Abstract Three-dimensional cell and organoid cultures rely on the mechanical support of viscoelastic matrices. However, commonly used matrix materials lack control over key cell-instructive properties. Here we report fully synthetic hydrogels based DNA libraries that self-assemble with ultrahigh-molecular-weight polymers, forming a dynamic DNA-crosslinked (DyNAtrix). DyNAtrix enables computationally predictable systematic its viscoelasticity, thermodynamic kinetic parameters by changing...

Abstract Due to the abundance of microplastics in environment, research about its possible adverse effects is increasing exponentially. Most studies investigating effect on cells still rely commercially available polystyrene microspheres. However, choice these model microplastic particles can affect outcome studies, as even nominally identical may interact differently with due different surface properties such charge. Here, we show that microspheres from eight manufacturers significantly...

Core-shell polystyrene-silica spheres with diameters of 800 nm and 1.9 microm were synthesized by soap-free emulsion dispersion polymerization the polystyrene core, respectively. The used as templates for synthesis silica shells tunable thickness employing Stöber method [Graf et al. Langmuir 2003, 19, 6693]. template was removed thermal decomposition at 500 degrees C, resulting in smooth well-defined (15-70 nm). elastic response these hollow probed atomic force microscopy (AFM). A point load...

A sessile droplet can deform the surface of a soft solid not only with its weight. The tension pulls up ridge at perimeter drop, and capillary pressure embosses quasi-spherical dimple underneath drop. This holds for case bulk solid. However, if forms film thickness comparable to deformation scale shape depth are strongly distorted. We investigated dimples on elastomer films Young's modulus 25 kPa in range 4–104 µm embossed by ionic liquid droplets. supported an undeformable glass slide....

Abstract Biohybrid micromotors propelled by motile cells are fascinating entities for autonomous biomedical operations on the microscale. Their operation under physiological conditions, including highly viscous environments, is an essential prerequisite to be translated in vivo settings. In this work, a sperm‐driven microswimmer, referred as spermbot, demonstrated operate oviduct fluid vitro. The viscoelastic properties of bovine (BOF), one fluids that sperm encounter their way oocyte, first...

Condensation on soft elastic surfaces differs significantly from condensation hard surfaces. On polymeric substrates with varying cross-linking density, we investigate the nucleation and growth of condensing water drops. With increasing softness substrates, find (1) (2) longer relaxation times for drop shape equilibration after merging two drops, (3) prevention very These effects lead to higher surface coverage overall condensed volume

Inspired by the amino acid 2-chloro-4,5-dihydroxyphenylalanine (Cl-DOPA), present in composition of proteinaceous glue sandcastle worm Phragmatopoma californica, a simple strategy is presented to confer antifouling properties polymer surfaces using (but not releasing) bioinspired biocide. Cl-Dopamine used functionalize materials and hydrogel films easily, prevent biofilm formation on them.

Surface roughness on different length scales is favourable for superhydrophobic behaviour of surfaces. Here we report (i) an improved synthesis hybrid raspberry-like particles and (ii) a novel method to obtain films good mechanical stability. Polystyrene spheres with diameter 400 nm–1 μm are decorated silica colloids < 100 nm in size, thus introducing surface asperities second scale. To improve resistance, then coated the polystyrene core attached smooth shell 10 40 thickness. All three...

The wetting of solid surfaces by fluids has been studied for more than two centuries. However, it was only in recent years that investigations the first milliseconds spontaneous drop spreading on started. For non-deformable surfaces, this fast dynamic process is known to be dominated inertia and controlled surface wettability. In work we liquids soft, viscoelastic rubber films with shear moduli |G| between 0.2 510 kPa thickness d 30 160 μm. We found early stage soft also dynamics follows a...

Paramagnetic particle chains in soft polymer gels can show pronounced buckling deformation under perpendicular external magnetic fields.

Magnetorheological elastomers are a type of smart hybrid material where elastic properties soft elastomer matrix combined with magnetic micro particles. This combination leads to complex interplay and phenomena, which the magnetorheological effect is best described. In this paper, magnetically hard NdFeB-particles were used obtain remanent properties. X-ray microtomography has been utilised analyse particle movement induced by fields. A tracking was performed; thus, it possible characterise...

Recent developments in the field of covalent organic frameworks (COFs) describe issue processability. The precise tunability delamination such structures to obtain few layered nanosheets by synthetic control has been ventured this study. Covalent anchoring a series linear and branched alkoxy side chains backbone was used achieve this. To support hypothesis, powder X-ray diffraction studies accompanied computational modeling revealed that elongation increases interlayer distances COFs. This...

