Mitigating cryogenic microcracking in carbon-fibre reinforced polymer composites using negative thermal-expansion nanoparticles functionalized by a polydopamine coating

Herein, we report a new method of mitigating cryogenic microcracking in carbon-fibre reinforced-plastics (CFRPs) using a negative thermal-expansion nanomaterial, zirconium tungstate (ZrW2O8), to simultaneously reduce the thermal residual stresses and enhance the fracture energy of the epoxy matrix of CFRPs. The results show that 1 wt% of added ZrW2O8 nanoparticles functionalized by polydopamine can increase the fracture energy of the matrix material by 140%, reduce the coefficient of thermal expansion by 20% and, more importantly, enhance the interlaminar fracture energy of the resulting CFRP by about 100% at −196 °C. The ZrW2O8-modified matrix has been demonstrated to successfully prevent microcracking at −196 °C in a blocked cross-ply CFRP laminate with a [04/908/04] fibre architecture. [Display omitted] •A new method of mitigating cryogenic microcracking in CFRP composites using ZrW2O8 which exhibits negative thermal expansion.•ZrW2O8 nano particles simultaneously toughen and reduce the thermal residual stress in matrix of CFRP at −196 °C.•Surface functionalization of ZrW2O8 nano-particles by polydopamine further enhances its effectiveness.•Toughened matrix has been found to effectively prevent matrix microcracking at cryogenic temperature.