Next Article in Journal
Thin Film Composite Membrane for Oily Waste Water Treatment: Recent Advances and Challenges
Next Article in Special Issue
Polysulfone/Polyamide-SiO2 Composite Membrane with High Permeance for Organic Solvent Nanofiltration
Previous Article in Journal
1D Mathematical Modelling of Non-Stationary Ion Transfer in the Diffusion Layer Adjacent to an Ion-Exchange Membrane in Galvanostatic Mode
Previous Article in Special Issue
Short Review on Porous Metal Membranes—Fabrication, Commercial Products, and Applications
Open AccessArticle

Dual Functional Ultrafiltration Membranes with Enzymatic Digestion and Thermo-Responsivity for Protein Self-Cleaning

Institute for Sustainable Industries and Liveable Cities, College of Engineering and Science, Victoria University, P.O. Box 14428, Melbourne, VIC 8001, Australia
Institute for Frontier Materials, Deakin University, Waurn Ponds, Geelong, VIC 3216, Australia
Authors to whom correspondence should be addressed.
Membranes 2018, 8(3), 85;
Received: 24 August 2018 / Revised: 11 September 2018 / Accepted: 17 September 2018 / Published: 19 September 2018
(This article belongs to the Special Issue Nanostructured Membranes)
Controlling surface–protein interaction during wastewater treatment is the key motivation for developing functionally modified membranes. A new biocatalytic thermo-responsive poly vinylidene fluoride (PVDF)/nylon-6,6/poly(N-isopropylacrylamide)(PNIPAAm) ultrafiltration membrane was fabricated to achieve dual functionality of protein-digestion and thermo-responsive self-cleaning. The PVDF/nylon-6,6/PNIPAAm composite membranes were constructed by integrating a hydrophobic PVDF cast layer and hydrophilic nylon-6,6/PNIPAAm nanofiber layer on to which trypsin was covalently immobilized. The enzyme immobilization density on the membrane surface decreased with increasing PNIPAAm concentration, due to the decreased number of amine functional sites. An ultrafiltration study was performed using the synthetic model solution containing BSA/NaCl/CaCl2, where the PNIPAAm containing biocatalytic membranes demonstrated a combined effect of enzymatic and thermo-switchable self-cleaning. The membrane without PNIPAAm revealed superior fouling resistance and self-cleaning with an RPD of 22%, compared to membranes with 2 and 4 wt % PNIPAAm with 26% and 33% RPD, respectively, after an intermediate temperature cleaning at 50 °C, indicating that higher enzyme density offers more efficient self-cleaning than the combined effect of enzyme and PNIPAAm at low concentration. The conformational volume phase transition of PNIPAAm did not affect the stability of immobilized trypsin on membrane surfaces. Such novel surface engineering design offer a promising route to mitigate surface–protein contamination in wastewater applications. View Full-Text
Keywords: thermo-responsive; ultrafiltration; enzymes; self-cleaning; nanofibers thermo-responsive; ultrafiltration; enzymes; self-cleaning; nanofibers
Show Figures

Graphical abstract

MDPI and ACS Style

Vanangamudi, A.; Dumée, L.F.; Duke, M.C.; Yang, X. Dual Functional Ultrafiltration Membranes with Enzymatic Digestion and Thermo-Responsivity for Protein Self-Cleaning. Membranes 2018, 8, 85.

Show more citation formats Show less citations formats
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Article Access Map

Back to TopTop