Preparation of hand-carry gravity-driven water filter with high throughput and water disinfection performance

A process for fabricating a nanofibrous membrane, the process comprising:

• preparing a solution by mixing and annealing in a sealed container a polymer mixture consisting of a certain amount of polymer and additives in an organic solvent at 50˜90° C. until homogenous, and cooling the polymer mixture to room temperature;
• applying voltage in the range of 10-30 kV (preferably 15-25 kV) to the solution at room temperature as it is ejected in a stream from a syringe toward a rotating metal drum;
• feeding the solution from the syringe at the rate 0.5-2.0 mL/h (preferably 1.0-1.5 mL/h);
• and
• collecting the stream as nanofibers on a rotating metal drum at a distance of 5.0-20.0 cm (preferably 10-15 cm) from the exit of the syringe to yield a nanofibrous membrane.

A non-solvent induced phase separation (NIPS) process for fabricating a nanofibrous membrane, the process comprising:

• preparing a solution by mixing and annealing in a sealed container a polymer mixture consisting of a certain amount of polymer and additives in an organic solvent at 50˜90° C. until homogenous, and cooling the polymer mixture to room temperature;
• casting with a thickness the solution at room temperature onto a clean and smooth glass plate;
• quickly and smoothly immersing the glass plate into a coagulation water bath;
• and
• after a substrate is formed by phase inversion, removing excess solvent and additives by soaking in DI water to yield a nanofibrous membrane from the substrate.