A link between structural ordering and slow dynamics has recently attracted much attention from the context of origin glassy dynamics. Candidates for such order are icosahedral, exotic amorphous, crystal-like. Each type is linked to a different scenario glass transition. Here we experimentally access local in polydisperse hard spheres by particle-level confocal microscopy. We identify key structures as icosahedral FCC-like order, both statistically associated with particles. However, when...

Biomaterials such as protein or polysaccharide gels are known to behave qualitatively soft solids and rupture under an external load. Combining optical ultrasonic imaging shear rheology we show that the failure scenario of a gel is reminiscent brittle solids: after primary creep regime characterized by power-law behavior whose exponent fully accounted for linear viscoelasticity, fractures nucleate grow logarithmically perpendicularly shear, up sudden gel. A single equation accounting those...

Colloidal gels have unique mechanical and transport properties that stem from their bicontinuous nature, in which a colloidal network is intertwined with viscous solvent, found numerous applications foods, cosmetics, construction materials for medical applications, such as cartilage replacements. So far, our understanding of the process gelation limited to long-time dynamical effects, where viewed phase separation interrupted by glass transition. However, this purely out-of-equilibrium...

We study experimentally the response of a dense sediment Brownian particles to self-propulsion. observe that ergodic supercooled liquid relaxation is monotonically enhanced by activity. By contrast nonergodic glass shows an order magnitude slowdown at low activities with respect passive case, followed fluidization higher activities. Our results theoretical predictions approach transition, summing up shift line. propose nonmonotonicity due competing effects activity: (i) extra energy helps...

We have developed a lab work module where we teach undergraduate students how to quantify the dynamics of suspension microscopic particles, measuring and analyzing motion those particles at individual level or as group. Differential Dynamic Microscopy (DDM) is relatively recent technique that precisely does constitutes an alternative method more classical techniques such light scattering (DLS) video particle tracking (VPT). DDM consists in imaging dispersion with standard microscope camera....

Most of the liquid-state theories, including glass-transition are constructed on basis two-body density correlations. However, we have recently shown that many-body correlations, in particular bond orientational play a key role both glass transition and crystallization transition. Here show, with numerical simulations supercooled polydisperse hard spheres systems, lengthscale associated any two-point spatial correlation function does not increase toward A growing is instead revealed by...

We study experimentally a sediment of self-propelled Brownian particles with densities ranging from dilute to ergodic supercooled, nonergodic glass, polycrystal. In compagnon letter, we observe nonmonotonic response activity relaxation the glass state: dramatic slowdown when become weakly self-propelled, followed by speedup at higher activities. Here map supercooled states standard passive glassy physics, provided monotonic shift packing fraction and replacement ambient temperature effective...

Particle tracking is a key to single-particle-level confocal microscopy observation of colloidal suspensions, emulsions, and granular matter. The conventional method has not been able provide accurate information on the size individual particle. Here we propose novel localise spherical particles arbitrary relative sizes from either 2D or 3D (confocal) images in dilute crowded environment. Moreover this allows us estimate each particle reliably. We use analyse local bond orientational...

We report the splitting of an oscillating DNA circuit into $\sim 700$ droplets with picoliter volumes. Upon incubation at constant temperature, display sustained oscillations that can be observed for more than a day. Superimposed to bulk behaviour, we find two intriguing new phenomena - slow desynchronization between compartments and kinematic spatial waves investigate their possible origin. This approach provides route study influence small volume effects in biology, paves way technological...

Abstract This work investigates the correlation between formulation of waterborne acrylic pressure‐sensitive adhesives (PSAs) and their resulting adhesive performance. A library n ‐butyl acrylate‐based latexes is synthesized via miniemulsion polymerization. Controlled variations in composition these polyacrylates – such as inclusion rigid comonomers, latent crosslinkers chain transfer agents enabled precise control over key network structures particles leading then to a range physical...

An important challenge in active matter lies harnessing useful global work from entities that produce locally, e.g., via self-propulsion. We investigate here the version of a classical capillary rise effect, by considering non-phase separated sediment self-propelled Janus colloids contact with vertical wall. provide experimental evidence an unexpected and dynamic adsorption layer at Additionally, we develop complementary numerical model recapitulates observations. show adhesive aligning wall...

The dance of a yoghurt and its whey, ruled by viscosity porosity, creates concentric wrinkles that mimic morphogenesis.

Many soft materials respond neither homogeneously nor linearly to an applied shear stress. The authors describe local oscillatory rheology from echography (LORE), a technique based on ultrafast ultrasonic imaging that provides access spatially resolved viscoelastic moduli under shear. LORE could be used study great range of phenomena and systems spanning fundamental practical interests, such as wall slip, strain hardening, thickening, heterogeneous like hardening concrete, foods, biocomposites.

We describe the preparation as well electrochemical and mechanical properties of a series novel well-defined poly(ionic liquids) (PILs) featuring finely tuned cross-linking ratio.

Usually, we expect large particles to sediment faster than small of the same material. Contrary this intuition, report a dynamical competition between sedimentation and phase ordering which leads smaller settling larger ones. We access phenomenon using suspensions polymers two colloidal species image with confocal microscopy. Polymers mediate attractions colloids, leading separation crystallisation. find that interplay sedimentation, crystal nucleation underlie phenomenon. Furthermore, under...

One of the first steps cheese making is to suppress colloidal stability casein micelles by enzymatic hydrolysis and initiate milk gelation. Afterwards, gel cut promote syneresis expulsion soluble phase milk. Many studies have reported on rheological properties gels at small strain, but they provide limited information ability be handled. In this study, we aim characterize non-linear yielding behavior during creep, fatigue stress sweep tests. We evidence both continuous oscillatory shear...

Among amorphous states, glass is defined by relaxation times longer than the observation time. This nonergodic nature makes understanding of glassy systems an involved topic, with complex aging effects or responses to further out-of-equilibrium external drivings. In this respect, active glasses made self-propelled particles have recently emerged as a stimulating systems, which broadens and challenges our current considering novel internal degrees freedom. previous experimental studies we...

Tuning the chain-end functionality of a short-chain cationic homopolymer, owing to nature initiator used in atom transfer radical polymerization (ATRP) step, can be mediate formation gel this poly(electrolyte) water. While neutral end group gives solution low viscosity, highly homogeneous is obtained with phosphonate anionic moiety, as characterized by rheometry and diffusion nuclear magnetic resonance (NMR). This novel type supramolecular control over poly(electrolytic) could find potential...

The origin of slow dynamics near glass transition and the mechanism crystal nucleation are two unsolved fundamental problems associated with metastable supercooled state a liquid. So far these phenomena have been considered rather independently, however, we revealed an intimate link between them. Recently found that crystallike bond orientational order develops in (nearly) single-component systems such as spin liquids weakly polydisperse colloidal liquids. In liquids, low free-energy...