Silicon Dioxide Powder In Anti Corrosive Coating

Why does silica need to be surface modified?

Silica is the main mineral in sandstone reservoirs, and its surface wettability directly affects the storage and migration characteristics

of oil and water in pores. In order to accurately study the effects and mechanisms of different wettabilities, it is first necessary to effectively

regulate the surface wettability of silica substrates.

Due to this special physical and chemical structure, ordinary silica particles are prone to a large number of surface adsorbed water molecules,

secondary aggregation between molecules, and excessive specific surface area when forming aggregates, which affects the effect of its industrial

application. Specifically, it is manifested as follows:

(1) Hydrophilic surface

Since the surface of silica aggregates contains a large number of polar hydroxyl groups, it will have a strong adsorption effect on external water

molecules, causing a large number of water molecules to be adsorbed on its surface. During the processing of rubber products, a large number of

water molecules adsorbed on the surface of silica particles will cause bubbles and cavities in the mixed rubber when the mixed rubber is vulcanized,

thereby affecting the performance of the colloid. At the same time, the surface of rubber products is generally not polar, while the surface of silica

contains a large number of polar hydroxyl groups, resulting in poor compatibility between the two, thus affecting the reinforcing effect of silica.

(2) Poor dispersibility

The structure of silica is a chain-like aggregate. Ordinary silica produced by precipitation method is prone to secondary aggregation when forming

aggregates and the structure is not easily destroyed. Compared with silica particles prepared by gas phase method, ordinary silica particles produced

by precipitation method often cross-link into a whole when agglomerating, resulting in poor dispersibility of silica particles. When used as an industrial

reinforcing agent, poor dispersibility is not conducive to the combination of silica and reinforcing matrix, which will reduce its reinforcing effect.

(3) Excessive specific surface area

Silica particles have a small particle size and a large specific surface area. Although a large specific surface area usually promotes the rubber reinforcement

process, an excessively large specific surface area will enhance the cohesion between silica particles, making it difficult to disperse in the rubber matrix. In

addition, during the processing of rubber products, it is easy to adsorb a large amount of accelerators, delay the vulcanization time, generate excessive heat,

and burn the matrix.

Therefore, silica mostly needs to be modified before industrial application to improve its industrial application performance.

Technical Parameters:

Anticorrosion Pigments, Inkjet Receptive Coating, Matting Agent