Study On Preparation Of Modified Cotton Fiber And Absorption Properties For Urotoxin

Chronic kidney disease is a kidney disease in which urotoxin accumulates due to gradual impairment of renal function.Hemodialysis is currently the main method for clinical treatment of chronic kidney disease.However,hemodialysis affects the normal work and life of the patient due to the limitation of treatment location and the frequency of treatment.Moreoverr the intermittent dialysis can make the kidney disease worse.Portable peritoneal dialysis can effectively solve the above problems.It is a device that is patient-driven,removes urinary toxins from peritoneal dialysis through a highly efficient adsorbent,realizes regeneration and recycling of dialysate,and can be carried around.At present,the adsorbents mainly used for the regeneration of peritoneal fluid include urease,activated carbon,zeolite,etc.,but these adsorbents have many disadvantages,such as by-products in the adsorption process,poor selectivity,and easy broken.Therefore,it is very important to develop an adsorbent material that selectively adsorbs urea,creatinine and uric acid.In this study,a series of different modified cotton fibers were prepared from a variety of renewable resources cotton fibers:Graphene oxide modified cotton fiber(GO-CF),3,5 dinitrobenzoyl chloride modified cotton fiber(NCF),oxidized cotton fiber(DCF)is used to selectively remove uric acid,creatinine,urea and from the peritoneal fluid to achieve cyclic regeneration of the peritoneal fluid.The details are as follows:(1)The graphene oxide modified cotton fiber adsorption film was prepared by NaIO4 selective oxidation of cotton fiber,cotton fiber amination and cotton fiber grafted graphene oxide three-step grafting reaction,and its adsorption capacity was explored.Qualitative and quantitative analysis was carried out by means of FT-IR,UV,SEM and the like.The adsorption amount per unit mass of uric acid was 28.78 mg·g-1.(2)the effects of elution conditions,flow rate,and concentration of uric acid solution on the adsorption-desorption process of GO-CF membrane were explored.The results showed that 0.2-2 mM NaOH solution was suitable for the dynamic elution of uric acid;the velocity of the uric acid had little effect on the adsorption of uric acid;the adsorption membrane had high sensitivity to uric acid adsorption,even at the low concentration of uric acid,it still has a good removal ability.After 8 cycles of experiments under the same conditions using the adsorption membrane,the reversible adsorption capacity of the membrane for uric acid was not significantly reduced,which proved that the GO-CF adsorption membrane was recyclable.(3)The off-line dynamic adsorption experiment of uric acid peritoneal dialysis solution was carried out by using GO-CF adsorption membrane.The results showed that the removal rate of uric acid in the peritoneal dialysate of GO-CF adsorption membrane is higher than 50%,which is about 87.92%of the adsorption amount of uric acid aqueous solution,indicating that the film has a good application prospect.(4)3,5 dinitrobenzoyl chloride modified cotton fiber adsorption membrane was prepared by epoxy activator activation and 3,5 dinitrobenzoyl chloride esterification grafting,and its adsorption capacity was explored.Qualitative and quantitative analysis was carried out by means of FT-IR,UV and N elemental analysis.The N element content in NCF was 8.23%,and the adsorption amount per unit mass of creatinine was 10.49 mg·g-1.Through the dynamic adsorption experiment,the results show that the injection concentration increases and the adsorption capacity increases.The higher the flow rate,the worse the adsorption capacity,but when the flow capacity is less than 1.5mL·min-1,the adsorption capacity is basically no difference.(5)The oxidized cotton fiber adsorption film was prepared by selectively oxidizing cotton fibers with NaIO4 and its static adsorption capacity was explored.Qualitative and quantitative analysis was carried out by means of FT-IR,UM,titration measurement and weight loss rate measurement.The suitable aldehyde group content in the obtained DCF should be 3.56-4.87 mmol·g-1,and the adsorption amount per unit mass of urea is 28.02 mg·g-1.