Characterizations of silicon-germanium nanocomposites fabricated by the marine diatom Nitzschia frustulum Public Deposited

http://ir.library.oregonstate.edu/concern/graduate_thesis_or_dissertations/q811kn282

Descriptions

Attribute NameValues
Creator
Abstract or Summary
  • Marine diatoms are a class of microalgae that possess cell walls composed of silica nanoparticles. These organisms actively assimilate silicic acid Si(OH)4 from seawater, polymerize silicic acid to silica nanoparticles by a protein-mediated precipitation process, and then assemble the silica nanoparticles into intricate patterns that constitute the cell wall microarchitecture (consists of around 30nm of SiO2 nanoparticles) of the diatom frustule. The biomineralization capacity of marine diatoms, Nitzschia,was harnessed to biologically manufacture silicon oxide / germanium oxide nanocomposite materials. Germanium was incorporated into living diatom cell mass by a two-stage cultivation process. The micro- and nanostructures of biogenic oxide nanocomposite before and after post processing were characterized by FT-IR, HR-TEM with EDX, and XRD. Photoluminescence (PL) measurements were performed on these biogenic nanocomposites after different post processing to remove the organics. Strong blue photoluminescence was observed from samples treated with H202 and oxygen plasma. However, no photoluminescence could be observed after NOT thermal annealing. A clear blueshift was observed from samples with the addition of germanium. Based on the comparison of the PL from diatom samples with that from synthesized silica, the self-trapped exciton (STE) affected by quantum confinement effect (QCE) is proposed as the mechanism of the PL from diatom.
Resource Type
Date Available
Date Issued
Degree Level
Degree Name
Degree Field
Degree Grantor
Commencement Year
Advisor
Academic Affiliation
Non-Academic Affiliation
Subject
Rights Statement
Language
File Format
File Extent
  • 5520572 bytes
Digitization Specifications
  • Master files scanned at 600 ppi (256 Grayscale, 24-bit Color) using Capture Perfect 3.0 on a Canon DR-9080C in TIF format. PDF derivative scanned at 300 ppi (256 B&W, 24-bit Color, 256 Grayscale), using Capture Perfect 3.0, on a Canon DR-9080C. CVista PdfCompressor 3.1 was used for pdf compression and textual OCR.
Replaces
Additional Information
  • description.provenance : Made available in DSpace on 2008-01-15T15:57:24Z (GMT). No. of bitstreams: 1 Liu_Shuhong.pdf: 5520572 bytes, checksum: e3dea0c4abab7a01627d5b7d8af72da8 (MD5)
  • description.provenance : Approved for entry into archive by Linda Kathman(linda.kathman@oregonstate.edu) on 2008-01-15T15:56:23Z (GMT) No. of bitstreams: 1 Liu_Shuhong.pdf: 5520572 bytes, checksum: e3dea0c4abab7a01627d5b7d8af72da8 (MD5)
  • description.provenance : Submitted by Anna Opoien (aoscanner@gmail.com) on 2008-01-14T19:34:46Z No. of bitstreams: 1 Liu_Shuhong.pdf: 5520572 bytes, checksum: e3dea0c4abab7a01627d5b7d8af72da8 (MD5)
  • description.provenance : Approved for entry into archive by Linda Kathman(linda.kathman@oregonstate.edu) on 2008-01-15T15:57:23Z (GMT) No. of bitstreams: 1 Liu_Shuhong.pdf: 5520572 bytes, checksum: e3dea0c4abab7a01627d5b7d8af72da8 (MD5)

Relationships

In Administrative Set:
Last modified: 08/08/2017

Downloadable Content

Download PDF
Citations:

EndNote | Zotero | Mendeley

Items