Water-in-water (W/W) emulsions formed by mixing incompatible water-soluble polymers cannot be stabilized with molecular surfactants. However, they can particles through the so-called Pickering effect. Recently, it was shown that its stabilization achieved also nanoplates. Here, we show for first time even nanorods in form of cellulose nanocrystals (CNCs) efficiently stabilize W/W emulsions. Static light scattering and confocal microscopy techniques were used to determine surface coverage...

We study the micellar solubilization of three thermotropic liquid crystal compounds by immersing single drops in aqueous solutions ionic surfactant tetradecyltrimethylammonium bromide. For both nematic and isotropic drops, we observe a linear decrease drop size with time as well convective flows self-propelled motions. The is accompanied appearance small droplets within or drop. At low temperatures, expell into environment. Smectic show spontaneous formation filament-like structures which...

Many promising approaches for designing interactions of synthetic materials with light involve solid optical monocrystals and nanofabricated photonic crystal structures spatially periodic variations refractive index. Although their high costs limit current technological applications, remarkably, such optically anisotropic have also evolved throughout nature enable narrow or broad-band spectral reflection light. Here we use self-assembly biomaterial cellulose nanocrystals to obtain...

Cellulose nanocrystals (CNC) are rod-like biosourced nanoparticles that widely used in a range of applications. Charged CNC was obtained by acid extraction from cotton and dispersed aqueous solution using ultrasound characterized light scattering. Aggregation gelation induced addition NaCl investigated scattering as function the concentration (30–70 mM), (0.5–5 g/L), temperature (10–60 °C). Formation fractal aggregates observed grow with time until they percolate form weak system spanning...

Abstract The cytoskeleton is a major focus of physical studies to understand organization inside cells given its primary role in cell motility, division, and mechanics. Recently, protein condensation has been shown be another intracellular organizational strategy. Here, we report that the microtubule crosslinking proteins, MAP65-1 PRC1, can form phase separated condensates at physiological salt temperature without additional crowding agents vitro. size droplets depends on concentration...

We demonstrate a new class of soft matter optical fibers, which are self-assembled in form smectic-A liquid crystal microtubes grown an aqueous surfactant dispersion crystal. The diameter the fibers is highly uniform and birefringent. They characterized by line topological defect core fiber with axis pointing from towards surface. guiding light along Whispering Gallery Mode (WGM) lasing plane perpendicular to fiber. as well threshold significantly dependent on polarization excitation beam....

Significance Liquid crystal (LC) research is rapidly expanding to include studies of curved and topologically nontrivial structures. Here, we explore the role bulk LC elasticity interfacial free energy under weak thermal stimuli achieve structural transformations in emulsions using two different surfactants. Our method universal could be used for any material or phase. A theoretical model transforming into uniform fibers vice versa presented. We also show self-shaping smectic vesicle...

Composites of flexible and rigid polymers are ubiquitous in biology industry alike, yet the physical principles determining their mechanical properties far from understood. Here, we couple force spectroscopy with large-scale Brownian Dynamics simulations to elucidate unique viscoelastic custom-engineered blends entangled DNA molecules semiflexible actin filaments. We show that composites exhibit enhanced stress-stiffening prolonged mechano-memory compared systems or alone, these nonlinear...

The diffusion of microscopic particles through the cell, important to processes such as viral infection, gene delivery, and vesicle transport, is largely controlled by complex cytoskeletal network, comprised semiflexible actin filaments rigid microtubules, that pervades cytoplasm. By varying relative concentrations cytoskeleton can display a host different structural dynamic properties that, in turn, impact composite network. Here, we couple single-particle tracking with differential...

Blends of polymers different topologies, such as ring and supercoiled, naturally occur in biology often exhibit emergent viscoelastic properties coveted industry. However, due to their complexity, along with the difficulty producing dynamics topological polymer blends remains poorly understood. We address this void by using both passive active microrheology characterize linear nonlinear rheological relaxed circular supercoiled DNA. we vary concentration from below overlap c* above (0.5c*...

Entangled ring polymers, along with blends of and linear continue to be a topic great interest debate due the conflicting experimental results in literature as well difficulty producing entangled synthetic rings devoid contaminants. Here, we create blended solutions DNA varying mass fractions DNA. We use optical tweezers microrheology measure nonlinear viscoelastic response these blends. Our measurements reveal strong non-monotonic dependence properties on fraction, pronounced maximum when...

