A series of novel chain-extended polyurethanes (CEPUs) featuring degradable sulfonyl ethyl urethane chain-extenders that permit degradation under base-triggered conditions to afford "debond-on-demand" elastomeric adhesives are reported. Exposure the CEPUs tetra-butylammonium fluoride (TBAF) triggered chain-extenders. Lap shear adhesion tests exposed TBAF revealed reductions in strength up 65% for both aluminum and glass substrates, from 2.18 0.76 MPa 1.13 0.52 MPa, respectively. The...

Abstract Glasses are among the most widely used of everyday materials, yet process by which a liquid’s viscosity increases 14 decades to become glass remains unclear, as often contradictory theories provide equally good descriptions available data. Knowledge emergent lengthscales and higher-order structure could help resolve this, but this requires time-resolved measurements dense particle coordinates—previously only obtained over limited time interval. Here we present an experimental study...

We report surface force balance measurements of the normal and friction between two mica surfaces separated by a nanofilm deep eutectic solvent ethaline. Ethaline, 1 : 2 mixture choline chloride ethylene glycol, was studied under dry conditions, ambient conditions with added water, revealing structural layers quantised frictional response highly sensitive to water content, including regions super-lubric behaviour water. also exceptionally long-ranged electrostatic repulsion far in excess...

Deep eutectic solvents (DESs) show promise as boundary lubricants between sliding surfaces, taking advantage of their physical stability, chemical and tunability. Here, we study friction forces across nanofilms two archetypal DES mixtures: choline chloride + ethylene glycol glycerol. Using a surface force balance, control the film thickness (to subnanometer precision) determine simultaneously. Measurements are made at different mole fractions salt molecular solvent, allowing us to role each...

Zwitterionic osmolytes are widely known to have a protein-protective effect against high salt concentration, but mechanistic picture of osmolyte function remains elusive. Here total scattering is used determine...

A highly-charged spherical colloid in a salt-free environment exerts such powerful attraction on its counterions that certain fraction condenses onto the surface of particle. The degree condensation depends curvature surface. So, for instance, is triggered sphere only if radius exceeds critical R*. R* expected to be simple function volume particles. To test these predictions, we prepare particles which contain covalently-bound ionic liquid, engineered dissociate efficiently low-dielectric...

Among the key insights into glass transition has been identification of a nonequilibrium phase in trajectory space which reveals coexistence between normal supercooled liquid (active phase) and glassy state (inactive phase). Here, we present evidence that such occurs experiments. In colloidal hard spheres, find non-Gaussian distribution trajectories leaning towards those rich locally favored structures (LFSs), associated with emergence slow dynamics. This interpret as for to an inactive...

Upon approaching the glass transition, relaxation of supercooled liquids is controlled by activated processes, which become dominant at temperatures below so-called dynamical crossover predicted Mode Coupling theory (MCT). Two main frameworks rationalising this behaviour are dynamic facilitation (DF) and thermodynamic scenario give equally good descriptions available data. Only particle-resolved data from MCT can reveal microscopic mechanism relaxation. By employing state-of-the-art GPU...

Time-resolved small-angle neutron scattering studies confirm that copolymer chain exchange occurs between sterically-stabilized diblock nanoparticles at elevated temperature.

Hydrocarbon films confined between smooth mica surfaces have long provided an experimental playground for model studies of structure and dynamics liquids. However fundamental questions regarding the phase behavior shear properties in this simple system remain unsolved. With ultra-sensitive resolution film thickness stress, control over crystallographic alignment confining surfaces, we here investigate forces transmitted across nanoscale dodecane down to a single molecular layer. We resolve...

Sterically-stabilized poly(methyl methacrylate) (PMMA) latexes dispersed in nonpolar solvents are a classic, well-studied system colloid science. This is because they can easily be synthesized with narrow size distribution and interact essentially as hard spheres. These PMMA charged using several methods (by adding surfactants, incorporating ionizable groups, or dispersing autoionizable solvents), due to the low relative permittivity of (εr ≈ 2 for alkanes εr 8 halogenated charges have...

