Preparation Of Cellulose Based Aerogel And Study On Selective Adsorption Behavior And Mechanism Of Dysprosium Ion

Dysprosium has been widely used in the fields of permanent magnets,hydrogen storage materials and superconducting materials.However,China’s dysprosium industry has been facing problems such as uncontrolled use,low utilization rate and insufficient product innovation.Over the years,the mining and application of dysprosium has caused serious damage to the environment.The adsorption method can effectively separate and recover dysprosium from the environment,thereby alleviating the supply crisis of dysprosium and reducing the burden of dysprosium pollution.Cellulose is the most abundant linear macromolecule in nature.It has excellent structural properties and biocompatibility,and it is a potential raw material for adsorbent preparation.In this paper,we took cellulose as the basic structure and introduced high adsorption performance materials to modify it.Combined production technology of aerogel and the ion imprinting technology to control the synthesis cost,three kinds of porous aerogels for selectively adsorbing dysprosium ions were prepared.The main contents of this paper are as follows:（1）In this study,the periodic imprinted porous aerogel（IGCPA）was constructed using cellulose nanocrystals with periodic structure as the basic structure,polyethyleneimine and graphene oxide as functional monomers,and combined with the ion imprinting technology for the selective adsorption of dysprosium ions.Subsequent experiments showed that the periodic cellulose nanocrystalline aerogel was effectively synthesized,and the imprinted aerogel had a maximum adsorption capacity of 36.495 mg g^-1 for dysprosium ions and excellent selectivity.In addition,the cellulose nanocrystalline aerogel has the advantages of environmental friendliness,high efficiency,and good repeatability,which is expected to provide a new direction for the recovery of rare earth elements.（2）Compared with cellulose nanocrystals,bacterial cellulose has the higher purity and stronger mechanical properties.In this study,bacterial cellulose with the unique three-dimensional network structure was used as the basic structure,graphene oxide and polyethylene glycol were introduced,and a green aerogel that could adsorb dysprosium ions with high selectivity was prepared by combining with the ion imprinting technology.The following test results showed that the composite aerogel has good stability and repeatability,and the large amount of carboxyl groups introduced also successfully promoted the effective coordination between the aerogel and dysprosium ions.The adsorption experiments showed that the maximum adsorption capacity of I-GO-OBC-p DA-PEG aerogel for dysprosium ions was 49.904 mg g^-1,which showed strong specificity for dysprosium ions and could efficiently recover dysprosium ions in water.（3）At present,the price of adsorbents that can recover rare earth ions is generally high,which is not conducive to the wide application of adsorbents in the industrial production of dysprosium.In this study,carboxylated bacterial cellulose was used as the substrate,and low-cost materials such as attapulgite and gelatin were used to replace expensive raw materials such as graphene oxide to improve the affinity of the materials for dysprosium ions,and to prepare the low cost I-APT-GT-OBC aerogel with a high adsorption capacity and a high selectivity.The adsorption experiment showed that the saturated adsorption capacity of the imprinted aerogel was 48.762 mg g^-1,and the partition coefficient for dysprosium ions was much higher than that of the non-imprinted aerogel,showing the good selective adsorption.The I-APT-GT-OBC aerogel is expected to be a low-cost adsorbent that can efficiently adsorb dysprosium ions from water.