Polymer Physics

Film formation and Rupture in Drying Polymer Films

The understanding of the film formation process in drying polymer films is critical for a number of applications such as in construction, pharmaceutical Industry and semiconductor. When a thin film of dilute polymer solution is applied on a substrate, the solvent evaporates to concentrate the polymer. With increasing concentration, stresses develop in the film. If the stress exceeds a critical value, the film may rupture or delaminate from the substrate. The critical stress depends on the nature of polymer, solvent, drying rate and the adhesion of the polymer film and the substrate.

Upcycling of thermoplastics and microplastic formation

This project will examine end-of-life issues with plastics. Currently, the annual global production of plastics is approaching 400 million tons. The vast majority of this goes into land-fills or otherwise leaks into the environment. Therefore, developing strategies to collect and efficiently recycle plastics has become increasingly important. One of the strategies is thermomechanical recycling. In this, thermoplastics can be melted and reprocessed. However, this results in degradation of functional properties.

Molecular Modeling of Elasticity of Spider Silk and Related Biopolymers (TA / FA)

In this project, the aim is to understand quantitatively the molecular elasticity of biopolymers with potential engineering applications. The first example is Spider Dragline Silk, which may be several times stronger than steel (after normalizing the density). The work involves experimental, computational and theoretical analyses of the molecular structure of the biopolymer system.

Accurate Molecular Models for Real Polymers (TA/FA)

We develop useable, closed form, but accurate molecular models as well as elasticity relationships for real polymers, incorporating structural aspects.

The applications include synthetic as well as high performance Bio-sourced polymers.

Polymer Dynamics in Turbulent Flows

Adding even a small amount of dissolved polymer into a fluid can have a dramatic impact on the way it flows. If the flow is turbulent (high-Reynolds-number) to begin with, then the polymer can strongly modify the turbulent eddies and reduce the drag force (in flow through pipes) or even make the flow laminar. Known as the Toms effect, this phenomena is exploited to reduce the pumping costs associated with transporting oil in pipelines. Polymers can also destabilize a low-Reynolds-number steady flow and make it unsteady and chaotic.

Polymer-grafted nanoparticles

Composites of polymer and nanoparticles have many property improvements compared to pure polymer.  These include improvements in mechanical strength, thermal conductivity, electrical conductivity, optical properties, and photoelectric properties.  However, the mixing of polymer with nanoparticles often poses a problem.  To over come this issue and others, there have been recent efforts toward the synthesis of polymer-grafted nanoparticles.  These new types of species show interesting phase behavior - often forming new types of self-assembled phases with new interesting properties (https://p

Gelation and network formation in polymer-grafted nanoparticles

Some initial work in our group, and from other groups suggests that polymer-grafted nanoparticles can for networks and equilibrium gels under the right conditions.  This is remarkable, since while gels are useful most gels represent non-equilibrium states that age, and disintegrate with time.  The idea of forming equilibrium gels which are non-perishable, is therefore attractive.  In this study we determine the conditions for the formation of equilibrium gels by grafted nanoparticles.

A basic understanding of coding is required.

Polymer grafted nanoparticles as separation and fuel cell membranes

Polymer membranes are popular in separation and fuel cell applications.  Moreover, nanoparticle-filled polymer membranes can simultaneously improve properties such as permeability and selectivity.  The challenge lies in stabilizing these membranes against phase separation.  Recent progress in grafting polymer onto the surface of nanoparticles may mitigate some of these challenges.  This project uses statistical mechanics to study the efficacy of grafted nanoparticles as effective membrane materials.

Basic programming ability is needed. 

The phase behavior of connected hard and soft particles.

A surprising new development in materials science and chemical engineering is the finding that mixtures of hard (colloidal), and soft (polymeric, or micellar) particles can self organize on length scales much larger than the diameter of either species.  In this project we explore the behavior of connected hard- and soft particles.  An elementary knowledge of coding is sufficient.

The role of shape in the self-assembly of polymer-grafted nanoparticles.

Traditionally, self-assembled structures are formed using chemical differences within a species.  Examples of this are the formation of micelles by detergents, and the formation of the phospholipid bilayer of the cell membrane.  In these systems it is the tendency to the hydrophobic and hydrophilic part to avoid each other that result in the self-assembled state.  However, a recent study (http://pubs.rsc.org/en/content/articlehtml/2017/sm/c7sm00230k) has pointed out that it is possible to form self-assembled states