Light scattering from hydrophobe-uptake spherical micelles near the critical micelle concentration

Multiple Association-Dissociation Equilibria in Solutions of Amphiphilic Molecules

Amphiphilic molecules form micelles and complexes with proteins in solutions to provide unique functions, utilized in various fields of chemistry and biology, and multiple association-dissociation equilibria, governing the micellization and complexation, are key issues in these fields. The present feature article first presents an overview of theoretical backgrounds of the multiple association-dissociation equilibria in solutions of amphiphiles and then applies the theoretical results to the following four solution systems of amphiphilic molecules to understand their micellization and complexation behavior: the reverse micelle of the polymer living anion, the hydrophobe-uptake spherical micelle, the cylindrical micelle of surfactants, and the protein-surfactant complex.

Structural Analysis of Hydrophobe-Uptake Micelle of an Amphiphilic Alternating Copolymer in Aqueous Solution

We investigated the structure of the hydrophobe-uptake micelle of an alternating amphiphilic copolymer in aqueous solutions, by combining light scattering and small-angle X-ray scattering (SAXS). When the copolymer micelle includes the hydrophobe (1-dodecanol), the unicore flower micelle transforms into the multicore flower necklace, and the flower necklace is slightly stiffer than the hydrophobe-free flower necklace of the same copolymer. Moreover, the hydrophobe is included not in the hydrophobic core region but in the intermingled region of the hydrophobic group and the loop chain of the unit flower micelle. Therefore, the structure of the hydrophobe-uptake micelle of the amphiphilic alternating copolymer is quite different from that of hydrophobe-uptake spherical micelles of low molar mass surfactants and of amphiphilic block copolymers, where the hydrophobe is included in the hydrophobic region of the micelles.

Light Scattering Strategy for the Investigation of Time-Evolving Heterogeneous Supramolecular Self-Assemblies

Supramolecular self-assembly is a multiple length-scale and time-dependent process involving many coexisting components. Such complexity requires suitable strategies to extract quantitative dynamical and structural information on all involved species. Here, we detail an original light scattering method to study the kinetics of tailored triarylamine molecules capable of self-assembling in supramolecular highly conductive nanowires upon light exposure. These micrometric assemblies cause the emergence of intermittences in the scattered intensity and the construction of a predominant slow mode in the correlation function making separation between small-and large-size species impossible using conventional treatments. Our strategy is based on the time monitoring of intermittences and allows us to determine the fraction of nanowires as well as those of small critical nuclei and triarylamine building blocks as a function of time and light exposure, in good agreement with recent theoretical predictions.