Conferència “Functional Nanofibers and Hierarchical Hybrids”

Dimecres, 22 de febrer de 2017, 12.00h, Sala Conferències Edifici TR1

Functional Nanofibers and Hierarchical Hybrids

 You-Lo Hsieh

University of California, Davis

Summary

Natural polymers are responsible for structural integrity and/or functions of living organisms and are among the most abundant renewable resources. Biopolymers such as polysaccharides, proteins and polyphenolics are, however, challenging to be engineered into products due to non-thermoplastic characteristics, limited solubility in common solvents and difficulty in molecular reorganization in the solid state. This conference presents diverse approaches to generate nanofibers with unique hierarchical structural hybrids to create novel functional properties. Robust solubility and electrospinning of cellulose, chitin and chitosan have been achieved via their chemical derivatives. Electrospinning of polyphenolics and proteins has been made possible by optimizing aqueous processing. From the most abundant and most structurally homogeneous cellulose, highly crystalline nanocellulose, either cellulose nanocrystals (CNCs) or nanofibrils (CNFs), have been derived from major under-utilized biomass. With varied nano-scale dimensions and surface chemistries, these nanocelluloses carry hydrophobic-hydrophilic moieties and different charge densities for applications as organic dispersible agents, coagulants for microbes, aerogels, templates for nanoprisms and various self-assembled structures. These electrospinning and self-assembling approaches have been exploited to create unique morphologies (multi-component hybrids, sheath-core, hierarchical porosity, etc.) and chemistries (protein/enzyme binding, ligand binding, antimicrobial) for applications in catalysis, separation, biochemical/drug-delivery and imaging, etc. In addition, various carbon and silica nanomaterials can also be derived from the parallel hemicellulose, lignin and silicon streams from the biomass.