Effect of 1-octanol on the stabilization of crude oil emulsions with hydrophobically modified polyacrylamide

The formation of a stable crude oil emulsion is of great significance for enhancing oil recovery in oilfield development. The effect of 1-octanol (C8OH) on the emulsifying properties of hydrophobically modified polyacrylamide (HMP) was studied based on a novel multiple light scattering method. The emulsions stabilized by different polymer systems were evaluated in terms of stability and rheological properties. The obtained results show that the combined system of HMP + C8OH gives more stable emulsion with smaller droplet size compared to individual HMP. There is a strong bulk and interface interaction between HMP and C8OH for stabilizing emulsions, while such effect was observed neither between partially hydrolyzed polyacrylamide and 1-octanol nor between HMP and 1-octane. In the bulk phase of aqueous solution, the C8OH can be solubilized in the micro-domains of HMP, enhancing the intermolecular association structure and slowing down the creaming rate of the corresponding emulsions. The adsorption at the oil-water interface of HMP can be enhanced and tighter interfacial film can be formed due to the formation of the hydrogen bond between HMP and C8OH. The obtained results are of obvious importance for designing the amphiphilic polymer-containing emulsion more suitable to improve oil recovery as well as for better understanding the self-assembling mechanism of amphiphilic polymers and fatty alcohols.