Preparation And Enantioseperation Ability Of Cellulose-Based Organic-Inorganic Hybrid Materials

Cellulose derivatives are widely used for the preparation of chiral stationary phases for high-performance liquid chromatography due to their excellent eaantioseparation ability.Until now,Most of cellulose chiral stationary phases are prepared by coating or immobilizing chiral selectors on the surface of inorganic silica gel.The content of the polymer in the chiral stationary phase material prepared by this method usually does not exceed 20%.This feature greatly limits the development of chiral stationary phases with high-efficiency chiral separation performance.Based on this background,this topic intends to explore the preparation method of organic-inorganic hybrid chiral stationary phase materials based on cellulose derivatives.Attempts have been made to develop a series of new organic-inorganic hybrid chiral stationary phase materials with high content of cellulose derivatives,and to explore the preparation methods and main factors affecting them.Firstly,cellulose-tris(3,5-dimethylphenylcarbamate)containing a small amount of 3-(triethoxysilyl)propyl group was synthesized by microcrystallization using microcrystalline cellulose as a matrix material.Characterization and analysis of the esters by means of Fourier transform infrared spectroscopy and nuclear magnetic resonance spectroscopy.Then,a series of organic-inorganic hybrid chiral stationary phase materials with high content of cellulose derivatives were prepared by combining the derivative with tetraethyl silicate by a sol-gel reaction.The particle size,morphology and organic-inorganic content ratio of the prepared chiral stationary phase materials were characterized and analyzed by means of scanning electron microscopy and thermogravimetric analysis.Furthermore,various reaction conditions such as reaction time,surfactant type and concentration,and the type of alcohol used in the reaction process were investigated for the morphology,particle size and other properties of the prepared hybrid materials.The results indicated that the prepared organic-inorganic hybrid materials have higher polymer content and excellent chiral separation performance.The reaction conditions have a regular effect on the performance of hybrid materials.When the surfactant is selected from cetyltrimethylammonium bromide(CTAB)and the concentration is 0.05%,the reaction time is 9 h,and the preparation is carried out using n-heptanol.The microspheres achieve the best regularity and dispersibility,the particle size is 10 ?m,and the organic component content of the hybrid material can reach 29%,In addition,the novel organic-inorganic hybrid chiral stationary phase containing a small amount of 3-(triethoxysilyl)propylcellulose prepared in this paper has good chiral separation performance and can effectively separate most of the enantiomers.Among them,the resolution(1.99)of the racemate No.2(2,3-diphenylethylene oxide)is even better than that of the commercial column Chiralpak IBN.It is indicated that the prepared organic-inorganic hybrid materials may have special splitting advantages for chiral compounds of such structures.