Themed collection Open access articles from Soft Matter

Formation, adhesion, and accumulation of ice, snow, frost, glaze, rime, or their mixtures can cause severe problems for solar panels, wind turbines, aircrafts, heat pumps, power lines, telecommunication equipment, and submarines.

We review recently developed methods to make stable multiple emulsions via a single mixing step. These successes may make it easier to exploit multiple emulsions in food science and elsewhere.

We quantify the asymmetry of single optically trapped red blood cells from the cross-correlation between their rotational and translational Brownian motion.

Multifrequency atomic force microscopy is used to gain sub-nanometre insights into the structure of aquaporin 0 and its interface with the surrounding water.

The design and characterisation of the nonsymmetric liquid crystal dimer, 1-(4-cyanobiphenyl-4′-yloxy)-6-(4-cyanobiphenyl-4′-yl) hexane (CB6OCB) is reported.

We develop a continuum theory for equilibrium elasticity of a network of crosslinked semiflexible filaments, spanning the full range between flexible entropy-driven chains to stiff athermal rods. Negative normal stress and network stability boundary follow from the compact analytical expressions of the theory.

While ions, which bind close to the glycerol group of DMPC membranes, cause minor increase in bilayer hydration, ions which bind to the phosphate were found to cause significant increases in hydration.

We investigate the drift-diffusion dynamics of particle inclusions embedded within the leaflets of curved lipid bilayer membranes. We consider the roles played by coupling through (i) intramembrane hydrodynamics, (ii) traction stresses with the external solvent fluid, and (iii) intermonolayer slip between the leaflets. Theoretical results and general simulation methods are presented for investigations of the collective drift-diffusion of interacting inclusion particles within curved lipid bilayers.

We show that capillary interactions induced by magnetic Janus particles can assemble monolayers of Janus particles into highly-ordered structures. Further, using theoretical models and computer simulations of two particles we show that the interactions between the particles are tunable. Our results have implications for the fabrication of re-configurable colloidal materials.

We study concentration fluctuations during diffusion of a dense colloidal suspension into water. We find two diffusion coefficients that depend on time and tend asymptotically to the same value for long times, when the concentration gradient vanishes.

The bending modulus κ is known to be a crucial parameter for the stability of the droplet phase. By combination of droplet radii and percolation temperature T_p it is found to increase under the addition of polymer, if the correct droplet radii at T_p are considered.

Specifically designed bionanoparticles with a function-oriented protein-coating layer interact with self-prepared receptor surfaces as the counterpart.

The formation of hexadecane-in-water emulsions stabilised by montmorillonite platelets was studied. Particle desorption needs to be taken into account to predict the steady-state droplet size distribution.

For reversible wrinkling to induce substantial tunability of friction force, this study proposes a new structural design with a biaxial textile sheet embedded on an elastomer surface.

We show that many-component addressable self-assembly of DNA bricks is possible to achieve with a coarse-grained but realistic off-lattice model.

We determine both experimentally and numerically the onset of elastic flow instabilities in viscoelastic polymer solutions with different levels of shear thinning.

β-Lactoglobulin adsorption layers at air–water interfaces were studied with sum-frequency generation, tensiometry, surface dilatational rheology and ellipsometry.

Silks are a family of semi-crystalline structural materials, spun naturally by insects, spiders and even crustaceans.

The influence of both polymer chain length and concentration on the mobility of solvent molecules in polymer solutions was studied by Monte Carlo simulations with the use of the dynamic lattice liquid (DLL) model.

Bile monomers can leave bile micelles rapidly, which may enable solubilization mechanisms not possible with head–tail surfactants.

This work investigates the mechanical coupling of surface instability and bulk bending.

For environmentally-switchable adhesive systems to be reused repeatedly, the adhesive strength must not deteriorate after each adhesion cycle.

The recoil process of viscoelastic free-standing liquid crystal filaments is investigated experimentally and theoretically.

Open and closed volume fractions determined for Stöber silica in deuterated and hydrogenous solvents.

Many real-world industrial processes involve non-spherical particles suspended in a fluid medium.

Hard rod behavior is found in dense suspensions of PEGylated filamentous viruses allowing for direct, i.e. without any free parameter, quantitative comparison with theory and computer simulations.

Particle deposition in a homogeneous or arbitrary distribution can be obtained by direct exposure to an infrared laser beam.

We study the state behaviour of self-propelled and Brownian squares as a function of the magnitude of self-propulsion and density using Brownian dynamics simulations.

We study the ageing and ultimate gravitational collapse of colloidal gels in which the interparticle attraction is induced by non-adsorbing polymers via the depletion effect.

Previously overlooked simple amphiphiles show an exciting capacity for complex hydrogen bond mediated self-association and diverse nanostructure formation.

pH-Responsive microgels can disperse carbon nanotubes and act as macro-crosslinkers to give hydrogel composites with ductilities that increase with increasing modulus.

Complex polymeric nanospheres in aqueous solution are desirable for their promising potential in encapsulation and templating applications.

Long-ranged dipolar interactions between charged particles trapped at a water interface are determined by the particles' apparent charge.

Bicontinuous Pickering emulsions (bijels) are a physically interesting class of soft materials with many potential applications including catalysis, microfluidics and tissue engineering.

–NO₂ and –OCH₃ substituents were shown to differ in their ability to interfere with the H-bond interactions between ureas during supramolecular gelation.

We extend the Widom particle insertion method [B. Widom, J. Chem. Phys., 1963, 39, 2808–2812] to determine an upper bound s_ub on the Edwards entropy in frictional hard-sphere packings.

