A cast-in-place fabrication of high performance epoxy composites cured in an in-situ synthesized 3D foam of nanofibers

Abstract A cast-in-place process is usually adopted to prepare bicontinuous composites which display good mechanical properties and excellent comprehensive performance. But the construction of an intercommunicating porous skeleton seems to be cumbersome and low efficient. Here we report a three-dimensional nanofibers foam (3D NFF), which has been fabricated and applied to enhance epoxy resin composite. The 3D NFF skeletons with densities from 0.028 to 0.218 g/cm3 were fabricated by regulating the conditions for the nanofiber growth. The 3D NFFs were conveniently modified with a silane coupling agent to improve the interface interaction with the epoxy matrix. Compared to the pure epoxy, the compressive strength of the cast-in-place processed 3D NFFs/epoxy composite was improved by 436.8% at loading of 3.9 wt%, and the flexural strength was increased by 133.5% at loading of 5.3 wt%. While the compressive and flexural strength of the NFPs/epoxy composite prepared through traditional mixing method was increased by 173.6% at loading of 3.9 wt%, and 63.1% at loading of 5.3 wt%, respectively.