Deagglomeration of two Carbon Black slurries using the ...domino.bhrgroup.com/Portals/0/Meeting Presentations... · Two carbon black dispersions were processed using two power intensive

www.bhrgroup.com BHR Group is a trading name of VirtualPiE Limited © BHR Group 2015

Deagglomeration of Carbon Black Dispersions Using the Ultrasonicator

Dr Gül Özcan-Taşkın [email protected] Mobile: +44 (0) 77856 21659

Direct dial: +44 (0) 330 119 19 01

23- 24 September 2015 DOMINO Autumn Meetings

Confidential to DOMINO Members

© BHR Group 2015 19-20/05/2015 2

Introduction- Background

During 2014 project meetings, DOMINO members were invited to make propositions for new materials to be used within DOMINO

Carbon black and graphite were materials favoured by members during September 2014 Meetings

© BHR Group 2015 19-20/05/2015 3

Materials

Two pre-dispersions of carbon black were received from membership to be processed using energy intensive devices: N134 and N234

These materials are typically used to reinforce natural and synthetic rubber products

The pre-dispersions were prepared by using a batch rotor-stator following the same protocol, i.e. under the same operating conditions

Particle concentration is 4% w:w for both

© BHR Group 2015 19-20/05/2015 4

Introduction- Objectives and scope of work

The overall objectives of the WP have been to assess

► the fineness of carbon black dispersions obtained using power intensive process devices and

► the kinetics of deagglomeration and stability of carbon black dispersions

Two carbon black dispersions were processed using the Microfluidizer M110-P and reported during May Meetings. One of these is now processed using the ultrasonicator.

© BHR Group 2015 5

Background- Microfluidizer M-110P

Z type interaction chamber: for deagglomeration; auxillary chamber upstream

Generic images obtained from Microfluidics website

© BHR Group 2015 8

Results- Power input

Pt

VP

i

i

P - power, W

Vi - volume of impulse, m3

ti - time of impulse, s

P - pressure drop, Pa

Pressure Power P/m*

(psi) (M Pa) (W) (W/kg)

5000 35 146 29333

10000 69 416 78146

20000 138 1471 249441

* based on mass per pulse (4.9- 5.9 ml)

© BHR Group 2015 9


Pt

VP

i

i

P - power, W

Vi - volume of impulse, m3

ti - time of impulse, s

P - pressure drop, Pa

Pressure Power P/m*

(psi) (M Pa) (W) (W/kg)

5000 35 146 29333

10000 69 416 78146

20000 138 1471 249441

* based on mass per pulse (4.9- 5.9 ml)

© BHR Group 2015 10


Process device

P (W)

Mass (kg) considered

P/m (W/kg)

In-line rotor-stator 60- 3600 100 0.6- 35.5

Ultrasonicator 55- 90 2 27.5- 45

Microfluidizer* 148- 1469 0.006** 2.9x104- 2.5x105

*4897 W/kg for 300 ml dispersion ** Pulse volume

© BHR Group 2015 19-20/05/2015 11

Conclusions (May 2015)

There are minor differences in terms of PSD between the two pre-dispersions supplied : N134 and N234

Break up appears to occur through rupture

Very little change in size noted during processing. Comparable final size range with both dispersions : ~2 to 20 µm

N234 dispersion reaches the finest size in 1 pass, N134 takes 4 passes and appears to be slightly coarser than N234.

Dispersions are stable over the 4 months tested

© BHR Group 2015 19-20/05/2015 12

Comparison of the pre-dispersions

0

1

2

3

4

5

6

7

8

1 10 100

Vo

lum

e %

Diameter (Microns)

N234

N134

PSDs of the two pre-dispersions are comparable

© BHR Group 2015 19-20/05/2015 13







© BHR Group 2015 19-20/05/2015 14

Deagglomeration of N134 dispersion using the Microfluidizer

0

1

2

3

4

5

6

7

8

9

10

0.5 5 50 500

Vo

lum

e %

Diameter (Microns)

pre-dispersion1 pass2 pass3 pass4 pass

Following on from a significant size reduction after 1 pass, further break up occurs gradually during further passes through what appears to be a rupture type break up

© BHR Group 2015 19-20/05/2015 15

0

1

2

3

4

5

6

7

8

9

10

1 10 100

Vo

lum

e %

Diameter (Microns)

pre-dispersion1 pass2 pass3 pass

Deagglomeration of N234 dispersion using the Microfluidizer

Single pass through the Microfluidizer is sufficient to obtain the finest possible dispersion with this formulation.

