Surfactant-free Microemulsion With Ester As Oil Phase And Its Application In The Preparation Of Nanomaterials

The thesis consists of four parts.The first part is Introduction.The second part is the structure,micropolarity of dimethyl carbonate/1,2-propanediol/water SFME and its application in preparation of mesoporous silica nanomaterials（MSNs）.The third part is the phase behavior and properties of a surfactant-free microemulsion containing ethyl acetate/propan-2-ol/water.The last part is preparation of nano-TiO₂ by surfactant-free microemulsion-hydrothermal method and its photocatalytic activity.Ⅰ IntroductionThe definition,microstructures,properties and characterization method of SFME were introduced.The construction and characterization of surfactant free microemulsion and its application in enzyme catalysis,chemical reaction and preparation of nanomaterials were reviewed.ⅡThephasebehavior,micropolarityofDMC/1,2-propanediol/water SFME and its application in preparation of MSNs.A new type surfactant-free microemulsion system consists of dimethyl carbonate/1,2-propanediol/water was first constructed.1.The single-phase region of the microemulsion is divided into three types of microstructuresbyelectricalconductivitymethod,thatis,dimethyl carbonate-in-water（O/W）,bicontinuous（B.C.）and water-in-dimethyl carbonate（W/O）.UV-Vis spectroscopy and surface tension method were also used to examine the microstructures of the SFME system.2.The solubizization of the O/W microemulsion for oil soluble Sudan Ⅲ（SRⅢ）was investigated by UV-Vis spectroscopy.At 25℃,when the oil content is 25%,the maximum saturated solubility of SR Ⅲ in O/W SFMEs was determined to be 84mg/L.3.The mesoporous silica nanospheres（MSNs）was synthesized using the O/W SFMEs as a template.The effects of different templates（O/W and W/O）,microemulsion composition,etching time and volume of ammonia on the morphology and size of the MSNs were investigated.The average diamaters of the MSNs increased with increasing oil content.Ⅲ The phase behavior and properties of a surfactant-free microemulsion containing ethyl acetate/propan-2-ol/waterA new type surfactant-free microemulsion system consists of ethyl acetate/propan-2-ol/water was constructed.1.The single-phase region of the microemulsion system is divided into three types of microemulsions,namely,O/W,B.C.and W/O.2.The micro-polarity of the system was studied by UV-Vis spectroscopy using methyl orange as a probe.The curve of the maximum absorption wavelength of MO(λ_max)with oil content（f_o）can be divided into three stages.The three stages are assigned to the three types of microemulsions,respectively,and are consistent with those measured by conductance method.3.The solubilization properties of the W/O microemulsion for inorganic salts and biochemical reagent riboflavin were investigated by UV-Vis spectroscopy.It is found that the W/O microemulsion has good solubilization ability for K₃Fe（CN）₆,CoCl₂ and riboflavin.The UV-Vis adsorption curves are all consistent with Lambrt-Beer law.This is similar to the traditional W/O microemulsion.ⅣPreparationofnano-TiO₂bysurfactant-free microemulsion-hydrothermal method and its photocatalytic activityEthyl acetate/propan-2-ol/water SFME was used as a template to synthesize TiO₂nanoparticles.The effects of the SFME composition and hydrothermal temperature on the crystallinity,crystalline size,surface area of the synthesized TiO₂ nanoparticles were investigated.1.Anatase-type titanium dioxide nanoparticles with IV isotherms and H2hysteresis loops were synthesized using O/W SFME as a template.the BET specific surface area of the synthesized nanoparticles increased with the decrease of oil content（f_O）of the SFME.2.With the increase in hydrothermal temperature,the crystallinity of titanium dioxide nanoparticles increases.Therefore,the photocatalytic activity of titanium dioxide nanoparticles increases significantly.The photocatalytic activity of nano-titanium dioxide prepared at 190℃is higher than that of Degusset P-25.3.The nanoparticles with high photocatalytic activity were successfully prepared at lower hydrothermal temperatures（below 200℃）.