Lipase and lauric acid were added into a copolymer system, which contained PEG400-dimethacrylate, trimethylolpropane trimethacrylate, and a surface-active agent.The polymerization was initiated by ultraviolet irradiat...Lipase and lauric acid were added into a copolymer system, which contained PEG400-dimethacrylate, trimethylolpropane trimethacrylate, and a surface-active agent.The polymerization was initiated by ultraviolet irradiation .Then recorded lipase polymers (RLP) of locking lipase conformation were obtained after lauric acid was extracted by a neat organic solvent.The adsorption of RLP in the lauric acid solution was studied.The adsorption isothermal curves were measured at temperature 30—50℃.The results indicated that RLP’s adsorption capacity was far stronger than blank carrier’s and immobilized lipase polymers (ILP)’s,about 8.7 and 3.9 times respectively.The adsorption process followed the Langmuir and Freundlich isothermal adsorption equations.展开更多
水镁石粉体是聚合物的常用填料,但水镁石极性较大,与基材的相容性也较差,因此必须通过表面改性,降低水镁石粉体表面能,增强亲油疏水性,从而增加与聚合物之间的相容性,而阴离子表面活性剂是合适的改性剂之一。水镁石粉体改性后的表面性能...水镁石粉体是聚合物的常用填料,但水镁石极性较大,与基材的相容性也较差,因此必须通过表面改性,降低水镁石粉体表面能,增强亲油疏水性,从而增加与聚合物之间的相容性,而阴离子表面活性剂是合适的改性剂之一。水镁石粉体改性后的表面性能,可以用固体表面能数值的变化来表征,本文选择丙三醇、水、1-溴代萘为探针液体,用直接测定法与Washburn方程间接计算法获得了改性前后水镁石的接触角,通过Lifshitz-van der Waals acid base三参数法计算其表面能。研究结果表明,不同的阴离子基团中,羧酸类、磷酸较之磺酸类硫酸类改性效果有明显优势,表面能的碱分量γ-S和酸分量γ+S降为0;随着改性剂中非极性链烃的碳原子个数增加,表面能非极性分量γLSW下降很多,最终导致总表面能下降,接触角增加,疏水性增强。展开更多
文摘Lipase and lauric acid were added into a copolymer system, which contained PEG400-dimethacrylate, trimethylolpropane trimethacrylate, and a surface-active agent.The polymerization was initiated by ultraviolet irradiation .Then recorded lipase polymers (RLP) of locking lipase conformation were obtained after lauric acid was extracted by a neat organic solvent.The adsorption of RLP in the lauric acid solution was studied.The adsorption isothermal curves were measured at temperature 30—50℃.The results indicated that RLP’s adsorption capacity was far stronger than blank carrier’s and immobilized lipase polymers (ILP)’s,about 8.7 and 3.9 times respectively.The adsorption process followed the Langmuir and Freundlich isothermal adsorption equations.
文摘以聚醚多元醇和甲苯二异氰酸酯(TDI)为原料,选用氨基酰化酶I作为模型酶,采用一步发泡法,将酶固定在软质聚氨酯泡沫塑料(FPUF)上,并对其进行表征.研究结果表明,在发泡过程中加入一定量的惰性蛋白质,对酶蛋白有一定的屏蔽效果,降低了被TDI损伤的概率,客观上对酶分子起到保护作用,使固定化后的酶活力收率有所提高.测得FPUF对蛋白质的负载率高达100%,固定化酶活力收率为81.03%,该固定化酶的最适pH值为6.8,与最适pH值为7的酶液相比,略向酸性偏移;最适反应温度与游离酶相似,在50～70℃.将固定化酶用于拆分乙酰-DL-甲硫氨酸的试验,体现了较好的连续使用稳定性,其半衰期为404.3 min.
文摘水镁石粉体是聚合物的常用填料,但水镁石极性较大,与基材的相容性也较差,因此必须通过表面改性,降低水镁石粉体表面能,增强亲油疏水性,从而增加与聚合物之间的相容性,而阴离子表面活性剂是合适的改性剂之一。水镁石粉体改性后的表面性能,可以用固体表面能数值的变化来表征,本文选择丙三醇、水、1-溴代萘为探针液体,用直接测定法与Washburn方程间接计算法获得了改性前后水镁石的接触角,通过Lifshitz-van der Waals acid base三参数法计算其表面能。研究结果表明,不同的阴离子基团中,羧酸类、磷酸较之磺酸类硫酸类改性效果有明显优势,表面能的碱分量γ-S和酸分量γ+S降为0;随着改性剂中非极性链烃的碳原子个数增加,表面能非极性分量γLSW下降很多,最终导致总表面能下降,接触角增加,疏水性增强。
