Construction And Characterization Of Environmental Responsive Composite Microcapsules Based On Montmorillonite

There are lots of species in the clay minerals,which montmorillonite has been the focus of many researchers.Montmorillonite is a layered silicate clay mineral with natural nanometer properties.In this paper,natural montmorillonite from the Chifeng in inner Mongolia was used as the basic research object.The organic modification of natural montmorillonite was performed with siloxane.With organic modified montmorillonite as raw materials and Pickering emulsion method,we prepared hollow PLA/OMMT composite microcapsules and investigated their adsorption properties for organic dyes.We prepared CHL-BSA@PLA/OMMT composite microcapsules and investigated their photocatalytic properties against organic dyes.We prepared lipase/PEG1000@OMMT composite microcapsules and investigated their catalytic properties of lipase under environmental temperature changes.Based on the analysis of experimental data and phenomena,the following conclusion are drawn.(1)Firstly,we modified montmorillonite with three different types of surfactants including Cationic surfactants CTAB,Span60,and then combined with organosilane.Through the above method,we successfully synthesized of modified montmorillonite loading silane,with the purpose to investigate the influence of different surfactants on the silanization of montmorillonite.These results found that cationic surfactant CTAB increased the spacing between montmorillonite layers,and more organosiloxane was laoded on the montmorillonite.The average contact angles of CTAB-MT-APTES and CTAB-MT-PTES showed significant hydrophobic and oily activity,indicating that more siloxane entered the interlayer of montmorillonite and produces interlayer locking effect.In the experiment,we concluded that the charge properties of surfactants had a significant effect on the organosilicylation of montmorillonite,and investigated on the load,interlayer structure and surface hydrophilicity of the silane.(2)By solution intercalation,PLA/OMMT composite was prepared successfully.The experimental results showed that the modified 0.5wt% OMMT with 5wt% PLA intercalation layer was of significant effect.Through the Pickering emulsion method,we successfully obtained the hollow PLA/OMMT microcapsules.PLA/OMMT microcapsules are spherical in shape with smooth surface,almost no microcapsules are broken,with good integrity but some microcapsules are shrunk.The microcapsules could maintain a complete morphology and appearance,which indicated that the surface boundary membrane of the microcapsules had certain strength and could resist changes in the external environment.Through controlling the microcapsule wall material concentration and reaction of p H solution environment,we concluded that adsorption curve of hollow PLA/OMMT microcapsules on organic dyes conformed to the first-order kinetics equation,and showed the selective adsorption of methylene blue best.(3)Inspired by the photosynthesis of primitive single-celled organisms,we constructed primitive biomimetic inorganic clay cells with photocatalytic activity.In this experiment,a photocatalytic active PLA/OMMT composite microcapsules were prepared by Pickering emulsion method.The CHL-BSA@PLA/OMMT photocatalytic activity composite microcapsules successfully simulated the photosynthetic system behavior of primitive biological cells.On the basis of a large number of previous studies,we have explained in detail the electron transfer mechanism of photocatalytic degradation of dyes in the above process according to the excellent literature of predecessors.Meanwhile,CHL-BSA@PLA/OMMT photocatalytic composite microcapsules were used for photocatalytic degradation of organic dyes.According to the experiment phenomenon,we could find that these are photocatalytic activity of the microcapsule could efficient rapid processing of organic dye.(4)In this experiment,lipase and PEG1000 were first used as the core material,the modified montmorillonite solution was used as the wall material,and the core material was successfully encapsulated inside the modified montmorillonite.The purpose of this step was to make the surface interface of the composite microcapsules had a certain strength,so as to maintain the appearance of the microcapsules.The optical microscope showed that the size of the composite microcapsules was uniform,and the original morphology of the composite microcapsules remained after cleaning.In order to better understand the preparation of lipase/PEG1000@OMMT composite microcapsules enzyme catalysis properties under high temperature,the results showed that compared with the other composite microcapsule content of PEG1000 including1:2 lipase/PEG1000@OMMT composite microcapsules were uniform distribution,and showed the enzyme catalytic activity at high temperature effect was best.