{"106371":{"#nid":"106371","#data":{"type":"news","title":"Nanorod-Assembled Order Affects Diffusion Rate and Direction","body":[{"value":"\u003Cp\u003ESome of the recent advancements in nanotechnology depend\ncritically on how nanoparticles move and diffuse on a surface or in a fluid\nunder non-ideal to extreme conditions. Georgia Tech has a team of researchers\ndedicated to advancing this frontier.\u0026nbsp; \u003C\/p\u003E\n\n\u003Cp\u003ERigoberto Hernandez, a professor in the School of Chemistry\nand Biochemistry, investigates these relationships by studying three-dimensional\nparticle dynamics simulations on high-performance computers. His new findings,\nwhich focus on the movements of a spherical probe amongst static needles, have\nlanded on the cover of February\u2019s \u003Cem\u003E\u003Ca href=\u0022http:\/\/pubs.acs.org\/doi\/abs\/10.1021\/jp207346j\u0022 target=\u0022_blank\u0022\u003EThe\nJournal of Physical Chemistry B\u003C\/a\u003E.\u003C\/em\u003E\u003C\/p\u003E\n\n\u003Cp\u003EHernandez and his former Ph.D. student, Ashley Tucker, assembled\nthe rodlike scatterers in one of two states during his simulations: disordered\n(isotropic) and ordered (nematic). When the nanorods were disordered, pointing\nin various directions, Hernandez found that a particle typically diffused\nuniformly in all directions. When every rod pointed in the same direction, the\nparticle, on average, diffused more in the same direction as the rods than\nagainst the grain of the rods. \u0026nbsp;In this\nnematic state, the probe\u2019s movement mimicked the elongated shape of the\nscatterers. The surprise was that the particles sometimes diffused faster in\nthe nematic environment than in the disordered environment. That is, the\nchannels left open between the ordered nanorods don\u2019t just steer nanoparticles\nalong a direction, they also enable them to speed right through.\n\n\u003C\/p\u003E\u003Cp\u003EAs the density of the scatterers is increased, the channels\nbecome more and more crowded. The particle diffusing through these increasingly\ncrowded assemblies slows down dramatically in the simulation. Nevertheless, the\nresearchers found that the nematic scatterers continued to accommodate faster\ndiffusion than disordered scatterers. \n\n\u003C\/p\u003E\u003Cp\u003E\u201cThese simulations bring us a step closer to creating a\nnanorod device that allows scientists to control the flow of nanoparticles,\u201d\nsaid Hernandez. \u201cBlue-sky applications of such devices include the creation of\nnew light patterns, information flow and other microscopic triggers.\u201d \n\n\u003C\/p\u003E\u003Cp\u003EFor example, if scientists need a probe to diffuse in a\nspecific direction at a particular speed, they could trigger the nanorods to\nmove into a specified direction. When they need to change the particle\u2019s\ndirection, scatterers could then be triggered to rearrange into a different direction.\nIndeed, the trigger could be the absence of sufficient nanoparticles in a given\npart of the device. The ensuing reordering of the nanorods would then drive a\nrepopulation of nanoparticles that would then be available to perform a desired\naction, such as to stimulate light flow. \n\n\u003C\/p\u003E\u003Cp\u003E\u201cWhile this NSF-funded work to better understand the motion\nof particles within complex arrays at the nanoscale is very fundamental,\u201d\nHernandez says, \u201cit has significant long-term implications on device\nfabrication and performance at such scales. It\u2019s fun to think about and\nprovides great training for my students.\u201d\n\n\u003C\/p\u003E\u003Cp\u003E\u003Cem\u003EThis project is supported\nby the National Science Foundation (NSF) (Award Numbers \u003C\/em\u003E\u003Cem\u003ECHE-0749580 and CHE-0946869\u003Cem\u003E). The content is solely the responsibility of the principal\ninvestigators and does not necessarily represent the official views of the NSF.