Sökning: onr:"swepub:oai:DiVA.org:kth-10998" >
Mediation of the Na...
Mediation of the Nanotribological Properties of Cellulose by Chitosan Adsorption
-
- Nordgren, Niklas, 1975- (författare)
- RISE,KTH,Yt- och korrosionsvetenskap,Yt- och korrosionsvetenskap, Surface and Corrosion Science,YKI – Ytkemiska institutet
-
Eronen, Paula (författare)
-
Österberg, Monika (författare)
-
visa fler...
-
Laine, Janne (författare)
-
- Rutland, Mark (författare)
- RISE,KTH,Yt- och korrosionsvetenskap,Yt- och korrosionsvetenskap, Surface and Corrosion Science,YKI – Ytkemiska institutet
-
visa färre...
-
(creator_code:org_t)
- USA : American Chemical Society, 2009
- 2009
- Engelska.
-
Ingår i: Biomacromolecules. - USA : American Chemical Society. - 1525-7797 .- 1526-4602. ; 10:3, s. 645-650
- Relaterad länk:
-
https://urn.kb.se/re...
-
visa fler...
-
https://doi.org/10.1...
-
https://urn.kb.se/re...
-
visa färre...
Abstract
Ämnesord
Stäng
- Cellulosic model surfaces functionalized with chitosan, a naturally occurring cationic biomacromolecule, by in-situ adsorption have been studied with an atomic force microscope (AFM) in colloidal probe configuration. The interaction forces on approach and separation, as well as the nanotribological properties, were shown to be highly pH-dependent and a significant difference in the behaviour was seen before and after chitosan adsorption. In general, all forces on approach showed a highly repulsive interaction at shorter distances due to deformation of the probe. At high pH, before chitosan adsorption, a long-range electrostatic repulsion was observed, consistent with DLVO theory. However at low pH no electrostatic contribution was found before adsorption probably due to charge neutralization of carboxyl groups. After chitosan adsorption, repulsive forces acting over a much longer distance than predicted by DLVO theory were present at low pH. This effect was ascribed to chain extension of the chitosan species of which the magnitude and the range of the force increased dramatically with higher charge at low pH. In all cases, a typical saw-tooth patterned adhesion was present with pull-off events occurring at different separations. The frequency of these events after chitosan adsorption was greatly increased at longer distances. Additionally, the adsorbed chitosan markedly reduced the friction where the largest effect was a 7-fold decrease of the friction coefficient observed at low pH.
Ämnesord
- NATURVETENSKAP -- Kemi -- Fysikalisk kemi (hsv//swe)
- NATURAL SCIENCES -- Chemical Sciences -- Physical Chemistry (hsv//eng)
Nyckelord
- AFM
- QCM-D
- cellulose
- chitosan
- nanotribology
- surface forces
- friction
- adhesion
- colloidal probe
- polysaccharide interactions
- Surface and colloid chemistry
- Yt- och kolloidkemi
Publikations- och innehållstyp
- ref (ämneskategori)
- art (ämneskategori)
Hitta via bibliotek
Till lärosätets databas