Realizing Cross-linking-free Acrylic Pressure-Sensitive Adhesives with Intensive Chain Entanglement through Visible-Light-Mediated Photoiniferter-Reversible Addition-Fragmentation Chain-Transfer Polymerization

A versatile and simplified synthesis scheme for intensively entangled acrylic pressure-sensitive adhesives (PSAs) was developed in this study by leveraging visible-light-driven controlled radical polymerization (photoiniferter/reversible addition-fragmentation chain-transfer polymerization) of acrylic copolymers under a controlled manner; the approach was differentiated by a single factor; molecular weight (Mw up to 2.8 MDa) with identical compositions. By manipulating Mw up to ultra-high ranges, PSAs with diversified viscoelastic properties were prepared and then assessed with a focus on realizing PSAs with a maximized degree of entanglement per chain through domination of high Mw contents, to help achieve excellent cohesiveness without a reinforcing cross-linking network. Moreover, fully linear solvent-soluble poly(acrylate)s were synthesized to facilitate reprocessing and reuse, highlighting the sustainability of the devised method and, consequently, its potential to be applied for effectively reducing industrial or daily waste.

The amphiphilic nanostructure of ionic liquids affects the dehydration of alcohols

The effect of the amphiphilic nanostructure of ionic liquids on the dehydration of secondary alcohols to alkenes has been investigated. The influence of these nanostructures was inverted when an acid catalyst was added to the reaction. This phenomenon was ascribed to a balance between ion-solute interactions and the formation of solute-catalyst hydrogen bonds, highlighting the complex interplay between interactions and reaction outcomes in these nanostructured solvent systems.

Structural investigations of molecular solutes within nanostructured ionic liquids

Ionic liquids (ILs) containing sufficiently long alkyl chains form amphiphilic nanostructures with well-defined polar and non-polar domains. Here we have explored the robustness of these amphiphilic nanostructures to added solutes and gained insight into how the nature of the solute and IL ions affect the partitioning of these solutes within the nanostructured domains of ILs. To achieve this, small angle X-ray scattering (SAXS) investigations were performed and discussed for mixtures of 9 different molecular compounds with 6 different ILs containing imidazolium cations. The amphiphilic nanostructure of ILs persisted to high solute concentrations, over 50 mol% of added solute for most 1-butyl-3-methylimidazolium ILs and above 80 mol% for most 1-decyl-3-methylimidazolium ILs. Solute partitioning within these domains was found to be controlled by the inherent polarity and size of the solute, as well as specific interactions between the solute and IL ions, with SAXS results corroborated with IR spectroscopy and molecular dynamics simulations. Molecular dynamics simulations also revealed the ability to induce π⁺-π⁺ stacking between imidazolium cations through the use of these added molecular compounds. Collectively, these results provide scope for the selection of IL ions to rationally influence and control the partitioning behaviour of given solutes within the amphiphilic nanostructure of ILs.

Double thermoresponsive pentablock copolymers: synthesis by one-pot RAFT polymerization and self-assembly in aqueous solutions

Pentablock copolymers synthesized by one-pot successive RAFT polymerization are double thermoresponsive and exhibit block sequence dependent aggregation in aqueous solutions.