Abstract: A method for extracting and isolating a lutein crystal from a vegetable oil resin containing a lutein diester, comprises: dissolving lipase into deionized water to form an enzyme solution; dissolving a lutein extract into an alcohol solvent containing the deionized water to form a uniform alcohol solution; adding the enzyme solution to the alcohol solution for performing hydrolysis, and stirring same to obtain a lutein solution; filtering and performing filtration isolation on the lutein solution to obtain a crystalline; re-dissolving the crystalline into a non-polar organic solvent, and using deionized water for washing a water-soluble impurity; recycling and cooling the organic solvent to obtain a recrystallization; and isolating and drying the recrystallization to obtain the lutein crystal. In this method, selectivity is strong, reaction time is short, no waste water is produced, process is environment-friendly and suitable for industrial production, and obtained lutein crystal is high in purity and yield.

Abstract: A compound dispersant which is composed of distilled water, a nonionic surfactant, an anionic surfactant and a wetting agent, wherein the nonionic surfactant is a Tween compound, and the wetting agent includes a hydrocarbyl sulfate salt compound and a hydrocarbyl sulfonate salt compound. The compound dispersant can block or slow down agglomeration of graphene in a dispersion solution. Also disclosed are preparation method of the compound dispersant, which is simple to operate and produces a compound dispersant that can effectively block or slow down the agglomeration of graphene in the dispersion solution, a mixed electroplating solution including the compound dispersant, in which the graphene is dispersed uniformly and stably, and a preparation method of the mixed electroplating solution, which is simple to operate, wherein graphene is distributed uniformly and stably.

Abstract: A compound dispersant which is composed of distilled water, a nonionic surfactant, an anionic surfactant and a wetting agent. The nonionic surfactant is a Tween compound, the anionic surfactant is a hydrocarbyl sulfonate salt compound, and the wetting agent is an amide compound. The compound dispersant can block or slow down agglomeration of graphene in a dispersion solution. In addition, disclosed are a preparation method of the compound dispersant, which is used for preparing the compound dispersant and is simple to operate, a mixed electroplating solution containing the compound dispersant, in which the graphene is dispersed uniformly and stably, and a preparation method of the mixed electroplating solution, in which graphene is distributed uniformly and stably.

Abstract: A compound dispersant which is composed of distilled water, a nonionic surfactant, an anionic surfactant and a wetting agent. The nonionic surfactant is a Tween compound, and the anionic surfactant is hydrocarbyl sulfate salts. The compound dispersant can block or slow down agglomeration of graphene in a dispersion solution. Also disclosed are a preparation method of the compound dispersant, which is simple to operate, a mixed electroplating solution containing the compound dispersant, in which the graphene is dispersed uniformly and stably, and a preparation method of the mixed electroplating solution, in which graphene is distributed uniformly and stably.

Abstract: A method for extracting and isolating a lutein crystal from a vegetable oil resin containing a lutein diester, comprises: dissolving lipase into deionized water to form an enzyme solution; dissolving a lutein extract into an alcohol solvent containing the deionized water to form a uniform alcohol solution; adding the enzyme solution to the alcohol solution for performing hydrolysis, and stirring same to obtain a lutein solution; filtering and performing filtration isolation on the lutein solution to obtain a crystalline; re-dissolving the crystalline into a non-polar organic solvent, and using deionized water for washing a water-soluble impurity; recycling and cooling the organic solvent to obtain a recrystallization; and isolating and drying the recrystallization to obtain the lutein crystal. In this method, selectivity is strong, reaction time is short, no waste water is produced, process is environment-friendly and suitable for industrial production, and obtained lutein crystal is high in purity and yield.