Preparation method of cetyl trimethyl ammonium bromide modified montmorillonite

Abstract

The invention relates to a preparation method of cetyl trimethyl ammonium bromide modified montmorillonite. According to the preparation method, sodium-based montmorillonite is taken as a raw material, the montmorillonite and water are first mixed according to a certain proportion, and after the montmorillonite is expanded by a large amount of water, a sol is formed and a Tyndall phenomenon is generated, wherein colloidal particles in the sol are all nano-sheets or nano-particles, and nanocrystallization is realized; then hexadecyl trimethyl ammonium bromide is taken as an intercalation agent,and the cetyl trimethyl ammonium bromide is intercalated into stripped nano sodium montmorillonite layers through a cation exchange reaction by mechanical stirring, so that the cetyl trimethyl ammonium bromide modified montmorillonite is obtained. According to the preparation method, the adopted raw materials are few and have low prices, operation is simple, production cost is low, performance such as mechanical strength, gas barrier property, hydrophobicity and the like of the montmorillonite are greatly improved, and the prepared organic montmorillonite can be widely used as a corrosion inhibitor in the field of corrosion prevention.

Description

[0001] (1) Technical field [0002] The invention relates to a preparation method of cetyltrimethylammonium bromide modified montmorillonite, belonging to the technical field of montmorillonite modification. [0003] (2) Background technology [0004] Montmorillonite is a layered hydrous aluminosilicate mineral, and its crystal structure is a 2:1 type layered silicic acid composed of two layers of silicon-oxygen tetrahedral platelets sandwiching a layer of aluminum-oxygen octahedral platelets. Salt, tetrahedron and octahedron are connected by common oxygen atoms to form a highly ordered quasi-two-dimensional wafer with a thickness of 0.96 nm and an aspect ratio of about 100 to 1000. They overlap at a certain distance along the c-axis direction. Its special unit cell structure makes It exhibits excellent ion exchange capacity, stability and adsorption. Si4 between its layers + , Al3 + It is easily replaced by low-priced cations, so the interlayers of montmorillonite show nega...

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Problems solved by technology

[0008] Wu Xuanjun et al. (Wu Xuanjun et al. Preparation and organic modification of Na-based montmorillonite [J]. Nonmetallic Minerals, 2008, 31(5):1-3.) first added sodium carbonate to natural bentonite and then added hexadecimal Sodium phosphate aqueous solution is used as a dispersant, and then the calcium-based montmorillonite is sodiumized and purified through a series of centrifugal operations, and then cetyltrimethylammonium bromide is used as a modifier to adjust the concentration of the solution under the action of dilute sulfuric acid. The pH value is used to modify the prepared sodium montmorillonite. Although the results show that cetyltrimethylammonium bromide has been intercalated into the montmorillonite layer, the interlayer distance is only increased by 0.69nm, and the modification effect is not significant. obvious

[0009] In addition, Yin Xuemei et al. (Preparation of organically modified montmorillonite-supported nickel catalyst and its catalytic performance of ethanol steam reforming for hydrogen production [D]. Taiyuan: Taiyuan University of Technology, 2016.) with dodecyl trimethyl bromide Ammonium chloride, cetyltrimethylammonium bromide and octadecyltrimethylammonium bromide were used as modifiers to modify montmorillonite by hydrothermal method. The chain growth and the amount of modifier increase, but the reaction time of the modification process is longer, and the modification process needs to consider the physical adsorption of ammonium salt, the influence of physical adsorption and ion exchange adsorption

[0010] CN 108756232 A Chinese patent discloses a preparation method for easily dispersible quaternary ammonium salt-modified nano-organic montmorillonite. The preparation method first uses rare earth oxides to modify the chemical structure of montmorillonite layered crystals, and then Organic quaternary ammonium salt cations are introduced into the interlayer region through ion exchange reactions, thereby obtaining organic ammonium salt-modified montmorillonite. The process of modifying the chemical structure of montmorillonite requires multi-step roasting procedures, which is relatively complicated and requires Add sulfuric acid, hydrochloric acid and other strong corrosive acids

However, if the montmorillonite structure is modified to be only rare earth ions / Si-O tetrahedron or only rare earth ions / Al-O dioctahedron, the effect of fully exfoliating and completely dispersing in the polymer matrix cannot be achieved.

[0011] CN101774598 A Chinese patent discloses a method for preparing modified clay intercalated with alkylammonium salt surfactants. The method is to prepare a suspension of clay and a mixture of alkylammonium salts dissolved in water, an organic solvent, or water and an organic solvent liquid solution, and then change the state of the alkylammonium salt surfactant by adjusting the composition of the reaction medium to obtain a modified clay. This preparation method needs to consider the physical adsorption process of the alkylammonium salt surfactant and The experimental process is more complicated

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