Sodium lauryl sulfate (K12) is white or light yellow powder or liquid with a slight grease smell. Easily soluble in water, it can reduce the surface tension of aqueous solutions and emulsify oils and fats. It is not sensitive to alkali and hard water, and has good compatibility with anions and non-ions. This product is flammable, irritating, and sensitizing. It is flammable when exposed to open flames and high heat. It decomposes when heated to release toxic gases.
Sodium lauryl sulfate has good emulsification, foaming, water solubility, biodegradability, alkali resistance, hard water resistance, and can be used in relatively Due to its stability in aqueous solutions with a wide pH value, ease of synthesis, and low price, it has been widely used in cosmetics, detergents, textiles, papermaking, lubrication, pharmaceuticals, building materials, chemicals, oil production and other industries. It can also be used in normal applications. Basic research on the properties of anionic surfactant compound systems, micelle catalysis, and molecularly ordered combinations.
When adding sodium lauryl sulfate in electroplating, the following aspects should be paid attention to:
Sodium lauryl sulfate is an anionic surfactant that has the ability to reduce the tension of the solution boundary, making it difficult for hydrogen bubbles to stay on the cathode surface. Therefore, it is used in ordinary nickel plating and bright nickel plating solutions. It can reduce pinholes and pitting in the coating, so it is also called anti-pinhole agent (or wetting agent).
The content of sodium lauryl sulfate in bright nickel plating solution should generally be controlled in the range of 0.05 to 0.1 g/L. When preparing the plating solution and adding it in between, attention should be paid to first using a small amount of water to make a paste, and then dissolving it in more than 100 times the amount of boiling water (it is best to boil for 10 to 15 minutes). After clarification and filtration, add the plating solution while it is hot while stirring. It is usually added after production is stopped before get off work. It cannot be added while production, and cold or undissolved sodium lauryl sulfate solution cannot be added to the plating solution, otherwise it will easily cause “orange peel” or blooming of the coating. and other phenomena.
In a high pH nickel plating solution, sodium lauryl sulfate can react with nickel ions to form insoluble compounds and precipitate, so it is consumed The quantity is larger. Even in plating solutions with low pH values, it is consumed to a certain extent. Therefore, it is best to supplement with a small amount of sodium lauryl sulfate every day. If the plating solution is treated with activated carbon, almost all sodium lauryl sulfate will be adsorbed and removed, and it needs to be added again.