Micron Spherical Silica Gel Powder for Cosmetics Additive and Column Chromatography
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Column chromatography silica gel powder, all you want to know is here


Overview of silica gel powder for column chromatography




White granular macroporous silica gel, insoluble in water and organic solvents. Absorbing moisture in the air can separate and purify various substances due to the difference in adsorption and retention time of different substances.


Crush the coarse porous silica gel to 40~200 meshes, and make it by screening, soaking in hydrochloric acid, washing with water, and drying (water content ≤ 5%). It is used for refining petroleum products (removing aromatic substances and other organic substances), selective adsorption and separation of liquids, and manufacturing catalysts and chromatographic carriers; It is also a simple, rapid and sensitive analytical reagent in the column layer analysis of pharmaceuticals, pesticides, dyes, rubber, etc.



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Introduction to the basic characteristics of silica gel powder for column chromatography


The silica gel powder of column chromatography is separated according to the different adsorption capacity of the material on the silica gel. Generally, substances with large polarity are easy to be adsorbed by silica gel, while substances with weak polarity are not easy to be adsorbed by silica gel. The whole chromatographic process is the process of adsorption, desorption, re adsorption and re desorption.


Silica gel powder by column chromatography is a colloidal system with solid characteristics, which is composed of colloidal particles forming agglutination structure. Colloidal particles are condensation polymers of hydrated silica gel (polysilicic acid), which are amorphous substances. The gap of colloidal particle aggregates forms the micro pore structure inside the silica gel particles for reagent column chromatography. Therefore, silica gel for column chromatography is a high-quality adsorption material with rich microporous structure, high specific surface area, high purity and high activity.



The microstructure of silica gel powder by column chromatography is not very different from that of general silica gel. SiO2, which forms the colloidal skeleton, is bound by silicon oxide tetrahedron, and the force field between atoms is balanced. Silica gel has a very high specific surface area. The surface structure of the pores inside the silica gel particles is different from the internal structure of the skeleton formed. The silicon atoms on the surface and the structural water contained in the colloid form a silanol group. The imbalance of this structure causes a free force field on the surface of silica gel, that is, it has the ability to adsorb water molecules or other polar molecules. The adsorbed substances are different due to the strength of molecular polarity, The adsorption capacity of colloidal particles on their surfaces varies in varying degrees


For this reason, the adsorption of silica gel on mixtures of different substances is selective. When the material component with strong molecular polarity passes through the silica gel surface, the adsorption force with the silica gel is also strong, and the retention time of the material component on the silica gel surface is long; On the contrary, the components with weaker molecular polarity have shorter retention time. Therefore, the mixture of different substances is separated due to the difference of retention time during the process of passing through silica gel. For substances with strong molecular polarity, silica gel has strong adsorption capacity, such as water molecules.


In this case, only when the adsorbed material molecules obtain enough energy can they overcome the potential barrier of the gravitational field generated on the surface of silica gel powder by column chromatography and leave the silica gel surface. In this way, under normal conditions, when the mixture containing strong polar substances passes through the silica gel column layer, the strong polar substances are retained in the pores of the silica gel, thus showing the ability of silica gel to dehydrate and refine or purify substances.


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Application of silica gel powder in column chromatography


The silica gel powder of column chromatography has outstanding advantages in the separation and purification of effective ingredients of Chinese herbal medicine, the preparation of high-purity substances, the refining of petroleum products, the dehydration and purification of organic substances, and the application of column chromatography silica gel in bioengineering technology.


During the production of raw materials, the acid bubble and aging time are strictly controlled, and the high-temperature calcination technology is adopted, so the column chromatography silica gel has a rigid framework structure, high mechanical strength, and can withstand the pressure within 30MPa.


Column chromatography silica gel has good thermal stability and chemical stability, and selectively adsorbs and purifies isomer components from multi-component solutions. In the process of preparing silica gel for column chromatography, a series of products with an average pore diameter of 20A ° - 2000A ° can be produced by controlling different process conditions to adapt to the separation and purification of substances with different properties, molecular weights and molecular structures.



The purity of silica gel for column chromatography is more than 99%. Compared with the organic column filler, silica gel is a solid colloid with SiO2 as the matrix, which has a compact structure. In application, organic matter will not be lost and the target product will not be polluted.