Abstract How local stresses propagate through polymeric fluids, and, more generally, how macromolecular dynamics give rise to viscoelasticity are open questions vital wide-ranging scientific and industrial fields. Here, unambiguously connect polymer force response, map the deformation fields that arise in materials, we present Optical-Tweezers-integrating-Differential -Dynamic-Microscopy (OpTiDMM) simultaneously imposes strains, measures resistive forces, analyzes motion of surrounding...

We report on transient structures, formed by thermotropic smectic-A liquid crystals, resembling the myelin figures of lyotropic lamellar crystals. The structures form during solubilization a droplet in an aqueous phase containing cationic surfactant at concentrations above critical micelle concentration. Similar to figures, myelins appear optical microscope as flexible tubelike growing smectic/aqueous interface. Polarizing microscopy and confocal fluorescence show that smectic layers are...

Polymer architecture plays critical roles in both bulk rheological properties and microscale macromolecular dynamics entangled polymer solutions composites. Ring polymers, particular, have been the topic of much debate due to inability celebrated reptation model capture their observed dynamics. Macrorheology differential dynamic microscopy (DDM) are powerful methods determine across scales; yet, they typically require different samples under conditions, preventing direct coupling underlying...

The clingfish attaches to rough surfaces with considerable strength using an intricate suction disc, which displays complex surface geometries from structures called papillae. However, the exact role of these in adhesion is poorly understood. To investigate relationship between papillae geometry and adhesive performance, we developed image processing tool that analyzed structural complexity papillae, then used model hydrodynamic adhesion. Our allowed for automated analysis thousands...

The composite cytoskeleton, comprising interacting networks of semiflexible actin and rigid microtubules, actively generates forces restructures using motor proteins such as myosins to enable key mechanical processes including cell motility mitosis. Yet, how motor-driven activity alters the mechanics cytoskeleton composites remains an open challenge. Here, we perform optical tweezers microrheology on actin-microtubule driven by myosin II motors show that increases linear viscoelasticity...

Mixtures of polymers varying topologies and stiffnesses display complex emergent rheological properties that often cannot be predicted from their single-component counterparts. For example, entangled blends ring linear have been shown to exhibit enhanced shear thinning viscosity, as well prolonged relaxation timescales, compared pure solutions rings or chains. These arise in part the synergistic threading by polymers. Topology has also play an important role composites flexible (e.g., DNA)...

Polymer topology has been shown to play a key role in tuning the dynamics of complex fluids and gels. At same time, polymer composites, ubiquitous everyday life, have exhibit emergent desirable mechanical properties not attainable single-species systems. Yet, how impacts structure composites remains poorly understood. Here, we create rigid rods (microtubules) polymerized within entangled solutions flexible linear ring polymers (DNA) equal length. We couple optical tweezers microrheology with...

Microtubule organization in cells is essential for the internal structure and coordination of events intracellular transport, mitosis, cell motility. For many types, microtubule dominated by centrosomal nucleation that use gamma-tubulin to template filaments. Yet, some types lack centrosomes or centrioles, such as plant cells. Instead, microtubules nucleate from regions with high concentrations binding nucleating proteins. A mechanism can drive local nucleators liquid-liquid phase separation...

It has been shown that the thermodynamics of bicontinuous microemulsions can be tailored via addition various different amphiphilic polymers. In this manuscript, we now focus on comb-type polymers consisting hydrophobic backbones and hydrophilic side chains. The distinct philicity backbone chains leads to a well-defined segregation into oil water domains respectively, as confirmed by contrast variation small-angle neutron scattering experiments. This polymer–microemulsion structure...

We demonstrate a new sort of optical fibers, which are self-assembled from smectic-A liquid crystal. When this crystal is put in contact with water solution surfactant CTAB, microfibers start spontaneously growing at the crystal-water interface. The fibers very uniform diameter and can be several hundreds micrometers long. They all have line topological defect core fiber local axis pointing towards surface. ends perfect spherical shape. By doping fluorescent dye, we guiding light along...

Blends of circular and linear polymers have fascinated researchers for decades, the role topology on their stress response dynamics remains fervently debated. While adopt larger coil sizes form stronger, more pervasive entanglements than counterparts, threading by chains can introduce persistent constraints that dramatically decrease mobility, leading to emergent rheological properties in blends. However, complex interplay between topology-dependent polymer overlap propensity, along with...

Understanding how polymers deform in response to local stresses and strains, strains propagate from a disturbance, are grand challenges wide-ranging fields materials manufacturing cell mechanics. These dynamics particularly complex for blends of distinct topologies, which several different species-dependent mechanisms may contribute. Here, we use OpTiDDM (Optical Tweezers integrating Differential Dynamic Microscopy) elucidate deformation propagation binary linear, ring supercoiled DNA...