(569a) Bio-Inspired Immobilization of Casein-Coated Silver Nanoparticles on Cellulose Acetate Ultrafiltration Membranes: From Laboratory to Scale-up

Casein-coated silver nanoparticles (casein-AgNP) had been previously loaded on cellulose acetate (CA) ultrafiltration membranes for biofouling control[1]. However, when physically added to the membrane casting solution, AgNPs tend to leach off the membranes. Therefore, there is strong interest in developing methods to chemically bind the AgNPs to the membranes without losing their activity, and in making these methods scalable. Inspired by the affinity of silver to the thiol groups of cysteine proteins in bacteria, CA membranes were cast and imbedded with AgNPs via attachment with functionalized thiol groups using polymerized glycidyl methacrylate (GMA) and cysteamine. However, the chemical reactions required three steps after casting the membranes, and each step needs a large amount of solution bath. To minimize the materials and energy needed in the chemical attachment process and maximize the reaction efficiency, this study integrated all the chemical reactions in the stage of preparing dope solutions. The recipe and procedures changed due to the difference of dope solution and membranes. Membranes immobilized with AgNPs were successfully cast for laboratory-scale studies as well as for scale up studies. This method successfully prevented leaching of AgNPs during cross-flow and dead-end studies. Pseudomonas fluorescens Migula in brackish water was used for biofouling test and the membranes displayed a significant reduction in the accumulation of bacterial cells. This method provided a promising approach of casting CA membranes immobilized with AgNPs.

1. Sprick, C.; Chede, S.; Oyanedel-Craver, V.; Escobar, I.C. Bio-inspired immobilization of casein-coated silver nanoparticles on cellulose acetate membranes for biofouling control. Journal of Environmental Chemical Engineering 2018, 6, 2480-2491.