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Rheological auxiliaries of vapor silica

Rheological property is an essential property of coatings, which directly affects the appearance, construction performance and storage stability of layers, and different coating systems have additional requirements for rheological additives. For the oily system, most rheological additives work by forming hydrogen bonds. The gas-phase white carbon black aggregates without surface treatment contain multiple hydroxyl groups, and one is an isolated and undisturbed free hydroxyl group. The second is linked, forming hydrogen bonds with each other bonded hydroxyl groups. The secret hydroxyl group accounted for 12 ~ 15% of the surface groups of the gas phase silica, and the hydrogen-bonded hydroxyl group accounted for 28 ~ 35%. Hydrogen bonding hydroxyl group is easy to form a uniform three-dimensional network structure in the oily system; this three-dimensional network structure (hydrogen bond) will be damaged by mechanical influence (shear force), and viscosity decreases, so the coating to restore good fluidity; When the shear force is removed, the three-dimensional structure (hydrogen bond) will recover on its own, and the viscosity will rise. In completely non-polar liquids, the viscosity recovery time is only a fraction of a second. In polar liquids, the recovery time is longer, depending on the concentration and dispersion of silica in the gaseous phase. This characteristic gives oily paint excellent storage and construction performance; incredibly thick slurry-type paint (such as ship paint) can ensure the colour has a good flow under a specific construction shear force and the thickness of the coating once constructed. If you are looking for high quality, high purity and cost-effective Fumed silica, or if you require the latest price of Fumed silica, please feel free to email contact mis-asia.

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