Wetting of TX-100 and Igepal CO-630 Surfactants on a PTFE Surface

Abstract

Nonionic surfactants are advantageous in a diversified range of applications from household cleaners, laundry detergents, and shampoo to paints, coatings, and food emulsifiers because of their low CMC and surface tension values over the ionic surfactants. Nonionic surfactants, in general, are very useful in mixed surfactant systems because of their electrical neutrality. Among the similar class of nonionic surfactants, structural difference is important in the performance. In this study, we report on the adsorption and wetting behavior of two nonionic surfactants (TX-100 and Igepal CO-630) having the same head group but structurally different tail groups. The kinetics of adsorption follows a pseudo-second-order kinetic model and a Langmuir-type isotherm for both the surfactants. The change in contact angle with the concentration of surfactant follows a trend similar to that for adsorption onto a PTFE surface. At low surfactant concentration, Igepal CO-630 shows a slightly higher adsorption density and better wetting properties than TX-100. Both surfactants show lower adsorption densities at the PTFEÀwater interface than at the airÀwater interface.

Wettability alteration by novel betaines at polymer–aqueous solution interfaces

“…The variations of the contact angle values with the increasing concentration of 18C and 18S are presented in Figure 2 for PTFE and PMMA surfaces. Figure 2a clearly depicts that the dependency of contact angle with the logarithm of concentrations on the PTFE surface are different from other researchers' conclusions[12,18,19,31] : for 18C and 18S, the contact angle keep almost a constant value in a wide range of surfactant concentration even more than CMC of individual surfactant solution.Above 1×10 -4 mol/L, the contact angles of both 18C and 18S show rapid downward trend and the values of 18C are significantly lower than that of 18S. However, for the conventional surfactants, there is a decrease in contact angle with the increase in surfactant concentration until CMC of surfactant solution and above that it is almost constant.…”

“…If the surface excess on the solid-air interface is assumed to be PTFE-liquid interface are less than that on air-liquid interface for both 18C and 18S. This phenomenon is different from the conventional surfactants [10,14,19] , such as SDS, CTAB, TX-100, whose slopes of It is worth noting that the adhesional tension values of PMMA decrease step by step to a certain minimum with the decrease of surface tension and then increases at a constant minimal surface tension value, which indicates that the adsorption behaviors of 18C and 18S at PMMA surface are different from that at PTFE surface. Based on the literature [8,34] , one can find that the -CO, -OCH 3 and-CH 3 groups are present at the PMMA surface, and in the Lewis approach, they give the basic character to this surface.…”

Interfacial and wetting behavior of natural–synthetic mixed surfactant systems

“…The contact angle (q) values at CMC and CVC for different mixing ratios that of the air-water interface for the pure surfactants, but the % reduction depends on the type of surfactant 41. 42 A comparison of surface excess values can be made if the plot of adhesion tension (g LG cos q) vs. surface tension follows a linear relationship…”

The wetting behavior of three different types of aqueous surfactant solutions on housefly (Musca domestica) surfaces

“…Equation applies to smooth solid surfaces, the slopes of γ LV cosθ versus γ LV on a smooth PTFE surface change little and have a value of around −1 regardless of the type of surfactant molecule adsorbed at the interface (e.g. TX‐100, SDS and DTAB) . This suggests that the adsorption of surfactant molecules at liquid–air and liquid–solid interfaces is almost the same, thus the surfactants adsorbed on the PTFE surface form a monomolecular adsorption layer …”