蛋白质在离子交换吸附剂颗粒中的扩散系数  

Diffusion Coefficients of Protein in Ion-Exchange Adsorbent

作　　者：苏雪丽[1] 史清洪[1] 吴玉龙[2] 张猛[1] 

机构地区：[1]天津大学化工学院,天津300072 [2]清华大学核能研究院,北京100084

出　　处：《化学工业与工程》2005年第5期362-366,F0003,共6页Chemical Industry and Engineering

基　　金：国家杰出青年科学基金资助项目(No.20025617)

摘　　要：采用以化学势梯度作为扩散推动力的MaxwellStephan扩散方程(MS方程),结合平行扩散模型,对阴离子吸附剂QSepharoseFF吸附牛血清白蛋白(BSA)的动态试验数据进行了模拟,拟合得到了BSA的表面扩散和孔扩散系数。研究表明表面扩散系数随pH降低、盐浓度增加而增大;孔扩散系数随pH增加、盐浓度降低而增加,随蛋白质初始浓度增加而减小。在表面扩散不容忽视且为非线性吸附的条件下采用Fick定律时得到的表面扩散系数是蛋白质浓度的函数,且大于根据MS方程得到的表面扩散系数。Parallel diffusion model was combined with the chemical potential gradient driving diffusion equation （Maxwell-Stephan Equation, or MS Equation in shortened form） to fit the uptake curves of BSA in anion ion-exchange adsorbent Q-Sepharose FF to study the influence of pH, salt concentrations and initial protein concentrations on diffusion coefficients in ion-exchange adsorbent. It shows that surface diffusion coefficients are larger with lower pH and higher salt concentration. Pore diffusion coefficients decrease with higher initial concentration of protein probably due to the blocking effect of adsorbed protein molecules to pores and increase with increasing pH and decreasing salt concentration. It is pointed out that in the case of surface diffusion not being negligible and non-linear adsorption, diffusion coefficients become a function of concentration when Fick law is adopted and it is necessary to adopt MS equation to describe the diffusion flux in the adsorbent.

关 键 词：扩散系数 离子交换 MS方程 

分 类 号：TQ931[化学工程]