Surfactants have the ability to strongly adsorb on the surface of particles

2022-12-21 11:01:17

Surfactant has the ability to strongly adsorb on the surface of particles, adding in the processing of pesticide formulations helps to disperse and suspend the particles, and ensure the re-dispersion when adding water to dilute in the spray barrel to prevent the aggregation of particles. When an ionic surfactant is selected, it adsorbs on the particle surface, providing electrical repulsion to keep the particles separated from each other i.e. providing particle charge stabilization; when a nonionic surfactant is selected, the lipophilic part of the surfactant adsorbs on the particles and the hydrophilic part extends into the aqueous phase around the particles, forming a spatial barrier i.e. providing spatial site resistance stabilization.

These help prevent the aggregation of pesticide particles during dosage form processing and storage. Commonly used dispersants in pesticides are lignin sulfonates, naphthalene sulfonate methacrylate condensates, polyoxyethylene alkyl phenols and EO/PO block copolymers and comb-type graft copolymers. 

Certain nonionic emulsifiers are the main surfactants used in the cosmetic industry. As emulsifiers for formulating skin care emulsions, alkyl glycosides must have good compatibility and mating properties. In order to take into account the requirements of safety, viscosity, drainage, etc., the polyether-modified polysiloxane containing silicone surfactants are commonly used emulsifiers in the formulation of silicone oil emulsions alkyl phosphate, amino acid-based surfactants, fatty acid ester derivatives of methyl glycoside and sucrose ester alkyl glycoside polyglycerol ester fatty acids are also commonly used emulsifiers.

In the cosmetic industry, solubilizers are mainly used in the production of make-up, hair growth oils, hair growth and hair care agents, and other products. Since the oily components in cosmetics are different in structure and polarity, their solubilization mechanisms are different. Non-ionic surfactants such as polyoxyethylene hardened castor oil, polyoxyethylene castor oil, polyoxyethylene sorbitol, polyglycerol fatty acid esters, and amphoteric derivatives of castor oil base can achieve good solubilization effects.

When the solubilizing object of cosmetic water is fragrance, alkyl polyoxyethylene ether should be used to solubilize. Other surfactants used as solubilizers are required to have high hydrophilicity. In addition, the solubilizer should be non-irritating to eyes and skin.

The phenomenon that causes non-water-soluble substances to form particles in water and be uniformly dispersed is called dispersion. Most of the surfactants used as dispersants are also emulsifiers, such as fatty alcohol polyoxyethylene ethers, which have good dispersing properties. In addition, amphoteric surfactants are widely used in cosmetics manufacturing for their good detergency, biodegradability, mildness, low toxicity and low irritation, etc., and play a good dispersing role.  

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