PEOPLE · FACULTY

FACULTY

Matthew Z. Yates
Associate Professor, Scientist LLE
Ph.D. 1999, University of Texas

249 Gavett Hall
(585)273-2335
myates@che.rochester.edu

Website:
http://www.che.rochester.edu/~myates/

Courses

ChE 150 Green Engineering for a Sustainable Environment
ChE 225: Thermodynamics
ChE 454 Interfacial Engineering

Research Topics: Colloids and Interfaces, Materials Synthesis in Microemulsions, Nanoparticle/Polymer Composites, Supercritical Fluids, Microencapsulation


Overview: We are interested in applying colloid and interface science to the development of advanced materials and environmentally responsible processes. A variety of techniques are used to synthesize materials with controlled structure on the nanometer length scale. The "nanoengineering" of materials allows control of optical, chemical, and physical properties of materials used in catalysis, controlled release of pharmaceuticals, and optics.

Materials Synthesis in Microemulsions. Under appropriate conditions, surfactants in oil water systems will self-assemble into nano-scale aggregates of surfactant molecules surrounding a fluid core. These microemulsion droplets can be used as "nano-reactors" for the synthesis of a variety of materials, including metal, semiconductor, or polymer nanoparticles. One little explored area is the synthesis of zeolites and molecular sieves in microemulsion droplets. Zeolites and molecular sieves are crystalline materials with well-defined pore sizes near molecular dimensions that are widely used in catalysis and separations. We are exploring ways to use microemulsions to control overall crystal size of zeolites and molecular sieves, and also to use microemulsion droplets as templates to control pore sizes within the crystal.

Supercritical Fluid-Assisted Microencapsulation. Polymer colloids are often used for the controlled release of pharmaceuticals, fragrances, or other "active ingredients". The most common techniques for encapsulating the active ingredients require either high temperatures or toxic solvents. We have recently demonstrated a versatile technique that employs liquid or supercritical carbon dioxide to facilitate microencapsulation through the reversible swelling of colloidal polymer particles (Yates, et al, Langmuir, 2000). Our process is effective at room temperature and the only solvents required are carbon dioxide and water. We are extending this process to the encapsulation of pharmaceuticals into biodegradable polymer colloids for controlled release applications.

Polymer/Nanoparticle Composites. Colloidal polymer particles may be coated with a thin layer of inorganic nanoparticles (diameter <10nm) to control the chemical or optical properties of the colloidal particles. For example, polymer colloids may be coated with a thin layer of zeolite or metal nanoparticles to provide a novel support for heterogeneous catalysis. Another example is the coating of polymer colloids with luminescent semiconductor nanoparticles to control optical properties of coatings. We are interested in exploring a variety of techniques for the synthesis of polymer/nanoparticle colloidal composites. In addition, we are interested in assembly of these colloidal particles into organized structures for application in catalysis, separations, and photonic crystals.