Bio-Inspired Polymer Membrane Surface Cleaning

Abstract

Abstract:To generate polyethersulfone membranes with a biocatalytically active surface, pancreatin was covalently immobilized. Pancreatin is a mixture of digestive enzymes such as protease, lipase, and amylase. The resulting membranes exhibit self-cleaning properties after "switching on" the respective enzyme by adjusting pH and temperature. Thus, the membrane surface can actively degrade a fouling layer on its surface and regain initial permeability. Fouling tests with solutions of protein, oil, and mixtures of both, were performed, and the membrane's ability to self-clean the fouled surface was characterized. Membrane characterization was conducted by investigation of the immobilized enzyme concentration, enzyme activity, water permeation flux, fouling tests, porosimetry, X-ray photoelectron spectroscopy, and scanning electron microscopy.

A General Overview of Support Materials for Enzyme Immobilization: Characteristics, Properties, Practical Utility

“…The greatest advantage of these materials is the possibility of forming them into various shapes and sizes. The materials can be used as enzyme supports in the form of particles, fibres, tubes, beads, membranes or sheets [165][166][167]. The wide variety of available organic-organic hybrids makes these materials suited for immobilization of enzymes belonging to all catalytic classes by adsorption, covalent binding and also by entrapment or encapsulation [168,169].…”

A novel strategy to immobilize enzymes on microporous membranes via dicarboxylic acid halides

“…It was consistent with previous studies in which very few enzyme molecules were immobilized. 28,41 The CLSM images in Fig. 2(C) revealed that the uorescence from the immobilized FITC-BSA was uniformly distributed on the membrane surface, indicating that the presented method could be applied to uniformly immobilize various biomolecules.…”

“…The membrane was analyzed regarding the amount of the immobilized trypsin via BCA assay. 40,41 The membrane sample was immersed into BCA working solution, incubated for 30 min at 37 C, and then agitated for 5 min at 25 C. The absorbance of this solution at 562 nm was measured using a UV-vis spectrophotometer (V-630, Jasco, Tokyo, Japan). For calibration, free trypsin concentrations of 100, 200, 400, 600, 800, 1000, and 1500 ppm were used.…”

“…The value of D at 25 C in this study was estimated to be 60 mg cm À2 , which was in good agreement with those reported values, ranging from several mg cm À2 to several tens mg cm À2 . 41,[44][45][46][47] Most of the previously reported values for SA were low such as 0.1 (ref. 43) or 1 U cm À2 .…”

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

“…Nanofibers are typically used as a surface functional layer along with a support layer during the treatment of complex wastewater [25]. Despite showing enhanced membrane antifouling performance and enzyme resuability, the reported biocatalytic UF membranes exhibited low permeability [1,26,27]. Thus, biocatalytic antifouling membranes with stable enzyme attachment and engineered porous structure offering long term operational stability and high membrane permeability are desired.…”