壳聚糖功能化磁性氧化石墨烯复合材料的制备及对甲基橙的吸附  

Synthesis of chitosan functionalized magnetic graphene oxide composite and adsorption on methyl orange

作　　者：黄文涛 邓呈逊[1] 吉宇尘 张典雅 俞志敏[1] HUANG Wentao;DENG Chengxun;JI Yuchen;ZHANG Dianya;YU Zhimin(School of Biology,Food and Environment,Hefei University,Hefei 230601,China)

机构地区：[1]合肥学院生物食品与环境学院,合肥230601

出　　处：《复合材料学报》2021年第4期1262-1271,共10页Acta Materiae Compositae Sinica

基　　金：安徽高校自然科学研究项目重点项目(KJ2019A0827);安徽省重点研发计划面上攻关项目(1804a09020096);合肥学院科研发展基金项目(自然科学·第一批)重大项目(18ZR03ZDA)。

摘　　要：用改进Hummers方法和水热法制备壳聚糖功能化磁性氧化石墨烯(CS/MGO)复合材料,通过SEM、FTIR、XRD、BET和振动样品磁强计(VSM)对材料结构和性能进行表征和测试,并对水中甲基橙(Methyl orange,MO)吸附研究。结果表明:氧化石墨烯(Graphene oxide,GO)与壳聚糖(Chitosan,CS)成功键合,热稳定性好,被壳聚糖修饰后比表面积为36.873 m^(2)·g^(-1),磁性粒子均匀分布在GO表面,磁性响应明显。考察p H值、MO初始浓度、CS/MGO复合材料添加量及再生性能对MO去除率的影响,结果表明:在pH=3、MO初使浓度为20 mg·L^(-1)、吸附材料为0.12 g·L^(-1)时,210 min后达到吸附平衡,经5次循环后为初使吸附容量的83.7%。吸附过程符合拟二级动力学模型,吸附等温线符合Langmuir模型,在298.15、303.15、308.15 K温度下最大吸附量分别为129.96、138.94、145.03 mg·g^(-1);吸附热力学表明,吸附过程为吸热、熵增自发的吸附过程。The chitosan/magnetic graphene oxide(CS/MGO) composites were synthesized by the modified Hummers and hydrothermal methods and applied as an adsorbent for the removal of methyl orange(MO). CS/MGO composite was characterized by SEM, XRD, BET, FTIR and a vibrating sample magnetometer(VSM). Results show that Fe3 O4 nanoparticles mainly exist on the surface of graphene oxide and chitosan(CS) composite with less aggregation and a good magnetic response. In addition, the thermal stability is good, and the specific surface area of CS/MGO is 36.873 m2·g^(-1). CS/MGO composite could be easily separated by magnetic separation and demonstrates good stability and reusability. The effects of pH, initial concentration of MO, CS/MGO composite amount and regeneration on the removal of MO were systematically investigated. The results reveal that the initial MO concentration of 20 mg·L^(-1), CS/MGO composite amount of 0.12 g·L^(-1), and pH=3 lead to the adsorption equilibrium after210 min. CS/MGO composite maintains 83.7% of its maximum MO adsorption capacity after five consecutive cycles.The adsorption process conforms to the pseudo-second-order kinetic model, and the adsorption isotherms conform to the Langmuir model. The maximum adsorption amounts at 298.15, 303.15 and 308.15 K are 129.96, 138.94 and 145.03 mg·g^(-1), respectively. The adsorption thermodynamics indicate that the adsorption process is endothermic;entropy increases the spontaneous adsorption process.

关 键 词：水热法 壳聚糖 氧化石墨烯 复合材料 吸附 甲基橙 

分 类 号：X703[环境科学与工程—环境工程] TQ424[化学工程]