The Modification Of Layered Material Magadiite And Its Application In Adsorption,Drug Carrier And Nacre-like Membrane

The layered material magadiite(MAG)was focused by material researchers for its characteristics including unique layered structure,autonomously controling layered structure,excellent ion exchange ability,adsorption capacity and so on.In order to expand the multiple functional applications of MAG,the modification was carried out,and the products would be studied in the fields of organic pollution adsorption,drug carriers and nacre-like membranes,which had an important research significance and practical value.The sodium carboxymethylcellulose,chitosan(CS),silane coupling agent(KH550),polyethylene glycol and polyvinyl alcohol were chosen as the organic modifiers for MAG.The products of MAG first directly modified by the above five organic modifiers respectively were discussed.As well as the products of MAG compoundly modified by cetyl trimethyl ammonium bromide(CTAB)or hexadecyl triphenyl phosphorus bromide and the above five organic modifiers respectively were studied.Besides,all the products were characterized by XRD and TG.The results showed that all the five kinds of organic modifiers could not be inserted into the layers of MAG.However,the five kinds of organic modifiers were sucessfully inserted into the layers of MAG after pillared compound modification with CTAB.When the dosage of organic modifier was less than 40% of the quality of MAG,the modified effect increased with the increasing dosages of organic modifier.The reactive balanced time was 6 hours,and the effect influenced little by the temperature.The MAG and MAG-CTAB-KH550 were chosen as the adsorbents of methylene blue(MB)and phenol.Three experimental projects were carried out to investigate the adsorption properties and mechanisms,including single-component adsorption,two-component simultaneously competitive adsorption and pre-loaded competitive adsorption.The results showed,the adsorption capacity of MAG-CTAB-KH550 was larger than MAG,and the adsorption capacity of MB was larger than phenol.In the single-component adsorption experiments,the unit adsorption capacity was increased with the increasing solution pH value,adsorption time and the initial concentration of the MB or phenol,but decreased with the increasing adsorbent dose and solution temperature.In the two-component simultaneously competitive adsorption experiments,the adsorption capacity and adsorbent force of phenol reduced with the increasing concentration of MB,and vice versa.And the effect of MB from the concentration of phenol was larger than the effect of phenol influenced by the concentration of MB.In the pre-loaded competitive adsorption experiments,while pre-loaded the MB,the adsorption capacity of phenol decreased comparing to the two-component simultaneous competitive adsorption because of the holes-plugged mechanism.While pre-loaded the phenol,the adsorption capacity of MB decreased more severely than phenol,because the little size of phenol were easier pre-empting the adsorption sites of adsorbents than MB.The effects of adsorption capacity on the MAG were more apparent than MAG-CTAB-KH550.The three kinds of drug carrier composite materials were prepared,called MAG/5-FU,MAG-CTAB/5-FU and MAG-CTAB-CS/5-FU,and their release behaviors under simulated gastric juice and intestinal juice were studied.The results showed that the oganic MAGs had higher drug loading capacities and drug using efficiencies than the pure MAG.5-FU and these carrier materials banded together and 5-FU reached a higher thermal stability,characterized by XRD,FT-IR,SEM,TEM and TG-DTG.All these three drug carrier composite materials had a slow-releasing effect,and the release mechanism was the synergistic result of the force ruptured and the barrier effects from the layered mesoporous structure.But the releasing power and capacities under acidic gastric juice were greater than alkaline intestinal juice.The CS/MAG and CS/KH550/MAG nacre-like nano hybrid membranes were successfully prepared via the solvent evaporation sediment self-assembly method.The structure and performances of mechanics,thermal stability,transparency and flame retardancy were discussed through the characterization of the XRD,SEM,FT-IR,TG,UV-vis and mechanical testing.The results showed that the unique "interpenetrating petals" layered structure played a significant role in increasing the performances of mechanics,thermal stability and flame retardancy in CS membranes.The CS/KH550/MAG hybrid membranes had higher performances of mechanics,thermal stability,transparency and flame retardancy than CS/MAG hybrid membranes,because it could improve the interfaced properties between the MAG and CS while adding the KH550.