\u003C\/em\u003E\u003C\/em\u003E\u003C\/p\u003E\n\n\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\n\n\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E","summary":null,"format":"limited_html"}],"field_subtitle":[{"value":"Three-dimensional computer simulations reveal diffusional behavior"}],"field_summary":[{"value":"\u003Cp\u003EProfessor Rigoberto Hernandez, School of Chemistry and Biochemistry, studied the movements of a spherical probe amongst static nanorods. He found that the particles sometimes\ndiffused faster in a nematic environment than in a disordered environment.\nThat is, the channels left open between the ordered nanorods don\u2019t just steer\nnanoparticles along a direction, they also enable them to speed right through.\u003C\/p\u003E","format":"limited_html"}],"field_summary_sentence":[{"value":"New reasearch focuses on the movements of a spherical probe amongst static needles."}],"uid":"27560","created_gmt":"2012-02-06 10:10:50","changed_gmt":"2016-10-08 03:11:37","author":"Jason Maderer","boilerplate_text":"","field_publication":"","field_article_url":"","dateline":{"date":"2012-02-06T00:00:00-05:00","iso_date":"2012-02-06T00:00:00-05:00","tz":"America\/New_York"},"extras":[],"hg_media":{"106331":{"id":"106331","type":"image","title":"Diffusion of Spherical Probe through Static Nematogens","body":null,"created":"1449178174","gmt_created":"2015-12-03 21:29:34","changed":"1475894723","gmt_changed":"2016-10-08 02:45:23","alt":"Diffusion of Spherical Probe through Static Nematogens","file":{"fid":"193975","name":"p49c_cover.jpeg","image_path":"\/sites\/default\/files\/images\/p49c_cover_0.jpeg","image_full_path":"http:\/\/www.tlwarc.hg.gatech.edu\/\/sites\/default\/files\/images\/p49c_cover_0.jpeg","mime":"image\/jpeg","size":72381,"path_740":"http:\/\/www.tlwarc.hg.gatech.edu\/sites\/default\/files\/styles\/740xx_scale\/public\/images\/p49c_cover_0.jpeg?itok=zda6yrQh"}},"106341":{"id":"106341","type":"image","title":"Rigoberto Hernandez","body":null,"created":"1449178174","gmt_created":"2015-12-03 21:29:34","changed":"1475894723","gmt_changed":"2016-10-08 02:45:23","alt":"Rigoberto Hernandez","file":{"fid":"193976","name":"rigoberto_.jpg","image_path":"\/sites\/default\/files\/images\/rigoberto__0.jpg","image_full_path":"http:\/\/www.tlwarc.hg.gatech.edu\/\/sites\/default\/files\/images\/rigoberto__0.jpg","mime":"image\/jpeg","size":5003730,"path_740":"http:\/\/www.tlwarc.hg.gatech.edu\/sites\/default\/files\/styles\/740xx_scale\/public\/images\/rigoberto__0.jpg?itok=Qu-ha1Ee"}},"106361":{"id":"106361","type":"image","title":"Rigoberto Hernandez 2","body":null,"created":"1449178174","gmt_created":"2015-12-03 21:29:34","changed":"1475894723","gmt_changed":"2016-10-08 02:45:23","alt":"Rigoberto Hernandez 2","file":{"fid":"193977","name":"rigoberto_again.jpg","image_path":"\/sites\/default\/files\/images\/rigoberto_again_0.jpg","image_full_path":"http:\/\/www.tlwarc.hg.gatech.edu\/\/sites\/default\/files\/images\/rigoberto_again_0.jpg","mime":"image\/jpeg","size":4976000,"path_740":"http:\/\/www.tlwarc.hg.gatech.edu\/sites\/default\/files\/styles\/740xx_scale\/public\/images\/rigoberto_again_0.jpg?itok=JX64nT6y"}}},"media_ids":["106331","106341","106361"],"groups":[{"id":"1183","name":"Home"}],"categories":[{"id":"149","name":"Nanotechnology and Nanoscience"},{"id":"135","name":"Research"}],"keywords":[{"id":"4498","name":"Chemistry and Biochemistry"},{"id":"107","name":"Nanotechnology"}],"core_research_areas":[],"news_room_topics":[],"event_categories":[],"invited_audience":[],"affiliations":[],"classification":[],"areas_of_expertise":[],"news_and_recent_appearances":[],"phone":[],"contact":[{"value":"\u003Cp\u003EJason Maderer\u003Cbr \/\u003EGeorgia Tech Media Relations\u003Cbr \/\u003E404-385-2966\u003Cbr \/\u003E\u003Ca href=\u0022mailto:maderer@gatech.edu\u0022\u003Emaderer@gatech.edu\u003C\/a\u003E\u003C\/p\u003E","format":"limited_html"}],"email":["maderer@gatech.edu"],"slides":[],"orientation":[],"userdata":""}}}