Polymer/surfactant interactions at the air/water interface

A promising strategy to design synthetic hydrogels with the ability to self-heal is to substitute the covalently cross-linked polymer chains by supramolecular ones. Although supramolecular hydrogels generally exhibit rapid self-healing without the need for any stimulus, they suffer from low mechanical strength which prevents them from any stress-bearing applications. Here, we describe a novel way for the production of self-healing hydrogels with shape memory behavior of high tensile strength (0.7–1.7 MPa) and stretch at break (800–900%). Hydrophobically modified poly(acrylic acid) (PAAc) chains with cetyltrimethylammonium (CTA) counterions form the physical network of such hydrogels. They were prepared via micellar copolymerization of acrylic acid with 2 mol % stearyl methacrylate (C18) as the hydrophobic comonomer in an aqueous NaBr solution of cetyltrimethylammonium bromide (CTAB). Extraction of free CTAB micelles from the physical gels results in a drastic increase in their Young’s moduli (from 8–30 to...

Self-Healing Poly(acrylic acid) Hydrogels with Shape Memory Behavior of High Mechanical Strength

Complexation of oppositely charged polyelectrolytes and surfactants in aqueous solutions. A review.

This tutorial review provides new insights into the binding interactions between anionic surfactant molecules and various macromolecules in solution. The systems are of inherent scientific interest because synergistic mixing between these two components leads to complexes commonly found in applications such as detergency, cosmetic products, rheology control, paint and pharmaceutical formulations. We describe how the basic foundations, which are prerequisite to characterize a given polymer/surfactant system are evaluated together with information on the binding mechanism and structure derived from several methodologies.

Insights on polymer surfactant complex structures during the binding of surfactants to polymers as measured by equilibrium and structural techniques

Self-assembled polyelectrolyte systems

Static and dynamic light scattering measurements have been made on poly(ethy1ene oxide) (PEO) in the presence of the ionic surfactant sodium dodecyl sulfate (SDS) in aqueous solution over a range of relative concentrations. The purpose was, in part, to demonstrate the polyelectrolyte effecte which arise in PEO on formation of the charged complex between the components in solution in which small SDS micelles are incorporated into the flexible PEO coil. The influence of the ionic strength of the medium was studied. Static light scattering measurements show that the radius of gyration changes as a function of SDS concentration and the ionic strength of the medium. Diffusion coefficients from dynamic light scattering (DLS) reflect changes in the pair interaction potential as the SDS and ionic strength are altered. Laplace inversion of the DLS time correlation function gives relaxation time distributions consisting of the PEO/SDS complex as the main component and free SDS micelles as the minor component. Changes in peak areas are related to the increase in the degree of binding between SDS and PEO as the relative concentrations change and also the increase in SDS micellar size with increase in the ionic strength of the medium.

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Poly(ethylene oxide)-sodium dodecyl sulfate interactions studied using static and dynamic light scattering

Poly(acrylic acid) (PAA) and cetyltrimethylammonium bromide (C(16)TAB) are found to interact strongly in aqueous solution. The properties of the system are determined mainly by the parameter beta, defined as [C(16)TAB]/[PAA]; the PAA concentration is expr

Poly(acrylic acid)-cetyltrimethylammonium bromide interactions studied using dynamic and static light scattering and time-resolved fluorescence quenching

Light scattering measurements (dynamic and total intensity) have been made on the complex formed between the polyelectrolyte sodium poly(styrene sulfonate) (NaPSS) and the ionic surfactant cetyltrimethylammonium bromide (CTAB). The influence on the coil conformation of the weight concentration ratio CTAB/NaPSS, of the total concentration of the formed complex, of added simple salt, and of temperature have been examined. The NaPSS coil contracts strongly with increasing CTAB concentration. It is reasoned that this is due in part to the neutralization of the polyion charge by the oppositely charged surfactant micelles and in part through adaption of the coil conformation to the micellar surface curvature

Polymer/Surfactant Interactions. Sodium Poly(styrene sulfonate) and CTAB Complex Formation. Light Scattering Measurements in Dilute Aqueous Solution

This paper describes changes in the cationic polyelectrolyte PCMA coil conformation when the anionic surfactant SDS is added in the presence of a simple salt. Four different SDS/PCMA mass concentration ratios (0.074, 0.149, 0.223, and 0.298, corresponding to 0.05, 0.10, 0.15, and 0.20 molar concentration ratios, respectively) have been examined at different NaCl concentrations. Higher ratios than the above give precipitation. When the polyelectrolyte−surfactant complex is formed, the hydrodynamic radius, Rh, is smaller than that for the pure polymer as a result of a combination of electrostatic and hydrophobic interactions. The decrease in Rh on addition of SDS to the PCMA/NaCl solutions is strong even at these low ratios. Inverse Laplace transformation (ILT) of the autocorrelation functions showed that at low salt concentrations there are two modes corresponding to the presence of aggregates (clusters) and the single-coil polymer−surfactant complex. The slow component is distinguished from the analogous ...

Poly((N,N,N-trimethylammonio)ethyl acrylate chloride salt) (PCMA)-SDS Complex Formation in Dilute Aqueous Solution. Light Scattering and Time-Resolved Fluorescence Quenching Measurements

Johan Fundin

Papers

Poly(ethylene oxide)-sodium dodecyl sulfate interactions studied using static and dynamic light scattering

Poly(acrylic acid)-cetyltrimethylammonium bromide interactions studied using dynamic and static light scattering and time-resolved fluorescence quenching

Polymer/Surfactant Interactions. Sodium Poly(styrene sulfonate) and CTAB Complex Formation. Light Scattering Measurements in Dilute Aqueous Solution

Poly((N,N,N-trimethylammonio)ethyl acrylate chloride salt) (PCMA)-SDS Complex Formation in Dilute Aqueous Solution. Light Scattering and Time-Resolved Fluorescence Quenching Measurements

Dynamical behavior of high molecular weight polystyrene in the marginal solvent 2-butanone