近日，我院张兴义教授及其团队在期刊《Carbon》上发表题为“Tunable negative thermal expansion of ultralight ZrW2O8/Graphene hybrid metamaterial”的文章。现摘要如下：
【Abstract】We fabricated a porous ZrW2O8/graphene hybrid meta-material (ZGHM) via a one-step in-situ hydrothermal process with the mixed suspension solution of graphene oxide (GO) and ZrW2O8 as the precursors. The porous ZrW2O8 accretion covers over the GO sheets to form the interconnected microstructure with two components assembled together strongly. After subsequent freeze-drying and thermal annealing processes, the as-obtained ZGHM presents a porous structure and lightweight density of 4.35？mg/cm3. Due to the synergy interaction and interfacial strengthening between GO and ZrW2O8, ZGHM demonstrates significantly enhanced negative thermal expansion (NTE) effect over a large temperature range 293–473？K. The maximum thermal expansion coefficient (−44.7？×？10−6？K−1) of ZGHM is three times over that of pure ZrW2O8. Moreover, in situ observation by scanning electron microscope reveals NTE by microstructural shrink evolution under controlled heating schemes as well as finite element simulation. A concomitant sharp displacement was triggered by thermal strain-induced buckling of micro-elements. Such NTE suggests smart modulating performance on thermal strain distribution in graphene-based ceramic composites for engineering.