A general and facile chemical avenue for the controlled and extreme regulation of water wettability in air and oil wettability under water

Abstract

A chemical approach for the regulation of oil (under water) and water (in air) wettability. The super-wetting properties are highly durable at harsh physical/chemical settings.

Assessment and Interpretation of Surface Wettability Based on Sessile Droplet Contact Angle Measurement: Challenges and Opportunities

“…This indirect CA evaluation is applicable when the liquid medium is opaque or exhibits comparable refractive index. An illustrative case is the characterization of underwater CA where the droplet is typically dyed to improve visualization based on the goniometry technique …”

Selective Cooperation with Liquids for Environmentally Friendly and Comprehensive Oil–Water Separation

“…aqueous phases. [31] Here, we designedasustainable super-oil-absorbentt hrough appropriate association of a naturallya bundant fibrous substrate and "reactive"m ultilayers of NC for facile ande nvironmentally friendly removal of different forms of oil spills at practically relevant diversea nd severe conditions. This super-oil-absorbent wasf urther explored in facile, comprehensive and ecofriendly cleaning of i) light oil from air-water interface (floating oil dropleto n water) and ii)heavy sediment oil under water through selective absorption of oil.…”

“…Moreover,t he same materialw as exploitedi n separation of oil droplets from ii)oil-in-water (o/w) emulsions through both filtration and absorption process at extremes of temperature, which could be useful in removing oily contaminants from aqueous media in diverse and practically pertinent conditions. [30,31] Next, we covalently modified the multilayer-coated cotton with octadecylamine (ODA)m olecules (having long-chain hydrocarbon, ÀC 18 H 37 )b ye xploiting the residuala crylate groupst hat are present in the multilayer coating. [30] After post-chemical modification with appropriate primary amine-containing small molecules, the NC multilayersw ere capable of displaying both underwater superoleophilicity and superoleophobicity with exemplary physical durability.…”

“…[30] Then, ar apid growth of this "reactive" NC was achieved through strategic incorporation of salt, and this approachw as furthere xtended for controlled and extreme modulation of both the oil-wettability under water and waterwettability in air,r espectively. [31] Here, we designedasustainable super-oil-absorbentt hrough appropriate association of a naturallya bundant fibrous substrate and "reactive"m ultilayers of NC for facile ande nvironmentally friendly removal of different forms of oil spills at practically relevant diversea nd severe conditions. In the past, fibrous substrates have been strategically used in developing efficient materials for removing oil spills.…”

“…The appearance of the IR peak at 1409cm À1 ,w hich corresponds to the symmetric stretching of the CÀHb ondf or the b carbon of the vinyl groups, unambiguously confirmed the presence of acrylate groups in the multilayers coatingo nt he fibrousc otton. [30,31] Next, we covalently modified the multilayer-coated cotton with octadecylamine (ODA)m olecules (having long-chain hydrocarbon, ÀC 18 H 37 )b ye xploiting the residuala crylate groupst hat are present in the multilayer coating. This post-chemical modification was furthere xamined with FTIR analysis, in which the intensity of the IR peak at 1409 cm À1 was significantly depleted with respectt ot he car- bonyl stretching at 1737cm À1 (Figure S2 O), mainly owing to the mutual reactionb etween the residual acrylate groups and primary amine groups from ODA molecules.…”