Development of a new opposed-nozzle fixture for measuring the … · 2016. 2. 12. · fixture for measuring the extensional properties of low viscosity liquids May-August, ... 2d

Development of a new opposed-nozzle fixture for measuring the extensional properties of low viscosity liquids

May-August, 2009 – MIT, Harvard University and University of Minnesota

1

J. Soulages,

G. H. McKinley

F. Le Goupil,

J. Hostettler,

Motivation

• RFX instrument by Rheometrics • ARES-G2 Add-on

• P. Dontula et al., “Can extensional viscosity be measured with opposed-nozzle devices?”, Rheol. Acta 36:429-448 (1997) 2

➡ Rheometer add-on to measure the apparent extensional viscosity of low-viscosity fluids at high deformation rates.

• G.G. Fuller et al., J. Rheol. 31:235-249 (1987)

LL

FFF

Working Equations

Extension rate:

Stress on nozzle:

Apparent extensional viscosity:

Volumetric flow rate

Nozzle to nozzle half distance

Force acting on jet Measured torque

Pivot arm length

Nozzle radius

3

Inertia Correction:

P. Dontula et al., Rheol. Acta 36:429-448 (1997)

Liquid density

2d

2r

Q Q

with

10-3 10-2 10-1 100 101 102 103 104 105

10-3

10-2

10-1

100

101

102

103

104

105

106

107

___ 1.37 mm___ 0.84 mm___ 0.51 mm

η E

[Pas

]

dε/dt [s-1]

Previous Work: ARES Operating Region

Minimum flow rate based on syringe pump specifications

Maximum flow rate based on syringe pump specifications

Maximum measurable

viscosity based on the maximum pressure drop

achievable with the syringe pump (8

bar):

ARES minimum resolvable torque

(2x10-6 Nm)

3 x zero-shear viscosity

(η0=0.1 Pas)

4

ARES-G2 minimum

resolvable torque (0.1x10-6 Nm)

Operating Region as a Function of Nozzle

Diameter

Nozzle length ( 8 mm )

*

*assuming

3 x zero-shear viscosity

(η0=0.7 Pas)

0 20 40 60

0.0

1.0x10-6

2.0x10-6

3.0x10-6

4.0x10-6

5.0x10-6

ARES minimum resolvable torque : 2x10-6 Nm

Residual Torque

RFX minimum resolvable torque : 0.5x10-6 Nm

ARES-G2 minimum resolvable torque : 0.1x10-6 Nm

Tor

que

[Nm

]

Time [s]

ARES minimum resolvable torque : 2x10-6 Nm

ARES/ARES-G2 Residual Torques

5

System Definition

Q

++-Suction (b=0)

+-+Expulsion (b=0)

Sign of Minertia

Sign of a Sign of Mmeasured

Mode

xz

y

Top view

F

Pivot Arm L

nozzle

ARES-G2 Torque reading : M > 0

Eps [s-1]

M [N

m]

Eps [s-1]

Expulsion

Suction

4x10-5

-4x10-5

3x104-3x104

ρ = 1225 Kg.m-3

η0 = 0.10 PasKI = 0.3

100 101 102 10310-2

10-1

100

101

η [P

as]

[s-1]

T = 27°C

Pure glycerol (η0 = 0.64 Pas)

Glycerol/Water (88/12 wt%) (η0 = 0.10 Pas)

10-1 100 101 102 103

10-2

10-1

100

101

η [P

as]

[s-1]

Newtonian + PEO solutions with η0 ≈ 0.7 Pas (high viscous set)

• Two sets of fluids :

Working Fluids : Zero-shear-rate Viscosity

Newtonian Fluids7

Non-Newtonian Fluids

T = 27°C

PEO 1wt% in Glycerol/Water (50/50 wt%) (η0 = 0.74Pas)

PEO/Water (1/99 wt%) (η0 = 0.12Pas)

Shear thinning

Newtonian + PEO solutions with η0 ≈ 0.1 Pas (low viscous set)

-1.0x10-4 0.0 1.0x10-4

1

1/T-1/T0 [K-1]

η 0(T)/

η 0(T0)

Time-Temperature Superposition

8

Newtonian Solutions Non-Newtonian Solutions

T0 = 27°C

-2.0x10-4 -1.0x10-4 0.0 1.0x10-4

1

η 0(T)/

η 0(T0)

1/T-1/T0 [K-1]

Glycerol/Water (88/12 wt%) (η0 = 0.10 Pas) PEO/Water (1/99 wt%) (η0 = 0.12 Pas)

-1.0x10-4 0.0 1.0x10-4

1

η 0(T)/

η 0(T0)

1/T-1/T0 [K-1]

PEO 1wt% in Glycerol/Water (50/50 wt%) (η0 = 0.74Pas)

-1.0x10-4 0.0 1.0x10-4

1

2

η 0(T)/

η 0(T0)

