The real-space dynamics in a model system of colloidal hard spheres was studied by means time-resolved fluorescence confocal scanning microscopy. Direct experimental evidence for the presence dynamical heterogeneities dense liquid obtained from an analysis particle trajectories two-dimensional slices bulk sample. These manifest themselves as non-Gaussian probability distribution displacements and also affect onset long-time diffusive behavior.

Charge control as a tool for assembly: Dense layers of individual, charged nanocrystals are formed at the aqueous/organic interface upon slight reduction surface charge. The remarkably robust, they creep up glass (see picture). This method should be widely applicable to broad range colloids and will lead production new materials.

Colloidal particles with site-specific directional interactions, so called “patchy particles”, are promising candidates for bottom-up assembly routes towards complex structures rationally designed properties. Here we present an experimental realization of patchy colloidal based on material independent depletion interaction and surface roughness. Curved, smooth patches rough colloids shown to be exclusively attractive due their different overlap volumes. We discuss in detail the case one...

We propose a mechanism for mesophase separation in system of aggregating colloids. Conditions are outlined under which colloids can form equilibrium clusters with very large sizes, i.e., aggregation numbers thousand or more. The driving force clustering is short range attractive interaction will be treated within capillarity approximation. stabilizing small amount charge per particle. Under the appropriate conditions these charges interact unscreened Coulomb potentials and, consequently,...

We show that under appropriate conditions, mixtures of oil, water, and nanoparticles form thermodynamically stable oil-in-water emulsions with monodisperse droplet diameters in the range 30--150 nm. This observation challenges current wisdom so-called Pickering are at most metastable points to a new class mesoscopic equilibrium structures. Thermodynamic stability is demonstrated by spontaneous evolution binary towards one intermediate size distribution. Equilibrium interfacial curvature due...

We present a thermodynamic evaluation of the self-assembly charged nanometer-sized particles at water/oil interface. The chemical potentials nanoparticles in bulk (aqueous) phase and interface are calculated taking into account interfacial energies, van der Waals interactions, electrostatic repulsions. An isotherm particle density as function surface charge on is obtained compared with experimental results gold CdTe self-assembled water/heptane Our model provides semi-quantitative...

A facile and flexible synthesis for colloidal molecules with well-controlled shape tunable patchiness is presented. Cross-linked polystyrene spheres a liquid protrusion were found to assemble into by coalescence of the protrusions. Similarly, cross-linked poly(methyl methacrylate) particles carrying wetting layer assembled layer. Driven surface energy, droplet on which solid are attached formed. Subsequent polymerization yields wide variety as well colloidosomes patchiness. Precise control...

We present the first real-space analysis on a single-particle level of dipolar chains and branched clusters self-assembling in magnetic fluids zero field. Spatial correlations chain-length distributions directly obtained from tracked particle positions vitrified films synthetic (Fe3O4) dispersions provide quantitative test for simulations theory fluids. A pertinent example is cluster-size distribution that can be analyzed with one-dimensional aggregation model to yield attraction energy...

We have investigated the effect of particle shape in Pickering emulsions by employing, for first time, cubic and peanut-shaped particles. The interfacial packing orientation anisotropic microparticles are revealed at single-particle level direct microscopy observations. uniform hematite adsorb irreversibly oil-water interface monolayers form solid-stabilized o/w via process limited coalescence. Emulsions were stable against further coalescence least 1 year. found that cubes assembled with a...

Fuel-driven assembly operates under the continuous influx of energy and results in superstructures that exist out equilibrium. Such dissipative processes provide a route toward structures transient behavior unreachable by conventional equilibrium self-assembly. Although perfected biological systems like microtubules, this class is only sparsely used synthetic or colloidal analogues. Here, we present novel system shows clustering driven chemical fuel. Addition fuel causes an increase...

What measurable physical properties allow one to distinguish surfactant-stabilised from Pickering emulsions? Whereas surfactants influence oil/water interfaces by lowering the interfacial tension, particles are assumed have little effect on tension. Here we perform tension (IFT) measurements three different systems: (1) soybean oil and water with ethyl cellulose nanoparticles (ECNPs), (2) silicone globular protein bovine serum albumin (BSA), (3) sodium dodecyl sulfate (SDS) solutions air....

We present a straightforward technique for the synthesis of asymmetric colloidal molecules with uniform and well-controlled bond angles. The new method makes use coalescence liquid protrusions on polystyrene spheres. angle between seed particles central sphere can be chosen as desired by adjusting size protrusion. surprising uniformity comprised small numbers is proven comparison 3D models. Considering different origins this we conclude that unique shape induced aggregation inside droplets...

We present the synthesis of polymer colloids with continuously tunable anisotropy dimensions: patchiness, roughness, and branching. Our method makes use controlled fusion multiple protrusions on highly cross-linked particles produced by seeded emulsion polymerization. Carefully changing conditions, we can tune number protrusions, or branching, obtained from spheres one to three patches raspberry-like protrusions. In addition that, roughness is generated seed adsorption secondary nucleated...

Cluster formation and gelation are studied in a colloidal model system with competing short-range attractions long-range repulsions. In contrast to predictions by equilibrium theory, the size of clusters spontaneously formed at low volume fractions decreases increasing strength attraction. Moreover, microstructure shape sensitively depend on attraction: from compact crystalline relatively weak disordered quasi-linear strong attractions. By systematically varying attraction fraction, we...

Concentration gradients play a critical role in embryogenesis, bacterial locomotion, as well the motility of active particles. Particles develop concentration profiles around them by dissolution, adsorption, or reactivity surface species. These change energy particles, driving both their self-propulsion and governing interactions. Here we uncover regime which solute-gradients mediate interactions between slowly dissolving droplets without causing autophoresis. This decoupling allows us to...

The co-assembly of spherical colloids and surfactant–cyclodextrin microtubes yields a library dynamic colloid-in-tube structures, including helices. In situ observations these their thermo-reversible assembly disassembly, demonstrate the potential interplay between molecular colloidal self-assembly, thereby providing novel route to temperature-sensitive particle alignment release.

The phase behavior of colloids that interact via competing interactions - short-range attraction and long-range repulsion is studied by computer simulation. In particular, for a fixed strength range repulsion, the effect an attractive interaction (ε) on investigated at various colloid densities (ρ). A thermodynamically stable equilibrium colloidal cluster phase, consisting compact crystalline clusters, found below fluid-solid coexistence line in ε-ρ parameter space. mean size to linearly...

Transient assembled structures play an indispensable role in a wide variety of processes fundamental to living organisms including cellular transport, cell motility, and proliferation. Typically, the formation these transient is driven by consumption molecular fuels via dissipative reaction networks. In networks, building blocks are converted from inactive precursor states active (assembling) (a set of) irreversible chemical reactions. Since activated state intrinsically unstable can be...

The depletion-induced phase separation in a mixture of colloidal particles (PMMA-latex) and nonadsorbing polymers [poly(styrene)] solvent (mixture tetralin, cis-decalin, carbon tetrachloride) was investigated real space with confocal scanning laser microscopy the initial, intermediate, final stage. It found that kinetics morphology strongly depend on polymer concentration, thus strength attraction between particles. At moderate concentrations, crystallization PMMA is enhanced. higher only...

Impurities affect the nucleation, growth, and structure of crystals. Here we report effect large, spherical, polymethylmethacrylate impurities on crystal growth monodisperse, hard, colloids in a density- optically matching apolar solvent mixture. Crystal initiated at bottom sample, was studied by imaging sequences two-dimensional xy slices plane impurity's center with laser scanning confocal microscope. form grain boundaries, single fluid particle layer around impurity persists all cases....