Influence of a Neutral Polymer (PVP) on the Solvatochromic Properties of SDS Micelles

Abstract

In the present work, we have studied the influence of a water-soluble neutral polymer (poly-N-vinyl pyrrolidin-2-one, PVP) on the Kamlet-Taft polarity parameters of sodium n-dodecyl sulfate (SDS) micelles. We have used pyrene as an independent dipolarity/polarizability (pi parameter) descriptor molecule. It has been found that the addition of polymer (0.1 wt % PVP) increases the pi value of SDS micelles, suggesting that PVP-SDS aggregates have a larger dipolarity/polarizability than that of SDS micelles. Linear solvation energy relationships involving the fluorescence transition energy of four structurally similar ketocyanine dyes have also been used to evaluate the polarity parameters. It is interesting to observe that the addition of polymer leads to a decrease in both the hydrogen-bond donation (alpha-parameter) and hydrogen-bond acceptance ability (beta-parameter) of the micellar aggregate formed by PVP-SDS, whereas the dipolarity/polarizability value shows an increasing trend. Moreover, convergent results have been obtained for the pi value for PVP-SDS aggregates, using pyrene as a pi descriptor and ketocyanine dyes as molecular probes.

Surfactant-Mediated Desorption of Polymer from the Nanoparticle Interface

“…Solution interactions between SDS and PVP have been observed in many contexts; ,− Goddard has reviewed the interactions between many water-soluble uncharged polymers and charged surfactants. Rheological analysis showed that the viscosity of aqueous PVP solution increases to a value expected for typical polyelectrolytes upon binding ionic surfactants .…”

Manipulating Interfacial Polymer Structures through Mixed Surfactant Adsorption and Complexation

“…10,12−24 Ion-dipole interaction between the micelles and the polymer is one of the molecular mechanisms that has been suggested for this phenomenon. [18][19][20][21]25 Ternary systems comprising one polymer and two surfactants have been recently studied. 25−30 Most of the studies involved a neutral polymer, an anionic surfactant, and a nonionic surfactant.…”

Self-assembly of NH2-(α,l-lysine)5-COOH and SDS into nanodiscs or nanoribbons regulated by pH

“…16 The cmc of SDS in the presence of NH 2 -(a,L-lysine) 5 -COOH at pH 5.0 is slightly decreased to about 7.8 mM most likely because NH 2 -(a,L-lysine) 5 -COOH is a small molecule as compared to reported polymers with a much larger molecular weight. 16,17 In contrast, the cmc of SDS in the presence of NH 2 -(a,L-lysine) 5 -COOH at pH 11.0 markedly dropped to 4.0 mM, a value 2-fold lower than that of SDS alone (Fig. S3, ESI †).…”