Research On Series Of Cardanol Anionic-Nonionic Surfactant By Molecular Dynamics Simulation

Because of differences in the structure and nature, they each are not identical, surfactants can produce different interfacial activity that gathered on interface behavior, it will also affect the discretion of the oil-water interfacial tension. Therefore, to study the molecular level of surfactants in oil-water interface on the aggregation behavior, to understand its structure characteristics and the influence factors of interface activity have a very important theoretical guiding significance and practical application value.In this paper, a molecular dynamics method is used on regarding as a collection of microscopic particles of the classical mechanics with real environment by the application of computer technology, to obtain the performance and behavior of the material,we study the microscopic state of the accumulation of the particles by microscopic state of particles in different ensemble trajectory. This article is research on cardanol polyoxyethylene ether sulfonates（CPES） as the research object in oil-water system by molecular dynamics simulation, to have an investigation of surfactant temperature resistance\salt resistance and compare their interfacial activity when CPES has different numbers of EO, to explore the relationship between the molecular structure and performance of surfactant behavior.The results of molecular dynamics simulation shows that CPES has an excellent interfacial activity. It will gathered on the decane and water interface, it can effectively reduce the interfacial tension of oil-water interface when it is in low concentration. In a saturated state, the system of interfacial tension is only 1.83mN/m, its majoy hydrophilic group is sulfonic group. temperature is within the scope of the 318 K to 373 K, interfacial tension has a slightly fluctuate with the temperature fluctuations. It means that the temperature sensitivity of CPES is not high, it has a good temperature resistance, C7 PES with more EO has a better ability to reduce interface. CPES can keep active in higher levels with the environment of monovalent and bivalent salts. CPES is stability compared with the number of hydrogen bonds formed between the water, CPES has excellent salt resistance, the salt resistance has an order is Na⁺> Ca²⁺> Mg²⁺. The same concentration of NaCl was added to in the system with surfactants with different molecular structures, CPES reduce the interfacial tension better,when it has more EO.