Preparation And Antibacterial Function Of Nano-Titanium Dioxide Stabilized Pickering Emulsion

With the development of science and technology and improvement of people’sliving standard, people’s requirements become more and higher for comfort, securityand health of living conditions. The antibacterial material is a green environmentalprotection material and is worthy to promote, which nano-TiO₂powder was added instyrene-acrylic emulsion, but also has a great application prospect and was applied toantibacterial and antifouling occasions in terms of various requirements.Polymer/inorganic composite materials play small size effect, quantum size effect,quantum tunneling and surface interface effect of inorganic nanoparticles, and canendow polymeric microspheres to be functional by means of polymers as carrier.Therefore, they have potential application value in functional devices, catalyticmaterials, optical materials, and sensors. The polymer/inorganic compositemicrospheres possess the performance advantages organic and performanceadvantages of inorganic materials, and can generate new features with performanceoptimization, so microspheres have caused widespread concern. The biggestdifference of Pickering emulsions and conventional emulsion is the use of solidpowder instead of traditional surfactants. Because it avoids the toxicity and negativeeffects of the surfactant （such as blistering, affect the material properties） as well asthe self-assembly effect of unique interface particle. Many domestic and foreignresearchers have been the widespread concern of the Pickering emulsion.Inorganic/polymer composite antibacterial materials, namely Pickeringantibacterial emulsion, were prepared by Pickering emulsion polymerization takingnanometer titanium dioxide as stabilizer, and were applied to the humidity controllingcoatings in this paper. It contains the following sections:Firstly, the current development and preparation methods of polymer/inorganiccomposite microspheres were described; the antibacterial properties, principles andapplications of nano-TiO₂; the profile, factors affecting and applications of thePickering emulsion and Pickering emulsions nano-TiO₂as solid stabilizer.Secondly, the Pickering emulsion （NT-BMPkE） was prepared with nano-TiO₂dispersed in the aqueous phase as a stabilizer, and the mixture as an oil phase withbutyl acrylate （BA） and methyl methacrylate （MMA） of vinyl monomers, by the copolymerization reaction. The thermostability, structure and particle morphologywere characterized by Fourier transform infrared spectroscopy （FT-IR）, thermalgravimetric analysis （TG）, transmission electron microscopy （TEM） and scanningelectron microscopy （SEM）. Finally, the optimization process of the NT-BMPkcopolymer emulsion also was confirmed, and the formation mechanism of theNT-BMPk emulsion was put forward. The basic performance of the emulsion and filmreached to the national standard, and the emulsion had antimicrobial function.Thirdly, the epoxy-phenylalanine Pickering emulsion （NT-SBPkE） was preparedwith nano-TiO₂dispersed in the aqueous phase as a stabilizer, and the mixture as anoil phase with BA, Styrene （St） and Glycidyl Methacrylate （GMA） of vinyl monomers,by the copolymerization reaction. The thermostability, structure and particlemorphology were characterized by FT-IR, TG, TEM and SEM. Finally, theoptimization process of the NT-BMPk copolymer emulsion also was confirmed. Thebasic performance of the emulsion and film reached to the national standard, and theemulsion had antimicrobial function.Fourthly, the epoxy-phenylalanine crosslinking Pickering emulsion（NT-HSBPkE） was prepared with nano-TiO₂dispersed in the aqueous phase as astabilizer, and the mixture as an oil phase with BA, St, GMA, and HydroxyethylMethylacrylate （HEMA） of vinyl monomers, by the copolymerization reaction. Thethermostability, structure and particle morphology were characterized by FT-IR, TG,TEM and SEM. Finally, the optimization process of the NT-BMPk copolymeremulsion also was confirmed. The basic performance of the emulsion and filmreached to the national standard, and the emulsion had antimicrobial function.Finally, the three humidity controlling coatings were prepared by the threenano-TiO₂stabilized Pickering copolymers which have functional film-formingproperties and pigments and fillers, such as bentonite, diatomite, palygorskite andother clay. Firstly, the basic performance of coatings were measured, the experimentalresults demonstrated that they reached to Chinese standard about interior wall coating（GB/T9756-2009）. Secondly, the dehumidifying/humidity increasing properties wereinvestigated; the experimental results demonstrated that three humidity controllingcoatings had excellent humidity controlling property. Moreover, the obtained coatings were characterized by SEM and the humidity mechanism was suggested. Finally, theantibacterial properties of humidity controlling coatings were investigated, and hadsome antibacterial properties.Coating as a kind of important chemical material, was transforming from theprotective, decorative development to specialization, functional and intelligentdevelopment. The humidity controlling coatings is a kind of functional coatings withdehumidifying and humidity increasing characteristics. Compared to traditionalhumidity controlling materials, its biggest advantage is that it could use interior spaceeffectively, and do not take up interior space. Therefore, the humidity controllingcoatings has broad prospects of market.In short, the prepared three types of nano-TiO₂stabilized Pickering copolymeremulsions had antibacterial function, non-toxic effects for the human body due tonon-traditional emulsifier in the emulsion, and very stability the emulsion,independent of these facts which contained the pH value, salt concentration, theinfluence of temperature, and an oil phase composition. The three difunctionalcoatings with humidifying function and antibacterial function were prepared bymixing these three Pickering emulsion copolymer emulsions as film-formingmaterials with porous fillers and pigments. The coatings had environmentally friendly,energy-saving features, and are expected to apply in painting of the building interiorwall.