Adsorption of Pure Nonionic Alkylethoxylated Surfactants down to Low Concentrations at a Silica/Water Interface as Determined Using a HPLC Technique

Adsorption and heterocoagulation of nonionic surfactants and latex particles on cement hydrates

“…The vanishing or negligible adsorption of ethoxylated on ionic surfactants on cement hydrates is in contrast with earlier results obtained with silica surfaces [21,[31][32][33][34][35][36][37], but it is in agreement with recent work in which no adsorption of TX10 could be detected on ordinary Portland cement [38]. In contrast, on silica under neutral pH conditions, TX100, TX405, and the other surfactants of the same family adsorb readily and reversibly and form dense surface assemblies.…”

Polydispersity of a Non-ionic Surfactant as Related to Its Adsorption Characteristics on Porous Silica Particles in Water

“…The same series of curves were obtained for the decyl, the tetrade- cyl, and the hexadecyl carbon chains (not shown). One observes the main features which are well recognized now for pure non-ionic surfactants: sigmoidal type curves are obtained for the shorter ethoxychains and Langmuir type isotherms as the polar chain gets longer (16). These isotherms correspond to three surfactant concentration domains: isolated molecules at very low concentration, followed by the formation of micellarlike aggregates (the so-called second adsorption mechanism) at higher concentration, and finally saturation of the particles corresponding to the coalescence of the surface aggregates and consequently to the appearance of the adsorption plateau.…”

“…This conclusion may be deduced from the observation that for these molecules, a Langmuir-type isotherm involving few, if any, surfactant/surfactant interactions could describe these profiles. The same types of curves were obtained and interpreted previously on Aerosil 200 particles including the crossing of the isotherms corresponding to the longer and the shorter oligomers at a given equilibrium concentration as the result of the interplay between the primary and the secondary adsorption mechanisms (12,16). In order to be in a better position to compare the adsorption capabilities of the nonporous Aerosil 200 and the porous Sorbsil C30, the discussion will be focused first on the overall adsorption isotherms on both silicas and then on some of the most important oligomers present in formulation C. Figure 2 compares the overall isotherms.…”

Adsorption of Ethoxylated Nonionic Surfactants From Siloxane-Based Solvent and Aqueous Systems: Use of QCM and Model Polymeric Surfaces

“…Most of these applications involve adsorption of the surfactants from their solutions onto various interfaces. Studies have been conducted to understand the adsorption behavior of the surfactants at various interfaces in aqueous environment (Blom et al, 2005;Brinck et al, 1999;Cai et al, 2003;Caruso et al, 1995;Desbene et al, 1997;Geffroy et al, 2000;Gilchrist et al, 2000;Grant et al, 2000;Kharitonova et al, 2005;Kjellin et al, 2002;Kumar and Tilton, 2004;Lindheimer et al, 1990;Portet et al, 1996;Somasundaran et al, 1991;Tahani et al, 1996;Thirtle et al, 1997;Torn et al, 2005). Parameters governing the adsorption behavior include morphology and chemistry of solid surface, functional groups involved, solute-solvent interactions, intermolecular forces between adsorbed molecules, pH, and temperature.…”