A macroscopically oriented double diamond inverse bicontinuous cubic phase (QIID) of the lipid glycerol monooleate is reversibly converted into a gyroid (QIIG). The initial QIID prepared in form film coating inside capillary, deposited under flow, which produces sample uniaxially with ⟨110⟩ axis parallel to symmetry sample. transformation induced by replacing water within capillary tube solution poly(ethylene glycol), draws out osmotic stress. This converts QIIG two coexisting orientations,...

A quasi two-dimensional colloidal suspension is studied under the influence of immobilisation (pinning) a random fraction its particles. We introduce novel experimental method to perform pinning and, with support numerical simulation, we find that increasing concentration smoothly arrests system, cross-over from regime high mobility and entropy low entropy. At local level, study fluctuations in area pins map them entropic structural signatures mobility, obtaining measure for system.

Cellular organisms regulate electrolyte composition in the cytosol to optimize intracellular molecular interactions at same time as balancing external osmotic pressure. While pressure can be tuned using multiple ionic, zwitterionic, and nonionic solutes, between proteins other macromolecules are sensitive precise of medium. Nonetheless, roles individual ions solutes mediating cellular remain relatively unexplored, standard buffer solutions used laboratory studies often contain only a few...

We demonstrate a method by which we can produce an oriented film of inverse bicontinuous cubic phase (Q(II)(D)) formed the lipid monoolein (MO). By starting with as disordered precursor (the L(3) phase) in presence butanediol, obtain Q(II)(D) showing high degree in-plane orientation controlled dilution sample under shear within linear flow cell. that direction is different from found bulk material have reported previously; therefore, now reproducibly form samples either [110] or [100] axis...

We consider the sedimentation of a colloidal gel under confinement in direction gravity. The allows us to compare directly experiments and computer simulations, for same system size vertical direction. also leads qualitatively different behaviour compared bulk systems: large systems gelation suppresses sedimentation, but small is enhanced relative non-gelling suspensions, although rate reduced when strength attraction between colloids strong. map interaction parameters model experimental...

Individual colloids often carry a charge as result of the dissociation (or adsorption) weakly-ionized surface groups.

Colloidal suspensions have long been studied as a model for atomic and molecular systems, due to the ability fluorescently label individually track each particle, yielding particle-resolved structural information. This allows various local order parameters be probed that are otherwise inaccessible comparable system. For phase transitions such crystallisation, appropriate which emphasise 6-fold symmetry natural choice, but vitrification choice of parameter is less clear cut. Previous work has...

Swimmers and self-propelled particles are physical models for the collective behavior motility of a wide variety living systems, such as bacteria colonies, bird flocks, fish schools. Such artificial active materials amenable to which reveal microscopic mechanisms underlying behavior. Here we study colloids in dc electric field. Our quasi-two-dimensional system electrically driven exhibits rich exotic phase exhibiting passive crystallites, motile an gas, banding. Amongst these two mesophases,...

We combine experiments and simulations to study the link between criticality gelation in sticky spheres. employ confocal microscopy image colloid-polymer mixtures, Monte Carlo of square-well (SW) potential as a reference model. To this end, we map our experimental samples onto SW find excellent structural agreement simulations, both for locally favored structures at single particle level large-scale fluctuations criticality. follow detail rapid change critical fluid when approaching...

Refractive index matched particles serve as essential model systems for colloid scientists, providing nearly hard spheres to explore structure and dynamics. The poly(methyl methacrylate) latexes typically used are often refractive by dispersing them in binary solvent mixtures, but this can lead undesirable changes, such particle charging or swelling. To avoid these shortcomings, we have synthesized colloids using polymerization-induced self-assembly (PISA) rather than polymer latexes....

Hard-sphere particles in nonpolar solvents are an essential tool for colloid scientists. Sterically stabilized poly(methyl methacrylate) (PMMA) have long been used as the exemplary hard-sphere system. However, neither themselves nor poly(12-hydroxystearic acid) (PHSA) stabilizer necessary to prevent aggregation commercially available. To counter this, several alternatives proposed. In recent years, there has increased interest poly(dimethylsiloxane) (PDMS) stabilizers a available alternative...