Expert in Crystallization, Research to Manufacturing; Also Photographic Science and Technology, Photochemistry
Expert ID: 716489 New York, USA
NUCLEATION; CHEMICAL PRECIPITATION PROCESS. Expert worked for 20 years in the precipitation of silver halides. In this time he developed new models and theories for the precision-control of precipitations, in particular by control of nucleation. Both batch and continuous precipitations were modeled and supported by experimental results. This work demanded a thorough knowledge of crystal growth, determination of crystal size distribution, and crystallizers. Expert developed a new model for the relationship between stirring/mixing and chemical reactions occurring in process crystallization. He has presented this work in seminars and publications. He has extended the nucleation model to seeded batch and continuous crystallization, including re-nucleation.
PHOTOGRAPHY; DIGITAL PHOTOGRAPHY; IMAGING SCIENCE; PHOTOGRAPHIC EMULSION; PHOTOPHYSICS; SILVER-HALIDE IMAGING SYSTEMS. Expert worked 30 years in the photographic industry in research and product development. He has publications and patents related to photographic science and technology. He gave presentations on photographic science at national and international meetings for which he received the Lieven-Gevaert Medal, the highest award in photographic science. He led product development teams and provided new materials for significantly improved products. He attended advanced seminars on electronic photography. He taught the first graduate course on Photochemistry at Texas Christian University. His work at Kodak routinely incorporated all aspects of photochemistry, photo-physics, and other aspects related to photography and imaging.
DYE CHEMISTRY; FLUORESCENCE; PHOSPHORESCENCE; DYE PHOTOCHEMISTRY. Expert's graduate work and initial career work in industry was on the synthesis and photo-physical and photochemical evaluation of dyes. During his industrial career he routinely used dyes for the sensitisation of photographic products. He published papers on the synthesis, absorption, luminescence (fluorescence and phosphorescence), nuclear magnetic resonance spectra, and molecular orbital calculations of dyes. His work furthered the knowledge of the relationship between molecular and electronic structure of dyes, and their photochemistry. Expert published papers relating the dye structure to their photographic activity towards spectral sensitization of various photographic systems. With a minor in organic chemistry, Expert applied the concepts of organic chemistry to synthesize dyes and their precursors. He estimates that he synthesized roughly 150 compounds, of which about 2/3 were novel compounds.
Chemical crystallization is used in the conversion of one type of crystals into another type. It is mainly used by adding a component that gives a material with lower solubility than the original crystals. In photographic systems, the desired result is improved light sensitivity, less chemical fog, or faster development.
Crystal growth is also a highly important part of the crystallization process (see 'balanced nucleation and growth' process). A little known limitation to growth is the maximum growth rate, which is determined by physical properties of the growing material, growth material, and environmental conditions (solvent, temperature). The quantitative relation of maximum growth rate was derived by expert's colleague Jong Wey and his coworkers. This information is a basis of the balanced nucleation and growth model which provides the basic understanding and quantitative description of the nucleation process.
Size enlargement is the result of the control of nucleation, where larger crystals are obtained if the number of growing nuclei is reduced by nucleation control (BNG, balanced nucleation and growth model). Existing crystal populations are enlarged by controlled crystal growth. Another process is the growth of smaller crystals onto larger crystals by the Thompson-Kelvin or Ostwald ripening process. The reaction conditions are essential to retain or modify the morphology of the growing crystal population. Similarly, the growth conditions will affect the morphology of the nuclei during the nucleation process. The growth rate can be increased by ripening agents or reduced by growth retainers. These techniques were applied in the work of the author.
