摘要
采用水热合成法制备了石墨烯基水凝胶(GH),并成功嫁接季铵基制备了石墨烯季铵基水凝胶(GHP)。采用扫描电镜、元素分析、红外吸收和Zeta电位对GHP理化性质进行了表征,考察了不同pH下GHP对阴离子染料甲基橙(MO)的吸附。结果表明:(1)GHP对MO的吸附行为更符合Langmuir和拟二级动力学模型,表明吸附过程为单层的化学吸附。(2)随溶液pH增加,材料表面官能团产生去质子化,所带负电荷增加,对MO的吸附能力下降,而在嫁接季铵基后,季铵基能在较宽pH范围内保持正电,使其与MO间静电斥力减弱,吸附量增加,使得聚二甲基二烯丙基氯化铵加入量(质量分数)为2%的GHP(GHP-2%)在pH为3.0、7.0下对MO的最大吸附量分别达到398.448、224.473 mg/g。(3)由于GHP-2%高度发达的孔隙结构,MO在其孔内扩散时间较长,导致其吸附MO的平衡时间明显长于其他材料。
Graphene hydrogel(GH)was prepared by hydrothermal method,while the graphene-quaternary ammonium hydrogel(GHP)was obtained through successful grafting of quaternary ammonium groups.SEM,elemental analysis,FT-IR and zeta potential were used to characterize the physicochemical characteristics of hydrogels,and its adsorption for methyl orange(MO)at different pH was examined.The results showed that:(1)the adsorption behavior of GHP on MO was more in line with Langmuir and pseudo second-order kinetic models,indicating that the adsorption process was monolayer chemical adsorption.(2)With the increase of solution pH,the surface functional groups of the material undergo deprotonation,resulting in an increase in negative charge and a decrease in MO adsorption capacity.After grafting the quaternary ammonium group,the quaternary ammonium group could maintain positive charge in a wide pH range,which weakened the electrostatic repulsion between it and MO,and increased the adsorption capacity.The maximum adsorption amount of MO by GHP with the addition amount(mass fraction)of 2%of polydimethyldiallylammonium chloride(GHP-2%)at pH=3.0 and 7.0 reached 398.448 and 224.473 mg/g respectively.(3)Due to the highly developed pore structure of GHP-2%,MO had a longer diffusion time in its pores,resulting in a significantly longer equilibrium time for adsorbing MO than other materials.
作者
刘士清
王志刚
邱军科
尹梦楠
石林
安珂
张迪
LIU Shiqing;WANG Zhigang;QIU Junke;YIN Mengnan;SHI Lin;AN Ke;ZHANG Di(Binzhou Ecological Environment Service Center of Shandong Province,Binzhou Shandong 256600;Yunnan Provincial Key Lab of Carbon Sequestration and Pollution Control in Soils,Faculty of Environmental Science and Engineering,Kunming University of Science and Technology,Kunming Yunnan 650500;Shandong Provincial Key Lab of Soil and Water Conservation and Environmental Conservation,School of Resources and Environment,Linyi University,Linyi Shandong 276005)
出处
《环境污染与防治》
CAS
CSCD
北大核心
2023年第8期1080-1085,1091,共7页
Environmental Pollution & Control
基金
山东省自然科学基金青年项目(No.ZR2022QD088)
滨州市2023年度社会科学规划课题(No.23-SKGH-050)。
关键词
石墨烯季铵基水凝胶
甲基橙
高效吸附
graphene-quaternary ammonium hydrogel
methyl orange
high-efficient adsorption
