Interaction between Gelatin and Anionic Surfactants

Abstract

The effects of alkyl chain length of homologous alkyl sulfate surfactants ranging from C8 to C14 on the diffusion behavior of both the surfactant and gelatin have been investigated by pulsed-gradient spin-echo NMR spectroscopy. Changes in the diffusivity of the surfactant can be rationalized in terms of a two-state model consisting of gelatin-bound micelles in equilibrium with freely diffusing unimeric surfactant. A minimum in the diffusivity of gelatin is observed when the binding of surfactant amounts to about 1 micelle/strand. The depth of this minimum increases with the chain length of the surfactant. These effects are explained in terms of micelle-mediated transient cross-links as proposed by Greener et al. (Macromolecules 1987, 20, 2490). The effective strength of the cross-links is a decreasing function of the number of micelles/strand because of the electrostatic repulsion between the micelles; the strength increases with an increase in the size of the micelles.

Physicochemistry of hexadecylammonium bromide and its methyl and ethanolic head group analogues in buffered aqueous and gelatin solution

“…Gelatin also forms coacervates with oppositely charged surfactants, and to this end, studies have been mainly made with anionic surfactants. [21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39][40] Interaction of gelatin with polyanions like sodium polystyrenesulfonate (NaPSS) or sodium poly(2-acrylamido-2-methylpropanesulfonate) 41 or mixed micelles of SDS and a sugar-based non-ionic surfactant 42 have been found to depend on the critical mole fraction, charge density, and chain length of the surfactants. But reports on the interaction of gelatin with non-ionic surfactants 43 or with cationic surfactants of varied types have been strikingly limited.…”

Probing interactions within complex colloidal systems using PGSE‐NMR

“…17), an effect that increases with increasing alkyl chain length. 34 The gelatin self-diffusion coefficient decreases to a local minimum and then rises to a plateau before finally decreasing again at higher surfactant concentrations. Similar profiles are exhibited in the viscosity behaviour.…”

“…At this point, CMC(2), free micelles form in solution. 34 The isotherm is monotonic-the bound micelles are charged, so binding of a second or subsequent micelle to the same polymer molecule must overcome the electrostatic repulsion introduced, hence Figure 16. Binding isotherm for SDS and 2.5 wt% poly(vinyl pyrollidone-vinyl acetate) (PVPVA) calculated from the self-diffusion coefficients presented in Fig.…”

“…Based on the stoichiometries extracted from the NMR analyses, it is possible to show that there is a correlation between the surface area of the micelle and the depth of the diffusion minimum. 34 Similarly, the inclusion of a second surfactant that does not interact with the gelatin-a non-ionic surfactant such as the sugar-based dodecyl malono-bis-Nmethylglucamide-can be used to alter the fraction of the micelle surface to which the gelatin will adsorb, without changing the micelle size and shape by SANS. In essence, 'patches' on the micelle surface are rendered non-adsorbing owing to the sugar headgroups.…”

Aggregation Properties of Sodium Hyaluronate with Alkanediyl-α,ω-bis(dimethylalkylammonium Bromide) Surfactants in Aqueous Sodium Chloride Solution

“…Some studies focus on interactions between anionic surfactant and polyelectrolytes with variable hydrophobicity (24,25) and between anionic surfactants and hydrophobically modified anionic polyelectrolytes as well (26). Other works are devoted to polypeptide-anionic surfactant interactions (27,28) and protein-anionic surfactant interactions (29).…”