摘要
采用一种简便的方法制备了生物高分子调控的氧化石墨烯凝胶用于水污染处理.将生物高分子白蛋白(BSA)、壳聚糖(CS)、及脱氧核糖核酸(DNA)与氧化石墨烯(GO)共混,自组装形成水凝胶,最后冻干得到生物高分子/氧化石墨烯复合凝胶.通过扫描电镜、原子力显微镜、纳米粒度分析仪等分析复合凝胶的组装结构与表面电位.结果表明凝胶呈现内部联通的三维多孔结构,该结构有利于被吸附分子的快速内部扩散.红外光谱证明了生物高分子被成功负载到了凝胶网络中.然后将该复合凝胶用于阳离子染料的吸附,吸附实验表明这类生物高分子/氧化石墨烯复合凝胶对阳离子染料有很好的吸附效果,同时也对阴离子和非离子毒性分子有一定的吸附能力.研究了吸附时间,初始浓度,pH值等对凝胶吸附量的影响,并考察了凝胶的解吸附.最后详细探讨了GO-BSA、GO-CS和GO-DNA凝胶对亚甲基蓝(MB)吸附的动力学和吸附等温式.经吸附动力学拟合,生物高分子/氧化石墨烯复合凝胶吸附MB复合二级动力学模型和Langmuir等温吸附,对MB分子是单分子层吸附,吸附初期为大孔隙扩散,后期为粒子内扩散.
A facile method was provided by using biopolymers to mediate and synthesize 3D graphene oxide（GO） based gels.Bovine serum albumin（BSA）,chitosan （CS） and deoxyribonucleic acid （DNA） were chosen as bio-polymeric cross-linking agents to approach the gelation,and the gels were freeze-dried to obtain GO/biopolymer gels.The chemical and physical properties of the GO/biopolymer gels were tested by scanning electron microscope （SEM）,atomic force microscopy （AFM） and zeta potential measurements.The results indicate that these obtained gels have well-defined and interconnected 3D porous network,which allows the adsorbate molecules to diffuse easily into the absorbent.Fourier transform infrared （FTIR） spectra confirmed that these biopolymers have been immobilized into the GO gels successfully.Then,the hybrid gels were used for the removal of cationic dyes from waste water.Adsorption experiments showed that the GO-biopolymer gels had good adsorption ability for the cationic dyes; meanwhile,the hybrid gels also presented certain amount of adsorption capability for anionic and nonionic toxic molecules.The influence of contacting time,initial concentration and pH value on the adsorption capacities of the prepared GO-biopolymer gels was also studied,and the desorption ratios were also investigated.The GO-biopolymer gels displayed an adsorption capacity as high as 1100 mg/g for MB dye.Furthermore,the adsorption kinetics and adsorption isotherm of MB on the GO-BSA,GO-CS and GO-DNA gels were studied and discussed in detail.As a result,the experimental data of MB adsorption turned out that it fitted well with the pseudo-second-order kinetic model and the Langmuir isotherm,which indicated that the adsorption process was well-regulated monolayer adsorption.Besides,the initial adsorption process was pore diffusion while the later adsorption process was intraparticle diffusion.
出处
《高分子学报》
SCIE
CAS
CSCD
北大核心
2014年第3期341-349,共9页
Acta Polymerica Sinica
基金
国家自然科学基金(基金号51173119)资助项目
关键词
氧化石墨烯
生物高分子
凝胶
吸附
水污染
Graphene oxide, Biopolymers, Gel, Adsorption, Wastewater treatment
