Chitosan/bovine serum albumin (BSA) ultrathin films were fabricated on modified quartz wafer through layer by layer deposition.The effects of experimental conditions, such as pH value, molecular weight of CS, ionic st...Chitosan/bovine serum albumin (BSA) ultrathin films were fabricated on modified quartz wafer through layer by layer deposition.The effects of experimental conditions, such as pH value, molecular weight of CS, ionic strength and polyanions coexisting in BSA solution, on the fabrication and the stability of films were investigated with a radio\|labeled method. The results show that the absorbed BSA is almost proportional to the number of assembly cycle except the first 2 cycles, and chitosan/BSA films are favorable to be fabricated in chitosan aq AcOH at pH=5.2 as compared with at pH=1.0. When two different molecular weight (MW) chitosans were used ( M η≈1.2×10 5, M η≈1.0×10 6), the lower MW chitosan adsorbs more BSA, but less stable ultrathin films are fabricated. Similar results were obtained that the amount of adsorbed BSA is higher but the films formed are less stable in water than in phosphate buffered saline (PBS). The adsorption of BSA is restricted greatly in the presence of poly(sodium styrene sulfonate) (PSS) mainly because of the competitive adsorption.展开更多
文摘以牛血清蛋白为主要原料对圣女果和小黄瓜进行涂膜保鲜实验,在20～25℃下测定果蔬的失重率,烂果率,维生素C、总叶绿素、总类胡萝卜素含量以及可溶性固形物含量.结果表明:涂膜处理对圣女果和小黄瓜具有良好的保鲜效果,能够明显抑制果蔬营养物质的消耗,降低失水、烂果率,抑制其呼吸强度,货架期分别达到15 d和10 d.
文摘Chitosan/bovine serum albumin (BSA) ultrathin films were fabricated on modified quartz wafer through layer by layer deposition.The effects of experimental conditions, such as pH value, molecular weight of CS, ionic strength and polyanions coexisting in BSA solution, on the fabrication and the stability of films were investigated with a radio\|labeled method. The results show that the absorbed BSA is almost proportional to the number of assembly cycle except the first 2 cycles, and chitosan/BSA films are favorable to be fabricated in chitosan aq AcOH at pH=5.2 as compared with at pH=1.0. When two different molecular weight (MW) chitosans were used ( M η≈1.2×10 5, M η≈1.0×10 6), the lower MW chitosan adsorbs more BSA, but less stable ultrathin films are fabricated. Similar results were obtained that the amount of adsorbed BSA is higher but the films formed are less stable in water than in phosphate buffered saline (PBS). The adsorption of BSA is restricted greatly in the presence of poly(sodium styrene sulfonate) (PSS) mainly because of the competitive adsorption.
