Construction Of RGO-based Magnetic Adsorption Materials And Its Application In Purification Of Polysaccharide-based Biomaterials

Heavy metals,bacterial endotoxins and other pollutants are commonly found in plants and animals.In recent years,the research and application of biological materials from natural have developed rapidly,and the potential pollution hazards should be paid more attention.Heavy metal elements are highly toxic to the human body,causing great damage to organs directly.bacterial endotoxin in the human body can cause sepsis and other serious diseases.For the safety of polysaccharides and biomedical materials,it is necessary to create an adsorbent with good biocompatibility,easy separation and stable adsorption performance in the environment of polysaccharides solution.As an excellent adsorptive material,graphene has been widely studied,it has good biocompatibility and adsorption capacity.However,it is often difficult to separate graphene materials from the reaction system.In this paper,ferric tetroxide?Fe₃O₄?was introduced as a magnetic source to prepare a class of graphene-based magnetic composites with excellent magnetic response properties for removal of contaminated impurities in natural polysaccharide solution.Firstly,Fe²⁺was used as the reducing agent to reducing GO and at the same time generate Fe³⁺,Fe²⁺and Fe³⁺were deposited on the rGO sheet layer at the environment of p H=10 and 80?to generate Fe₃O₄nanoparticles,from which the rGO/Fe₃O₄complex was prepared.Then,using calcium chloride/ethanol solution as a coagulation bath,the mixture of Fe²⁺and GO was formed into gel balls.After hydrothermal reduction,the rGO/Fe₃O₄aerogel balls with good pore structure were prepared by freeze-drying.Subsequently,the structure and properties of rGO/Fe₃O₄composites were analyzed by means of Transmission Electron Microscopy?TEM?,Scanning Electron Microscopy?SEM?,X-ray Diffraction Analysis?XRD?,Raman Analysis?Raman?,Vibration Magnetic Intensity Meter?VSM?,Specific Surface Area Aperture Analysis?BET?,etc.In addition,the adsorption properties of rGO/Fe₃O₄composites to heavy metal elements and bacterial endotoxins were investigated through a large number of adsorption experiments,and their application prospects were evaluated.The experimental results showed that Fe₃O₄ was successfully deposited on the rGO sheet layer with uniform distribution and small particle size,resulting in excellent magnetic response performance of the composite material,which could be separated from the reaction system in a few seconds.In addition,the heavy metal adsorption experiments show that rGO/Fe₃O₄?1:8?prepared with the mass ratio of GO and Fe Cl₂·4H₂O of 1:8 has good adsorption performance and magnetic separation performance,and can maintain good adsorption performance under most circumstances in different carbohydrate environments.The adsorption experiment of endotoxin showed that the rGO/Fe₃O₄aerogel ball had high adsorption efficiency and adsorption capacity for bacterial endotoxin,the maximum equilibrium adsorption capacity of rGO/Fe₃O₄was 854.701 EU/mg,the adsorption rate was improved after the surface modification was loaded with Polymyxin B?PB?,and the adsorption performance was maintained in different carbohydrate environments.