Elastic properties of soft, three-dimensional dimers, interacting through site-site n-inverse-power potential, are determined by computer simulations at zero temperature. The degenerate crystal of dimers exhibiting (Gaussian) size distribution of atomic diameters i.e. size polydispersity is studied at the molecular number density 1/ √ 2; the distance between centers of atoms forming dimers is c...

2014 We extend the renormalization group approach to polymer solutions of arbitrary chain length distribution (polydispersity). In the excluded volume limit polydispersity can be classified as neither relevant, irrelevant, nor marginal. The qualitative properties (the exponents) are not influenced by polydispersity. The quantitative results (scaling functions) are influenced, however, and our m...

Real systems always contain some degree of polydispersity and yet the effects of this real and very important problem have not been studied in great detail in NMR diffusion experiments. The effects of polydispersity become even less clear when we are outside the short gradient pulse (SGP) limit (which we generally are). Here we investigate the effects of polydispersity, in the form of a Gaussia...

The effect of polymer polydispersity on the fluid–fluid demixing of an athermal mixture of colloids and self-excluding polymers is analysed with the first-order thermodynamic perturbation theory (TPT1) of Wertheim. The colloidal particles and the segments making up the polymer chains are modeled as hard spheres of different diameters. The polydispersity of the polymer is represented by a distri...

We calculate the phase behavior of hard spheres with size polydispersity, using accurate free energies for the fluid and solid phases. Cloud and shadow curves are found exactly by the moment free energy method, but we also compute the complete phase diagram, taking full account of fractionation. In contrast to earlier, simplified treatments we find no point of equal concentration between fluid ...

By using theoretical analysis and molecular dynamics simulations, we investigate the structure of colloidal crystals formed by nonmagnetic microparticles (or magnetic holes) suspended in ferrofluids (called inverse ferrofluids), by taking into account the effect of polydispersity in size of the nonmagnetic microparticles. Such polydispersity often exists in real situations. We obtain an analyti...

We analyze the effect of polydispersity in the arm number on the effective interactions , structural correlations and the phase behavior of star polymers in a good solvent. The effective interaction potential between two star polymers with different arm numbers is derived using scaling theory. The resulting expression is tested against monomer-resolved molecular dynamics simulations. We find th...

A physical parameter for predicting the thermal stability of proteins was provided by a new approach using dynamic light scattering (DLS). The relationship between the melting point measured by differential scanning calorimetry (DSC) and the polydispersity of the hydrodynamic diameter determined by DLS analysis was examined. Calmodulin (CaM) and concanavalin A (ConA) were used as model proteins...

A theoretical scheme developed earlier [Y. V. Kalyuzhnyi et al., Chem. Phys. Lett. 443, 243 (2007)] is used to calculate the full phase diagram of polydisperse athermal polymer-colloidal mixture with polydispersity in both colloidal and polymeric components. In the limiting case of bidisperse polymer-colloidal mixture, theoretical results are compared against computer simulation results. We pre...

We present hard-sphere crystallization kinetics for three samples with small differences in polydispersity. We show that an increase in polydispersity of 1% is sufficient to cause dramatic changes in the crystallization kinetics: crystallization is delayed by almost one decade in time and quantitative and qualitative changes in the crystallization scenario are observed. Surprisingly the nucleat...