Study On The Phase Behavior Of Sodium Lauroyl Glutamate

Surfactant is an indispensable chemical product,which is widely used in various fields,especially in fields that are directly related to people’s daily life,such as cosmetics,medicines,food,etc.The demand for surfactants is in the process of industrial modernization.China continues to increase.Surfactants not only make great contributions to people’s production and life,but also cause serious environmental problems due to the discharge of waste water and slag into the water body and soil after use.Therefore,in recent years,the "green" which is easily degraded and has low toxicity The development and application of surfactants have attracted more and more attention.Amino acid-based surfactants not only have good degradability,antibacterial properties,and safety,but also because of its special structure,it has many excellent properties such as good water solubility,strong salt resistance,and broad application prospects.At present,the research on amino acid surfactants is mainly focused on application performance,and there are few research reports on the direct relationship between its interface properties and its phase behavior.This subject investigated the interfacial properties and phase behavior of sodium lauroyl glutamate,and also studied the interfacial properties and phase behavior of the composite system of sorbitan monolaurate(Span-20)and sodium lauroyl glutamate.The interfacial properties and phase behavior of the compound system of dodecyl trimethyl ammonium chloride(DTAC)and sodium lauroyl glutamate were paid attention to.The theoretical understanding obtained from the experiment has guiding significance for the application of the amino acid surfactant sodium lauroyl glutamate in the daily chemical and industrial fields.This paper is mainly divided into 3 parts:The first part discusses the change of the molecular structure of sodium lauroyl glutamate(SLG)with pH by measuring surface tension,titration curve,combined with ultraviolet-visible spectrophotometer and calculation of the limit adsorption capacity,and confirms the follow-up The experimental conditions for phase behavior research,and the relationship between interface properties and phase behavior is analyzed.The experimental results show that the hydrophilic head group of the sodium molecule has a large cross-sectional area,and it is difficult to change its critical accumulation parameters by adding inorganic salts,which is the key reason why it is difficult to thicken it.The second part investigated the interfacial properties and phase behavior of sodium lauroyl glutamate(SLG)and nonionic surfactant sorbitan monolaurate(Span-20).The experimental results show that the hydrophilic group has no direct interaction force at the interface between Span-20 and SLG and the formation of micelles;however,when Span-20 with high CPP value is added to the system and forms mixed micelles,it still makes The increase of the overall CPP value of the system indicates that the phase state of SLG in the solution can be effectively controlled by the appropriate compounding of other types of surfactants.The third part discusses the interfacial properties and phase behavior of sodium lauroyl glutamate(SLG)and dodecyl trimethyl ammonium chloride(DTAC)after compounding.The research results show that DTAC and SLG have a good synergistic effect.The hydrophilic groups of DTAC and SLG directly have a certain electrostatic attraction.The Krafft point of the compound surfactant system formed by the existence of this force is greatly reduced.And the viscosity of the SLG/DTAC system compounded in a certain proportion at low concentration can be effectively controlled.