Synthesis And Properties Of Head Hydroxyl Type Gemini Surfactants

The current ternary compound flooding has a lot of negative problems in the process of oil due to the presence of a large number of alkali,therefore if there is no coordination of alkali,efficient surfactants are particularly important.And Gemini surfactants can overcome these harsh and complex conditions,therefore,it is very important to study the synthesis and performance of the novel Gemini surfactants.1,4-Butanediyl-N,N'-bis(dodecyle hydroxyethyl methyl ammonium bromide)(DHMABn)surfactants were synthesized via intermediate products N,N-bis(hydroxyethyl tertiary amine)(HAn)by using diethanolamine in this paper.The molecular structures of the DHMABn were characterized by IR and 1H NMR.And the surface/interface properties,foam properties,emulsifying properties and wetting properties were investigated.Then,the experiment was carried out on the core simulation of Yumen oil and mineralized water to study DHMABn effect on oil recovery.The main experiment results are listed as follows:1.The DHMABn series surfactants were synthesized by using raw materials diethanolamine,long chain bromoalkane and 1,4-dibromobutane.The synthesis conditions of products were optimized by using single-factor and orthogonal experiment method.The molecular structures of the HAn and DHMABn were characterized by IR and 1H NMR.2.The cmc values of DHMAB12,DHMAB14 and DHMAB16 were 0.5mmol/L,0.069mmol/L,and 0.032mmol/L,respectively.The ?cmc were 30.9mN/m,27.4mN/m,and 26.8mN/m,respectively.For both of these products,the cmc and ?cmc of DHMABn decrease with the increase of hydrophobic chain length.3.In the range of salt concentration,the introduction of inorganic salts will enhance the surface activity of DHMABn,and the effect of CaCl2 on surface activity is more obvious than that of NaCl.4.Study on the foam property,emulsion property and wettability of DHMABn.5.The ability of DHMABn to reduce the oil-water interfacial tension was investigated.The results show that DHMAB12 can reduce the Yumen oil oil-water interfacial tension to the low interfacial tension of 10-4mN/m.The static saturated adsorption capacity of DHMAB12 is 2.9 mg/g when the fixed water sand ratio is 15:1.6.Using DHMAB12 and AES(twelve alkyl alcohol polyoxyethylene ether sodium sulfate)for the core flooding experiment.The results show that DHMAB12 enhances oil recovery of increment is 17.89%;compared with the common AES to improve the recovery rate was 5.13%higher.