uu.seUppsala University Publications
Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • 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
Grazing-Incidence Small Angle Neutron Scattering from Structures below an Interface
Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Physics. (Material physics)
Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Physics. (Material physics)
Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Physics. (Material physics)
Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Physics. (Material physics)
2017 (English)In: Journal of applied crystallography, ISSN 0021-8898, E-ISSN 1600-5767, Vol. 50, no 4, p. 1066-1074Article in journal (Refereed) Published
Abstract [en]

Changes of scattering are observed as the grazing angle of incidence of an incoming beam increases and probes different depths in samples. A model has been developed to describe the observed intensity in grazing incidence small angle neutron scattering (GISANS) experiments. This includes the significant effects of instrument resolution, the sample transmission, which depends on both absorption and scattering, as well as the sample structure. The calculations are tested with self-organised structures of two colloidal samples with different size particles that were measured on two different instruments. The model allows calculations for various instruments with defined resolution and can be used to design future improved experiments. The possibilities and limits of GISANS for different studies are discussed using the model calculations. 

Place, publisher, year, edition, pages
2017. Vol. 50, no 4, p. 1066-1074
Keywords [en]
GISANS, Solid/liquid interface, colloidal particles
National Category
Physical Sciences
Research subject
Physics
Identifiers
URN: urn:nbn:se:uu:diva-322577DOI: 10.1107/S1600576717007518ISI: 000407040700011PubMedID: 28808432OAI: oai:DiVA.org:uu-322577DiVA, id: diva2:1098773
Funder
Swedish Research Council, 621-2012-4382Available from: 2017-05-26 Created: 2017-05-26 Last updated: 2018-10-13Bibliographically approved
In thesis
1. Structure formation at solid/liquid interfaces: Understanding self-assembly and environmental challenges
Open this publication in new window or tab >>Structure formation at solid/liquid interfaces: Understanding self-assembly and environmental challenges
2018 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

The work described in the present dissertation has explored the structure of particles and molecules at solid/liquid interfaces, aiming to understand the physics of self-organizing systems and use this knowledge to address some environmental issues. Surface-sensitive neutron scattering techniques, such as reflectometry and grazing incidence small angle scattering, have been used as the primary tool to investigate structures in proximity to an interface. Some of the challenges in the interpretation of neutron scattering data are discussed, and new methods for analyzing the signal have been proposed.

It was shown that charged stabilized colloidal particles can self-assemble and form large areas (20 cm2) of crystalline structures, close to a smooth solid surface extending to depths of several micrometers, while orienting themselves into smaller crystallites in the bulk of the suspension. The adsorption of proteins from the seeds of different species of Moringa trees on alumina, silica and polystyrene surfaces was studied, as a means for using proteins from different sources and with different properties, for the water clarification step in the purification process. The seed proteins also showed to enable locking the structure of colloidal particles at the solid/liquid interface, acting as a molecular glue.

Perfluorinated surfactants (PFASs), widely used in industrial, pharmaceutical and food packing products, have been identified as emerging pollutants, raising a global concern for the environment and wildlife. The present study has shown how PFASs molecules of different fluorocarbon chain length and with different functional groups, create defects in model membranes by partitioning and removing phospholipids from the bilayer, making the bilayer thin and less dense.

The effect of interface roughness was studied on the lamellar structure of a non-ionic surfactant. Concentrated solutions of the surfactant have been shown to form well-ordered and well-aligned structures at a smooth interface, which could be modified further by simply heating the sample. However it was found that even small roughness, of the same order as the bilayer thickness, can distort the structure to a depth of several micrometers from the interface. Heating the sample could improve the alignment but not as much as that formed at a smooth surface.

Place, publisher, year, edition, pages
Uppsala: Acta Universitatis Upsaliensis, 2018. p. 64
Series
Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology, ISSN 1651-6214 ; 1732
Keywords
Solid/liquid interface, neutron scattering, colloidal particles, self-assembly, perfluoroalkyl substance, Moringa seed proteins, adsorption, lamellar disorder, thermal fluctuations.
National Category
Physical Sciences
Identifiers
urn:nbn:se:uu:diva-362075 (URN)978-91-513-0475-5 (ISBN)
Public defence
2018-12-14, Å80127, Ångströmlaboratoriet, Uppsala, 09:15 (English)
Opponent
Supervisors
Available from: 2018-11-19 Created: 2018-10-13 Last updated: 2018-11-30

Open Access in DiVA

GISANS_Nouhi_2017(1931 kB)70 downloads
File information
File name FULLTEXT01.pdfFile size 1931 kBChecksum SHA-512
fea3b3aa5cf28d0e2afd53a70f587bf7858f48a3378fd34c2e8053fa9608633b80688604742010de9cb2e299cd6f1b4c05f225b62e0aecec2df3c738476e5147
Type fulltextMimetype application/pdf
fulltext(782 kB)3 downloads
File information
File name FULLTEXT02.pdfFile size 782 kBChecksum SHA-512
3a810cc1c7135a4c58e105741f3c72e71fa0f3937bca86c1edbe674eb64647ad41a3375ad6d80a521473b17f32fdf2a80454e522f7519c0b3f4c19bd2ef7d418
Type fulltextMimetype application/pdf

Other links

Publisher's full textPubMed

Authority records BETA

Nouhi, ShirinHellsing, Maja S.Kapaklis, VassiliosRennie, Adrian R.

Search in DiVA

By author/editor
Nouhi, ShirinHellsing, Maja S.Kapaklis, VassiliosRennie, Adrian R.
By organisation
Materials Physics
In the same journal
Journal of applied crystallography
Physical Sciences

Search outside of DiVA

GoogleGoogle Scholar
Total: 73 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

doi
pubmed
urn-nbn

Altmetric score

doi
pubmed
urn-nbn
Total: 436 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • 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