Application Of Surface Active Agents Effect In Preparation Of Zirconium Dioxide Hollow Microspheres By Template-free Method

In recent years, the research on nanometer materials have become one ofthe most important and the fastest developing areas. Especially, all kinds ofspecial material preparation and properties study are domestic and foreignmaterials scientists’ concern. As a new function material, hollow microspheresexhibit high surface area, low densities, surface permeability and inclusion withguest molecules in hollow part. Owing to these features, they have foundextensive application in many high-tech fields including filling materialsbiomedicine and catalyst carrier, etc. Therefore, it is important to study on thesynthesis and application of hollow microsphere materials with nanostructure.Zirconium dioxide (ZrO2), which is an excellent structural functionmaterial, has attracted increasing attention because of its uniquephysicochemical properties in the wide applications of machinery,chemicalindustry, insulated materials and thermal curtain coating, etc. Moreover, ZrO2has a great many of advantages on the organic synthesis as a catalyst, which hasa large number of strong Lewis acid and bases sites on the zirconia surface. Sofar, hollow ZrO2microspheres are usually synthesized by sacrificial templatesmethod. Although the principle of sacrificial templates process is very simple, itgenerally involves the removal of the templates, and faces disadvantages relatedto requiring organic solvent or high temperatures, resulting in the complicationof preparation, cracking of microsphere shell and limit of their application. Thelaboratory predecessors had successfully used template-free synthesis to prepare zirconium dioxide hollow microspheres by alcohothermal method. Comparedwith other methods, the present synthetic procedure has the advantages ofsimplicity, efficiency and more homogeneous particle size distribution. Butaccording to the test results, the hollow microspheres prepared by this methodare different from the general methods. Samples of the surface area are smaller,adsorption is worse, so in filling materials and other aspects of the applicationwill be limited.In view of the above mentioned, refer to the surfactants modified thenanomaterials/hollow microspheres’ surface, combined with the preliminarywork, we investigate the influence on the zirconia hollow microspheres’ surfacedue to all sorts of surfactants. Based on the experimental results and thephenomenon analysis, we draw the most ideal surfactant.This thesis still uses theoriginal preparation process.The prepared sample has more homogeneousparticle size distribution.The most important is its high specific surface area andadsorption performance.The main works and conclusions of this thesis aresummarized as follows:A solution containing absolute ethanol, glacial acetic acid and All kinds ofsurface active agent was stirred heavily.After that, Zr(OC4H9n)4was addedslowly.Used alcohothermal method prepare zirconium oxide.High resolutionFESEM image reveals the shell structure of zirconium oxide.1. Introduce the template-free route for the synthesis of hollow ZrO2microspheres via alcohothermal technique. The prepared sample has more homogeneous particle size distribution, but the surface adsorption is poor, soneed to modify the surface.2. Adding the surface active agent is an anionic surfactant, adjust the type,quantity, concentration.SEM image show that the sample added anionicsurfactant is not ideal,Particles more, microspheres reunion and small specificsurface area.Added anionic surfactant did not have a good effect in the samplesurface.3. Add cationic surface active agent--sixteen alkyl three methyl ammoniumbromide CTAB. Adjusting the addition amount, observe and analysis,theprepared zirconia sample ’s morphology, crystallization degree and its specificsurface area.Through the characterizations,the zirconia sample’s diameter is reducedand its particulated zirconia is gradually increased. The zirconia balls joined0.05g CTAB are uniform, its surface is smooth and its nanoparticles are less.Thezirconia samples are calcined by high temperature and its specific surface areaincreases sightly.Evidence show that CTAB plays a certain role on themicrospheres.4. The zirconium oxide hollow microsphere prepared added non-ionicsurface active agent via alcohothermal technique are different.Therefore,different surfactants play different roles.So, discuss the zirconium oxide samplewith different non-ionic surface active agent.Polyvinyl alcohol--PVA, the sample consists mostly of nanoparticles and microspheres with little apparent holes.Styrene, not impact the zirconia microspheres obvious.Polyethylene glycol PEG2000, to form rod-like micelles in the process ofpreparation and play the template function.It joins against zirconia hollowmicrospheres formation.Polyethylene glycol PEG1000, zirconium oxide samples are micro sphereand its diameter is unchanged. The sample after calcined crystallize steadily.With the amount of polyethylene glycol PEG1000increased, the crystallizationchanges from square opposite to monoclinic phase. Through measure thesample’s surface area, the sample joined7ml PEG1000solution is great. Itsmorphology, crystallization degree and adsorption capacity are optimal.