In this paper, we demonstrate that it is principally not possible to separate a misalignment or gap error from an apparent slip length when employing a varying measuring gap analysis as the Kramer method or the Mooney analysis. Such error sources become important when utilizing parallel plates in rotational rheometry at low gap separation as for the determination of slip, for low sample volume availability, or for the study of confinement effects. While rheologists are generally aware that gap settings on the order of O(0.1 mm) and below can be affected by gap errors or nonparallelism, this is seldom discussed together with (or in comparison to) other error sources as slip, instabilities, compressibility, or normal stresses. However, other error sources such as slip lengths can easily be of the same order as the generally reported misalignment error of O(0.01 mm). We demonstrate with an experimental example that both error sources can be of similar order of magnitude, and can principally not be separated with a gap variation analysis. This should again raise awareness that, unless one of both effects can be ruled out or can be determined separately with an independent measurement technique, discussions of only slip velocities (or only gap error effects) should be taken with care if the results were obtained from a gap variation analysis.
References
1.
Buscall
, R.
, “Letter to the Editor: Wall slip in dispersion rheometry
,” J. Rheol.
54
, 1177
–1183
(2010
).2.
Buckin
, V.
, and E.
Kudryashov
, “Ultrasonic shear wave rheology of weak particle gels
,” Adv. Colloid Interface Sci.
89–90
, 401
–422
(2001
).3.
Kojić
, N.
, J.
Bico
, C.
Clasen
, and G. H.
McKinley
, “Ex vivo rheology of spider silk
,” J. Exp. Biol.
209
, 4355
–4362
(2006
).4.
Laiho
, A.
, and O.
Ikkala
, “A rheo-optical apparatus for real time kinetic studies on shear-induced alignment of self-assembled soft matter with small sample volumes
,” Rev. Sci. Instrum.
78
, 015109
(2007
).5.
Reichel
, E. K.
, M.
Heinisch
, B.
Jakoby
, J.
Vermant
, and C. E.
Kirschhock
, “Viscoelasticity sensor with resonance tuning and low-cost interface
,” Procedia Eng.
25
, 623
–626
(2011
).6.
Erni
, P.
, M.
Varagnat
, C.
Clasen
, J.
Crest
, and G. H.
McKinley
, “Microrheometry of sub-nanolitre biopolymer samples: Non-Newtonian flow phenomena of carnivorous plant mucilage
,” Soft Matter
7
, 10889
–10898
(2011
).7.
Livak-Dahl
, E.
, J.
Lee
, and M. A.
Burns
, “Nanoliter droplet viscometer with additive-free operation
,” Lab Chip
13
, 297
–301
(2013
).8.
Rust
, P.
, D.
Cereghetti
, and J.
Dual
, “A micro-liter viscosity and density sensor for the rheological characterization of DNA solutions in the kilo-hertz range
,” Lab Chip
13
, 4794
–4799
(2013
).9.
Bertola
, V.
, F.
Bertrand
, H.
Tabuteau
, D.
Bonn
, and P.
Coussot
, “Wall slip and yielding in pasty materials
,” J. Rheol.
47
, 1211
–1226
(2003
).10.
Clasen
, C.
, “Determining the true slip of a yield stress material with a sliding plate rheometer
,” Rheol. Acta
51
, 883
–890
(2012
).11.
Clasen
, C.
, H. P.
Kavehpour
, and G. H.
Mckinley
, “Bridging tribology and microrheology of thin films
,” Appl. Rheol.
20
, 45049
(2010
).12.
Hatzikiriakos
, S. G.
, “Wall slip of molten polymers
,” Prog. Polym. Sci.
37
, 624
–643
(2012
).13.
Hatzikiriakos
, S. G.
, and J. M.
Dealy
, “Wall slip of molten high density polyethylene. I. Sliding plate rheometer studies
,” J. Rheol.
35
, 497
–523
(1991
).14.
Mewis
, J.
, and N. J.
