Low-cost nanofabrication of isoporous nanomembranes using hybrid lithography

Abstract

This work demonstrates an improved route to develop low-cost and robust isoporous polyvinylidene fluoride (PVDF) nanomembranes for industrial separation and purifications processes. The 4-step process excels at making uniform 100 nm and 20 nm pore membranes that exhibit high flux in both dead-end and cross-flow filtration. Our tests demonstrate that 90–100% rejection rates could be achieved in these membranes for perfluorooctanoic acid, sulfamethoxazole, bovine serum albumin, and SARS-COV-2 in high-concentration aqueous solutions. The membranes are nominally 50 μm thick and retain structural integrity, exhibiting high tensile strengths of 8.56 MPa and 8.31 MPa, respectively, due to improved routes to β crystalline formations of the PVDF. Our useful fabrication procedure is compatible with developed technologies that can quickly expand the opportunities of isoporous PVDF for processing of advanced materials and devices.

Keywords

• Isoporous nanomembranes
• Nanosphere lithography
• Soft lithography
• Nanoparticle monolayer