p(AA-co-CTS)两性型规整吸附介质的制备及动态吸附性能

Preparation and Adsorption Properties of p(AA-co-CTS) Amphoteric Continuous Adsorption Medium

以丙烯酸(AA)、壳聚糖(CTS)为单体,选用抗坏血酸(VC)为还原剂取代传统胺类还原剂,通过低温冷冻聚合法一步制备了富含—COOH基团和—NH2基团的两性型规整吸附介质p(AA-co-CTS),聚合时间从文献报道的18h缩短至5h。通过SEM对p(AA-co-CTS)规整吸附介质进行表征,其内部孔隙连续,孔径范围为100～500μm。聚合最优配方为:引发剂过硫酸铵(APS)与VC总质量分数为0.75%(以聚合体系总质量计,下同),VC与APS的质量比为0.5∶1.0,单体总质量分数为7%(以聚合体系总质量计,下同),m(CTS)∶m(AA)=0.2∶1.0,交联剂N,N?-亚甲基双丙烯酰胺(MBA)质量分数为1.05%(以聚合体系总质量计,下同)。借助吸附传质单元数(NTU)法探究了传质参数与多肽吸附操作条件的关系,并确定最佳吸附条件为:吸附液流速3～4 mL/min,吸附温度293.15 K,进料液质量浓度400～500 mg/L。所制备的两性型分离介质属于超大孔隙规整介质,最大动态吸附容量为74.5～79.4 mg/g,应用上可取代传统吸附工艺中需过滤、离心及层析等单元操作的散装吸附树脂介质。

A continuous amphoteric adsorption medium p(AA-co-CTS)rich in carboxyl and amino groups was prepared by one step copolymerization using acrylic acid(AA)and chitosan(CTS)as raw materials,and ascorbic acid(VC)as reducing agent instead of traditional amine reductant.The polymerization time was shortened from 18 hours reported in literature to 5 hours.SEM showed that the pore structure of p(AA-co-CTS)adsorption medium prepared was continuous and the pore size scale was 100~500μm.The optimum polymerization parameters were as follows:ammonium persulfate(ASP)and VC as initiator had0.75%total mass fraction,m(VC)∶m(APS)=0.5∶1.0.Monomers had 7%mass fraction,m(CTS)∶m(AA)=0.2∶1.0.Cross-linking agent N,N’-methylene bisacrylamide(MBA)had 1.05%mass fraction.The relationship between mass transfer parameters and the operation conditions of polypeptide adsorption was studied by number of mass transfer units(NTU)method.The optimum adsorption operation conditions were determined as follows:the flow rate of adsorption liquid was 3~4 mL/min,the adsorption temperature was 293.15 K,and the feed concentration was 400~500 mg/L.The prepared amphoteric separation medium was a super porous continuous medium with a maximum dynamic adsorption capacity of 74.5~79.4 mg/g,which could replace bulk adsorption resin medium in the traditional adsorption process of filtering,centrifugation and chromatography and other units operations.