Wagner
, Colloidal Suspension Rheology
, 1st ed. (Cambridge University
, New York
, 2012
).15.
Clasen
, C.
, “High shear rheometry using hydrodynamic lubrication flows
,” J. Rheol.
57
, 197
–221
(2013
).16.
Crawford
, N. C.
, S. K. R.
Williams
, D.
Boldridge
, and M. W.
Liberatore
, “Shear thickening of chemical mechanical polishing slurries under high shear
,” Rheol. Acta
51
, 637
–647
(2012
).17.
Davies
, G.
, and J.
Stokes
, “Thin film and high shear rheology of multiphase complex fluids
,” J. Non-Newtonian Fluid Mech.
148
, 73
–87
(2008
).18.
Li
, J. X.
, L. G.
Westerberg
, E.
Höglund
, P. M.
Lugt
, and P.
Baart
, “Lubricating grease shear flow and boundary layers in a concentric cylinder configuration
,” Tribol. Trans.
57
, 1106
–1115
(2014
).19.
Mriziq
, K. S.
, H. J.
Dai
, M. D.
Dadmun
, G. E.
Jellison
, and H. D.
Cochran
, “High-shear-rate optical rheometer
,” Rev. Sci. Instrum.
75
, 2171
–2176
(2004
).20.
Pipe
, C. J.
, T. S.
Majmudar
, and G. H.
McKinley
, “High shear rate viscometry
,” Rheol. Acta
47
, 621
–642
(2008
).21.
Baik
, S. J.
, P.
Moldenaers
, and C.
Clasen
, “A sliding plate microgap rheometer for the simultaneous measurement of shear stress and first normal stress difference
,” Rev. Sci. Instrum.
82
, 035121
(2011
).22.
Gross
, M.
, T.
Krüger
, and F.
Varnik
, “Rheology of dense suspensions of elastic capsules: Normal stresses, yield stress, jamming and confinement effects
,” Soft Matter
10
, 4360
–4372
(2014
).23.
Jofore
, B. D.
, P.
Erni
, G.
Vleminckx
, P.
Moldenaers
, and C.
Clasen
, “Rheology of microgels in single particle confinement
,” Rheol. Acta
54
, 581
–600
(2015
).24.
Lázaro
, G. R.
, A.
Hernández-Machado
, and I.
Pagonabarraga
, “Rheology of red blood cells under flow in highly confined microchannels. II. Effect of focusing and confinement
,” Soft Matter
10
, 7207
–7217
(2014
).25.
Pfleiderer
, P.
, S. J.
Baik
, Z.
Zhang
, G.
Vleminckx
, M. P.
Lettinga
, E.
Grelet
, J.
Vermant
, and C.
Clasen
, “X-ray scattering in the vorticity direction and rheometry from confined fluids
,” Rev. Sci. Instrum.
85
, 065108
(2014
).26.
Awati
, K.
, Y.
Park
, E.
Weisser
, and M.
Mackay
, “Wall slip and shear stresses of polymer melts at high shear rates without pressure and viscous heating effects
,” J. Non-Newtonian Fluid Mech.
89
, 117
–131
(2000
).27.
Carotenuto
, C.
, and M.
Minale
, “On the use of rough geometries in rheometry
,” J. Non-Newtonian Fluid Mech.
198
, 39
–47
(2013
).28.
Carotenuto
, C.
, A.
Vananroye
, J.
Vermant
, and M.
Minale
, “Predicting the apparent wall slip when using roughened geometries: A porous medium approach
,” J. Rheol.
59
, 1131
–1149
(2015
).29.
Kramer
, J.
, J. T.
Uhl
, and R. K.
Prud'Homme
, “Measurement of the viscosity of guar gum solutions to 50 000 s−1 using a parallel plate rheometer
,” Polym. Eng. Sci.
27
, 598
–602
(1987
).30.
Peyla
, P.
, and C.
Verdier
, “New confinement effects on the viscosity of suspensions
,” Europhys. Lett.
