Hydrophobic poly(ionic liquid)s as “two-handed weapons”: Maximizing lipase catalytic efficiency in transesterification of soybean oil toward biodiesel

Abstract

The mesoporous supports of alkylated poly(ionic liquid)s (PILs) are got through free radical copolymerization. With an immobilization yield of 99% for Candida antarctica lipase B (CalB), the biocatalyst showed high advantage for biodiesel production under mild conditions. Typical catalyst CalB0.2@PIL-C8 was capable of effectively converting soybean oil into biodiesel with a yield of 68.2%, which is higher than Novozym 435 for 57.5%. The biodiesel yield was almost 1.5 folds compared to that of free CalB under the same conditions. And the catalyst remained about 80% activity in a seven-run recovery test with no CalB leaching in the whole process. The hydrophobic PILs not only provide a suitable reaction micro-environment but also can help CalB keep an open conformation in immobilizing with its flexible hydrophobic alkyl chains. This research offered a green and effective strategy for regulating the hydrophobicity and surface potential of support to enhance the performance of immobilized lipase.