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Chao, Xing (2013) CRYSTALLINE COLLOIDAL ARRAY FILTER AND RAMAN IMAGING. Master's Thesis, University of Pittsburgh. (Unpublished)

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The background and diffraction theory of crystalline colloidal arrays (CCAs) are briefly reviewed. Crystalline colloidal arrays were fabricated by using silica particles and polystyrene (PS) particles for deep ultraviolet (UV) and visible regions, respectively. I used a modified Stöber method to synthesize small (<100 nm) silica particles. The silica particles were surface functionalized with a strong acid, non-UV absorbing silane coupling agent. PS particles were also synthesized with emulsion polymerization method. These monodisperse, highly charged particles self-assemble into face-centered cubic CCAs that show Bragg diffraction of UV and visible light. The diffraction wavelength was 248 nm for silica CCA filter at normal incidence. The PS CCAs diffracted 518 nm and 580 nm light at normal incidence.
These CCA filters were tested with UV/vis/NIR spectrophotometer and lasers. UV/vis/NIR extinction showed high rejection efficiency and narrow diffraction bands. 244 nm argon laser light was used to study the transmission, reflection and scattering of the silica CCA filter. Teflon Raman scattering measurement was also performed with 244 nm light and a silica CCA filter used as the Rayleigh rejection filter. The filter rejected 99.91% of the Rayleigh scattering light.
We attempted to develop a Raman imaging spectrometer. Towards this affect, I attempted to do fluorescence imaging by using 514.5 argon laser light with PS visible filters. Spectra of fluorescence bands and fluorescence images were recorded.


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Item Type: University of Pittsburgh ETD
Status: Unpublished
CreatorsEmailPitt UsernameORCID
Chao, Xingxic28@pitt.eduXIC28
ETD Committee:
TitleMemberEmail AddressPitt UsernameORCID
Committee ChairAsher, Sanford Aasher@pitt.eduASHER
Committee MemberWaldeck, David Hdave@pitt.eduDAVE
Committee MemberRosi, Nathaniel Lnrosi@pitt.eduNROSI
Date: 24 January 2013
Date Type: Publication
Defense Date: 19 November 2012
Approval Date: 24 January 2013
Submission Date: 3 December 2012
Access Restriction: No restriction; Release the ETD for access worldwide immediately.
Number of Pages: 48
Institution: University of Pittsburgh
Schools and Programs: Dietrich School of Arts and Sciences > Chemistry
Degree: MS - Master of Science
Thesis Type: Master's Thesis
Refereed: Yes
Uncontrolled Keywords: crystalline colloidal arrays, photonic crystals, silica colloidal, polystyrene colloidal, UV Raman imaging, Raman spectroscopy, Rayleigh rejection filter, wavelength-selecting filter
Date Deposited: 24 Jan 2013 21:24
Last Modified: 15 Nov 2016 14:07


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