Preparation And Properties Of Biomimetic Membrane Containing Aquaporin

Membrane separation technology is an important for water treatment.Because of its clean,low energy consumption,water stability and other advantages,and widely used.However,the traditional membrane treatment technology will be hindered by the "upper limit balance"effect,and cannot achieve the double high ratio of retention rate and water flux.To address this question,this study introduced aquaporins in the biomimetic membrane.The charged negative electric membrane of the hydrophilic group is combined with the polylysine and polyglutamate protective layer containing aquaporin to prepare the aquaporin-negative electric membrane with high water flux.The specific research contents are as follows:Transmembrane proteins,which have spindle pores on the cell membrane,can allow water molecules to pass quickly through the because of hydrogen bonds.Make full use of this function of aquaporin to design a charge-negative electric separation membrane containing aquaporin.Effective binding of aquaporins to the membrane is a research focus.Poly-l-lysine is a positively charged hyperpolymer polypeptide formed by 1-lysine polymerization,which acts as a protective layer for proteoliposomes,while also positively charging liposome proteins to the membrane by electrostatic attraction and covalent bonding.Polyglutamate is a negatively charged high-polymer polypeptide polymerized by glutamate,which can also function to protect phospholipid proteins.In addition,the spreading of the polylysine layer and the polyglutamate on the membrane surface will make the membrane surface denser and flatter,and can enhance the antibacterial activity of the membrane.Based on this,this study used dopamine to modify the polyether sulfone membrane and bind to poly-l-lysine and polyglutamate-protected aquaporin layers to obtain a charge-negative electric membrane containing aquaporin.The water permeability of phospholipid vesicles containing aquaporins can be characterized by residence spectroscopy,zeta potential,and particle size testing.Through x-ray photoelectron spectroscopy and Fourier infrared spectroscopy,the appearance of characteristic groups on the charged negative electric membrane proves the successful binding of the protective layer to the polydopamine layer.Changes in membrane surface morphology and roughness can be observed by scanning electron microscope and atomic force microscopy.Furthermore,in the isolation test,the water flux of the charge-negative electric membrane prepared with aqueous channel protein was 11.80 lmh/bar and 9.83 lmh/bar,respectively.However,the retention ratio of divalent salt and monovalent salt is as high as 7.42 and 7.78.It is proved that the charge-negative electric membrane containing aquaporins indeed increases the water flux of the membrane while maintaining the retention rate,breaking through the "upper limit equilibrium" effect.However,in the stability and durability tests,the water flux was not significantly decreased for 68 h,proving that the polylysine-polyglutamate protective layer effectively protected the aquaporin.In conclusion,this study used poly-lysine and polyglutamate layers to protect aquaporin-containing phospholipid vesicles or phospholipid layers and construct an aquaporin-containing charged-negative electric membrane on a polydopamine-modified poly ether sulfone membrane.When separating the divalent salt and monovalent salt in the feed liquid,the charged negative electric membrane shows good stability,high water flux and high score salt ratio,which provides a new idea for the treatment of industrial wastewater containing a large amount of divalent salt,and promotes the d evelopment of the field of charged membrane and water treatment.