February 7, 2012
Some of the recent advancements in nanotechnology depend critically on how nanoparticles move and diffuse on a surface or in a fluid under non-ideal to extreme conditions. Georgia Tech has a team of researchers dedicated to advancing this frontier.
Rigoberto Hernandez, a professor in the School of Chemistry and Biochemistry, investigates these relationships by studying three-dimensional particle dynamics simulations on high-performance computers. His new findings, which focus on the movements of a spherical probe amongst static needles, have landed on the cover of February’s The Journal of Physical Chemistry B.
Hernandez and his former Ph.D. student, Ashley Tucker, assembled the rodlike scatterers in one of two states during his simulations: disordered (isotropic) and ordered (nematic). When the nanorods were disordered, pointing in various directions, Hernandez found that a particle typically diffused uniformly in all directions. When every rod pointed in the same direction, the particle, on average, diffused more in the same direction as the rods than against the grain of the rods. In this nematic state, the probe’s movement mimicked the elongated shape of the scatterers. The surprise was that the particles sometimes diffused faster in the nematic environment than in the disordered environment. That is, the channels left open between the ordered nanorods don’t just steer nanoparticles along a direction, they also enable them to speed right through.
February 4, 2012
Nanodiamonds designed to toughen artificial joints also might prevent the inflammation caused when hardworking metal joints shed debris into the body, according to an early study published this week in the journal Acta Biomaterialia.
In the race to create longer-lasting and less-painful artificial joints, University of Alabama at Birmingham researchers are exploring whether nanodiamond coatings can reduce wear on joints made of metal alloys. The work is important because, according to the American Academy of Orthopedic Surgeons, more than 418,000 knee replacements and 328,000 hip replacements are performed in the United States each year; the numbers are expected to balloon as the nation’s population ages.
November 18, 2011
Researchers at HRL Laboratories, LLC, announced today they have developed the world’s lightest material with a density of 0.9 mg/cc, approximately one hundred times lighter than Styrofoam™. The results of their research?a collaborative effort between HRL, The California Institute of Technology and the University of California, Irvine?are published in the November 18 issue of Science.