Austin Williams

ahwilli5@ncsu.edu

M.S., Chemical Engineering, 2018
North Carolina State University

B.S., Chemistry, 2016
Birmingham-Southern College

 

Research Focus #1: Soft Dendritic Colloids

Our group has recently developed a scalable, shear-driven precipitation technique to fabricate polymeric particles with controlled morphologies to the nanoscale. One particle morphology resulting from this technique is the Soft Dendritic Colloid (SDC), which is characterized by a branched corona of nanofibers spread out in all directions about the particle. This technique enables the production of nanofibrous materials from most polymer and biopolymer materials including hydrogels. We are also able to show control over the morphology of the resulting particulates from highly fibrous SDCs to extremely thin, nano-sheet particles. The combination of choice in regard to the polymer material and choice in regard to the morphologies of the produced particulates presents the shear-driven precipitation technique as a powerful tool to fabricate designer colloidal materials.

SDCs are the most interesting of the materials resulting from the technique, with their unique structure enabling remarkable colloidal structure-building and network-forming capabilities including strong physical adhesion through a mechanism similar to the “gecko leg” effect. This adhesive effect allows the facile formation of SDC surface and textile coatings as well as highly porous nonwoven SDC sheets. In suspension, the “stickiness” of SDCs gives rise to an inter-particle, colloidal fiber network throughout the fluid, inducing gelation at very low volume fractions. Along with broadening our understanding of the thermodynamic and physical parameters that govern particle formation, our group continues to find applications for these particles including superhydrophobic and anti-icing coatings, novel biopolymer hydrogel fillers for 3D printing applications. Other applications of interest include making porous aerogels and nonwovens for cell scaffolding applications.

Publications:

Roh, S.; Williams, A. H.; Bang, R. S.; Stoyanov, S. D.; Velev, O.D. Soft Dendritic Microparticles with Unusual Adhesion and Structure Properties. Nat. Mater. 2019, 1-6. DOI: 10.1038/s41563-019-0508-z