Porous Gelatin Membrane Obtained from Pickering Emulsions Stabilized by Graphene Oxide

This article presents a novel procedure for preparing porous membranes from water-soluble polymers involving the formation of a Pickering emulsion. Gelatin is a biodegradable biopolymer obtained by the partial hydrolysis of collagen. A biopolymer such as gelatin is capable of adsorbing at an oil/water interface, resulting in decreased interfacial energy. Hence, gelatin is widely employed as an alternate for synthetic surfactants to stabilize emulsions in the food industry. However, high-molecular-weight gelatin leads to large emulsion droplets and poor emulsion stability. The amphoteric nature of graphene oxide (GO) nanosheets was helpful in stabilizing the oil/water interface and allows for the preparation of a stable gelatin/GO emulsion. Membranes fabricated using gelatin/GO have a uniformly distributed porous structure. However, prepared membranes are highly hydrosoluble, so the membranes were cross-linked without affecting their morphology. XRD results evidenced that gelatin effectively exfoliated the graphite oxide which is essential to stabilizing the emulsion. Fabricated gelatin/GO membranes possess uniformly distributed pores and are highly stable in aqueous solution. Pure water filtration tests were conducted on the membranes. The permeability results proved that the membranes fabricated by a Pickering emulsion are promising materials for filtration.