A novel extensional viscometer was developed to measure the extensional properties of aqueous solutions of polymeric material and coal water slurries (CWS) containing additives. When a drop of viscoelastic liquid or CWS containing additives is allowed to form at the end of a capillary tube, it starts to fall once its weight exceeds the retaining force exerted by surface tension. In experiments ...

The coordination compounds of Fe (II) and Fe(III) with phthalic acid were synthesized. The compounds were studied by X-Ray Diffraction (XRD), Differential Thermal Analysis (DTA), and IR spectroscopy. It has been established that, regardless of the oxidative number of iron, the synthesis products have the same chemical composition and chemical formula - [Fe2(o-C6H4...

We experimentally investigate the drag-reduced channel flow of an inelastic, shear-thinning rigid polymer solution. Particle image velocimetry and shear-viscosity measurements are used to obtain instantaneous distributions shear viscosity within turbulent domain. elucidate that drag reduction for polymers is primarily driven by a thin lubricating layer consists low-viscosity fluid near wall.

We perform molecular dynamics simulations on a bead-spring model of pure polymer grafted nanoparticles (PGNs) and of a blend of PGNs with a polymer melt to investigate the correlation between PGN design parameters (such as particle core concentration, polymer grafting density, and polymer length) and properties, such as microstructure, particle mobility, and viscous response. Constant strain-ra...

Dilute polymer solutions and polymer melts in shear flow have been extensively studied experimentally and theoretically. However, a systematic experimental study to understand the influence of concentration, temperature and molecular weight on the rheology of semidilute polymer solutions is currently lacking. Such knowledge is of crucial importance in a number of industrial and biological conte...

This paper discusses shear viscosity measurements of polymer melts by the capillary rheometer. Particular emphasis is placed on investigating the effects of viscous heating and pressure dependence of viscosity in capillary flows. The capillary flow problem is addressed by means of numerical simulation using the finite element method to solve the equations of continuity, momentum and energy alon...

Molecular rotors are a group of fluorescent molecules that form twisted intramolecular charge transfer (TICT) states upon photoexcitation. When intramolecular twisting occurs, the molecular rotor returns to the ground state either by emission of a red-shifted emission band or by nonradiative relaxation. The emission properties are strongly solvent-dependent, and the solvent viscosity is the pri...

We report a small angle neutron scattering (SANS) and rheology study of cellulose derivative polyelectrolyte sodium carboxymethyl cellulose with a degree of substitution of 1.2. Using SANS, we establish that this polymer is molecularly dissolved in water with a locally stiff conformation with a stretching parameter[Formula: see text]. We determine the cross sectional radius of the chain ([Formu...

We have experimentally investigated multicomponent diffusion in a protein-polymer-salt-water quaternary system. Specifically, we have measured the nine multicomponent diffusion coefficients, D(ij), for the lysozyme-poly(ethylene glycol)-NaCl-water system at pH 4.5 and 25 degrees C using precision Rayleigh interferometry. Lysozyme is a model protein for protein-crystallization and enzymology stu...

Particle tracking has been shown to be a powerful technique for measuring bulk and interfacial rheology of fluids. The Brownian motion of microparticles trapped at interfaces is very sensitive to the viscosity of the subphase, and to the contact angle of the particles. The Stokes-Einstein relation is fulfilled if the friction factor is properly taken into account. The diffusion coefficient of t...