Measurement Methods for Complex Fluid Formulation

On May 3, 2011, the Complex Fluids Group and the Microrheometry Project hosted a meeting with manufacturers (in the United States and United Kingdom) to discuss measurement advances and needs in the formulation of complex fluids. This dialogue was coordinated with the Chemistry Innovation Knowledge Transfer Network, a U.K. governmental organization that supports R&D projects to encourage manufacturing. Participants included representatives from both large multinational and small companies, and the topics of discussion were measurement, process methods, and formulation methods. NIST representatives from MML, PML, EL, CNST, NCNR, and the Program Office were in attendance.

Purpose:
An international dialogue on state-of-the-art measurement methods and emerging needs in the formulation and manufacture of complex fluids.

Background:
Complex fluids are multicomponent liquids with structures on the mesoscopic length scale that are responsible for the performance of the fluids and are highly susceptible to external perturbations, such as flow or temperature. Common examples include emulsions, polymer solutions, and pharmaceuticals, with applications in a broad range of technology sectors. Formulation is the process of mixing several components to achieve the desired structure and product performance. In personal care products, the value added through formulation is generally four to 10 times more than the value of all of the ingredients. In pharmaceuticals, formulation is equally important, not to add value to a costly drug, but to improve its performance dramatically, for example, by stabilizing it against degradation or controlling time release properties.

Agenda:
Discussion and presentations focused on the need to bridge the gap between measurements of properties, such as the viscosity of a fluid, and measurement of performance, such as how well a detergent formulation cleans in a washing machine. Closing this gap is necessary to increase manufacturing efficiency and to compete in an environment where environmental, economic, and climate factors force frequent modifications of formulations.

Program:

Introductions to NIST and UK Formulations
Getting to know NIST,  Mike Fasolka
UK innovation landscape & national strategy for chemistry-using industries, Colin Tattam (Chemistry Innovation)

NIST Programs
Complex Fluids Intro, Kalman Migler (NIST)
Micro Viscometry and Rheometry, Kalman Migler (NIST)
Addressing Carbon Nanotube Polydispersity, Jeff Fagan (NIST)
Causal Factors in Protein Stability, Marc Cicerone (NIST)
Fast Dynamics of Glass-Forming Liquids for Protein Preservation: What Exactly Are We Measuring?, David Simmons (NIST)
Particle Standards for Protein Stability, Dean Ripple (NIST)
Interfacial Rheometry, Kendra Erk (NIST)
The nSoft Consortium – Advancing Neutron Methods for Soft Materials Manufacturing, Ron Jones (NIST)

Industry Needs and Capabilities
Characterization Challenges for Home and Personal Care Products, Mark Baker (Unilever HT program)
High Throughput Formulation at CMD, Neil Jones (Centre for Material Discovery/U Liverpool)
Understanding drug formulation behavior through gastric modeling, Martin Stocks (the Model Gut)
Process measurement needs for complex fluids as intermediates to making solid products, David York (P&G)
Complex phase behavior of liquid crystalline phases for a commercial non-ionic surfactant system, Helen Dutton (U Manchester)
Parallel detection and particle characterization in concentrated systems, David Goodall (Paraytec)
Emulsion/Dispersion Manufacturing and Image Analysis, Richard Holdich (Micropore/U Loughborough)
Microfluidic processing for dispersion, Mimi Panagiotou (Microfluidics)

Discussion:
Throughout the program the following questions were discussed.

1. Is screening appropriate for manufacturing processes (unit operations and conditions)? What processes do you want to understand better?
2. To screen composition, is it better to measure material properties or to devise a test based on a key process step and measure characteristics of the output? What are the relative merits of each if both are necessary?
3. What are the best measures for product stability? (Improved test precision or implementing adverse conditions?)
4. What are the best performance metrics? For which performance metrics are there needs to develop better tests or models?
5. How to connect performance measures to measures of material properties? What constitutive relationships, models and modeling techniques are lacking?
6. For which material properties are there needs to develop better tests or models?

Organizing committee:
Steve Hudson
Eric Lin
Kalman Migler
Fred Phelan