摘要
采用石英晶体微天平(QCM)、原子力显微镜(AFM)研究了胶原在聚乳酸旋涂膜表面的吸附,考察了溶液浓度(0～9.25μg/mL)和温度(10～50℃)对胶原吸附的影响.实验结果表明,随着胶原浓度的增加,胶原在聚乳酸表面的吸附量和吸附初速率都相应增加.采用Langmuir模型和Freundlich模型拟合实验数据得到吸附等温线方程,分别为q=11690.99c1+0.99c和q=610c3.179.实验结果显示,Langmuir模型拟合效果要好于Freundlich模型.采用Lagergren拟一阶吸附速率方程和Lagergren拟二阶速率方程拟合不同浓度下的吸附动力学数据.在低浓度下Lagergren拟一阶速率方程拟合效果比较好,在高浓度下Lagergren拟二阶速率方程拟合效果比较好,说明在低浓度时扩散过程是胶原吸附的控速步骤,高浓度时胶原和聚乳酸表面的相互作用是吸附的控速步骤.原子力显微镜显示,吸附在聚乳酸表面的胶原形成网状结构.胶原的吸附受温度影响显著,说明胶原是一种对温度非常敏感的物质.实验结果表明随着温度的升高,在10～40℃范围内胶原的吸附量逐渐降低,在40～45℃范围内锐减,40℃是本实验条件下胶原的变性温度.
The adsorption of collagen on spin-coated poly（lactic acid） （PLA） surface was investigated using quartz crystal microbalance （QCM）. The effects of concentration （0 ～ 9. 25 μg /mL） and temperature （10 ～ 50℃ ） on adsorption were studied. The results show that： with the increasing concentration of collagen,the adsorption amount and initial adsorption rate on spin-coated PLA surface increases correspondingly. Langmuir model and Freundlich model were applied for data fitting. The isotherm equations q = 1169 0. 99c1 ＋ 0. 99c and q = 610c 1 3. 79 were obtained. It is found that Langmuir model described experiments better than the Freundlich model. The kinetic experimental data were correlated with the Lagergren pseudo-first order kinetic model and the Lagergren pseudo-second order kinetic model. It is shown that under low concentrations the Lagergren pseudo-first order kinetic model fits the results better and the Lagergren pseudo-second order kinetic fits the results better under high concentrations. It means that the diffusion process is the rate-controlling step under low concentration and the interaction between collagen and PLA surface is the rate-controlling step under high concentrations. The AFM images show that the collagen adsorbed on PLA surface formed mesh-like structure. The adsorption was significantly influenced by temperature changes in the adsorption buffer,indicating that the collagen is a kind of temperature-sensitive material. The results also indicate that collagen denaturalizes gradually with increasing temperature in the range （10 ～ 40℃ ）. The adsorption quantity drops sharply when the temperature approaches （40 ～ 45℃ ）,40℃ is the denaturizing temperature of collagen under present experimental conditions.
出处
《高分子学报》
SCIE
CAS
CSCD
北大核心
2010年第11期1262-1268,共7页
Acta Polymerica Sinica
基金
国家高技术研究发展计划(863计划
项目号2007AA02Z450)资助项目
关键词
吸附
石英晶体微天平
胶原
聚乳酸
Adsorption
Quartz crystal microbalance
Collagen
Poly（lactic acid）
