viscoelasticity – TechConnect Briefs

Rheological Behavior of Novel Switchable Cationic Surfactant in High Salinity Carbonate Reservoirs

Gurusinghe N., Ramadan G., Liebum M., Nguyen Q.P., The University of Texas at Austin, US

The use of viscoelastic (VES) or polymer-like surfactant solutions are important in applications related to enhanced oil recovery and subsurface conformance control. VES resembles polymer where it acts as a mobility control agent to promote [...]

Rheological Characterization of a Novel Viscoelastic Surfactant for Subsurface Applications

Liebum M., Nguyen Q.P., The University of Texas at Austin, US

Viscoelastic solutions (VES) are used in many applications including oil and gas operations regarding reservoir stimulation and enhanced oil recovery to modify rheology properties in the subsurface. In general, the viscoelastic property of the surfactant [...]

Dynamic Nanoindentation Analysis using Generalized Maxwell Model for Viscoelastic Materials Characterization

Yuya P.A., Patel N.G., Clarkson University, US

Nanoindentation has become a very useful tool for materials properties characterization at nanoscale. The Kelvin-Voigt (two-parameter) solid has been used as the conventional model for the tip-sample forces for viscoelastic contact where the sample stiffness [...]

POSS–Substituted Hyperbranched Polyester Blends with Thermoplastic Polyurethanes

Spoljaric S., Shanks R.A., RMIT University, AU

The aim of this research is to prepare and disperse in an elastomer a multi-branched form of POSS. Hyperbranched polymers (HBP) can be formed by grafting from a central core. POSS may be joined with [...]

Magnetic Carbon-Nanotube Thermoplastic Polyurethane Composites

Kong I., Spoljaric S., Shanks R.A., RMIT University, AU

The aim was to prepare composites of PU and magnetite-functionalized CNTs, using physical blending techniques in melt and solution. Objectives included functionalizing the CNT with magnetite (Fe3O4), preparing PU-CNT-Fe3O4 composites using solvent dispersion and melt [...]

Graphite Layer Nano-composites with Polyurethane Matrix

Czajka M., Shanks R.A., RMIT University, AU

The aim was to prepare expanded graphite oxide (GO, Graftech Inc.) and disperse it in a polyol (poly(oxypropylene glyceride), Dow Chemicals) using ultrasonication. The dispersion was polymerized and crosslinked with methane 4,4’-diphenyldiisocyanate to form a [...]

Effects of Crosslinking Condition on Mechanical and Biological Properties of Biomimetic Fibrous Composite Material for Arterial Medial Equivalent

Madhavan K., Belchenko D., Tan W., University of Colorado at Boulder, US

This study involves the mechanical and biological characterization of crosslinked collagen-based scaffolds for arterial medial-equivalent. These scaffolds are made from a mixture of collagen, chitosan and elastin and crosslinked with genipin. The method of optimization [...]

A Computational Model with Experimental Validation for DNA Flow in Microchannels

Nonaka A., Gulati S., Trebotich D., Miller G.H., Muller S., Liepmann D., UC Davis / Lawrence Livermore National Laboratory, US

We compare a computational model to experimental data for DNA-laden flow in microchannels. The purpose of this work in progress is to validate a new numerical algorithm for viscoelastic flow of an Oldroyd-B fluid. Significant [...]

A Numerical Algorithm for Complex Biological Flow in Irregular Microdevice Geometries

Trebotich D., Colella P., Miller G.H., Nonaka A., Marshall T., Gulati S., Liepmann D., Lawrence Livermore National Laboratory, US

We present a numerical algorithm to simulate non-Newtonian flow in complex microdevice components. The model consists of continuum viscoelastic incompressible flow in irregular microscale geometries. Our numerical approach is the projection method of Bell, Colella [...]

A Numerical Model of Viscoelastic Flows in Microchannels

Trebotich D., Colella P., Miller G., Liepmann D., Lawrence Livermore National Laboratory, US

We present a numerical method to model non-Newtonian, viscoelastic flow at the microscale. The equations of motion are the incompressible Navier-Stokes equations coupled with the Oldroyd-B constitutive equation. This constitutive equation is chosen to model [...]