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

IFPRI Your Outlook on Particle Technology Liege, Feb. 2010

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

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

How IFPRI Works Liege, Feb. 2010

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

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

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

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

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

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

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

Modification of Latex through Protein Adsorption Liege, Feb. 2010

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

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

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

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

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

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

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

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

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

Bridging Flocculation in Practice Liege, Feb. 2010

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

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

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

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

Thank you Liege, Feb. 2010