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VERSION:2.0
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METHOD:PUBLISH
BEGIN:VEVENT
DTSTAMP:20260814T215635Z
LAST-MODIFIED:20121116T203436Z
DTSTART:20090811T154500Z
DTEND:20090811T171500Z
UID:event468@bu.edu
URL:http://physics.bu.edu/internal/events/show/468
SUMMARY:Slippage at the Solid/Liquid Interface - Probing the Hydrodynamic B
	oundary Condition by Dewetting Experiments
DESCRIPTION:Featuring Oliver Bäumchen \, Saarland University\, Saarbrücke
	n\, Germany\nHosted by: Ophelia Tsui\n\nPart of the Biophysics/Condensed Ma
	tter Seminar Series.\n\nAbstract:\nUnderstanding liquid flow in confined ge
	ometries plays a key role in the field of microand nanofluidics. Nowadays\,
	 so-called lab-on-a-chip devices open up new possibilities to perform chemi
	cal reactions or biological analysis. Thereby\, friction at the solid/liqui
	d interface strongly affects the flow dynamics. Nanoscale liquid polymer fi
	lms are ideal candidates to probe the solid/liquid boundary condition: Prep
	ared on smooth nonwettable surfaces like hydrophobized Si wafers\, the film
	s are not stable\, they dewet and bead off the substrate. That way\, a flow
	 is induced without applying an external force or pumping of the liquid. Th
	e force inducing dewetting is an "internal force" and can be inferred from 
	the effective interface potential. Probing the dynamics of the dewetting pr
	ocess enables us to deduce the energy dissipation by viscous flow and by fr
	iction at the solid/liquid interface. Moreover\, the slip length\, i.e. the
	 extrapolation length of the velocity profile in the vicinity of a wall\, c
	an be inferred by characterizing the profile of a liquid front that is form
	ed by the liquid while dewetting. Theoretical thin film models are applied 
	to catch the front profile. A variation of the type of hydrophobic layer en
	ables us to tune the boundary condition from a no-slip to a nearly full-sli
	p condition. The experimental results concerning the slip lengths as functi
	on of viscosity and molecular weight of the polymer film will be compared t
	o theoretical concepts.\n\n[1] R. FETZER\, K. JACOBS\, A. MÜNCH\, B. WAGNE
	R and T. P. WITELSKI\, "New Slip Regimes and the Shape of Dewetting Thin Li
	quid Films"\, Phys. Rev. Lett. 95 (2005) 127801.\n[2] R. FETZER\, M. RAUSCH
	ER\, A. MÜNCH\, B. A. WAGNER and K. JACOBS\, "Slip-controlled thin-film dy
	namics"\, Europhys. Lett. 75 (2006) 638-644.\n[3] R. FETZER\, A. MÜNCH\, B
	. WAGNER\, M. RAUSCHER and K. JACOBS\, "Quantifying Hydrodynamic Slip: A Co
	mprehensive Analysis of Dewetting Profiles"\, Langmuir 23 (2007) 10559-\n10
	566.\n[4] R. FETZER and K. JACOBS\, "Slippage of Newtonian Liquids: Influen
	ce on the Dynamics of Dewetting Thin Films"\, Langmuir 23 (2007) 11617-1162
	2.\n[5] O. BÄUMCHEN\, K. JACOBS and R.FETZER\, "Probing Slippage and Flow 
	Dynamics of Thin Dewetting Polymer Films"\, Proceedings of 1st Conference o
	n Microfluidics in Bologna 2008 Dez 10-\n12 ISBN 2-906831-76-X.\n[6] O. BÄ
	UMCHEN\, R. FETZER\, A. MÜNCH\, B. WAGNER and K. JACOBS\,Comprehensive Ana
	lysis of Dewetting Profiles to Quantify Hydrodynamic Slip"\, IUTAM Symposiu
	m on Advances in Micro- and Nanofluidics\, edited by M. Ellero\, X. Hu\, J.
	 Fröhlich\, N. Adams (Springer\, 2009).\n[7] O. BÄUMCHEN\, R. FETZER and 
	K. JACOBS\, „Liquid Front Profiles Affected by Entanglementinduced Slippa
	ge"\, submitted (arXiv:0907.2113v1 [cond-mat.soft]).
LOCATION:SCI 352\, 590 Commonwealth Avenue\, 02215
STATUS:CONFIRMED
CLASS:PUBLIC
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