Preparation of seaweed polysaccharide based hydrophobic composite membranes for the separation of oil/water emulsion and protein

Agarose is a seaweed-based polysaccharide and is widely used for the separation of nucleic acids in molecular biology. Cross-linked agarose beads are also used as solid-phase matrices in size exclusion chromatography for the separation of proteins. To find the application of agarose for the separation of oil/water emulsion and protein, herein hydrophobic derivative of the seaweed biopolymer [MW (1.27 ± 0.17) × 10 5 g/mol; sulphate content (0.29 ± 0.09) %, gel strength (2242 ± 21) g/cm2] is prepared by reacting the biopolymer with stearic acid and was used to prepare a composite membrane on polyester fabric. The oil and BSA rejection performance of the composite membrane was greater than 98%. The rejection rate increased with the increase in polymer content in the respective membranes for both oil/water and protein separation. The composite membrane showed a stable oil/water emulsion and protein separation performance over a period of six hours. Due to the biodegradable nature of the major components of the membrane, it has the potential for industrial applications. A hydrophobic derivative of the agarose is prepared by reacting the biopolymer with stearic acid and was used to prepare membrane by casting on polyester fabric. The composite membranes thus produced were found to separate oil from oil/water emulsion and protein from aqueous protein solution with rejection rate more than 98%. [Display omitted] •A hydrophobic derivative of the agarose is prepared with stearic acid.•The derivative was used to prepare membrane by casting on polyester fabric.•The composite membranes can separate oil and protein from mixtures.