In principle there are three type of crystallizers that combine nucleation and growth: single jet, double-jet, and continuous controlled crystallizers (continuous stirred tank reactor, CSTR or MSMPR). Stop-flow continuous crystallizers are derivatives of CSTR reactors. Our work brings the controlled double-jet and the controlled continuous crystallizers under one universal concept. Growth crystallizers are defined by a given crystal population which is grown by addition of further growth material. Growth in the controlled double-jet growth crystallizer is defined by reactant addition rate and the maximum growth rate of the growing crystal population. Growth in continuous growth crystallizers is limited by the same factors. The latter was modeled by Randolph-Larson model and was extended by Expert. Expert's BNG (balanced nucleation and growth) model is the basis for the complete treatment of the controlled double-jet and continuous crystallizers. The BNG theory is applicable to the single-jet crystallizer. However, there are presently no controlled experiments and results to test modeling results.
Particle size analysis determines the size distribution of a crystal population, and defining parameters, like median and maximum crystal size. The techniques for size determination include microscopic and electron microscopic analysis, light scattering, disk centrifuge, and others. The author has evaluated over fifteen hundred crystal populations by particle-size analysis techniques and is thus familiar with a wide range of techniques and crystal size and morphology populations.
Mixing and stirring are related, but not the same. The degree of mixing can significantly affect the outcome of crystallization and chemical reactions. To some degree, mixing and stirring can be varied and controlled by mixer design. The author has developed models and designed mixing / stirring devices that allow to control mixing for given stirring.
Expert consulted with TempTime Corp, Morris Plains, NJ, on the control of precipitation of diacetylene compounds which resulted in a patent. His industrial consulting experience includes pharmaceuticals, imaging materials, and inorganic and organic materials. Sizes of materials started at nanoparticle size (0.01nm) and larger. Organic compounds example.Expert consulted with Southern Clay Products, Inc., Gonzales, TX on the crystallization of clay particles. Inorganic ExampleExpert is consulting with Dr. Kui Yu, Canadian Research Council, Ottawa, Ontario, Canada on the formation of cadmium chalgonide nano crystals.
Expert may consult nationally and internationally, and is also local to the following cities: Buffalo, New York - Rochester, New York - Syracuse, New York - Utica, New York - Niagara Falls, New York
|Year: 1966||Degree: PhD||Subject: Physical Chemistry||Institution: Technical University Munich, Germany|
|Year: 1964||Degree: MS||Subject: Chemistry||Institution: Technical University Munich, Germany|
|Year: 1961||Degree: BS||Subject: Chemistry||Institution: Technical University Munich, Germany|
|Years: 1998 to Present||Employer: Undisclosed||Title: President||Department:||Responsibilities: Consulting to industry and academic institutions, and teaching workshops for the precision control of size and size distribution in crystallizations. He is developing and publishing improved models for the precision control of precipitations.|
|Years: 1969 to 1998||Employer: Eastman Kodak Company Rochester, NY||Title: Senior Research Scientist||Department:||Responsibilities: He had responsibility for basic research in photographic science and for applied research and product development for photographic films, papers, and other products, including transfer to production|
|Years: 1968 to 1969||Employer: Texas Christian University||Title: Welch Research Fellow||Department:||Responsibilities: Determined the decay rate of phosphorescence of benzene and derivatives as a function of temperature between 4 and 120 K for fundamental understanding of these processes. He published three publications on this work.|
|Years: 1966 to 1968||Employer: Technical University Munich, Germany||Title: Postdoctoral Fellow||Department:||Responsibilities: He studied the relationship between the molecular structure and color of dyes. For this purpose, he synthesized dyes and their precursors, and measured their absorption, fluorescence, and phosphorescence spectra at 77K and room temperature. He worked with others on quantum mechanical calculations of these dyes and of related compounds. This work was published. In addition, he measured and published nuclear magnetic resonance spectra of selected dyes.|
|Years||Country / Region||Summary|
|Years: 1998 to Present||Country / Region: Germany||Summary: Expert has consulted in Germany. He was educated in Germany and is fluent in German.|
|Years: to Present||Country / Region: Netherlands||Summary: Expert consulted with Akzo- Nobel company on the crystallization of alkali halides.|
|Associations / Societies|