Abstract We describe the preparation and characterization of uniaxial magnetic gels. Fibril formation embedded particles generates easily detectable optical anisotropies. A finite magnetization is frozen‐in leads to a ferromagnetic‐like response in small homogeneous external fields. present, for first time, frequency dependent measurements shear modulus G ′. Despite their anisotropy, gels are mechanically isotropic. The time‐dependent ′ ferrogel parallel orientation field 200 mT. magnified image

A supramolecular organogel was prepared by mixing the glycidyl triazole polymers (GTP) functionalized with crown ether and secondary ammoniumion at side groups. The form an above a concentration of 3 wt % via physical cross-links inclusion complex. responds to multiple stimuli, e.g., temperature, acid/base, chemical species. number effective estimated from storage modulus affine network model suggests that some part binding sites could not work as cross-links. Rheological measurement under...

Reversible assembly of Janus particles was manipulated by host-guest interaction β-cyclodextrin (β-CD) and azobenzene. One side every particle modified with β-CD. Superstructures were formed adding azobenzene-containing polymers to the dispersion particles. The superstructures reversibly disassembled α-CD or light irradiation.

Abstract Photoisomerization in some azobenzene‐containing polymers (azopolymers) results reversible solid‐to‐liquid transitions because trans ‐ and cis ‐azopolymers have different glass transition temperatures. This property enables photoinduced healing processing of azopolymers with high spatiotemporal resolution. However, a general lack knowledge about the influence polymer structure on hinders design such novel polymers. Herein, synthesis photoresponsive behavior new lengths spacers...

When studying the condensation of vapor to liquid drops on solid hydrophobic surfaces volume V is found increase linearly with time, V∝t. Constant-contact-angle evaporation studies showed that drop volumes decrease according V∝t3/2. Since both processes are diffusion limited, one would expect same kinetics. Here, we demonstrate experimentally, theoretically and by finite-element simulations spacing between condensing or evaporating affects growth. The single, isolated changes For a dense...

Capillary penetration of a series entangled poly(ethylene oxide) melts within nanopores self-ordered alumina follows an approximate t1/2 behavior according to the Lucas-Washburn equation; t is time. However, dependence on capillary diameter deviates from predicted proportionality d1/2; d pore diameter. We observed reversal in dynamics rise with polymer molecular weight. Chains 50 entanglements (Mw ≤ 100 kg/mol) or less show slower than theoretically as opposed chains more ≥ 500 that display...

To describe many-particle systems suspended in incompressible low-Reynolds-number fluids, effective hydrodynamic interactions can be introduced. Here, we consider particles embedded elastic media. The between spherical are calculated analytically, inspired by the approach fluid case. Our experiments on interacting magnetic confirm theory. In view of huge success method hydrodynamics, similarly expect many future applications case, e.g., for composite materials.Received 2 July...

Polymer brushes, consisting of densely end-tethered polymers to a surface, can exhibit rapid and sharp conformational transitions due specific stimuli, which offer intriguing possibilities for surface-based sensing the stimuli. The key toward unlocking these is development methods readily transduce signals from polymer changes. Herein, we report on single-fluorophore integrated ultrathin (<40 nm) brush surfaces that changing fluorescence properties based conformation. basis our change in...

In this work we show that the forced dynamic dewetting of surfactant solutions depends sensitively on concentration. To measure effect, a hydrophobic rotating cylinder was horizontally half immersed in aqueous solutions. Dynamic contact angles were measured optically by extrapolating contour meniscus to line. Anionic (sodium 1-decanesulfonate, S-1DeS), cationic (cetyl trimethylammonium bromide, CTAB) and nonionic surfactants (C4E1, C8E3 C12E5) with critical micelle concentrations (CMCs)...

We investigate the rheological property of microgel monolayers at water/oil interface using passive and active microrheological methods. At low surface coverage, microgels have a tendency to form aggregated structures (networks) with dominating elasticity. high coverage densely packed monolayers. Using microsized magnetic particles as local probes in dense monolayers, we perform situ study their properties structures. observe four regimes where elasticity monolayer has different dependence...

The environmental fate and toxicity of microplastic particles are dominated by their surface properties. In the environment, an adsorbed layer biomolecules natural organic matter forms so-called eco-corona. A quantitative description how this eco-corona changes particles' colloidal interactions is still missing. Here, we demonstrate with probe-atomic force microscopy that formation on introduces a compressible film surface, which mechanical behavior. We measure single particle–particle find...