Preparation of multi-layer nylon-6 nanofibrous membranes by electrospinning and hot pressing methods for dye filtration

We report the formation of multi-layer nylon-6 (PA-6) nanofibrous membranes by electrostatic spinning coupled with a hot pressing process. The structure and porosity of multi-layer PA-6 nanofibrous membranes were characterized using a scanning electron microscope and the N(2) nitrogen adsorption and desorption isotherms. We show that multi-layer PA-6 nanofibrous membranes can be used for efficient and continuous indigo dye filtration. Under the condition of constant pressure at the 0.1 MPa dead end filtration, continuous filter for a period of time, the filtration efficiency for indigo dye increases with the increase of the number of layers in PA-6 nanofibrous membranes. The 10 layer PA-6 nanofiber membrane can completely remove the indigo dye, and early filtration flux was high, with extended time, the filtration flux decline and gradually stabilized.