1/T-1/T0 [K-1]

Pure glycerol (η0 = 0.64 Pas)

0

0

= =

==

0.0 0.5 1.0 1.5 2.01E-4

1E-3

0.01

0.1

R/R

0

time [s]

0.0 0.1 0.2 0.3 0.4 0.51E-4

1E-3

0.01

0.1

R/R

0

time [s]

1wt%PEO in Water (η0 = 0.12 Pas)

Minimum resolvable diameter ratio

CaBER Measurements

9

1wt%PEO in Glycerol/Water (50/50 wt%) (η0 = 0.74 Pas)

Based on Oldroyd-B model, the onset of extensional-thickening occurs for

Extensional-thickening expected whenFor 1wt%PEO in Water

For 1wt%PEO in Glycerol/water (50/50 wt%)

Minimum resolvable diameter ratio

10-1 100 101 102 103 104 105

10-2

10-1

100

101

Operating Enveloppe ARES Operating Enveloppe ARES-G2

η E [P

as]

dε/dt [s-1]

• Even for Newtonian solutions,

probably due to dynamic pressure and shear in the nozzles

ARES-G2 Measurements with Newtonian Fluids

10

Expulsion mode, Nozzle diameter = 0.84 mm, T = 27°C

Pure glycerol

3η0 = 1.92 Pa s

3η0 = 0.30 Pa s

Glycerol/Water (88/12 wt%)

• The increase in the apparent extensional viscosity due to liquid inertia is more visible at higher extension rates

Inertia correction*

*

Tests with Smaller Nozzle Diameter

1110 100 1000 10000

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.80.9

1

ARES-G2 (nozzle diameter=0.84mm) expulsion 3η

0= 0.3 Pas

ARES (nozzle diameter=0.51mm) expulsion ARES (nozzle diameter=0.51mm) suction ARES-G2 (nozzle diameter=0.84mm) suction

dε/dt [s-1]

η E [P

as]

Onset of Cavitation

Glycerol/Water (88/12 wt%) (η0 = 0.10 Pas)

T = 27°C

• The data at higher extension rates confirm the increase in the apparent extensional viscosity due to inertia

• Cavitation issues must be solved to observe the effect of inertia for the suction mode

• The onset of extensional thickening based on the CABER relaxation time is not experimentally observed, probably due to the fact that the strain experienced by a fluid element is not sufficient :

• For this low constant strain, the strain hardening phenomenon is expected to be small. However, it could be possible to observe it by going to higher extension rates.

10-1 100 101 102 103 104 105

10-2

10-1

100

101

102

Enveloppe ARES-G2 Enveloppe ARES

dε/dt [s-1]

η E [P

as]

ARES-G2 Measurements with Non-Newtonian Fluids

12

Expulsion mode, Nozzle diameter = 0.84 mm, T = 27°C

PEO 1wt% in (Glycerol/Water) (50/50 wt%)

3η0 = 2.22 Pa s

PEO/Water (1/99 wt%)3η0 = 0.35 Pa s

Inertia correction*

*

for

1 10 100 10000.1

1

10

100

Expulsion Suction

dε/dt [s-1]

η E [P

as]

Suction mode with Non-Newtonian Fluids

13

Expulsion mode (□) and suction mode (○), Nozzle diameter = 0.84 mm, T = 27°C

PEO 1wt% in (Glycerol/Water)

(50/50 wt%)

3η0 = 2.22 Pa s

PEO/Water (1/99 wt%)

3η0 = 0.35 Pa s

Onset of Cavitation

Onset of Cavitation

Onset of extensional thickening

Onset of extensional thickening

• Significant discrepancy between the two modes

• Extensional thickening is observed in suction mode (stretching) but not in expulsion (compression)

• Cavitation starts at lower extension rates for more viscous solutions

10 100 1000 100000.1

1

10

dε/dt [s-1]

η E [P

as]

Suction mode : Comparison Newtonian/Non-Newtonian

14

Suction mode, Nozzle diameter = 0.84 mm, T = 27°C

PEO/Water (1/99 wt%)

3η0 = 0.35 Pa s

Onset of Cavitation

Onset of extensional thickening • Extensional thickening is observed

in suction mode for the non-Newtonian solution but not for the Newtonian counterpart

• Cavitation starts at lower extension rates for the non-Newtonian solution, which is more viscous

Glycerol/Water (88/12 wt%)

3η0 = 0.30 Pa s

Onset of Cavitation

10 100 10000.1

1

10

100

3η0= 1.92 Pas

ARES Expulsion RFX Expulsion RFX Suction ARES Suction

dε/dt [s-1]

η E [P

as]

Comparison with RFX Data : Newtonian Solutions

10 100 1000 100000.1

1

10

100

3η0= 0.30 Pas

ARES Expulsion ARES Suction RFX Expulsion RFX Suction

dε/dt [s-1]

