Temperature and Concentration Dependence of Human Whole Blood and Protein Drying Droplets.

The drying of bio-colloidal droplets can be used in many medical and forensic applications. The whole human blood is the most complex bio-colloid system, whereas bovine serum albumin (BSA) is the simplest. This paper focuses on the drying characteristics and the final morphology of these two bio-colloids.

An Overview of Emergent Order in Far-from-Equilibrium Driven Systems: From Kuramoto Oscillators to Rayleigh-Bénard Convection.

Soft-matter systems when driven out of equilibrium often give rise to structures that usually lie in between the macroscopic scale of the material and microscopic scale of its constituents. In this paper we review three such systems, the two-dimensional square-lattice Ising model, the Kuramoto model and the Rayleigh-Bénard convection system which when driven out of equilibrium give rise to emergent spatio-temporal order through self-organization. A common feature of these systems is that the entities that self-organize are coupled to one another in some way, either through local interactions or through a continuous media.

Concentration-driven phase transition and self-assembly in drying droplets of diluting whole blood.

Multi-colloidal systems exhibit a variety of structural and functional complexity owing to their ability to interact amongst different components into self-assembled structures. This paper presents experimental confirmations that reveal an interesting sharp phase transition during the drying state and in the dried film as a function of diluting concentrations ranging from 100% (undiluted whole blood) to 12.5% (diluted concentrations).

A comparative study of the drying evolution and dried morphology of two globular proteins in de-ionized water solutions.

Pattern formation in drying protein droplets continues to attract considerable research attention because it can be linked to specific protein-protein interactions. An extensive study of the drying evolution and the final crack patterns is presented, highlighting the concentration dependence (from 1 to 13 wt%) of two globular proteins, lysozyme (Lys) and bovine serum albumin (BSA), in de-ionized water. The drying evolution starts with a constant contact radius mode and shifts to a mixed mode where both fluid front and contact angle changes.

Coexisting Ordered States, Local Equilibrium-like Domains, and Broken Ergodicity in a Non-turbulent Rayleigh-Bénard Convection at Steady-state.

A challenge in fundamental physics and especially in thermodynamics is to understand emergent order in far-from-equilibrium systems. While at equilibrium, temperature plays the role of a key thermodynamic variable whose uniformity in space and time defines the equilibrium state the system is in, this is not the case in a far-from-equilibrium driven system. When energy flows through a finite system at steady-state, temperature takes on a time-independent but spatially varying character.

Aging and efficiency in living systems: Complexity, adaptation and self-organization.

Living systems are open, out-of-equilibrium thermodynamic entities, that maintain order by locally reducing their entropy. Aging is a process by which these systems gradually lose their ability to maintain their out-of-equilibrium state, as measured by their free-energy rate density, and hence, their order. Thus, the process of aging reduces the efficiency of those systems, making them fragile and less adaptive to the environmental fluctuations, gradually driving them towards the state of thermodynamic equilibrium.

Calorimetric study of phase transitions in ocylcyanobiphenyl-barium titanate nanoparticle dispersions.

High-resolution ac-calorimetry is reported on the weakly first-order isotropic to nematic (I-N) and the continuous nematic to smectic-A (N-SmA) phase transitions in the liquid crystal octylcyanobiphenyl (8CB) doped with a ferroelectric nanoparticle barium titanate, BaTiO3 (BT). Measurements were performed as a function of BT concentration and over a wide temperature range well above and below the two transitions. From the thermal scans of all samples (having BT mass fraction φ(m) = 0.

Calorimetric study of the nematic to smectic-A phase transition in octylcyanobiphenyl-hexane binary mixtures.

The continuous nematic to smectic-A (N-SmA) phase transition has been studied by high-resolution ac-calorimetry in binary mixtures of the liquid crystal octylcyanobiphenyl (8CB) and a nonmesogenic, low-molecular weight, solvent n-hexane (hex) as a function of temperature and solvent concentration. Heating and cooling scans about the N-SmA transition temperature were repeatedly performed on pure and six 8CB+hex samples having hexane molar concentration ranging from x(hex)=0.02 to 0.

Study of the isotropic to smectic-A phase transition in liquid crystal and acetone binary mixtures.

