Current methods for characterizing nanostructures are typically destructive or applicable to thin films exposed on one side. Molecular probes encased in nanoparticles permit nondestructive measurement of several properties via fluorescence. Our probes are designed and synthesized to combine fluorescence with interfacial compatibility. Localized measurements such as this can be applied to measure water content, temperature, and species concentrations in many environments including fuel cell membranes and polymer blends.

Research Interest: 3D Imaging

The 3D structure of heterogeneous materials is often complex, and leads to complex relationships between the structure and properties. For example, X-ray micro CT illustrates how well ordered 2D textiles develop disordered 3D structures in a composite material. Image analysis indicates that layer nesting and shifting is responsible for the variety of microstructures observed. Other imaging technologies such as optical coherence tomography are also being used to image features such as damage and void distribution at better resolution and with more sensitivity than X- ray CT can provide.

Research Interest: Flow in Porous Media

The disordered and irreproducible microstructures seen in the center image can lead to broad distributions in macroscopic properties, as illustrated in the distribution of permeability shown in the upper right image. The permeability is a critical processing parameter in composite manufacturing operations such as liquid molding and pultrusion. High throughput experimental techniques were developed to permit the acquisition of sufficient permeability data to reveal the stochastic nature of the permeability of fabric preforms. Fluid mechanics modeling of the center image structure using lattice Boltzman and pore network techniques clearly show the relationship between the experimental distribution on the right and the structural distribution in the center.

Research Interest: New Feedstocks for the Commodity Plastics Market

New plastics are being developed from plant protein, a renewable and biodegradable resource. Small quantities of designed molecules are added to the protein to improve the toughness by an order of magnitude without decreasing stiffness. The current challenge is stabilizing the properties of the protein based plastic. Understanding the interactions of moisture with the modified protein structure is expected to help develop the processing and formulation strategy for maximizing property stability.