Design and simulation of particle aggregates and determination of stability


Researchers Hans Moosmüller and Rajan Chakrabarty of the Desert Research Institute’s Division of Atmospheric Sciences focus on physical and chemical analysis, optical properties of atmospheric aerosols, and aerosol aggregation kinetics.

Technology Summary
Morphology (describing the structures of compound molecules) can be an important property for particle-related applications and can be useful for bulk production of nano-materials used in pharmaceutical modeling, synthesis of tires, printer ink/toner design, etc. Accurately determining the morphology of aggregates (groups of particles) can be difficult as they can have complex, fractal-like morphologies that require expensive, time consuming electron microscopy or light scattering measurements to analyze. Although some studies claim to simulate the particles as they exist in a fluid, such as air, they do not describe how the particles appear when located on the surface, such as the surface of a filter or other collection device.

The DRI computer implemented method for simulating an aggregate allows for more accurate design of products using nanoparticles. In the method, test aggregates are modeled and then rotated to analyze how the aggregate’s various positions would rest on a given surface. It identifies the spherical or linear fractal morphologies and can offer 2-D and 3-D simulation of aggregates based on specific input parameters.

The DRI method includes forming a test aggregate from a plurality of particles, then rotating the test aggregate. The stability of the rotated aggregate is determined by first defining a surface, and then determining potential point contacts of the aggregate with the surface. Contact points in the aggregate are classified into groups, and the center of mass is determined for each group to be a number of average contact points. The algorithm then determines whether the three-dimensional projection of the center of mass of the aggregate lies within a triangle formed by the average points of contact. If the center of mass does fall within the triangle, the aggregate is deemed stable. Determining the stability of aggregates allows for proper identification, selection, and orientation of particles for a given surface.

Potential Applications

  • Pharmaceuticals synthesis and processing

  • Manufacture and/or design of printer ink/toners, paints, and fillers

  • Fiber-optics products

  • Synthesis of tires

  • Aerosol synthesis

  • Carbon nanotube manufacturing

  • Other nanoparticle manufacturing needs

DRI is seeking expressions of interest from parties interested in collaborative research to further develop, evaluate, or commercialize this technology.

FracMAP: A user-interactive package for performing simulation and orientation-specific morphology analysis of fractal-like solid nano-agglomerates

IP Status
DRI ID# DRI08-001
Aggregate Simulation
US Patent No.: 8,396,700


Patent Information:
For Information, Contact:
April Sferrazzo
Account Tech
University of Nevada, Reno and Desert Research Institute
Hans Moosmuller
Rajan Chakrabarty
Mark Garro
Christopher Herald