Effect of surfactant concentration on the responsiveness of a thermoresponsive copolymer/surfactant mixture with potential application on “Smart” foams formulations

Abstract

The Cop-L/DTAB mixtures were capable of producing thermoresponsive foams but only in a very narrow surfactant concentration (c) range, 0.3 < c< 1.6 mM. The responsiveness is due to a modification of the interfacial compression elasticity induced by conformational changes of the Polyeletrolyte/surfactant aggregates at the interface. This is possible only for c < 1.6 because higher surfactant concentrations induce the polymer collapse at all temperatures, eliminating the thermal responsiveness.

Interaction of Low Molecular Weight Poly(diallyldimethylammonium chloride) and Sodium Dodecyl Sulfate in Low Surfactant–Polyelectrolyte Ratio, Salt-Free Solutions

“…Accompanying such phase separation, is the formation of nanostructures with different morphologies and organisation, including soluble complexes, precipitates, gels and liquid crystalline phases [ 5,6 ]. Complex coacervation is further complicated by the presence of interfaces [ [7][8][9][10], but the continued focus on studying coacervation is driven by its relevance to many and diverse applications of formulated, nanostructured systems [ [11][12][13][14][15][16][17].…”

Hydroxypropyl cellulose as a green polymer for thermo-responsive aqueous foams

“…Thermo-responsive foams and particularly foam films from poly( N -isopropylacrylamide) (PNIPAm) solutions have been studied extensively in the past 12,23–25. Depending on the molecular weight, PNIPAm has a lower critical solution temperature (LCST) of ∼32 °C 26,27.…”

“…For that reason, foams from PNIPAm and SDS mixtures have been investigated, which show an improved stability but have lost their responsiveness to temperature 23. Lencina et al 12 reported stable foams from mixtures of alginate- g -PNIPAm graft copolymer and DTAB, with half-life times up to one hour and thermo-responsive properties in a narrow range of surfactant concentrations.…”

The aqueous Triton X-100 – dodecyltrimethylammonium bromidemicellar mixed system. Experimental results and thermodynamic analysis

“…These complex surfactant mixtures allow to formulate systems with designed properties, for instance, mixtures of a cationic surfactant with a thermorsponsive anionic polyeletrolyte was used for stabilizing liquid foams whose stability responds to an external stimuli [7]. In the case of detergent formulations, mixtures of ionic and nonionic surfactants are frequently used.…”