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On the interaction between adsorbed layers of monoolein and the lipase action on the formed layers

Campos, J; Eskilsson, K; Nylander, Tommy LU and Svendsen, A (2002) In Colloids and Surfaces B: Biointerfaces 26(1-2). p.172-182
Abstract
We used the Surface Force Apparatus (SFA) and ellipsometry techniques to study the interaction forces and the adsorption behavior of monoolein (MO), respectively. MO was adsorbed from water to a hydrophobised mica or silica surface. In addition the effect of added lipase, Thermomyces (Humicula) lanuginosa lipase (TLL), to an adsorbed layer of MO was investigated. The force versus distance curves between two MO covered surfaces feature a strong repulsive interaction beneath 400 A. The range of the repulsive force decreases, however, with the number of approaches. No adhesion was observed, provided that the surfaces were not taken to hydrophobic contact. The surface separation at MO-MO contact was determined to about 55 Angstrom This means a... (More)
We used the Surface Force Apparatus (SFA) and ellipsometry techniques to study the interaction forces and the adsorption behavior of monoolein (MO), respectively. MO was adsorbed from water to a hydrophobised mica or silica surface. In addition the effect of added lipase, Thermomyces (Humicula) lanuginosa lipase (TLL), to an adsorbed layer of MO was investigated. The force versus distance curves between two MO covered surfaces feature a strong repulsive interaction beneath 400 A. The range of the repulsive force decreases, however, with the number of approaches. No adhesion was observed, provided that the surfaces were not taken to hydrophobic contact. The surface separation at MO-MO contact was determined to about 55 Angstrom This means a layer thickness of about 27 Angstrom, which is comparable to the thickness (25 Angstrom) determined by ellipsometry. The repulsive force may arise from compression of a cubic phase of MO. This phase are suggested to form between the surfaces when they approach close contact due to capillary induced phase separation (CIPS) from the saturated MO solution. The repulsive force changes significantly with time after addition of TLL (concentration of about 1 x 10(-8) M). In contrast to the force curves recorded before adding TLL, the surfaces do not seem to be completely covered with MO as we always observed an attractive force (inward jump) of similar range as was observed between pure OTE surfaces. Ellipsometry measurement of TLL action on MO covered hydrophobic surface reveals a significant and sharp decrease of the amounts adsorbed. Furthermore, the rate of decrease and reduction in adsorbed amount increased with TLL concentration. (C) 2002 Elsevier Science B.V. All rights. reserved. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
ellipsometry, surface forces, action, lipase, adsorption, Thermomyces (Humicula) lanuginosa lipase, monoolein
in
Colloids and Surfaces B: Biointerfaces
volume
26
issue
1-2
pages
172 - 182
publisher
Elsevier
external identifiers
  • wos:000179487200017
  • scopus:0036074334
ISSN
1873-4367
DOI
10.1016/S0927-7765(02)00036-X
language
English
LU publication?
yes
id
c80006d7-ac68-4cd2-958e-3cb33b908663 (old id 322671)
date added to LUP
2007-08-13 10:40:55
date last changed
2017-01-01 06:59:54
@article{c80006d7-ac68-4cd2-958e-3cb33b908663,
  abstract     = {We used the Surface Force Apparatus (SFA) and ellipsometry techniques to study the interaction forces and the adsorption behavior of monoolein (MO), respectively. MO was adsorbed from water to a hydrophobised mica or silica surface. In addition the effect of added lipase, Thermomyces (Humicula) lanuginosa lipase (TLL), to an adsorbed layer of MO was investigated. The force versus distance curves between two MO covered surfaces feature a strong repulsive interaction beneath 400 A. The range of the repulsive force decreases, however, with the number of approaches. No adhesion was observed, provided that the surfaces were not taken to hydrophobic contact. The surface separation at MO-MO contact was determined to about 55 Angstrom This means a layer thickness of about 27 Angstrom, which is comparable to the thickness (25 Angstrom) determined by ellipsometry. The repulsive force may arise from compression of a cubic phase of MO. This phase are suggested to form between the surfaces when they approach close contact due to capillary induced phase separation (CIPS) from the saturated MO solution. The repulsive force changes significantly with time after addition of TLL (concentration of about 1 x 10(-8) M). In contrast to the force curves recorded before adding TLL, the surfaces do not seem to be completely covered with MO as we always observed an attractive force (inward jump) of similar range as was observed between pure OTE surfaces. Ellipsometry measurement of TLL action on MO covered hydrophobic surface reveals a significant and sharp decrease of the amounts adsorbed. Furthermore, the rate of decrease and reduction in adsorbed amount increased with TLL concentration. (C) 2002 Elsevier Science B.V. All rights. reserved.},
  author       = {Campos, J and Eskilsson, K and Nylander, Tommy and Svendsen, A},
  issn         = {1873-4367},
  keyword      = {ellipsometry,surface forces,action,lipase,adsorption,Thermomyces (Humicula) lanuginosa lipase,monoolein},
  language     = {eng},
  number       = {1-2},
  pages        = {172--182},
  publisher    = {Elsevier},
  series       = {Colloids and Surfaces B: Biointerfaces},
  title        = {On the interaction between adsorbed layers of monoolein and the lipase action on the formed layers},
  url          = {http://dx.doi.org/10.1016/S0927-7765(02)00036-X},
  volume       = {26},
  year         = {2002},
}