CAMP Professor Dipankar Roy uses Electrochemical Techniques for the Characterization and Processing of Materials

Professor Dipankar Roy is using electrochemical methods to characterize and process materials for a variety of applications. The ongoing characterization studies in his laboratory are strongly centered on nanomaterials, for advanced energy storage and conversion devices. This work is part of a CAT Development Project with NanoDynamics (ND) and MetaMateria Partners (MMP, a wholly owned subsidiary of ND). Nanomaterials of various metal oxide ceramics and carbon nanotube based composites are designed and fabricated by MMP for applications in advanced lithium ion batteries, supercapacitors and similar energy storage/conversion devices. Professor Roy's group is involved in quantitative electrochemical characterization of these materials.

Material processing studies in Professor Roy's laboratory are linked to several electrochemical mechanical planarization (ECMP) projects. A major focus of these projects is on the development of ECMP strategies for residual copper removal. Although bulk Cu-removal by ECMP is already in manufacturing, handling of the Cu-clearing step still poses several challenges in ECMP (such as maintaining an adequate removal rate throughout the clearing step due to increasing film resistance during Cu thinning, and minimization of "island"-like Cu residuals). Bulk removal of copper in ECMP is often achieved through electrochemical dissolution of cupric (and sometimes cuprous) ions. For residual copper removal, the solution chemistry is designed to suppress these steps to some extent, along with a substantial lowering of chemical etching. Soluble surface complexes (that are not necessarily cupric ions, at least in the first step) are formed in this case through electrochemical reactions. The experimental strategy here is to activate electrochemical (rather than chemical) surface complex formation under voltage-controlled conditions that are different from those necessary to directly electro-dissolve copper as Cu2+. The surface layer removal rate can be precisely controlled in this approach by limiting the activation voltage to a relatively low value, and by tuning the temporal profile of the voltage, together with careful adjustments of electrolyte compositions.

For the ECMP work, a home-built laboratory scale planarization machine is employed, which can also be coupled with electrochemical impedance measurements to probe the mechanisms and kinetics of the relevant surface reactions. Professor Roy is collaborating with CAMP Director Professor Babu on a number of ECMP projects. A polisher (Center for Tribology), equipped with an ECMP module, is set up in Professor Babu's laboratory and being used for these studies. More information regarding Professor Roy's current research can be found at the following website. http://people.clarkson.edu/~samoy/cr_projects.htm





CAMP's Spring Meeting

CAMP will hold its Spring Meeting on April 4, 2008 at the Desmond Hotel in Albany, New York. It will cover the broad range of CAMP research activities and give industrial scientists / engineers a chance to interact with CAMP faculty on their expertise. This enlightening and stimulating event will include a reception and dinner on April 3.

Clarkson Professor Igor Sokolov and Collaborators Have Two of the Most Accessed Articles

Professor Igor Sokolov

Clarkson University Physics Professor Igor Sokolov, along with postdoctoral researcher Sajo P. Naik, and two collaborators in Japan have one of the most-accessed articles published in The Journal of Physical Chemistry C. Their article, "Morphology Control of Mesoporous Silica Particles," was one of the journal's most accessed articles from July to September 2007. In the paper, the scientists described a novel method of synthesis for nanoporous silica (glass) particles. The particles are highly porous with a pore size of about 2.5 nanometers. The researchers showed that by changing the synthesis conditions, one can control the shape of the particles, for example, obtain curved micron-size particles such as discoids and spheres.

This research was published in the July 7, 2007 issue of The Journal of Physical Chemistry C. An abstract of the article is at http://pubs.acs.org/cgi-bin/abstract.cgi/jpccck/2007/111/i30/abs/jp0727042.html.

CAMP Professor Igor Sokolov and his team have discovered a method of making the brightest ever synthesized fluorescent silica particles. This work is published in the March 5th issue of the nanotechnology journal Small. Their paper was one of the journal's most accessed articles of the year (from September 2006 - August 2007). The full article is at http://www3.interscience.wiley.com/cgi-bin/fulltex t/114088575/HTMLSTART .

Professor Sokolov, along with Ph.D. student Yaroslav Y. Kievsky (now a research fellow at the National Research Council of Canada) and Clarkson undergraduate student Jason M. Kaszpurenko, has created a process to physically entrap a large number of organic fluorescent molecules inside a nanoporous silica matrix. The fluorescence of these particles is 170 times brighter than any particle of a similar size created so far. These nanostructured microscopic silica particles have potential applications in medicine, forensic science and for environmental protection.