Conformational properties of complexes of poly(propylene imine) dendrimers with linear polyelectrolytes in dilute solutions

Fully bio-based hydroxy ester vitrimer synthesized by crosslinking epoxidized soybean oil with doubly esterified starch

Catalyst-free fully bio-based hydroxyester (BHE) vitrimers were synthesized by crosslinking and plasticizing epoxidized soybean oil with synthesized acetylated starch succinate monoesters to investigate the effects of different starch structures on the properties of the BHE vitrimers. The BHE vitrimers possessed a lower glass transition temperature as well as better solvent resistance and reprocessing performance compared to traditional starch-based materials. Owing to dynamically covalent bonds, the migration and exudation of plasticizers were avoided. A maximum strain of 230 % was achieved to prevent the retrogradation and brittleness of starch-based materials. Furthermore, the mechanical properties remained unchanged after three reprocessing cycles. Consequently, the obtained BHE vitrimers are eco-friendly and sustainable.

The effect of external salts on the aggregation of the multiheaded surfactants: All-atom molecular dynamics studies

Tailoring the molecular design of the surfactants leads to changes in the aggregation properties. The role of external salts on the aggregation properties of the multiheaded surfactants is investigated using molecular dynamics simulations. The multiheaded surfactants show differential aggregation properties on addition of external salts, as reported earlier from experimental studies. We have modelled the multiheaded surfactants to study the effect of external salts (potassium bromide and sodium salicylate) at three different concentrations using the all-atom modelling and explicit solvation. The influence of external salts on the hydration and aggregation propensity, hydrogen bonding, and the structural characteristics of the surfactant aggregates are probed using various analyses across the four groups of multiheaded surfactants. The larger salicylate ion masks the repulsion between the cationic head groups and acts as an effective promoter of aggregation.