Adsorption of Triton X-100 and cetyltrimethylammonium bromide mixture with ethanol at nylon-6–solution interface with regard to nylon-6 wettability: I. The effect of adsorption on critical surface tension of nylon-6 wetting

Abstract

The contact angle measurements of the aqueous solutions of p-(1,1,3,3-tetramethylbutyl)phenoxypoly(ethylene glycol) (TX-100) and cetyltrimethylammonium bromide (CTAB) mixture with ethanol on nylon-6 were made in the range of the total concentration of CTAB and TX-100 mixture from 1 9 10 -6 to 1 9 10 -3 M and ethanol from 0 to 17.13 M. In the CTAB and TX-100 mixture the mole fraction of TX-100 was equal to 0; 0.2; 0.4; 0.6; 0.8 and 1. On the basis of the obtained results, the critical surface tension of nylon-6 wetting was determined from the dependence of cosine of contact angle and the adhesion tension as a function of the surface tension of the solution. This tension was compared to the components and parameters of nylon-6 surface tension taken from literature and discussed in the light of the surface excess concentration of the surface active agents at the nylon-6-solution interface calculated from the Lucassen-Reynders equation and the Gibbs isotherm.

Adsorption of Triton X-100 and cetyltrimethylammonium bromide mixture with ethanol at nylon-6–solution interface with regard to nylon-6 wettability: II. Work of adhesion and activity of surfactants at interfaces

“…In the previous paper (Bielawska et al 2013), the wettability of nylon-6 by the aqueous solutions of TX-100 and CTAB mixture with ethanol was considered. It was deduced that the critical surface tension of nylon-6 wetting (c C ) (Bielawska et al 2013) is considerably lower than its surface tension and even the Lifshitz-van der Waals component of this tension (Szymczyk et al 2012) and depends on the way of its evaluation.…”

“…It was deduced that the critical surface tension of nylon-6 wetting (c C ) (Bielawska et al 2013) is considerably lower than its surface tension and even the Lifshitz-van der Waals component of this tension (Szymczyk et al 2012) and depends on the way of its evaluation. If c C is determined at the constant concentration of the TX-100 and CTAB mixture, it practically has a constant value in the whole range of the concentration and composition of the surfactant mixture.…”

“…This suggestion was confirmed by the calculations of the Gibbs surface excess concentration of ethanol at the nylon-6-solution and nylon-6-air interfaces as well as the comparison of the ratio between the difference of the surface excess concentration of ethanol at the nylon-6-air and nylon-6-solution interfaces to that at the solution-air one to the slope of the linear dependence between the adhesion tension and the surface tension of the aqueous solutions of the TX-100 and CTAB mixture with ethanol (Bielawska et al 2013).…”

“…The slope of the c LV cos h À c LV plot for nylon-6 depends on the composition and concentration of the TX-100 and CTAB mixture (Bielawska et al 2013). This indicates that there should be a direct correlation between the activity of surfactants and ethanol adsorbed at the solution-air and nylon-6-solution interfaces, the interaction parameter across the nylon-6-solution interface, the critical surface tension of nylon-6 wetting and the work of adhesion of the aqueous solution of the surfactant mixture with ethanol to the nylon-6 surface.…”

“…For this study, the data from the measurements of the contact angle and the surface tension of the aqueous solutions of the TX-100 and CTAB mixture with ethanol were applied (Bielawska et al 2012(Bielawska et al , 2013.…”