Show simple item record

dc.contributor.authorDursun, Azizen_US
dc.date.accessioned2011-08-22T18:53:09Z
dc.date.available2011-08-22T18:53:09Z
dc.date.issued2003-05-13en_US
dc.identifier.otheretd-10262003-200453en_US
dc.identifier.urihttp://hdl.handle.net/10919/11093
dc.description.abstractSelective dissolution also known as dealloying is a corrosion process in which one component of a binary alloy system is selectively removed through an electrochemically controlled process which leads to the formation of a porous metal "sponge" with a porosity that is completely interconnected and random in direction. Nanoporous metals are desirable since they have larger surface areas than an equal volume of non-porous material. Because of their enormous surface area per volume, these highly porous metal electrodes are superior materials for high surface area applications such as in biomedical devices, microfilters and catalysts. Understanding the kinetic processes governing the development of porosity during dealloying and having ability to change the electrochemical conditions will allow us to better control over the average ligament size and distribution in porosity. The basic kinetic processes involved in the formation of these structures are related to such issues as environmental effects and electrochemical conditions on diffusion, microscopic coarsening phenomenon at room temperature and elevated temperatures, alloy passivation, and Gibbs-Thomson effects. The average pore size and distribution was found to depend on the electrolyte composition, dealloying rate, applied potential and time. The porosity was found to significantly coarsen at room temperature during the dealloying process and this coarsening was highly dependent on the applied potential. It is showed that the commonly accepted measurement of the critical potential for alloy dissolution calculated based on extrapolation of anodic polarization data results in an overestimation of this quantity. A series of constant applied potential experiments prove to be a more accurate method for critical potential determination.en_US
dc.format.mediumETDen_US
dc.publisherVirginia Techen_US
dc.relation.haspartthesis_aziz.pdfen_US
dc.rightsThis Item is protected by copyright and/or related rights. Some uses of this Item may be deemed fair and permitted by law even without permission from the rights holder(s), or the rights holder(s) may have licensed the work for use under certain conditions. For other uses you need to obtain permission from the rights holder(s).en_US
dc.subjectsmall angle neutron scatteringen_US
dc.subjectdealloying critical potentialen_US
dc.subjectporous metalsen_US
dc.subjectselective dissolutionen_US
dc.subjectcoarseningen_US
dc.subjectsurface diffusionen_US
dc.titleNanoporosity Formation in Ag-Au Alloysen_US
dc.typeDissertationen_US
dc.contributor.departmentMaterials Science and Engineeringen_US
dc.description.degreePh. D.en_US
thesis.degree.namePh. D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen_US
thesis.degree.disciplineMaterials Science and Engineeringen_US
dc.contributor.committeechairCorcoran, Sean Geralden_US
dc.contributor.committeememberKampe, Stephen L.en_US
dc.contributor.committeememberMarand, Hervé L.en_US
dc.contributor.committeememberFarkas, Dianaen_US
dc.identifier.sourceurlhttp://scholar.lib.vt.edu/theses/available/etd-10262003-200453en_US
dc.contributor.committeecochairReynolds, William T. Jr.en_US
dc.date.sdate2003-10-26en_US
dc.date.rdate2004-01-21
dc.date.adate2004-01-21en_US


Files in this item

Thumbnail

This item appears in the following Collection(s)

Show simple item record