　要

A mechanical cleavage (MC) approach has been demonstrated to synthesize graphene nanosheets (GNs) as heat sink materials from artificial graphite paper (GP). The facile MC method is composed of three main steps: GP isolation, GP exfoliation, and GN collection. The method is capable of preparing few layers of GNs repeatedly without using chemical oxidizing agents and costly deposition apparatus. The as-prepared GN powders are well characterized by X- ray diffraction and Raman spectroscopy. On the basis of the experimental results, the MC method shows a great feasibility to synthesize high- quality GN products with high repeatability and environmental friendliness. We also report that the addition of GN onto Cu foil induces an improved capability for heat dissipation, as compared with original GP and Cu heat foil. According to the calculations of Fourier's law, the thermal conductivity of the GN/Cu composite heat sink can reach as high as 2142 W/m K, leading to 26% increase of thermal conductivity compared to the GP heat sink. (C) 2015 Elsevier Masson SAS. All rights reserved.