The influence of the ratio between poor and good solvent on stability dynamics supramolecular polymers is studied via a combination experiments simulations. Step-wise addition to assembled cooperative (nucleated) growth mechanism results in complete disassembly at critical good/poor ratio. In contrast, gradual profiles upon are observed for isodesmic (non-nucleated) systems. Due weak association molecules monomers, solvent-dependent aggregate can be described by linear free-energy...

The photoactive layer of polymer solar cells is commonly processed from a four-component solution, containing semiconducting and fullerene derivative dissolved in solvent-cosolvent mixture. nanoscale dimensions the polymer-fullerene morphology that formed upon drying determines cell performance, but fundamental processes govern size phase-separated domains are poorly understood. Here, we investigate formation an alternating copolymer diketopyrrolopyrrole thiophene-phenyl-thiophene oligomer...

Liquid-liquid phase separation is emerging as a crucial phenomenon in several fundamental cell processes. A range of eukaryotic systems exhibit liquid condensates. However, their function bacteria, which, general, lack membrane-bound compartments, remains less clear. Here, we used high-resolution optical microscopy to observe single bacterial aggresomes, nanostructured intracellular assemblies proteins, undercover role stress. We find that proteins inside aggresomes are mobile and undergo...

We theoretically study the impact of solvent evaporation on dynamics isothermal phase separation ternary polymer solutions in thin films. In early stages we obtain a spinodal length scale that decreases with time under influence ongoing evaporation. After rapid demixing occurs at well-defined lag time, morphology emerges which compositions coexisting phases rapidly approach binodal values. find type morphology, can be either bicontinuous or dispersed, strongly depends rate if solubility two...

Abstract Biopolymer topology is critical for determining interactions inside cell environments, exemplified by DNA where its response to mechanical perturbation as important biochemical properties cellular roles. The dynamic structures of chiral biopolymers exhibit complex dependence with extension and torsion, however the physical mechanisms underpinning emergence structural motifs upon physiological twisting stretching are poorly understood due technological limitations in correlating...

The morphological evolution is initiated by L–L or L–S phase separation (left) and further developed molecular mobility, governed polymer–solvent interactions which determine the final domain size of BHJ layer (right).

The condensation of Rubisco holoenzymes and linker proteins into “pyrenoids,” a crucial supercharger photosynthesis in algae, is qualitatively understood terms “sticker-and-spacer” theory. We derive semianalytical partition sums for small Rubisco-linker aggregates, which enable the calculation both dilute-phase titration curves dimerization diagrams. By fitting to surface plasmon resonance single-molecule fluorescence microscopy data, we extract molecular properties needed predict use these...

Abstract Although ternary solar cells (TSCs) offer a cost‐effective prospect to expand the absorption bandwidth of organic cells, only few TSCs have succeeded in surpassing performance binary (BSCs) primarily due complicated morphology blends. Here, key factors that create and limit are elucidated. The origin formation is explored role kinetic investigated. results reveal TSC blends considered this study characterized with either single length‐scale or two features depending on composition...

Silk is one of the most intriguing examples biomolecular self-assembly, yet little understood molecular mechanisms behind flow behavior generating these complex high-performance fibers. This work applies polymer physics entangled solution rheology to present a first microphysical understanding silk in linear viscoelastic regime. We show that solutions can be approximated as reptating polymers with "sticky" calcium bridges whose strength controlled through potassium concentration. approach...

The morphology of solution-cast, phase-separated polymers becomes finer with increasing solvent evaporation rate. We address this observation theoretically for a model polymer where demixing is induced by steady evaporation. In contrast to what the case classical, thermal quench involving immiscible blends, spinodal instability initially develops slowly and associated length scale not time invariant but decreases as t(-1/2). After lag, phase separation accelerates. Time lag characteristic...

The solubilization of lipid membranes by Tween-20 is crucial for a number biotechnological applications, but the mechanistic details remain elusive. Evidence from ensemble assays supports model that encompasses surfactant association with membrane and release mixed micelles to solution, whether this process also involves intermediate transitions between regimes unanswered. In search origins, increasing focus placed on identifying interactions controllable mimetics. Here, we employed...

Membraneless droplets formed through liquid-liquid phase separation (LLPS) play a crucial role in mRNA storage, enabling organisms to swiftly respond environmental changes. However, the mechanisms underlying integration and protection within remain unclear. Here, we unravel of bacterial aggresomes as stress granules (SGs) safeguarding during stress. We discovered that upon onset, mobile molecules selectively incorporate into individual proteinaceous SGs based on length-dependent enthalpic...