η E [P

as]

15

Glycerol/water (88/12 wt%) (η0 = 0.10 Pas) Pure Glycerol (η0 = 0.64 Pas)

T = 27°C T = 27°C

Good agreement with RFX data

Comparison with RFX Data : Non-Newtonian Solutions

10 100 10000.1

1

10

100

ARES Expulsion ARES Suction 3η

0= 0.35 Pas

RFX Expulsion RFX Suction

η E [P

as]

dε/dt [s-1]

16

1wt%PEO in Water (η0 = 0.12 Pas) 1wt%PEO in Glycerol/water (50/50 wt%) (η0 = 0.74 Pas)

10 100 10000.1

1

10

100

3η0= 2.22 Pas

ARES Expulsion ARES Suction RFX Expulsion RFX Suction

η E [P

as]

dε/dt [s-1]

T = 27°C T = 27°C

Suction mode : increase of ηE : extensional-thickening confirmed by the RFX dataExpulsion mode : increase of ηE at higher rates : extensional-thickening ?

10 100 1000 100000.1

0.2

0.3

0.4

0.5

0.6

0.7

0.80.9

1

dε/dt [s-1]

η E [P

as]

T = 24°C

KI = 0.7

KI = 0.2

3η0 = 0.28 Pa s

Expulsion

Suction

Tests with New Tubing

17

Glycerol/Water (88/12 wt%) (η0 = 0.09 Pas)

• Expulsion mode : the increase of ηE at higher extension rate is well captured with an inertia correction coefficient KI = 0.7

• Suction mode : cavitationissues are solved and ηE also increases but with a smaller coefficient KI = 0.2

• At lower extension rates :

101 102 103 104

10-1

100

Expulsion new tubing Suction new tubing Expulsion old tubing Suction old tubing

η E [P

as]

dε/dt [s-1]

1wt% PEO in Water (η0 = 0.12 Pas)

T = 24°C

Tests with New Tubing

18

• Expulsion mode : the increase of ηE is well captured with an inertia correction coefficient of KI = 0.70, which is in agreement with that of the Newtonian fluid counterpart

• Suction mode : the extensional-thickening and cavitation are still observed

• The decay of ηE at lower extension rates has not been completely eliminated : there probably still exists a shear contributionKI = 0.7

3η0 = 0.45 Pa s Expulsion

Suction

-2.0x10-6 -1.0x10-6 0.00.0

1.0x10-4

2.0x10-4

3.0x10-4

4.0x10-4

5.0x10-4

6.0x10-4

7.0x10-4

Min

ertia

[Nm

]

Q [m3s-1]0.0 1.0x10-6 2.0x10-6

0.0

1.0x10-5

2.0x10-5

3.0x10-5

4.0x10-5

5.0x10-5

6.0x10-5

MIn

ertia

[Nm

]

Q [m3s-1]

Inertia Correction : KI measured (KIm) with one single nozzle

19

Expulsion/Suction in immersion with one single nozzle at 24°C

Suction KIm ≈ 0.2Expulsion KIm≈ 2.2

According to Dontula’s notations :

Water (0.51mm)KIm=2.2

Water (0.51mm) KIm=0.1Gly/H2O (88/12 wt%)

(0.84mm) KIm=2.2

Gly/H2O (88/12) (0.84mm) KIm=0.3

Water (0.84mm) KIm=2.3

Water (0.84mm) KIm=0.2

100 1000 100000.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

dε/dt [s-1]

η E [P

as]

T = 24°C

KI = 0.7

KI = 0.2

3η0 = 0.28 Pa s

Expulsion

Suction

Inertia Correction : Comparison of KI and KIm

20

Glycerol/water (88/12 wt%) (η0 = 0.09 Pas)

KIm = 0.2

KIm = 2.2 • Another contribution decreasing the apparent extensional viscosity during the inertia measurement ?

with

• Suction mode :

• Expulsion mode :

→ Wall effect ?

• Inertia calibration: different correction coefficients in suction and expulsion

• Measured inertia coefficients and sign different from those proposed by Dontula

• Good agreement with RFX results for the Newtonian and viscoelastic solutions

• Extensional-thickening observed only in suction mode

Conclusions

21

• At lower extension rate :

• Cavitation issues in suction mode solved by using shorter tubing

• Flexibility of the fixture that can be mounted on ARES-G2 or ARES

As good as original RFX

Better than original RFX

Expulsion : Suction :

Acknowledgments

• Dr. Johannes Soulages

• Prof. Gareth H. McKinley, MIT

• Jürg Hostettler, ETH Zürich

• Russell Ulbrich, TA Instruments

• Aadil Elmoumni, TA Instruments

• Sujit S. Datta, Harvard University

• Prof. David Weitz, Harvard Univeristy

• David Gilles, University of Minnesota

• Prof. Christopher W. Macosko, University of

Minnesota

22