摘要
采用自由基聚合法,先用丙烯酸(AA)改性壳聚糖(CS),再以N-异丙基丙烯酰胺(NIPA)和改性后的壳聚糖(AA-co-CS)为主链单体制备了AA-co-CS/NIPA温度敏感型水凝胶。研究了pH、温度、时间等对AA-co-CS/NIPA吸附U(Ⅵ)的影响。结果表明,在温度30℃,pH为6,初始U(Ⅵ)浓度10 mg/L时,AA-co-CS/NIPA改性水凝胶对U(Ⅵ)去除率达到95.59%,较CS/NIPA复合水凝胶的去除率提高8%,其吸附过程遵循准二级和Langmuir等温线模型。AA-co-CS/NIPA具有由温度刺激引起的良好的溶胀性能,经过5次吸附(20℃)-解吸(40℃)后,对U(Ⅵ)的去除率仍保持在78.39%。SEM结果表明,丙烯酸对壳聚糖的改性,增大了水凝胶的接触面积、增加了结合位点。FTIR和XPS结果表明,AA-co-CS/NIPA对铀的吸附主要是羧基、羟基和氨基与铀酰离子进行共价键结合。
The free radical polymerization method was used.Acrylic acid(AA)was used to modify chitosan(CS),and then N-isopropylacrylamide(NIPA)and acrylic acid modified chitosan(AA-co-CS)were used to modify chitosan(CS).Preparation of AA-co-CS/NIPA temperature-sensitive hydrogel with main chain monomer.The experiment has studied the influence of pH,temperature,time,etc.on the adsorption of U(Ⅵ)by AA-co-CS/NIPA.The results show that when the temperature is 30℃,the pH is 6,and the initial U(Ⅵ)concentration is 10 mg/L,the removal rate of U(Ⅵ)by AA-co-CS/NIPA hydrogel reached 95.59%,which was 8%higher than the removal rate of CS/NIPA hydrogel before modification.Its adsorption process followed the quasi-secondary and Langmuir isotherm models.AA-co-CS/NIPA has good swelling properties caused by temperature stimulation.After 5 times of adsorption(20℃)-desorption(40℃),the removal rate of U(Ⅵ)remains at 78.39%.SEM results showed that the modification of chitosan by acrylic acid increased the contact area of the hydrogel and increased the binding sites.FTIR and XPS results show that the adsorption of uranium by AA-co-CS/NIPA is mainly the covalent bonding of carboxyl,hydroxyl and amino groups with uranyl ions.
作者
黄鑫
谢水波
王水云
刘迎九
刘晓阳
HUANG Xin;XIE Shui-bo;WANG Shui-yun;LIU Ying-jiu;LIU Xiao-yang(School of Civil Engineering,University of South China,Hengyang 421001,China;Hunan Provincial Key Laboratory of Pollution Control and Resources Technology,University of South China,Hengyang 421001,China;Changsha Nonferrous Metallurgical Design and Research Institute Co.,Ltd.,Changsha 410000,China;Yiyang City Water Resources Bureau of Ziyang District,Yiyang 413000,China)
出处
《应用化工》
CAS
CSCD
北大核心
2022年第9期2618-2624,共7页
Applied Chemical Industry
基金
湖南省教育厅重点项目(19A421)。
