Hierarchical Pore Titanium Dioxide Used As HPLC Column And It's Performance

In recent years,with the development of science and technology,the requirement to the separation analysis technology is increasing.This makes ultra high performance liquid chromatography?HPLC?technology was developed rapidly.With the decrease of the chromatographic column packing size,column pressure increase obviously,which makes that how to balance the relationship between the particle size and the column pressure and efficiency become particularly important.Develop new kinds chromatographic materials becomes more and more critical for the improvement of liquid chromatography.For the titanium dioxide is not only a more wide pH stability,but also better mechanical strength and thermal stability than silica gel,this makes the titanium dioxide as chromatographic media research by more and more attention recently.There are still some problems about chromatographic medium currently.These problems are mainly that TiO₂ particle size is small,the high pressure,easy to reunite.For dealing with the above problems the following several parts work mainly done in this paper;1?Taking butyl titanate as precursor,acetonitrile and n-butyl alcohol as the solvent,titanium dioxide was synthesized by the method of hydrothermal and solvothermal method,and its size distribution at around 700 nm.And then the titanium particles were used as packing material filling in to the chromatographic column of 5 cm long and 4.6 mm in diameter.And under the condition that the n-heptane and acetonitrile as mobile phase the chromatographic column was investigated and the column efficiency and separation were tested.This method of preparation titanium dioxide as chromatographic column was simple and the titanium dioxide microsphere were uniform and had good dispersion property.2?The ammonia was used as pore-forming agent in this article.How the different concentration of ammonia affects the titanium microspheres was examined and the column efficiency was tested accordingly.The results show that with the increase of ammonia concentration,the specific surface area of titanium dioxide increased,the permeability of column was enhanced,and the pressure of chromatography dropped.While the liquid chromatographic column efficiency was down for the surface activity is reduced due to the adding of the ammonia.The TiO₂ microspheres were filled into a 5cm 4.6mm chromatographic column,and were tested in the liquid chromatography?LC-10 AD?.Benzene,toluene,naphthalene can be effectively separated under the positive phase chromatographic mode.The experiment results show that when the ammonia dosage was 0.5 ml the column pressure and efficiency were most satisfied.Titanium dioxide microspheres were dipped using concentrated sodium hydroxide solution,the results showed that the concentration of sodium hydroxide solution made the smooth surface TiO₂ spheres became rough.3?Using silica spheres as template and butyl titanate as the precursor the SiO₂/TiO₂ core-shell structure was prepared in this article.The results showed that the titanium dioxide successfully coated on the surface of silica spheres,but evenness of dioxide the decline after cladding.