Three-dimensional Assembly Cu@4A Adsorbent And Its EVAL Functional Film Preparation And BHb Adsorption Performance

Hemoglobin is an important oxygencarrying protein with various functional activ ities,which has been developed in many fields,e.g.biopharmaceutical,clinical treatm ent and food industry.Membrane adsorption,integratig ltration with adsorption,posse sses low mass transfer resistance,fast adsorption/desorption rates,and low energy con sumption compared to other adsorption strategies,but is still limited by the low adsor ption capacity.The three-dimensional nanostructured material is constructed from two-dimensional materials,which not only retains the structural and performance characteristics of the two-dimensional material itself,but also avoids stacking and agglomeration.It can provide a large specific surface area and more Active site.In this paper,a three-dimensional nanostructured functional adsorbent?Cu@4A?was prepared by growing a disordered Cu O and Cu?OH?₂nanosheet in situ on the surface of 4A zeolite.The large specific surface area and chelation adsorption mechanism of Cu@4A were beneficial to to adsorbing bovine hemoglobin.Combining the three-dimensional nanostructured adsorbent with a hydrophilic ethylene-vinyl alcohol copolymer?EVAL?via phase inversion method to get the Cu@4A/EVAL adsorptive membrane.Moreover,the bovine hemoglobin?BHb?adsorption performance of the Cu@4A/EVAL were also investigated.The results showed that the large three-dimensional assembly was observed on the surface of Cu@4A,which was fabricated by the two-dimensional nanosheets.The nanostructure of the Cu@4A provided a high specific surface area for adsorption.h The surface two-dimensional nanosheets were mainly composed of Cu O/Cu?OH?_2,which was obtained from the results of XRD and XPS.The maximum BHb adsorption amount of the Cu@4A was 2921.90 mg/g when the p H was close to the isoelectric point of BHb,and the maximum adsorption amount of the surface three-dimensional nanosheet structure is 25271.10 mg/g.The Cu@4A/EVAL adsorp-tive membrane was porous and the pore sizes were smaller than that of the Cu@4A.Such membrane structure not only provided an interconnected path for convective flow in the adsorption process,but also limited the leakage of the Cu@4A.A large amount of Cu@4A were decorated on wall of pore structure and the morphologies of the Cu@4A were well preserved.The Cu@4A adsorbents in membrane were evenly distributed throughout the internal structure of the membrane.When the doping ratio is 65%,The static BHb adsorption amount of the Cu@4A/EVAL membrane was817.99 mg/g when the percentage?wt%?of Cu@4A was 65%.During the dynamic adsorption,when the flow rate was 0.29 m L/min,the dynamic adsorption capacity of the membrane was 645.97 mg/g,which was close to 80%of the static adsorption.During the dynamic desorption,the BHb was enriched in the eluent and the desorption rate was 82.6%.