Inorganic/organic modification of bentonite

⑤Inorganic/Organic Modification Because the spacing of pillared bentonite prepared by polymerized hydroxy metal cations as a pillaring agent is still not large enough, some surfactants can be introduced between the bentonite layers to synthesize inorganic/organic pillars with larger pore diameters.
Supporting bentonite can significantly improve its thermal stability
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The selected surfactants are generally soluble quaternary ammonium salts with different molecular sizes.

Ren Li takes polypyridine as the key research object.
According to the current situation, he adopts organic/inorganic nanocomposite system to introduce nano-inorganic particles of silicon dioxide (SiO ₂ ) and layered clay (Clay) into intrinsically conductive polypyridine.
Polypyridine/ silica (PPy/SiO ₂ ) and polypyridine/clay (PPy/Clay) nanocomposites were prepared based on the polymerization method
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The nano-effect not only improves the mechanical properties of the material, but also overcomes the disadvantages of the general method that the electrical properties are reduced due to the improvement of the mechanical properties

Method 1: Fe-Ni organic composite bentonite
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Take a certain mass of iron-nickel cross-linked soil to prepare a suspension with a mass fraction of 2%, and add 5.

Method 2: Al/hexadecyltrimethylammonium bromide composite bentonite
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Add a certain amount of cetyltrimethylammonium bromide to the AICl ₃ solution under the condition of a water bath at 60°C , stir for 10 minutes to prepare a composite modifier, then add bentonite that has passed through a 100-mesh sieve, and stir for 60 minutes.

⑥ Thermal activation The thermal activation method is to roast the bentonite at different temperatures.
Through volatilization and combustion, the molecular water and organic matter on the surface and structural layers of the montmorillonite are evaporated, and the clay mineral structure becomes loose
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At the same time, as the temperature increases, part of the hydroxyl groups of the clay minerals are lost, the number of exposed broken bonds increases, and the specific surface area of ​​the minerals increases, resulting in an increase in the activity of bentonite

⑦Mechanical activation Mechanical activation is a process of using mechanical force to improve certain activities and properties of bentonite, including ultrafine pulverization and extrusion
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Ultrafine pulverization is the use of mechanical force to purposefully activate the mineral surface during the crushing process of bentonite, which changes the crystal structure, solubility, chemical adsorption and reactivity of the bentonite mineral to a certain extent
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In the process of ultra-fine pulverization of bentonite by a ball mill, the bentonite is broken by mechanical force between the sphere and the sphere or between the sphere and the cylinder.

The squeezing effect is mainly reflected in the sodiumization process of calcium-based bentonite.
Because calcium-based bentonite is not easily soluble in water, it is often suspended in water in the form of crystal aggregates.
After the surface of the particles is sodiumized, a water barrier film will be formed, which prevents Sodiumization of calcium-based bentonite inside the granules is advanced, and the squeezing action can promote the perfection of the sodiumization process
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Extrusion sodiumization especially plays a decisive role in the upgrading process of low-grade bentonite.

①The peeling sheet is under the action of large shearing force, the particles and the crystal layer produce relative movement and separation, which accelerates the speed of ion movement and increases the contact area of ​​bentonite and Na+

②Temperature action generates a lot of heat due to squeeze friction, which further accelerates the speed of ion movement, expands the range of ion movement, and increases the speed of the sodiumization reaction

③ Bond breaking is under the action of large mechanical force, some of the chemical bonds inside the montmorillonite structure are destroyed, which is conducive to the adsorption of the oppositely charged Na+ and also helps the sodiumization reaction to proceed
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