1. President International Fine Particle Research Institute (IFPRI)
Mixing Of Latex Concentrate With Protein Solutions A Combined PS / ZETA Study
Nikolaas De Jaeger
President International Fine Particle
Research Institute (IFPRI)
Wilmington, DE-USA
PARCOTEC BVBA
Hove Belgium
Liege, Feb. 2010

2. IFPRI Your Outlook on Particle Technology
Liege, Feb. 2010

3. About IFPRI A consortium/club of industrial members (20)
Common interest in making, handling, measuring particles
Diverse - both in activities and location
Membership fees fund global research programme
Members define programme
Strategic to meet long term goals
Dynamic to reflect changing needs
Target specific researchers to join the programme
Work in strong partnership with researchers
Research is
Pre-competitive
Aims to establish fundamental understanding
Supports technical programme of c. $M 0.5
8 Full projects
2 Collaborations
3 Reviews
Liege, Feb. 2010

4. IFPRI Industrial Membership
Arranged by Sector
Fine Chemical
Syngenta
Pharmaceutical
Merck
Pfizer
J&J, Jansen Pharma
Eli Lily
Fast Moving Consumer Goods
Proctor & Gamble
Unilever
Cosmetics
L’ Oréal
Mineral
Umicore
Equipment
Gen. Chemicals
DSM
Lafarge
Spec. Chemicals
UOP
Biotec
Purac
Novozymes
Liege, Feb. 2010

5. How IFPRI Works
Liege, Feb. 2010

6. IFPRI Technical Programme
Dynamic - responds to Member Company needs
Managed within 5 Subject Areas which have strong interactions and weak boundaries
Sols & Dispersions
Flow / Separations
Dry Powder Flow
Characterization &
Measurement
Particle Formation
Size Reduction
Transition from wet to dry
Engineered Products
Attrition
Interparticle
Forces
Liege, Feb. 2010

7. Overview Project Portfolio
System Type
Project Objetives
Particle Flow & Handling
Particle Formation & Modification
Measurement& Characterization
Dry Systems
Powder flow towards the real challenges
G. Tardos
NYCC
Milling of organic materials
Yulong
Ding
Leeds 3D
Characte-rization
E. Pierard
ULG
Dynamics & Rheology of Cohesive & Deformable Granular Materials
R. Behringer 
Univ.
Duke
Powder Structure Control
F. Stepanek  
Univ. Prague
Wet Systems
Microstructures in Gelled Systems
M. Solomon
E. Furst     
Michigan
Univ. Delaware
Granulation
control
Doyle
UC Santa
Barbara
Determina-tion of interaction forces between mineral surfaces at high ionic strength
V. Craig
Australian
Nat.
Liege, Feb. 2010

8. Danger: Bridging Floculation
General Introduction
Mixing Colloidal Suspensions with polymer / protein solutions is a common operation while formulating Dispersed Materials
Mixing also shows up during sample prep. for PSA
Danger: Bridging Floculation
Liege, Feb. 2010

9. Adsorption of Polymers and Oligomers
Solution
Flat-on adsorption
Interface
Liege, Feb. 2010

10. Adsorption of Polymers and Oligomers
Solution
Random coil adsorption
Interface
Liege, Feb. 2010

11. Adsorption of Polymers and Oligomers
Solution
Tails
Loops
Trains
Interface
Liege, Feb. 2010

12. Charged Polymer “Gelatin”
Schematic representation of gelatine adsorption on a charged surface
expansion
Ph < IEP
Electrostatic
Ph  4.8 = IEP
Ph > IEP
Hydrofobic
expansion
 min
Charged surface
Liege, Feb. 2010

13. Modification of Latex through Protein Adsorption
Liege, Feb. 2010

14. Mixing Dispersions with Concentrated Polymer Solutions Flocculation Mechanisms
1. Charge neutralisation
2. Bridging
3. Microparticles
4. Patchwise charge coagulation
5. Depletion
6. Floccuculation through sterically stabilised latices
Liege, Feb. 2010

15. 1. Charge Neutralisation
Mechanism: VDW attraction dominant
Liege, Feb. 2010

16. 2. Bridging Mechanism: one polymer chain adsorbs on multiple particles
Liege, Feb. 2010

17. Compression of double layer Microbridging Limitation of conformatios
Important Parameters
1. MW
2. Celec.
Compression of double layer
Microbridging
Limitation of conformatios
3. pH
4. CColloid
5. PS and distribution
6. Mixing Mode
Liege, Feb. 2010

18. 3. Microparticles
Mechanism: Classical bridging + bridging via microparticles
Liege, Feb. 2010

19. 4. Patchwise Charge Neutralisation
Mechanism: Bridging + charge neutralisation
Liege, Feb. 2010

20. 5. Depletion
Mechanism: Osmotic pressure due to local differences in polymer concentration and MW of polymer
Liege, Feb. 2010

21. 6. Flocculation Trough Latices
Mechanism: Bridging through sterically stabilised Latices
Liege, Feb. 2010

22. Schematical Representation of the Effect of Polymers on the Stability of Dispersed Particles
Clow
Sterical stabilization
Cintermediate
Bridging flocculation
Depletion flocculation
Chigh
Depletion stabilization
Chigher
Liege, Feb. 2010

23. Bridging Flocculation in Practice
Liege, Feb. 2010

24. Mixing Dispersion / Polymer Solution
Particle size of P.E.A. (clean H+) in presence of gelatine (0.025%) and a poststabilising agent
150
Natrosol
KX-4
Melflux-ND-2
Lomard 50
PS of P.E.A. (clean)
PS of P.E.A. origial
Liege, Feb. 2010

25. Mixing Dispersion / Polymer Solution
Zeta potential of P.E.A. (clean H+) in presence of gelatine (0.025%) and a poststabilising agent
Zetapotential of P.E.A. (clean)
-25
-50
-75
Natrosol
KX-4
Melflux-ND-2
Lomard
Zetapotential of P.E.A. (clean) mixed with gelatine
Liege, Feb. 2010

26. One should not theorise before one has data, automatically one starts to twist data to suit theory instead of developing a theory to suit facts…
Sherlock Holmes
Liege, Feb. 2010

27. CONCLUSIONS
Mixing dispersion concentrates with Protein / Polymer Solutions is industrially not an easy task
Bridging adsorption resulting in PS increase is a main problem
Characterise both the protein and Particle concentrate
How to avoid Bridging
Don’t add Prot. Sol. to the Dispersion Concentrate
Control pH & try to use a pH whereby the 2 colloids have the same sign
Dilute Particle Concentrate before mixing
Add Poststab. to Particle Concentrate before mixing
Combined PS/Zeta measurements are an excellent tool to choose the adequate nature and quantity of the Poststab.
Liege, Feb. 2010

28. Thank you
Liege, Feb. 2010