Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Fabrication of new silica nano structures and development of new concepts for MALDI-TOF mass spectrometry
KTH, Superseded Departments, Chemistry.
2004 (English)Doctoral thesis, comprehensive summary (Other scientific)
Abstract [en]

A technique to alter the morphology of the inner surface of fused silica capillaries has been developed. The internal surface area is enlarged by means of nano-wires of silica, which are grown from the capillary walls. The growth is initiated by the decomposition of the etchant precursor 2-chloro-1,1,2–trifluoroethylmethyl ether at elevated temperature and pressure. It is suggested that the formation of the nano-wires is a process where hydrogen fluoride is continuously consumed and re-liberated. The amorphous bulk silica wall is dissolved, vaporized and finally condensed, yielding a directional re-formation of silica into nano-wire structures. The unidirectional growth of the nano-wires seems to follow the well-known vapor-liquid-solid (VLS) mechanism since characteristic attributes of the VLS mechanism can be observed in the modified capillaries, such as spherical particles terminating each nano-wire. An alternative procedure was developed based on non-isothermal etching which enabled nano-wire outgrowth in fused silica capillaries with internal diameters exceeding 5 µm. The etched and modified capillaries are expected to be suitable for fluidic applications where a higher surface-to-volume ratio is beneficial, such as open tubular liquid chromatography as well as solid-phase micro-reactors and catalysis including enzymatic reactions.

The last part of the thesis describes new techniques developed for matrix-assisted laser desorption/ionization (MALDI) mass spectrometry. A set of novel matrices based on polymers/oligomers of benzodioxins and thiophenes has been introduced. Using this approach, which has been given the name Polymer-Assisted Laser Desorption/Ionization (PALDI), the low m/z-range of the mass spectrum, from 180 to 1.000 Da, could be used without the abundant chemical noise which normally disturbs such MALDI-MS spectra. Some of the PALDI matrices also showed excellent behavior in the analysis of low molecular weight polymers. A methodology based on non-linear regression of cumulative frequency distributions in polymers has been developed to compare and evaluate different matrix/polymer/cation agent sample combinations for MALDI and PALDl-MS analyses of low molecular weight polymers.

Place, publisher, year, edition, pages
Stockholm: Kemi , 2004. , viii, 130, viii p.
Keyword [en]
Chemistry
Keyword [sv]
Kemi
National Category
Chemical Sciences
Identifiers
URN: urn:nbn:se:kth:diva-79ISBN: 91-7283-904-X (print)OAI: oai:DiVA.org:kth-79DiVA: diva2:14769
Public defence
2004-12-10, sal E3, Lindstedtsvägen 3, Stockholm, 10:00
Opponent
Supervisors
Available from: 2004-12-10 Created: 2004-12-10 Last updated: 2012-03-22

Open Access in DiVA

fulltext(6122 kB)1900 downloads
File information
File name FULLTEXT01.pdfFile size 6122 kBChecksum MD5
c51509abfb14b492c91ffd6a4fa510e47566dcaa0a638e819b9d9ba017447f1bdca6ceed
Type fulltextMimetype application/pdf

Search in DiVA

By author/editor
Woldegiorgis, Andreas
By organisation
Chemistry
Chemical Sciences

Search outside of DiVA

GoogleGoogle Scholar
Total: 1900 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

isbn
urn-nbn

Altmetric score

isbn
urn-nbn
Total: 813 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf