The microstructure regulation, strengthening, toughening and hydrophilicity of polyamide6 in fabricating poly (vinylidene fluoride)-based flat membrane via the thermally induced phase separation technique

•The addition of PA leads to cellular pore during the TIPS process.•The mechanism of S-L phase separation combining slower pore-former and NIPS was proposed.•The strengthening mechanism of particle, fiber and network fiber was proposed.•PA can act pore-former and enhanced permeability and anti-fouling capacity.