Highly hydrophilic electrospun fibers for the filtration of micro and nanosize particles treated with coagulants
Electrospinning has been widely used in the last decade for research in the field of nanotechnology because of its ability to create sub-micron to nanoscale fibers. In this research work, hydrophilic nanofiber membranes were produced by using the electrospinning process at three different spinneret distances (20 cm, 25 cm, and 30 cm) utilizing a polymeric solution of polyvinyl chloride (PVC) incorporated with polyvinylpyrrolidone (PVP) at different weight proportions ranging from 2% to 5%. Water contact angle values were measured for all of the membranes, and it is observed that membranes produced by maintaining a spinneret distance of 30 cm resulted in a lower contact angle in comparison with other spinneret distances. At the spinneret distance of 30 cm, the 2% and 3% PVP membranes exhibited hydrophobic properties. At 5%, PVP membranes exhibited that of a super hydrophilic nature. The membranes produced at 4% PVP showed the desired hydrophilic nature, which were utilized for the filtration process. Three water samples were selected for the filtration experiments including: lake water, abrasive particles from a water jet cutter, and magnetite nanoparticles. The main concentration of the current research work was to create highly hydrophilic nanofiber membranes and utilize them to filter water at an optimal level of purification (i.e., drinking water). In order to overcome the fouling property of the membrane, coagulation, which enhances the efficiency of the membrane in the removal of colloidal particles, was used as a pre-treatment process. Two coagulants, Tanfloc and Alum, were used during the coagulation process. The removal efficiency of the suspended particles in liquid was measured in terms of turbidity, pH, and total dissolved solids (TDS). It was observed that the coagulation/filtration experiments have shown higher efficiency in the removal of turbidity in comparison with the direct filtration process.