Insight into the Interaction Between Carbopol^® 940 and Ionic/Nonionic Surfactant

Abstract

Mixtures of a cross-linked polyacrylic acid (Carbopol Ò 940) and two types of surfactants, namely anionic sodium dodecylsulfate (SDS) and nonionic Tween Ò 80, were investigated by viscometry, conductometry, tensiometry, spectrophotometry, fluorimetry and scanning electron microscopy (SEM). The addition of nonionic surfactant decreased the reduced viscosity and the transmittance of the Carbopol Ò polymer aqueous solutions. Furthermore, the interaction between Carbopol Ò 940 and SDS was characterized by two significant concentration values: the critical aggregation concentration of SDS was particularly independent of Carbopol Ò polymer concentration while the polymer saturation point of both surfactants increased with the increase in polymer content. The values of critical aggregation concentration and polymer saturation point obtained using various techniques confirmed the occurrence of Carbopol Ò polymer-surfactant associations. The effect of different SDS and Tween Ò 80 concentrations on the conformation of Carbopol Ò 940 in aqueous solution could be explained through hydrophobic association between surfactant micelles and Carbopol Ò polymer tails and through hydrogen bonding in the case of Tween Ò 80. Additionally, the surfactant-induced structural changes were confirmed in Carbopol Ò 940-SDS and Carbopol Ò 940-Tween Ò 80 aqueous solutions by SEM measurements.

Self-Assembly of the Bio-Surfactant Aescin in Solution: A Small-Angle X-ray Scattering and Fluorescence Study

“…A similar behavior was also observed for different surfactants like sodium dodecyl sulfate (SDS) and cationic lysosomotropic substances [53][54][55]. In all cases, the increase in the surface tension above the cmc was assigned to impurities of the surfactants, whereby a substance with a higher surface activity compared to the surfactant investigated might be present [55]. Because the aescin powder used in this study has a purity of 95 %, presence of impurities is possible.…”

Influence of Hydrophilic Polymers on theβFactor in Weibull Equation Applied to the Release Kinetics of a Biologically Active Complex ofAesculus hippocastanum

“…PA1 and PA2 were used in hydrophilic gels in preparations P2 and P4, respectively. Polyacrylic acid derivatives are anionic polymers, which have the ability to create complexes with cationic residues of other compounds [22]. The bulky structural form of PA1 and PA2, as a net of polyalkene polyether, may immure the EH components and interrupt the active compounds diffusion [23].…”

Impact of surfactant addition on non-Newtonian fluid behavior during viscous fingering in Hele-Shaw cell

“…Various studies have characterized the physical nature of water soluble polymers -surfactant systems and several factors influence the interactions between surfactant and polymers such as the addition of electrolyte, the type of surfactant chain and structure, polymer molecular weight and concentration, surfactant and polymer adsorption, intermolecular interactions, colloidal stability, micellization effects and the respective rheological behaviors of polymers and surfactants in solution [23][24][25][26][27][28] . The viscosity of hydrophilic polymers is thus found to be very sensitive to surfactant concentration [29][30][31][32] .…”