The hierarchical structure of a dipeptide micellar phase is characterised and linked with the corresponding salt-triggered hydrogel phase.

We investigate, via a modified mean field approach, the dynamic magnetic response of a polydisperse dipolar suspension to a weak, linearly polarised, AC field.

Nanostructured scaffolds are employed as vibrating reeds with retinal tissue cultured on top. From a change in vibration frequency, the mechanical properties of the retina at the nanoscale can be quantified using finite element calculations.

We observe a change in the segmental dynamics of hydrogels based on hydrophobically modified ethoxylated urethanes (HEUR) when hydrophobic magnetite nanoparticles (MNPs) are embedded in the hydrogels.

We have studied the contributions of stored elastic energies in liquid-ordered (Lo) and liquid-disordered (Ld) domains to transmembrane proteins using the lateral pressure concept.

A membrane mediated interaction leads to the formation of peptide clusters inside the bilayers, which may serve as nuclei for further growth into amyloid fibrils.

We present a mm-sized, all-optical probe that can accurately quantify and map the viscoelastic properties of highly heterogeneous soft matter.

The self-assembly of a family of benzene-1,3,5-tricarboxamides (BTAs) in water is studied systematically to elucidate the role of hydrophobic and hydrogen-bond interactions.

Master rheological spectra of our caramels over 12 orders of magnitude of frequency.

In this work it is shown that the selection of heterocyclic capping group for a dipeptide hydrogel affects the self-assembly pathway taken, resulting in differences in mechanical strength, network structure and thixotropic properties.

Magnetic Janus particles with anisotropic magnetization distribution provide bistable self-assembly patterns, allowing for the growth of complex, flexible networks.

Fluorescence spectroscopy on a series of aqueous solutions of poly(acrylic acid) containing a luminescent label showed that polymers with molar mass, M_n < 16.5 kDa did not exhibit a pH responsive conformational change, which is typical of higher molar mass poly(acrylic acid).

We demonstrate, using atomic force microscopy and ellipsometry, that commonly-used buffers aggregate at the surface of mica and lipid bilayers, altering the structure of the interfacial water.

We model elasticity and fracture mechanisms giving rise to a critical pressure during soft material property characterization using cavitation rheology.

The high-temperature nematic phase of all-aromatic lath-like 2,6-biphenyl naphthalene (PPNPP) exhibits a surprisingly strong tendency towards molecular layering (i.e. SmA-like cybotaxis) and an orientational order parameter slightly deviating from Maier–Saupe theoretical prediction.

Shearing polymer melts at constant normal pressure produces different rheology than shearing at a constant volume, as revealed by AdResS-enabled open boundary MD simulations of star polymer melts.

The newly developed elasticity theory for bolalipid membranes predicts an increased splay modulus that decelerates membrane fusion and fission.

A deconvolution protocol is developed for obtaining material responses from time-resolved small-angle scattering data from light (SALS), X-rays (SAXS), or neutrons (SANS).

Cracks in thin layers are influenced by what lies beneath them.

Crowding by hard-sphere colloids affects shape distribution of a polymer coil, modeled as a fluctuating ellipsoid, modifying depletion-induced interactions.

Using molecular dynamics simulations we investigate the self-assembly behaviour of colloidal particles with laterally shifted dipoles.

The influence of weak reversible cross-linking on the mechanical properties of aligned, polymeric fiber bundles is investigated using computer simulations. It is shown that the presence of cross-links may effectively weaken the material. This effect strongly depends on the grafting density of the system.

Antibiotic resistance is a major concern in medicine, and a better understanding of the interactions of antibiotics with the lipid molecules found in bacterial membranes is therefore highly desirable. We study the permeation of the antibiotic norfloxacin across vesicle lipid membranes of variable lipid compositions, and show that norfloxacin permeation is dependent on both the type and relative concentration of lipid molecules in the membrane.

A supramolecular polyelectrolyte complex (SPEC) consisting of polyacrylic acid and guanidine is reported which can carry functional moieties like drugs and dyes and release them in certain pH conditions owing to pH dependent phase transitions of the complex.

Designed complementary peptides self-assembled into β-sheet fibrils under physiological conditions to give cell-compatible hydrogels. N-terminal modification of one peptide component with RGD improved fibroblast viability and attachment.

We investigated the morphology of a new graft-type anion exchange membrane by SANS technique.

Ionic liquid solutions of cellulose can be spun into Lyocell-type textile fibers by dry-jet wet spinning.

Polyacrylamide composite hydrogels containing micrometer-sized pH-responsive hollow particles have tuneable mechanical properties that are governed by percolation.

Unidirectional, bidirectional and tridirectional imbibition of oils is demonstrated on silicon micropillar arrays with overlaid surface chemistry patterns.

Saddle-splay elastic interaction can notably affect the orientational ordering of nematic fluids in distinct regimes, including patterned geometries and complex-shaped colloids.

This article presents a study of layer-by-layer (LbL) formation of poly-electrolyte multilayers (PEMs).

The influence of electrostatic heterogeneity on the electric-field-induced destabilization of thin ionic liquid (IL) films is investigated to control spatial ordering and to reduce the lateral dimension of structures forming on the films.

Relatively hydrophobic particles of different type, size and shape are shown to be effective stabilisers of emulsions containing immiscible oils of low dielectric constant. Transitional and catastrophic phase inversion can be effected and both simple and multiple emulsions are stable for a long period of time.

A flow regime map for suspended particles that unifies aspects of colloidal, granular and soft-particle rheology across remarkably diverse scales.