The first-order transition from the isotropic (I) to smectic-A (Sm A) phase in the liquid crystal 4-cyano-4(')-decylbiphenyl (10CB) doped with the polar solvent acetone (ace) has been studied as a function of solvent concentration by high-resolution ac-calorimetry. Heating and cooling scans were performed for miscible 10CB+ace samples having acetone mole fractions from x(ace)=0.05 (1 wt %) to 0.

Orientational coupling enhancement in a carbon nanotube dispersed liquid crystal.

We present a detailed study of a dilute suspension of carbon nanotubes (CNTs) in a pentylcyanobiphenyl (5CB) liquid crystal (LC) by probing the dielectric properties as a function of applied ac voltage and frequency. In principle, to minimize the elastic distortion in the nematic matrix, the monodispersed CNTs follow the nematic director without disturbing the director field significantly. A strong anchoring energy due to π-π electron stacking between LC-CNT molecules results in an increase in the dielectric anisotropy for the hybrid system, indicating a significant enhancement in the orientational order parameter.

Evidence for directed self-assembly of quantum dots in a nematic liquid crystal.

Assembling quantum dots (QDs) into nanoscale configurations over macroscopic dimensions is an important goal to realizing their electro-optical potential. In this Rapid Communication, we present a detailed study of a pentylcyanobiphenyl liquid crystal (LC) and a CdS QD colloidal dispersion by probing the dielectric property epsilon and relaxation as a function of an applied ac electric field Eac. In principle, dispersing QDs in a nematic LC medium can direct the dots to align in nearly one-dimensional chainlike structures along the nematic director and these assemblies of QDs can be directed by external electric fields.

Induced thermal dynamics in the melt of glycerol and aerosil dispersions.

A high-resolution calorimetric spectroscopy study has been performed on pure glycerol and colloidal dispersions of an aerosil gel in glycerol covering a wide range of temperatures from 300 to 380 K, deep in the liquid phase of glycerol. The colloidal glycerol+aerosil samples with 0.07, 0.

Kinetics of induced crystallization of the LC(1-x)Sil(x) system.

This study explores the kinetics of a new feature, called "induced crystallization (IC)", observed in an Aerosil dispersed octylcyanobiphenyl (8CB) liquid crystal system. Heating rate dependent experiments were performed using modulation differential scanning calorimetry (MDSC) at various heating ramp rates. In the presence of Aerosil nanoparticles, a well-defined exothermic peak was found as an additional feature on the heating scan before the melting transition, which was absent in the bulk 8CB; hence, we like to call it an "IC" as it is induced by Aerosil nanoparticles in the system.

Role of aerosil dispersion on the activated kinetics of the LC1-xSilx system.

This study explores the role of aerosil dispersion on activated phase transitions of bulk octylcyanobiphenyl (8CB) liquid crystals by performing heating rate-dependent experiments. Differential scanning calorimetry (DSC) was used at various heating ramp rates in order to probe the activated phase dynamics of the system. The system, LC1-xSilx, was prepared by mixing aerosil nanoparticles (7 nm in diameter) in the bulk 8CB by the solvent dispersion method (SDM).

Thermodynamics of activated phase transitions of 8CB: DSC and MC calorimetry.

The present paper reports the heating rate effect on the phase transitions of a pure liquid crystal octylcyanobiphenyl (8CB) with use of Differential Scanning Calorimetry (DSC) and Modulation Calorimetry (MC) techniques. The DSC runs were taken at various temperature ramp rates from 20 to 0.5 K/min for heating and cooling scans.

Smectic ordering in liquid-crystal-aerosil dispersions. II. Scaling analysis.

Liquid crystals offer many unique opportunities to study various phase transitions with continuous symmetry in the presence of quenched random disorder (QRD). The QRD arises from the presence of porous solids in the form of a random gel network. Experimental and theoretical work supports the view that for fixed (static) inclusions, quasi-long-range smectic order is destroyed for arbitrarily small volume fractions of the solid.

Elastic coupling of silica gel dynamics in a liquid-crystal-aerosil dispersion.

The dynamics of a thixotropic silica aerosil gel dispersed in an octylcyanobiphenyl liquid crystal were directly probed by x-ray intensity fluctuation spectroscopy. For all samples, the time-autocorrelation function of the gel was well described by a modified-exponential function over the q range studied. Compared to a pure gel sample, a dilute (0.