2015年1月28日星期三

Performance and structure of molecular sieve

Performance: zeolite powdery crystals with metallic luster, hardness of 3 to 5, the relative density of 2 to 2.8, color natural zeolite, synthetic zeolite adsorbentobtained as a white, water-insoluble, heat stability and acid resistance as SiO2 / Al2O3 composition ratio increases and improved. Molecular sieves have a great specific surface area, up to 300 ~ 1000m2 / g, the inner surface of the crystal highly polarized, as a class of highly efficient adsorbents, also a type of solid acid, the surface has a high acid concentration and acid strength, can cause carbonium catalytic ionic reactions. When the composition of the metal ions and other ions in solution were exchanged, adjustable aperture, changes its absorption properties and catalytic properties, which molecular sieve catalyst prepared with different properties.
Structure: proteoglycan thus formed polymer tortuous coiled, forming a sieve-like microporous structure, known as molecular sieves. Microporous molecular sieve which only allows material through is less than, greater than the pores of macromolecular substances, bacteria and the like having a barrier function is. The matrix becomes the limiting diffusion of harmful substances such as bacteria defensive barrier. Hemolytic streptococcus and cancer cells can produce hyaluronidase, the decomposition of proteoglycan, destruction of the matrix structure, to be spread. On binding proteoglycan aggregate also many hydrophilic groups, capable of binding water molecules, forming extracellular "reservoirs."

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