PVDF/AFMS杂化膜的制备及对Cu^2＋的吸附

Preparation of PVDF/AFMS hybrid membrane and its adsorption on copper ions

为提高膜对水溶液中铜离子的吸附效果,采用共缩聚法制备了氨基功能化介孔二氧化硅(AFMS)微球,然后将AFMS微球与聚偏氟乙烯(PVDF)以不同质量比共混,通过浸没沉淀相转化法制备了PVDF/AFMS杂化膜.采用SEM、FTIR对膜结构进行表征,并考察PVDF/AFMS杂化膜对水溶液中Cu^(2+)(初始质量浓度为300 mg/L)的吸附效果.结果表明:AFMS成功嵌入PVDF膜中;随着AFMS质量分数、pH(<7.0)、Cu^(2+)溶液体积和接触时间的增加,杂化膜对Cu^(2+)的吸附量逐渐增大,直至达到吸附平衡;当AFMS在铸膜液固含量中所占质量分数为40%、pH值为6.0、Cu^(2+)溶液体积为20 mL、接触时间为120 min时,PVDF/AFMS杂化膜对Cu^(2+)的吸附量高达57.3 mg/g;经过5次吸附-脱附实验,该杂化膜对Cu^(2+)的吸附量为54.6 mg/g,为初始吸附量的95%以上.说明该杂化膜具有良好的吸附性能和再生性能,且操作简便.

In order to improve adsorption capacity of membrane to Cu^2＋ from aqueous solution, amino functionalized meso- porous silica （AFMS） was synthesized through co-condensation method. Then, AFMS was blended with poly （vinylidene fluoride） （PVDF） in different mass ratios to prepare hybrid membranes by immersion precipitation phase inversion method. The hybrid membranes were characterized using FTIR and SEM. In addition, the adsorption capacity of the prepared hybrid membrane to Cu^2＋ in aqueous solution （initial Cu^2＋ concentration is 300 mg/L） was investigated. Results indicated that AFMS were successfully immobilized in PVDF membrane. The adsorption capacity of hybrid membrane to Cu^2＋ increased with the increase of AFMS mass ratio, pH （〈 7.0）, volume of Cu^2＋ solution and contact time till the adsorption equilibrium. The hybrid membrane showed maximum adsorption of 57.3 mg/g under the optimal adsorption condition （AFMS mass ratio = 40%, pH = 6.0, solution volume = 20 mL, contact time = 120 min）. The adsorption capacity of hybrid membrane to copper ions was 54.6 mg/g after five adsorption -desorption cycles and above 95% of the adsorption capacity of virgin hybrid membrane, which indicated that hybrid membrane displayed a good adsorption performance and a high reusability for copper uptake. Furthermore, the hybrid membranes can be used conveniently.