|Expert is a Fellow of Sigma Xi, and member of the American Chemical Society, the Society for Imaging Science and Technology, the American Association for the Advancement of Science, the American Geographical Union, the Rochester Academy of Science, and the Rochester Professional Consultants Network. He is listed in American Men and Women in Science and in Who’s Who in Science and Engineering.|
|Awards / Recognition|
|Expert was elected Fellow and received the Lieven-Gevaert Medal for outstanding contributions to Photographic Science from the Society for Imaging Science Technology. He and his coauthors also received the Journal Award (Honorable Mention), from the Journal of Photographic Science and Engineering.|
|Publications and Patents Summary|
|Expert authored a review of the balanced nucleation and growth model for crystallization. He has over 50 publications, patents, and research disclosures in the areas of crystallization, photographic science, photochemistry, and organic synthesis. In addition he has given numerous presentations and seminars at national and international meetings on crystallization, photochemistry, photographic science. He presented in the field of astrophysics on the Big Bang as a crystallizationo process, the stability of the solar system and other aspects.|
|Training / Seminars|
|For Nano to Macro sized crystals, Expert's precision crystallization course offers vital practical and quantitative concepts for the precision preparation of such particles. This knowledge is essential to in-house preparations, as well as for knowledgeable interaction with suppliers. The course focuses on control of crystal nucleation, the most important and challenging factor for controlled crystallizations. Crystal growth is a natural part of the presentation.
Five experimental control variables determine the particle and crystal size. The course teaches the necessary information and methods for controlling crystal size through these variables. Non-significant factors - previously considered important - are discussed.
This course applies to inorganic materials such as silver halides in the photographic industry and of clays, and to organic crystal systems like polyacetylenes and organophosphates. It is essential for other systems such as pharmaceuticals, latexes, dyes, imaging pigments, toners, and of catalysts.
The presenter and coworkers have developed new and practical models and equations that relate the crystal number and size distribution (nucleation) to experimentally controllable reaction variables. This sets these models apart from all other models. The crystal number is quantitatively related to reactant addition rate, crystal solubility, temperature, and solvent and crystal properties, crystal ripening agents (macro-sizing) and crystal growth restrainers (nano-sizing). By knowing the model, the number of necessary experiments is minimized. For continuous precipitations the reactor residence time is an additional modeled critical factor.
For the first time, equations for both controlled batch and continuous precipitations are available using the same fundamental model. Unanticipated predictions of the models were experimentally confirmed, confirming their power for crystallization needs.
The course provides a unique opportunity to learn up to date principles for precision controlled precipitations for precision size control, providing better crystals for better products.
A short course of this material is included in the consulting process.
|Expert's crystallization consulting firm has consulted with many large and medium sized industries, and has been consultant to the US and Belgian governments. The course has been presented at national and international conferences. These experiences have resulted in insights that benefit anyone needing crystallization insights and support.|
|Other Relevant Experience|
|Our background includes a full study of chemistry and physical chemistry together with chemical engineering, which provide necessary insights in the chemical challenges of crystallization processes|
|German||Fully proficient in all aspects|
|French||Reading and some speaking and writing knowledge. Four years education in high school. He has examined scientific articles and patents in his area of expertise|
Fields of Expertise
chemical precipitation process, crystallization, digital photography, dye, imaging science, nucleation, photographic emulsion, photography, photophysics, silver-halide imaging system, crystal size distribution, photographic film, photographic material, photographic paper, process crystallization, chemical recrystallization, crystal growth, particle-size control, particle-size enlargement, crystallizer, particle-size analysis, mixing, motion picture technology, photographic X-ray film, photographic technology, dye chemistry, scale-up, design for manufacturability, new product development, motion picture film, phosphorescence, photochemistry, organic chemistry, microfilm, fluorescent dye, fluorescence, chemical process control, chemical engineering