Synthesis And Properties Of Aryl Oleic Acid Surfactants

The better interfacial properties of the aryl alkyl sulfonates make them potential candidates for a wide variety of surfactant applications in Enhanced Oil Recovery. This kind of surfactants differing from existing products by having the sulfonate group attached to the alkyl chain rather than the ring have been produced in our laboratory. Alpha-olefin used as the raw material is expensive with price of the crude oil increasing. So, aryl oleic acid surfactants have been synthesized by the oleic acid as the raw material that has the similar structure to a-olefin and an abundance of source in our country. The relationship of their interfacial properties and structures would be found in order to enhance their further applications.Aryl alkyl sulfonates were synthesized, the following works have also been done in this paper.1) Fluorescent surfactant was designed and synthesized and its surface properties and fluorescent properties were also determined.2) Nonionic aryl oleic acid surfactants were designed, synthesized and their surface tensions were obtained. The results show these surfactants have weak solubility and would better be used as surfactant assisters.3) Anionic aryl oleic acid surfactants were designed, synthesized and their surface tensions were also determined. The results show that the introduction of aromatic ring in the alkyl chain increases the size of the hydrophobic group and decreases the capability of surfactant in reducing water surface tension. One series of surfactant solutions exhibit good interfacial properties when they interacted with crude oil (Daqing), and their minimal interfacial tensions below the ultra-low value (10^-2mN/m) are in the optimum range of alkaline concentrations.4) Unsymmetrical bolaamphiphile surfactants were also designed, synthesized and their interfacial properties were determined. The surface tension measurements of these surfactants indicate the low limiting surface tension (about 20 mN/m) and the existence of two discontinuities, referred to as the 'first CMC and the second CMC, similar to the conventional bolaamphiphiles in the weak alkaline solutions. The variation of the low limiting surface tension with pH is explained by the different states of carboxyl group at different pH. Moreover, besides the layer structure of crystal provide by the XRD results, TEM measurements also present another symmetrically regular arrangement.The results would provide opportunities for their further industrialization due to their good washing and solubilization capacity.5) A model of minimal interfacial tension was built and integral of the model would be used as the estimation of the capability of surfactant in reducing the interfacial tension of solution/crude oil systems. This would play rather important and valuable role in solving the practical problems in the choice of surfactants for Enhanced Oil Recovery.