一种纤维素/钛白粉阳离子交换扩张床吸附剂

为了使得扩张床吸附技术更好地用于蛋白质分离，提出一种含有羧甲基阳离子交换基团的扩张床吸
附剂.采用了反相悬浮热再生法，将超细钛白粉包埋于再生纤维素骨架之中，制备成均质型纤维素/钛白粉
复合微球；再以复合微球作为扩张床吸附基质，用环氧氯丙烷交联后与一氯乙酸反应，得到羧甲基阳离子
交换型扩张床吸附剂；测定了吸附剂在扩张床中的扩张特性和蛋白质吸附性能.结果表明，该吸附剂具有
良好的扩张床膨胀和吸附性能，每升吸附剂的溶菌酶饱和吸附容量达98.7 g，扩张床中蛋白质穿透曲线形
状与填充床基本相似，每升吸附剂的10％穿透吸附容量可达到69.3 g溶菌酶.

Cellulose/titanium dioxide composite cation exchanger for expanded bed adsorption

To obtain improved performance of protein separation by expanded bed adsorption process, a novel expanded bed adsorbent for cation exchange was prepared and characterized. The cellulose/TiO2 composite microspheres were exploited with the method of reversed-phase suspension thermal regeneration, and superfine TiO2 particles were embeded into the regenerated cellulose skeleton, then the composite microspheres were used as the matrix for expanded bed adsorption. After cross-linking with epichlorohydrin and coupling with chloroacetic acid, the composite matrix was found to function as a cation exchanger, and the properties of the bed expansion and protein adsorption were measured. The results indicate that the proposed adsorbent exhibits stable expansion properties and good adsorption behavior. The adsorption capacity reaches 98.7 g per liter adsorbent with lysozyme as model protein. The protein breakthrough behavior in expanded bed is similar to that in packed bed. The dynamic adsorption of lysozyme is 69.3 g per liter adsorbent at 10% breakthrough.