Synthesis And Properties Of Diacetylpiperazine Quaternary Ammonium Gemini Surfactant

Gemini surfactants can be regarded as dimeric amphiphilic molecules connected by chemical bonds near the hydrophilic head group of traditional surfactants,and their surface activity is much higher than that of general surfactants.It has been a focus of researchers’attention since its inception.In recent years,with the increasing requirements for environmental protection,the development of new environmentally friendly and biodegradable surfactants has become a trend.Therefore,in this paper,a series of novel Gemini quaternary ammonium salt surfactants containing amide in the spacer were designed and synthesized-diacetylpiperazine quaternary ammonium salt Gemini surface activity,and their surface activity and oil displacement application were studied.The main research contents and conclusions of the paper are as follows:(1)The synthesis,characteristics and application of Gemini surfactants are summarized,and the research ideas of this topic are put forward on this basis.(2)Three types of Gemin surfactants containing amide groups were synthesized,and their molecular structures were characterized by infrared and ~1H-NMR.The results showed that the synthesized products were all target compounds with high purity.(3)The surfactant and micellization properties of Gemini surfactants were investigated by surface tension,electrical conductivity and dynamic light scattering methods.The research shows that the new diacetylpiperazine quaternary ammonium salt Gemini surfactant has excellent surface activity;increasing the length of the head group and the tail chain,the CMC of the diacetylpiperazine quaternary ammonium salt Gemini surfactant decreases,and the aggregation tendency is enhanced.Due to the increase in the rigidity of the linking chain,the surface activity of diacetylpiperazine quaternary ammonium salt Gemini surfactant is slightly lower than that of diacetylethylenediamine quaternary ammonium salt Gemini surfactant with relatively flexible linking chain,but in terms of solubility and emulsifying properties,Diacetylpiperazine quaternary ammonium salt Gemini works better.In the tested temperature range,the aggregation of 12 Gemini surfactants in aqueous solution is a spontaneous process,and the aggregate morphology is mostly vesicles.(4)The oil film displacement performance of diacetylpiperazine quaternary ammonium salt Gemini surfactant was studied through laboratory simulated oil displacement experiments.The results show that the diacetylpiperazine quaternary ammonium salt Gemini surfactant has oil displacement effect,and as the number of carbon atoms in the tail chain increases from 12 to 18,the oil displacement effect shows a trend of first increasing and then decreasing.The best effect is when the number of carbon atoms is 16.Except for the Gemini surfactant of diacetylpiperazine quaternary ammonium salt with 18 carbon atoms in the tail chain,other Gemini surface active oil displacement effects are better than those of commercially available oil displacement surfactants Petroleum sulfonate.Under the condition of the same tail chain length,the diacetylpiperazine quaternary ammonium salt Gemini surfactant with smaller head group has better oil displacement performance.