The Additive Influence of Propane-1,2-Diol on SDS Micellar Structure and Properties

Micellar systems are colloids with significant properties for pharmaceutical and food applications. They can be used to formulate thermodynamically stable mixtures to solubilize hydrophobic food-related substances. Furthermore, micellar formation is a complex process in which a variety of intermolecular interactions determine the course of formation and most important are the hydrophobic and hydrophilic interactions between surfactant–solvent and solvent–solvent. Glycols are organic compounds that belong to the group of alcohols. Among them, propane-1,2-diol (PG) is a substance commonly used as a food additive or ingredient in many cosmetic and hygiene products. The nature of the additive influences the micellar structure and properties of sodium dodecyl sulfate (SDS). When increasing the mass fraction of propane-1,2-diol in binary mixtures, the c.m.c. values decrease because propane-1,2-diol is a polar solvent, which gives it the ability to form hydrogen bonds, decreasing the cohesivity of water and reducing the dielectric constant of the aqueous phase. The values of ΔGm0 are negative in all mixed solvents according to the reduction in solvophobic interactions and increase in electrostatic interaction. With the rising concentration of cosolvent, the equilibrium between cosolvent in bulk solution and in the formed micelles is on the side of micelles, leading to the formation of micelles at a lower concentration with a small change in micellar size. According to the 1H NMR, with the addition of propylene glycol, there is a slight shift of SDS peaks towards lower ppm regions in comparison to the D2O peak. The shift is more evident with the increase in the amount of added propane-1,2-diol in comparison to the NMR spectra of pure SDS. Addition of propane-1,2-diol causes the upfield shift of the protons associated with hydrophilic groups, causing the shielding effect. This signifies that the alcohol is linked with the polar head groups of SDS due to its proximity to the SDS molecules.

Structure and Location of Protein Sites Binding Self-Associated Congo Red Molecules with Intercalated Drugs as Compact Ligands—Theoretical Studies

In the search for new carriers capable of transporting toxic drugs to a target, particular attention has been devoted to supramolecular systems with a ribbon-like micellar structure of which Congo red is an example. A special promise of the possible use of such systems for directing drugs to a target emerges from their particular affinity to immune complexes and as an independent property, binding many organic compounds including drugs by intercalation. Serum albumin also appeared able to bind micellar particles of such systems. It may protect them against dilution in transport. The mathematical tool, which relies on analysis of the distribution of polarity and hydrophobicity in protein molecules (fuzzy oil drop model), has been used to find the location of binding area in albumin as well as anchorage site for Congo red in heated IgG light chain used as a model presenting immunoglobulin-like structures. Results confirm the suggested formerly binding site of Congo red in V domain of IgG light chain and indicated the cleft between pseudo-symmetric domains of albumin as the area of attachment for the dye.

Bioinorganic Membrane Using Kurumi, A New Liquid Crystal

The work characterizes develop a single layer bioinorganic membrane using nano-molecule Kurumi C13H20BeLi2SeSi / C13H19BeLi2SeSi, is well characterize computationally. As its scientific name 3-lithio-3-(6-{3-selena-8-beryllatricyclo [3.2.1.02,⁴] oct-6-en-2-yl}hexyl)-1-sila-2-lithacyclopropane. The work was based on a molecular dynamics (MD) of 1ns, using the CHARMM22 force field, with step 0.001 ps. Calculations indicate that the final structure, arrangement have the tendency to form a single layer micellar structure, when molecular dynamics is performed with a single layer. However, when molecular dynamics were carried out in several layers, indicates the behavior of a liotropic nematic liquid crystal order. Kurumi features the structure polar-apolar-polar predominant. Limitations our study has so far been limited to computational simulation via quantum mechanics e molecular mechanics (QM/MM), an applied theory. Our results and calculations are compatible and with the theory of QM/MM, but their physical experimental verification depend on advanced techniques for their synthesis, obtaining laboratory for experimental biochemical. Going beyond imagination, the most innovative and challenging proposal of the work advances the construction of a structure compatible with the formation of a “new DNA”, based now on the kurumi molecule.

Complexes of Surfactant Micelles with Polymers in Aqueous Liquid Systems

Researches on the structural self-organization and aggregation in aqueous liquid systems of surfactants and polymers have been reviewed. Main attention is focused on the results obtained for the interaction of ionic surfactants with non-ionic polymers. Capabilities of the small-angle neutron scattering and neutron reflectometry methods for the study of the micellar structure, micelle-polymer aggregates, and complex multicomponent systems with nanoparticles are considered. Brief information is provided on some complementary methods used for the structural analysis of liquid systems with self-organization.

Micellar structure and transformations in sodium alkylbenzenesulfonate (NaLAS) aqueous solutions: effects of concentration, temperature, and salt

We investigate the shape, dimensions, and transformation pathways of micelles of linear sodium alkylbenzenesulfonate (NaLAS), a common anionic surfactant, in aqueous solution.

Mesoscopic Detection of the Influence of a Third Component on the Self-Assembly Structure of A2B Star Copolymer in Thin Films

The most common self-assembly structure for A2B copolymer is the micellar structure with B/A segments being the core/corona, which greatly limits its application range. Following the principle of structure deciding the properties, a reformation in the molecular structure of A2B copolymer is made by appending three segments of a third component C with the same length to the three arms, resulting (AC)2CB 3-miktoarm star terpolymer. A reverse micellar structure in self-assembly is expected by regulating the C length and the pairwise repulsive strength of C to A/B, aiming to enrich its application range. Keeping both A and B lengths unchanged, when the repulsion strength of C to A is much stronger than C to B, from the results of mesoscopic simulations we found, with a progressive increase in C length, (AC)2CB terpolymer undergoes a transition in self-assembled structures, from a cylindrical structure with B component as the core, then to a deformed lamellar structure, and finally to a cylindrical structure with A component as the core. This reverse micellar structure is formed with the assistance of appended C segments, whose length is longer than half of B length, enhancing the flexibility of three arms, and further facilitating the aggregation of A component into the core. These results prove that the addition of a third component is a rational molecular design, in conjunction with some relevant parameters, enables the manufacturing of the desired self-assembly structure while avoiding excessive changes in the involved factors.