Proposal Number: CTS-0553763 Principal Investigator: McCarthy, Joseph J. Affiliation: University of Pittsburgh Proposal Title: Macroparticle Self-(de)Assembly: Using Janus Beads to Control Cohesive Mixing/Segregation of Fine Particles
Intellectual Merit
The primary hindrance to good particle mixing lies in the fact that particles that differ even slightly in size, density, etc. easily segregate, or behave as "immiscible" materials, and little is known regarding limiting this unmixing tendency. This work is aimed at addressing the control of mixing and segregation of fine particles,
The proposed work makes a direct analogy to the handling of immiscible liquids when treating sine particle systems. The project will use amphiphilic particles - sometimes called "Janus beads" - as dry surfactants in order to dramatically improve control of the mixing of fine powders. Instead of manipulating the binary interparticle force directly, as is done in L-systems through changes in interstitial fluid, an additive component that mediates the binary interaction in order to make it favorable will be used. Moreover, in analogy to liquid-liquid extraction, the converse will also be possible: tailored particles may be used as extraction agents to separate particles that would normally tend to mix.
The project will result in the introduction of novel amphiphilic particle production methods; the development and validation of optical characterization techniques for pull-off force applicable to tailored particles in the size range of 10-250-m; development of a tested and validated cohesive mixing theory for predicting the impact of interstitial liquid and surface forces on the behavior of powders; and availability of a potentially commercially viable technique for novel particle processing applications of mixing and segregation (separation) using dry surfactants and particle extractors, respectively.
Broader Impacts
The broader impacts of the work lie in enhancing infrastructure, integrating teaching and research, and training of graduate students (with emphasis on under-represented groups). During the course of the project training will be provided for one full-time graduate student. Every effort will be made to recruit students from underrepresented groups. In particular, strong ties to two HBCU's - Clark Atlanta University and Morgan State University - will be leveraged for recruiting purposes. The proposed work will enhance infrastructure through the generation of novel and potentially commercially viable techniques for controlling particle processing behavior.
