2014 AIChE Annual Meeting

(598f) Creation of Complex Phase Behavior Diagrams for Industrial Applications Leveraging High Throughput Image Analysis Techniques

Authors

Tate, M. - Presenter, The Dow Chemical Company

Understanding the fundamentals of phase behavior in complex multi-component systems, and how that phase behavior impacts performance is crucial to many applications.  Cleaning formulations, whether for household or industrial applications, are a premier example of systems that contain complex phase behavior due to the presence of multiple solvents, surfactants, salts, and other components in the formulations.  Multiple theories to describe the phase behavior of individual components, but a complete understanding of multi-component system phase behavior remains elusive.  As such, experimental techniques and subsequent empirical models tend to dominate the development and use of these formulated systems.  However, due to the complex and non-linear phase behavior often exhibited by these systems, the development of empirical models based on experimental designs of minimal data lack the necessary complexity to be predictive.

We present image capture and analysis techniques that determine the phase behavior of a multi-component liquid formulation, which when combined with high throughput formulation techniques enable the mapping of multi-component phase diagrams in a thorough and rapid manner.  Specifically, we present 2 image capture and analysis techniques (one based on transmitted light and the other on reflective light) to determine the phase behavior of 2 separate industrial formulations.  In each case, formulations are prepared robotically using multi-channel liquid handlers before image capture.  The images are captured under well-controlled, uniform lighting conditions, which enable subsequent image analysis to be automated.  Standardized methods and standards have been established to ensure the highest degree of precision and accuracy for batch processing and testing.  Useful data output from the analysis program for liquid in liquid phases includes characterization of the formulation, largest phase clarity (grayscale), largest phase volume fraction, phase count, phase analysis graphs, and volume fraction of each phase- which can be calculated into the percent of non-soluble material in the formulation.  This change from traditional methods where a research visually inspects a formulation, reduces subjectivity in the creation of phase behavior diagrams, and adds quantitative information to those diagrams.  Determination of the phase behavior of the formulation is made more complex when different soils or other components are added at the time of application.  To test this method against industrial cleaning applications, complex formulations were created from base, salt, solvents, and surfactants and tested to determine temperature stability and their ability to suspend a wide array of soils including used motor oil, asphalt, and a carbon black containing soil.  The solvent package in the formulation contained 2 solvents from a list of 7, while the surfactant package contained 2 surfactants from a list of 5 surfactants with both solvent and surfactant packages varying total concentration as well as ratios.  The result for each of the 2 applications was a formulation data set created from a D-optimal statistical design of experiment with >1000 samples.  Despite the large data set covering an even larger design space, only a small fraction of the samples were stable at all tested temperatures (20 – 80 deg C) and able to suspend the soils.  These small windows of stability will be discussed in terms of the overall phase behavior of the original formulations.  Finally, the image capture and analysis techniques impact on the development of other industrial applications will also be discussed.