Vdc Copolymer The Multifunction Adsorption Fiber Preparation And Performance

Ion exchange fiber has bigger specific surface area and faster speed of exchange and elution than ion-exchange resin.It can be applied to the preparations of electronic pure water,medical water and biological agent,the purification of industrial sewage, adsorption of poisonous and mephitic gases,the carrier of catalysts,the recovery of heavy metals and rare-earth element and so on.It is a new type ion-exchange material with broad developing prospects.The researches of new ion exchange fiber with much more excellent adsorption capacity have been set store by many countries due to the enhancement of people's environment protection.The wet-spun absorbable AN-VDC copolymer fibers containing various contents of activated carbon were produced via coagulation stragety,whereas the ion exchange AN-VDC copolymer fibers were obtained with aq-hydrazine and hydrolysis in basic solution successively.The ion exchange fiber thus prepared with actived carbon's adsorption property has great exchange capacity,short regeneration time,long service life,stable adsorption decoloring and other advantages;and may be used widely in many fields.The experiment showed that the new fiber is a type of more effective sorbent compared with actived carbon and actived carbon fiber in treating complex pollution.The character of this new adsorption fiber unmodified and modified has been investigated by using Scanning Electronic Microscopy(SEM),Differential Scanning Calorimetry(DSC),X-ray Diffraction(XRD),Infrared Spectroscopic Analysis(IR), specific surface analyzer and absorption spectrophotometer etc.In addition,the adsorption behavior,adsorption process and principle have been also studied particularly.The conclusions are showed as follows.On keeping the property of actived carbon intact the particle diameter suitable for spinning is about 0.8μm.In this experiment,the temperature of drawn bath 70℃, the temperature of coagulation bath 6-10℃,coagulation bath concentration 55wt% and spinning speed 3.33m/min are the best spinning parameters.The actived carbon are distributing in fiber uniformityly.The property of heat resistance has been improved after mixing actived carbon in fiber.Adsorption capacity and adsorption speed both decreased after mixing actived carbon in fiber.Not only the actived carbons distributing mainly on surface of the fiber exert adsorption effect,but in amorphous region in fiber also exert adsorption effect.High Crystallization has low adsorption ability.By contrast,the orientation has little effect on adsorption.The pore and the micropore is the main factor to affect the adsorption capacity.The isothermal adsorption of actived carbon in fiber can be well described by Langmuir and Freundlich model.The effective diffusion coefficient D_efof methyl orange in the actived carbon particle in polymer is 10^-16.When the temperature is 50℃the fiber has good adsorption efficiency.The adsorption speed increase with the temperature rising.Entropy effectiveness is the main impetus of the actived carbon in fiber.The new fibers show a very high adsorption ability in the Pb²⁺and methylene blue co-existing solution.The maximum adsorption capacity of methylene blue and Pb²⁺ are 9.5mg.g^-1and 487.8mg.g^-1respectively.We initially think that the physical adsorption of actived carbon and ion exchange happened at the same time.It may be noticed that the chemical adsorption has great effect on physical adsorption.It has been found that Langmuir model is more fitable to describe the adsorption kinetic behavior than Freundlich on Pb²⁺on the obtained fibers.Also,Increasing the temperature may improve the fiber's physical adsorption ability.The fibers have good adsorption efficiency when pH=7.