Preparation Of Several Glyphosate Zirconium-based Composite Materials And Their Application Research

In recent years,layered materials have drawn much attention due to their unique and excellent properties.Among them,a kind of metal phosphate,which named zirconium phosphate,has been widely studied.The hydroxyl groups in zirconium phosphate can be replaced by organic groups,thus many new kinds of organic zirconium phosphonate can be prepared.Glyphosate zirconium(ZrGP)is an organic zirconium phosphate which was synthesized by glyphosate and zirconium oxychloride.ZrGP has many excellent properties and it deserves to be further developed.In this thesis,the author summarizes the research progress of layered materials and zirconium phosphate(phosphonate)according to the previous literature.Modification to ZrGP was carried out and a variety of composite materials were synthesized.The related properties and applications of these composite materials were also investigated.The main research contents are as following:1.A new kind of composite material composed of Ag and ZrGP was successfully synthesized by two methods.In the first method,ZrGP was prepared and then mixed with AgNO3.Then Ag+ions in the composite were reduced to Ag NPs.In the second method,glyphosate was firstly mixed with AgNO3 for coordination interaction and then ZrGP was synthesized.After that,Ag+ions were reduced to Ag NPs.The TEM results indicate that the Ag NPs with an average diameter about 3 nm were formed and dispersed on the inner board of ZrGP homogeneously in the second method.The catalytic properties of the obtained Ag@ZrGP composites were investigated by the reduction of 4-nitrophenol to 4-aminophenol as a model reaction,and the Ag@ZrGP composites showed excellent catalytic activity.More than 99%of 4-nitrophenol was reduced to 4-aminophenol within 10 min by using the products of second method as catalysts.The catalysts can keep high activity(over 95%)after it was used for seven times.2.Three new composites:Cu@ZrGP,Ni@ZrGP and Co@ZrGP were synthesized by ZrGP and metal nitrates(copper nitrate,nickel nitrate and cobalt nitrate).The research results show that the products are all amorphous lamellar and the metal ions were coordinated with organic groups in ZrGP.Cu@ZrGP has got the highest metal content among the composites.These composites were used as an adsorption material for controlling ethylene concentration in a storage system.Research results indicate a correlation between metal ions in ZrGP and ethylene adsorption capacity of the composite.Cu@ZrGP exhibited the highest activity for ethylene adsorption at room temperature(24.6 mL/g)among the products.The capacity of ethylene adsorption and the mechanism of nanocomposite in extending fruit storage life were also studied carefully.Cu@ZrGP got the best performance,which could extend the shelf life of fresh banana in a hermetic space at 30? for 13 days compared to the banana under the same conditions without the adsorbent.3.Different diameter Silica(SiO2)nanosphere coated with zirconium glyphosate was prepared,and Candida lipolytica lipase was loaded on the surface of ZrGP@SiO2 in this study.ZrGP was in situ synthesized on the surface of SiO2 and formed a "gully-like" structure.The composite was used to enhance the catalytic stability of lipase by the "gully-like" structure on the surface of SiO2.Optimal immobilization conditions were studied carefully,which included pH value of the buffer solution,immobilization time,immobilization temperature,the amount of the lipase added and the diameter of the support.Under the optimum conditions,including an enzyme dosage of 110.0 mg/g,immobilization time of 6.0 h,immobilization temperature of 38?,immobilization pH value of 7.9,and an average diameter of the original silica nanoparticle about 30 nm,an immobilization efficiency of 69.0%and an activity recovery over 71.2%were obtained based on immobilization of lipase on the support.Also a higher temperature stability(relative activity over 80%from 31 to 43?)and a wider pH value adaptation(relative activity over 80%from pH 6.9 to 8.4)of the Candida lipolytica lipase in the reaction were found after immobilization,while the stability of the free lipase is best at 21-36? and pH 7.0-8.0.Moreover,the immobilized lipase could be used at least four times(relative activity over 80%)in the olive oil hydrolysis reaction.