Understanding of possible molecular interactions at liquid-liquid and solid-liquid interfaces can shed lights onto the nature's design and authorise fine manipulation aptitude in biological, manufacturing, microfluidic and oil recovery applications. Of particular interest is the capability to control the aggregation of organic and biological macromolecules, which typically poses significant challenges for oil industry and human life, respectively. Following asphaltene aggregation phenomenon through π-stacking and hydrogen bonding interactions, asphaltene aggregates can form a thin layer at the crude oil-brine interface through noncovalent interactions such as -O-H···O hydrogen bonds and/or alter the wettability state of the solid surface from initially water-wet into mixed-oil wetting. Here, we probe the impact of water with variety of salinities and ion types on formation of water in oil micro-emulsions, asphaltene deposition, and induced water wettability transition at micro scale. For the first time we investigate the influence of water in oil micro-emulsions on asphaltene aggregation and deposition phenomena at elevated pressure and temperature conditions. We also monitor the micro-wettability alterations of gold surface of the QCM owing to ion valency/concentration changes using state of the art ESEM imaging facility. Our results depict that owing to the substitution of divalent cations with monovalent ones, asphaltene deposition is repelled and the solid surface becomes more hydrophilic, proposing a generalizable strategy to control wettability and an elucidation for the profitability of so-called low salinity water flooding, an enhanced oil recovery methodology. For the biological applications, this study provides insights into the potential roles of ions and hydrogen bonds in the protein deposition in tissues and self-assembly interactions and efficiency of drugs against protein aggregation drivers.
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