Preparation And Properties Of Chitosan/Attapulgite Composite Resin

Chitosan is prepared by chitin taking off the acetyl. Chitosan has a wideapplication due to its rich resources and excellent performances, such as food,medicine, textile, water treatment, and so on. Resently, the focus of research aboutchitosan are chemical modification or composite with other materials so that we canget various chitosan derivatives or composite materials with different properties andapplications. The composites of chitosan and inorganic materials has aroused theinterests of researchers, as it not only overcome the deficiencies of chitosan,but alsohave the advantages of both materials. These materials also have a broad applicationprospect.In this paper, the crosslinked chitosan/attapulgite resins with tannic acid astemplate molecules (TA-CS/ATP) were prepared by template synthesis. Themorphology and structure of resins were characterized by FT-IR, SEM, and TG andthe performance of resins was evaluated by pore parameters. The effects of pH andtemplate molecules amount on the adsorption of resins were investigated. The elutionof the template molecules was chosen according to elution rate, while the capacity ofresin regeneration was researched. The adsorption kinetic experimental data werefitted using the pseudo first-order, the pseudo second-order and the intraparticlediffusion model. The results revealed that the saturation adsorption capacity ofTA-CS/ATP was445.7mg/g, when the pH was8and CS:TA (w/w)was1:0.5. Theremoval rate of the template molecules could be more than90%using0.1mol/LNaOH.TA-CS/ATP also showed a good reusability, the saturation adsorption capacity couldreach to355.5mg/g after four times reuse. The study of adsorption kinetics showedthat the sorption processes were better fitted by pseudo-second-order model.The paper also prepared chitosan/attapulgite resins by curing using NaOH thencrosslinking using glutaraldehyde. The morphology and structure of resins werecharacterized by FT-IR, and TG. The adsorption capacity and release performance ofthe resins which were prepared using chitosan and different kind of modified ATPwere discussed with Aspirin as a model drug. The effects of the glutaraldehyde on theadsorption capacity and release performance of resins were studied, and drug releasecurve of the best resin was fitted by dynamic models. The results showed that amongthree kinds of resin, the adsorption and drug release capacities of CS/O-ATP were thebest one. Its drug loading and encapsulation efficiency were12.2%and39.88%respectively and also the slow-release effect was good, when the glutaraldehyde was6ml.The drug release process of CS/O-ATP were better fitted by Higuchi equation, suggested that the resin could be a long-term drug control-released system.