Fluorescent aerogel films for TNT sensing

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buir.advisorBayındır, Mehmet
dc.contributor.authorYıldırım, Adem
dc.date.accessioned2016-01-08T18:11:27Z
dc.date.available2016-01-08T18:11:27Z
dc.date.issued2009
dc.departmentGraduate Program in Materials Science and Nanotechnologyen_US
dc.descriptionAnkara : The Graduate Program of Materials Science and Nanotechnology and the Institute of Engineering and Sciences of Bilkent University, 2009.en_US
dc.descriptionThesis (Master's) -- Bilkent University, 2009.en_US
dc.descriptionIncludes bibliographical references leaves 67-78.en_US
dc.description.abstractSilica aerogels are unique materials with extraordinary properties such as, high porosity, large surface area and low refractive indices. Due to these properties, they can be applied to a wide range of areas including, insulation, catalyst support, sensors and dielectric materials. However, until know because of their poor mechanical properties and costly production a few applications of aerogels were realized. Ambient pressure drying method is a promising way to produce low cost aerogels and thus expanding the realized application areas of aerogels. This method is based on lowering the surface tension on the gel network, in order to minimize the collapse of the gel during drying. For this purpose gel surface can be modified to make it hydrophobic. In the first part of this work, ambient pressure production of fluorescent aerogel thin films are described. The produced fluorescent films were characterized to identify their morphological, optical and surface properties. The gel was produced by using methlyltrimethoxysilane (MTMS) to produce hydrophobic gel. A porphyrin derivative (TCPPH2) was simply mixed with the sol before gelation for the fluorescence property. After gelation and aging the produced gels are homogenized and spin coated on glass substrates. The produced films were found to be highly porous (60.3-77.1%), fluorescent and transparent in visible region (82-89%). In the second part, sensing performances of the films were examined by using the common explosive trinitrotoluene (TNT). All films show fluorescence quenching based sensing against TNT exposure. The quenching efficiency of the films is highly thickness dependent. For the thinnest film (120 nm) the quenching efficiency was found to be 8.6% in 10 seconds and for the thickest film (1100 nm) film 2.1% in 10 seconds.en_US
dc.description.degreeM.S.en_US
dc.description.statementofresponsibilityYıldırım, Ademen_US
dc.format.extentxiv, 78 leaves, illustrationsen_US
dc.identifier.urihttp://hdl.handle.net/11693/14954
dc.language.isoEnglishen_US
dc.publisherBilkent Universityen_US
dc.rightsinfo:eu-repo/semantics/openAccessen_US
dc.subjectAerogelen_US
dc.subjectSilicaen_US
dc.subjectSol-gel methoden_US
dc.subjectExplosive detectionen_US
dc.subjectThin filmen_US
dc.subject.lccTA418.9.T45 Y55 2009en_US
dc.subject.lcshThin films.en_US
dc.subject.lcshSilica--Surfaces.en_US
dc.titleFluorescent aerogel films for TNT sensingen_US
dc.typeThesisen_US

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Graduate Program in Materials Science and Nanotechnology - Master's degree