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Ralph Colby

address: 305 Steidle Building
location: Earth and Mineral Sciences
phone: 8148633457
department: Materials Science & Engineering


Flow-induced crystallization of polymers

Semi-crystalline polymers are a very important class of engineering thermoplastic. When subjected to flow, the polymer chains get stretched and crystallize more readily. We try to understand this flow-induced crystallization using AFM, calorimetry, optical microscopy, rheology and X-ray scattering experiments.

Number of undergraduates needed: 2
Minimum qualifications: Materials Science or Chemical Engineering undergradautes

Solutions of Native Cellulose in Ionic Liquids

Certain ionic liquids are good at breaking hydrogen bonds and can dissolve native cellulose. For many years humans have chemically modified cellulose to make it soluble for fiber spinning and coating. By dissolving native cellulose, all the hydrogen bonding in wood allows higher modulus fibers and since the ionic liquids can be easily recovered, this new processing of native cellulose is very green and sustainable.

Number of undergraduates needed: 2
Minimum qualifications: knowledge of cellulose structure and hydrogen bonding

Semiflexible Conjugated Polymers

Conjugated polymers find uses in flexible electronic devices, such as solar cells. This class of polymer has chains that are naturally more rigid than standard flexible-chain polymers. Rigidity means that the polymers entangle more easily but also crystallize and perhaps form nematic phases above their melting point. Together with Professors Enrique Gomez and Scott Milner (both in Chemical Engineering) we aim to develop a better fundamental understanding of semiflexible conjugated polymers, using a combination of computer simulations and experiments.

Number of undergraduates needed: 3
Minimum qualifications: undefined