Cross-Linking Combined with Surfactant Bilayer Assembly Enhances the Hydrophilic and Antifouling Properties of PTFE Microfiltration Membranes

Abstract

The inherent strong hydrophobicity of Polytetrafluoroetylene (PTFE) microfiltration membranes results in low separation efficiency and easy contamination. In order to enhance its hydrophilic and antifouling properties, we first modified the PTFE microfiltration membrane by using Polyethylene glycol laurate (PEGML) for first layer deposition and then used Polyvinyl alcohol (PVA)/citric acid (CA) cross-linked coatings for second layer deposition. The Scanning Electron Microscope (SEM) results showed that the fibers and nodes of the modified PTFE microfiltration membrane were coated with PVA/CA hydrophilic coating. FT-IR Spectromete and X-ray photoelectron spectrometer (XPS) analysis results confirmed that crosslinking of PVA and CA occurred and that PEGML and PVA/CA were successfully deposited onto the membrane surface. The modification conditions were optimized by hydrophilicity testing, and the best hydrophilicity of the modified membrane was achieved when the crosslinking content of PEGML was 2 g·L−1, PVA was 5 g·L−1, and CA was 2 g·L−1. PTFE microfiltration membranes modified by the optimal conditions achieved a water flux of 396.9 L·m−2·h−1 (three times that of the original membrane) at low operating pressures (0.05 MPa), and the contact angle decreased from 120° to 40°. Meanwhile, the modified PTFE microfiltration membrane has improved contamination resistance and good stability of the hydrophilic coating.

Hydrophilic Modification of Polytetrafluoroethylene (PTFE) Capillary Membranes with Chemical Resistance by Constructing Three-Dimensional Hydrophilic Networks

“…Surface crosslinking, a physical modification method, involves intertwining hydrophilic substances around membrane fibers to form a stable structure [ 38 , 39 , 40 , 41 ]. Wang intertwined hydrophilic polyvinyl alcohol on PTFE membranes using electrospinning, followed by glutaraldehyde crosslinking, creating a dual-layer membrane resistant to oil contamination [ 38 ].…”

Novel Polymeric Membranes Preparation and Membrane Process

“…One review article describes the fouling problems in the membrane technology for use in water and wastewater treatment, as well as the methods of both initial treatment and the least-advanced technologies in treatment processes, such as introducing nanochemistry into the area of water treatment [1]. Six research papers illustrated high-performance NF membrane for the lithium recovery from brine [2], molecular dynamics (MD) simulation of gas transporting in polydimethylsiloxane (PDMS) membrane [3], zeolite molecular sieve SAPO-34/polydimethylsiloxane (PDMS) mixed matrix membranes (MMMs) preparation to recover propane [4], polyvinylidene fluoride (PVDF)-pressurized ultrafiltration membrane on the treatment of steel wastewater and analyzing [5], poly (vinyl alcohol) (PVA)-based MMMs preparation for high ethanol dehydration performance [6], hydrophilizing the polytetrafluoroetylene (PTFE) microfiltration membrane combining of surfactants and cross-linked co-deposition double-layer self-assembly method [7].…”

“…Shijie Xu et al contribute their work to the antifouling modification of PTFE microfiltration membranes [7]. They use a combination of surfactants and a cross-linked co-deposition double-layer self-assembly method to hydrophilize the PTFE microfiltration membrane.…”