Synthesis of CoAl-layered double hydroxide/graphene oxide nanohybrid and its reinforcing effect in phenolic foams:

A graphene oxide (GO) immobilized with layered double hydroxide (CoAl-LDH/GO) nanohybrid was prepared via a hydrothermal method and characterized by transmission electron microscopy, field emission scan electronic microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy and thermogravimetric analysis (TGA). The TGA results show that the immobilization of CoAl-LDH nanoparticles on GO surface greatly promotes the thermal stability of GO. More importantly, the incorporation of the CoAl-LDH/GO nanohybrid into PF foams leads to not only a great improvement in their mechanical strengths but also a reduction in their brittleness and friability. Specifically, compared to neat phenolic (PF) foam, at only 0.9 phr (parts per hundred of resin by mass) of CoAl-LDH/GO, the compressive and flexural strengths of the modified PF foam increase by 54.8% and 35.2%, respectively, and pulverization ratio decreases by 55.2%. The addition of the CoAl-LDH/GO nanohybrid also results ...