Preparation Of Cellulose/Graphene Oxide Composite Membrane And Its Adsorption Performance Research

In recent years,graphene oxide?GO?has been widely used as a new type of adsorbent material for its unique nano-structure,larger specific surface area,large number of-OH,-COOH,C=O and other oxygen-containing functional groups as well as delocalized?electrons,which have a good adsorption effect to conjugated system of organic compounds and heavy metals.However,it can not be separated from the aqueous solution using traditional methods as centrifugal or filtration,because of its small size and soft sheet,thus limiting its application in the field of adsorption.Therefore,it's necessary to functionalize the graphene oxide to improve its adsorption performance and recycling capacity in the actual separation process.This paper discussed the functional modification of GO by filtrating cellulose/graphene oxide composite membrane?CGCM?as well as the adsorption behavior of RhB,heavy metals(Cd²⁺?Pb²⁺and Cu²⁺)and the extraction of Lonicerae japonicae Flos.It mainly includes the following three parts:We prepared cellulose/graphene oxide composite membrane?CGCM?by a facile one-step vacuum filtration,the cellulose mainly played a role of skeleton support,so that the composite membrane not only maintained the original adsorption capacity,but also easy to separate from the aqueous solution.The structure and morphology of GO and CGCM were characterized by XRD,SEM,IR and Raman.The results indicated that the graphene oxide is successfully compounded into the cellulose and the cellulose/graphene oxide composite membranes have highly ordered layered structure.Observing the adsorption of different proportions of CGCM on rhodamine B,we found that the maximum adsorption capacities of the CGCM for RhB were approximately 85.7 mg/g when the mass ratio of cellulose and graphene oxide was 8:1?labeled C8G1?.In addition,the adsorption capability for RhB after the 5th cycle was still over 90%through the utilization of C8G1/RhB as a simple ethanol organic solvent.The adsorption of heavy metal ions(Cd²⁺?Pb²⁺and Cu²⁺)by C8G1 were investigated by using C8G1 to absorb them,the maximum adsorption capacities of the CGCM for heavy metal ions(Cd²⁺?Pb²⁺and Cu²⁺)were respectively 11.99 mg/g,17.95 mg/g and 20.98 mg/g.Investigating the adsorption of different proportions of CGCM on the extraction of honeysuckle leaves?labeled TEH?.Then compared the filtrate and raw liquid after adsorption by HPLC,we found that TEH was not selectivity absorbed by C2G1,but by C4G1,C6G1 and C8G1 which only contain neochlorogenic acid,chlorogenic acid,caffeic acid and isochlorogenic acid C.And C4G1 adsorption of the four kinds of organic acids in the filtrate content is relatively high,so C4G1 has the best proportion in the selective adsorption of TEH.Investigated and compared the elution of C4G1/TEH with different volume fraction?30%,50%,70%and 90%?by ethanol,then compared the detergent and raw liquid by HPLC.The results showed that only 70%ethanol elutes C4G1/TEH selectively,and HPLC comparison of the eluent and the original solution showed that the four kinds of organic acids which were new chlorogenic acid,chlorogenic acid,caffeic acid and chlorogenic acid were found in the eluent.Therefore,it proves that CGCM can effectively separate four kinds of organic acids which were chlorogenic acid,chlorogenic acid,caffeic acid and isochromic acid C from the extraction of honeysuckle leaves with proportions of 79.95%,49.93%,83.35%and 70.42%respectively,which were calculated by standard curve line.