Shedding Light on the Role of Short-Chain Alcohols in Amphiphilic Polymer Assembly: Implications for Oil and Gas Recovery Operations.

Abstract

In this work, we investigated the supramolecular organization of self-assembled poly(LMA-co-PEGMA) structures in aqueous solution in the presence of short-chain alcohols, focusing on their compartmentalization between molecular aggregates and the bulk aqueous phase, as well as their implications for polymer-based methods in enhanced oil recovery. Polymers were synthesized using reversible addition-fragmentation chain transfer polymerization and characterized by nuclear magnetic resonance and size exclusion chromatography coupled with multi-angle light scattering and differential refractive index detectors. Dynamic light scattering revealed differences in the supramolecular organization of self-assembled aggregates in the presence of short-chain alcohols, reflected by changes in the aggregation number and critical aggregation concentrations. Additionally, fluorescence-based experiments were carried out to characterize compartment properties within the aggregates─such as polarity and microviscosity─and the influence of spatial organization and conformation. Moreover, we used nuclear Overhauser effect spectroscopy and inversion recovery experiments to gain deeper insight into monomer-alcohol and copolymer-alcohol interaction and dynamics. Finally, oil transfer experiments reflected the effect of short-chain alcohols on the solubilization process. The obtained results allowed us to propose a cooperative mechanism that explained the aggregation behavior observed for different alcohols and its effects on oil solubility, a key factor considering applications related to enhanced oil recovery.