In a combined experimental and theoretical approach, we investigate the supramolecular polymerization of ionic discotic amphiphiles into nanorods varying mean length, depending on temperature strength buffered aqueous solution. Invoking nucleated model that explicitly deals with effects screened Coulomb interactions, correlate degree cooperativity solution, as probed by means circular dichroism spectroscopy. Experiment theory show electrostatic interactions between in rods make less...

Solution-cast, thin-film polymer composites find a wide range of applications, such as in the photoactive layer organic solar cells. The performance this crucially relies on its phase-separated morphology. Efficient charge-carrier extraction requires each components to preferentially wet one two electrodes. It is often presumed that experimentally observed surface enrichment required for caused by specific interactions active ingredients with surface. By applying generalized diffusion model,...

We have developed a method to couple kinetic Monte Carlo simulations of surface reactions at molecular scale transport equations macroscopic scale. This is applicable steady state reactors. use finite difference upwinding scheme and gap-tooth efficiently limited amount simulations. In general the stochastic results do not obey mass conservation so that unphysical accumulation could occur in reactor. perform balance corrections based on stoichiometry matrix least-squares problem reduced...

A major pathogenic hallmark of Alzheimer's disease is the presence neurotoxic plaques composed amyloid beta (Aβ) peptides in patients' brains. The pathway plaque formation remains elusive, though some clues appear to lie dominant Aβ1 - 42 these despite Aβ1-40 making up approximately 90% Aβ pool. We hypothesize that this asymmetry driven by hydrophobicity two extra amino acids are incorporated Aβ1-42. To investigate hypothesis at level single molecules, we have developed a molecular...

Using the simple ‘allosteron’ model, we show that it is possible, in principle, to elicit pathways by which fluctuation allostery affects self-assembly of protein complexes. We treat cases (i) fibrils and nucleation, (ii) n -mer complexes, (iii) weakly attractive allosteric interactions protein-like soft nanoscale objects can be tuned define exclusive self-associating families. This article part a discussion meeting issue ‘Allostery molecular machines’.

Understanding of stationary charge transport in disordered organic semiconductors has matured during recent years. However, charge-carrier relaxation nonstationary situations is still poorly understood. Such can be studied dark injection experiments, which the bias applied over an unilluminated semiconductor device abruptly increased. The resulting transient current reveals both and characteristics. We performed such experiments on hole-only devices a polyfluorene-based semiconductor....

Spontaneous liquid-liquid phase separation is commonly understood in terms of phenomenological mean-field theories. These theories correctly predict the structural features fluid at sufficiently long time scales and wavelengths. However, these conditions are not met various examples biology materials science where mixture slowly destabilised, strongly affected by critical thermal fluctuations. We propose a mechanism pretransitional structuring that approaches miscibility gap scaling...

Silk is a semidilute solution of randomly coiled associating polypeptide chains that crystallize following the stretch-induced disruption, in strong extensional flow extrusion, solvation shell around their amino acids. We propose natural silk spinning exploits both exponentially broad stretch distribution generated by polymers and criterion critical concentration sufficiently stretched to nucleate flow-induced crystallization. To investigate specific-energy input needed reach this start-up...

The flow-induced self-assembly of entangled Bombyx mori silk proteins is hypothesised to be aided by the ‘registration’ aligned protein chains using intermolecularly interacting ‘sticky’ patches. This suggests that upon chain alignment, a hierarchical network forms collectively stretches and induces nucleation in precisely controlled way. Through lens polymer physics, we argue if all would stretch similar extent, clear correlation length stickers direction flow emerges, which may indeed...

Fluids with spatial density variations of single or mixed molecules play a key role in biophysics, soft matter and materials science. The fluid structures usually form via spinodal decomposition nucleation following an instantaneous destabilisation the initially disordered fluid. However, practice quench is often not viable, rate may be gradual rather than instantaneous. In this work we show that commonly used phenomenological descriptions structuring are inadequate under these conditions....

Abstract Liquid-liquid phase separation is emerging as a crucial phenomenon in several fundamental cell processes. A range of eukaryotic systems exhibit liquid condensates. However, their function bacteria, which general lack membrane-bound compartments, remains less clear. Here, we used high-resolution optical microscopy to observe single bacterial aggresomes, nanostructured intracellular assemblies proteins, undercover role stress. We find that proteins inside aggresomes are mobile and...