Experimental evaluation of cationic-Schiff base surfactants based on 5-chloromethyl salicylaldehyde for improving crude oil recovery and bactericide

In this study, a new family of cationic and cationic-Schiff Base surfactant was synthesized namely; N-(3-formyl-4-hydroxybenzyl)-N, N-dimethylhexadecan-1-aminium chloride (FHDHAC), (E)-N-(3-((butylimino)methyl)-4-hydroxybenzyl)-N,N-dimethylhexadecan-1-aminium chloride (4-IMHDAC), (E)-N-(3-((hexylimino)methyl)-4-hydroxybenzyl)-N,N-dimethylhexadecan-1-aminium chloride (6-IMHDAC) and (E)-N-(4-hydroxy-3-((octylimino) methyl)benzyl)-N,N-dimethylhexadecan-1-aminium chloride (8-IMHDAC) were prepared from 5-chloromethyl salicylaldehyde compound (5-CMS). The chemical structures of 5-CMS, 4-IMHDAC, 6-IMHDAC, and 8-IMHDAC arc characterized using FTIR, H-1 NMR instruments. The surface activity measurements of the prepared compounds showed a gradual inaease in surface activity by increasing the alkyl chain length. Adsorption and micellization thermodynamic functions revealed the higher tendencies of the different surfactants towards adsorption at the organic/polar phase. The synthesized surfactants were evaluated in the enhanced oil recovery process and showed excellent efficiency (63.98%, 71.25%, and 75.72% for 4-IMHDAC, 6-IMHDAC, and 8-IMHDAC, respectively) during the recovery process near their critical micelle concentrations. The prepared surfactants showed high antimicrobial efficacy against different bacteria and fungi. (C) 2020 Elsevier B.V. All rights reserved.