© BHR Group 2015 19-20/05/2015 16

Conclusions (May 2015) and future work





Further work can be performed using

► the ultrasonicator and

► with a dispersing agent

© BHR Group 2015 19-20/05/2015 17

Comparison of final PSDs

0

1

2

3

4

5

6

7

8

9

10

1 10 100

Vo

lum

e %

Diameter (Microns)

Final

N234

N134

© BHR Group 2015 19-20/05/2015 22

N234 (before processing) SEM Micrographs

© BHR Group 2015 19-20/05/2015 23

N234 (before processing) SEM Micrographs (2)

© BHR Group 2015 19-20/05/2015 24

N234 (after processing) SEM Micrographs

© BHR Group 2015 19-20/05/2015 25

N234 (after processing) SEM Micrographs

© BHR Group 2015 19-20/05/2015 26







© BHR Group 2015 19-20/05/2015 27

Comparison of Sauter mean diameters

0

2

4

6

8

10

12

14

0 0.5 1 1.5 2 2.5 3 3.5 4

N134

N234

Nb of passes

d3

2 (

µm

)

© BHR Group 2015 19-20/05/2015 28







© BHR Group 2015 19-20/05/2015 30

N234 Ageing of Samples

0

1

2

3

4

5

6

7

8

9

10

0.1 1 10 100 1000

Vo

lum

e %

Diameter (Microns)

N234 - fresh

N234 - 4 months

Dispersions are stable over the 4 months period tested.

© BHR Group 2015 19-20/05/2015 31







Further work can be performed using

► the ultrasonicator and

► with a dispersing agent

© BHR Group 2015 19-20/05/2015 32

Contents

Introduction- background

Experimental

► Equipment

► Materials

Results and discussions

Conclusions and future work


Experimental set up

N234 was processed using the ultrasonic processor Hielscher

UP200S Ultrasound Disperser (24 kHz )

Titanium, 14 mm diameter sonotrode

100% Amplitude

Calculated power output: ~89 W

Total mass of dispersion: ~ 180 mg

P/V = ~ 494 W/kg

Samples taken at pre-determined time intervals


Particle Size Distribution Measurements

Beckman Coulter LS230

Laser diffraction (0.4 – 2000 mm) + PIDS (Polarization Intensity Differential Scattering) (0.04 – 0.4 mm)

Refractive index for carbon black: 1.84+0.85i

(ASTM Carbon Black Reference Materials: Particle Sizing Using a Brookhaven Instruments BI-DCP, Disc Centrifuge Photosedimentometer by W. W. Tscharnuter, L. Zu, Bruce B. Weiner)

PSD measurements:

► on fresh samples then

► after 24 h


Evolution of PSD in time using the ultrasonicator

0

1

2

3

4

5

6

7

8

9

0.5 5 50 500

Dif

fere

nti

al V

olu

me

, %

Particle Diameter, Microns

4% Carbon black (N234) with ultrasonicator at 100% amplitude

t= 0 min

t= 2.5 min

t= 5 min

t= 10 min

t= 60 min

Insignificant change in PSD over a period of 60 min processing- in line with findings with Microfluidizer


Evolution of d32 in time

6

7

8

9

10

11

12

0 10 20 30 40 50 60 70

4% Carbon black(N234) with ultrasonicator at 100%

Processing time (min)

d3

2 (m

icro

ns)


Results of ageing test

6

7

8

9

10

11

12

0 10 20 30 40 50 60 70

4% Carbon black(N234) with ultrasonicator at 100%

N234- u-s

24 h aged


d3

2 (m

icro

ns)

The dispersions maintain their properties as also observed with those obtained with the Microfluidizer


Ageing test: PSD after 24 hours

0

1

2

3

4

5

6

7

8

9

0.5 5 50 500

Dif

fere

nti

al V

olu

me

, %


4% Carbon black (N234) with ultrasonicator at 100% amplitude

t= 0 min

t= 60 min

24 h ageing


Comparison with the Microfluidizer

0

1

2

3

4

5

6

7

8

9

10

1 10 100 1000

Dif

fere

nti

al V

olu

me

, %


4% Carbon black (N234) comparison of u-s and Microfluidizer

t= 0 August 2015 U-S

t= 0 April2015 MF

U-S 60 min

MF 3rd pass


Comparison with the Microfluidizer

5

6

7

8

9

10

11

12

13

14

15

0 5 10 15 20 25 30

4% Carbon black(N234)- Ultrasonicator and Microfluidizer

N234- u-s N234 MF


d3

2 (m

icro

ns)


Concluding remarks and future work

Two carbon black dispersions were processed using two power intensive process devices: Microfluidizer M-110P and the ultrasonicator.

This allowed a specific power input of ~500- 5000W/kg to be covered.

Very little change in PSD was noted during processing.

The samples were stable over the period tested.

These results provide a baseline for future work to study the effect of formulation.

© BHR Group 2015 19-20/05/2015 42

Acknowledgements

The work was performed by Brian Perkins

www.bhrgroup.com BHR Group is a trading name of VirtualPiE Limited © BHR Group 2015

Thank you

Dr Gül Özcan-Taşkın

[email protected] Mobile: +44 77856 21659

Direct dial: +44 (0) 330 119 19 01

http://www.bhrgroup.com/

Documents

Deagglomeration of two Carbon Black slurries using the ...domino.bhrgroup.com/Portals/0/Meeting Presentations... · Two carbon black dispersions were processed using two power intensive