94
, 44001
(2011
).31.
Yoshimura
, A.
, and R. K.
Prud'Homme
, “Wall slip corrections for couette and parallel disk viscometers
,” J. Rheol.
32
, 53
–67
(1988
).32.
Mooney
, M.
, “Explicit formulas for slip and fluidity
,” J. Rheol.
2
, 210
–222
(1931
).33.
Sorbie
, K.
, “Depleted layer effects in polymer flow through porous media: I. Single capillary calculations
,” J. Colloid Interface Sci.
139
, 299
–314
(1990
).34.
Anastasiadis
, S. H.
, and S. G.
Hatzikiriakos
, “The work of adhesion of polymer/wall interfaces and its association with the onset of wall slip
,” J. Rheol.
42
, 795
–812
(1998
).35.
Meeker
, S. P.
, R. T.
Bonnecaze
, and M.
Cloitre
, “Slip and flow in pastes of soft particles: Direct observation and rheology
,” J. Rheol.
48
, 1295
–1320
(2004
).36.
Cheikh
, C.
, and G.
Koper
, “Stick-slip transition at the nanometer scale
,” Phys. Rev. Lett.
91
, 156102
(2003
).37.
Schmatko
, T.
, H.
Hervet
, and L.
Leger
, “Friction and slip at simple fluid-solid interfaces: The roles of the molecular shape and the solid-liquid interaction
,” Phys. Rev. Lett.
94
, 244501
(2005
).38.
Barnes
, H. A.
, “A review of the slip (wall depletion) of polymer solutions, emulsions and particle suspensions in viscometers: its cause, character, and cure
,” J. Non-Newtonian Fluid Mech.
56
, 221
–251
(1995
).39.
Sochi
, T.
, “Slip at fluid-solid interface
,” Polym. Rev.
51
, 309
–340
(2011
).40.
Clasen
, C.
, “A self-aligning parallel plate (SAPP) fixture for tribology and high shear rheometry
,” Rheol. Acta
52
, 191
–200
(2013
).41.
Manneville
, S.
, L.
Bécu
, P.
Grondin
, and A.
Colin
, “High-frequency ultrasonic imaging: A spatio-temporal approach of rheology
,” Colloids Surf. A: Physicochem. Eng Aspects
270–271
, 195
–204
(2005
).42.
Vleminckx
, G.
, and C.
Clasen
, “The dark side of microrheology: Non-optical techniques
,” Curr. Opin. Colloid Interface Sci.
19
, 503
–513
(2014
).43.
Macosko
, C. W.
, Rheology: Principles, Measurements and Applications
(Wiley-VCH, Inc.
, Weinheim, Germany
, 1994
), p. 568
.44.
Morrison
, F. A.
, Understanding Rheology
(Oxford University
, Oxford, United Kingdom
, 2001
), p. 395
.45.
Hatzikiriakos
, S. G.
, and K. B.
Migler
, Polymer Processing Instabilities: Control and Understanding
, edited by S. G.
Hatzikiriakos
and K. B.
Migler
(CRC
, Boca Raton, FL
, 2004
), Chap. 4, pp. 73
–120
.46.
Clasen
, C.
, and G. H.
McKinley
, “Gap-dependent microrheometry of complex liquids
,” J. Non-Newtonian Fluid Mech.
124
, 1
–10
(2004
).47.
Clasen
, C.
, B. P.
Gearing
, and G. H.
McKinley
, “The flexure-based microgap rheometer (FMR)
,” J. Rheol.
50
, 883
–905
(2006
).48.
Sanchez-Reyes
, J.
, and L. A.
Archer
, “Interfacial slip violations in polymer solutions: Role of microscale surface roughness
,” Langmuir
19
, 3304
–3312
(2003
).49.
Mhetar
, V.
, and L. A.
Archer
, “Slip in entangled polymer melts. 2. Effect of surface treatment
,” Macromolecules
31
, 8617
–8622
(1998
).© 2016 The Society of Rheology.
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