B.Sc. (Universidad del Zulia – Venezuela), M.A.Sc., Ph.D. (University of Oklahoma), Professor, Department of Chemical Engineering and Applied Chemistry, University of Toronto
Areas of expertise
Interfacial curvature of surface active compounds
Low surface tension films
Lecithin-based microemulsions as drug delivery vehicles
Surfactant-oil-water systems maybe used as templates to produce nanostructured materials, as delivery vehicles for drugs and food additives, and as solvents in: degreasing, cleaning, bio-separations, polymerization, environmental remediation, and enhanced oil recovery. Formulation of surfactant solutions for these and other applications requires significant experimental work and expertise. From the engineering point of view, most surfactant-based processes are “black boxes” because of the complex thermodynamics of these systems. Current equations of state are just starting to tackle simple systems but are not yet capable of reproducing the phase behavior of complex surfactant-water-oil systems. Recently, a “net-average curvature” model has been proposed to predict the interfacial curvature and physical properties of these complex surfactant-oil-water systems. This project seeks to further develop the net-average curvature model into an “expert system” capable of predicting the properties of surfactant formulations (e.g. solubilization capacity, interfacial tension, droplet size, and viscosity) as a function of surfactant/oil type and composition, electrolyte concentration, temperature, and pressure.
Low Surface Tension Films
This project will focus on studying the properties and potential applications of low surface tension films consisting of mixtures of negatively-charged (anionic) and positively-charged (cationic) surfactants. This research seeks to gain a fundamental understanding in the thermodynamics of anionic-cationic surfactant films at air/water and air/solid interfaces, and to evaluate the performance of mixed anionic-cationic films in two target areas: hydrophobic coatings, and dewatering agents. Success in these areas could lead to an alternate environmentally safe waterproofing technology and reduction in energy costs in waste treatments facilities.
Lecithin-Based Microemulsions as Drug Delivery Vehicles
Modern drug delivery vehicles strive to supply drugs on the specific tissues where they are needed, and at a specific rate. Some of the challenges in drug delivery include: the low water solubility of certain drugs, the presence of hydrophilic/hydrophobic zones in living tissues, the metabolism and adsorption of drug and vehicle in other tissues, toxicity associated with the drug and delivery vehicle, the rate of release and others. Drug delivery systems include the use of polymer solutions, surfactant solutions, vesicles, emulsions and microemulsion systems. Microemulsions, in particular, have demonstrated to be excellent vehicles for fast and efficient delivery, but they have the limitation that, in most cases, formulations may contain alcohols and other toxic additives. This work seeks to produce alcohol-free formulations containing phospholipids and sugar-derived bio-compatible surfactants. Drug delivery efficiency and cytotoxicity of these micoemulsions will be evaluated using a transdermal delivery test.
Lung Surfactants
Lung surfactants consist of a complex mixture of phospholipids, glycolipids (mostly saturated), and proteins. These surfactants have the ability of reducing the surface tension of aqueous solutions to values less than 1 mN/m under compression. This property of lung surfactants facilitates respiration and prevents alveoli collapse. Insufficient production or surface activity of lung surfactants produce a condition known as respiratory distress syndrome (RDS). RDS is a common problem among premature babies. Surfactant replacement therapy is the method of choice to treat this condition. Commercial surfactant replacement formulations are expensive and in some cases become inactive by a number of physiological conditions that affect the composition of lung surfactant films. In collaboration with Professor A. W. Neumann (Department of Mechanical and Industrial Engineering), we will be evaluating the use of biocompatible polymers in lung surfactant replacement formulations to improve the surface activity, film stability and oxygen and carbon dioxide transport through lung surfactant films.
Ph.D. (Queen’s), P.Eng. Associate Professor, Teaching Stream Department of Chemical Engineering and Applied Chemistry, University of Toronto Cross-appointed to Institute for Studies in Transdisciplinary Engineering Education and Practice (ISETP)
Areas of Expertise
Chemical process scale-up and simulation
Process safety analysis
Life-cycle analysis
Data analytics research
VR/AR immersive technology development for education and training
Current Projects
Technical advice on chemical product and process design, including performing process simulation for equipment sizing, engineering drawing, cost estimation, process safety analysis, and life-cycle analysis.
Technical advice on chemical product and process design, including performing process simulation for equipment sizing, engineering drawing, cost estimation, process safety analysis, and life-cycle analysis.
About
Professor Chan obtained her Bachelor’s and PhD degrees in Chemical Engineering from Queens University, Canada. During her graduate studies, she worked with Genencor Inc/Dupont Bioscience in the US and later continued her Postdoctoral Fellowship at Agriculture Canada in biomaterials and bioplastics development. Prof. Chan began her academic career at the University of Waterloo in 2012. In 2017, she joined the Department of Chemical Engineering and Applied Chemistry at the University of Toronto as the Assistant Professor, Teaching Stream. She is also a practicing professional engineer registered in Ontario, Canada. Her teaching and research focus on chemical process design and scale-up simulation and modernizing chemical engineering laboratory curriculum. In addition, she uses virtual/augmented technology and data analytics techniques to facilitate individualized learning.
Ph.D., P.Eng., C.Eng, C.F.S., OC, O.Ont, F.C.I.C, F.C.A.E., F.C.I.F.S.T., F.A.O.C.S., F.I.A.Fo.S.T., F.E.C., F.R.S.C. Professor Emeritus, Department of Chemical Engineering and Applied Chemistry, University of Toronto
Areas of Expertise
Food process engineering
Membrane processes
Oilseed processing
Food fortification
Current Projects
Salt fortification with minerals and vitamins
Tea fortification
Proteins and peptides for diabetes prevention
Fortification of Bouillon cubes, local soft drinks
Food process engineering, separation processes, nutraceuticals, micronutrient fortification
Consulting Activity
Technical advice on food processing, production of food proteins, edible oils and oil products, nutraceuticals, essential oils and spices. Laboratory planning. Support of insurance claims and litigation.
About
Levente L. Diosady is an Honour Graduate (1966) in Chemical Engineering from the University of Toronto . He is a registered Professional Engineer, and a designated Consulting Engineer in the Province of Ontario . After graduation he returned to the University of Toronto , where he obtained his M.A.Sc. (68) and Ph.D. (71) degrees in the Department of Chemical Engineering and Applied Chemistry. In 1972 Dr. Diosady joined the Cambrian Engineering Group as a process engineer, and in 1974 he was appointed Director, Research and Development for the Company. In this capacity he was responsible for establishing the company’s research and contract analytical laboratories. He initiated an ambitious program of process development in the areas of edible oil processing and environmental control. Under his direction the laboratory group had grown to 35 scientists and technicians by 1979, and performed some 10,000 contract analyses monthly in the food, feed and environmental control fields. In addition to his research and development duties he participated in several engineering projects. In 1974 he reviewed the environmental treatment systems of the mining and ore processing complex of Ecstall Mining in Timmins, and initiated a major water and air management program at the site. He was responsible for the design of a major pilot-plant for Environment Canada, and the process design for the POS Pilot Plant Corporation facilities in Saskatoon. He supervised the design and construction of several industrial waste water treatment systems.
In October 1979 Dr. Diosady was invited to the University of Toronto, Department of Chemical Engineering and Applied Chemistry as Associate Professor, where he joined Dr. L.J.Rubin in establishing the first Canadian engineering program in food process engineering. Together they developed four undergraduate and three graduate courses, and initiated a multi-faceted research and development program. Dr. Diosady was promoted to Professor in 1985. In 1990 he has been appointed Adjunct Professor in the University of Guelph, School of Engineering.
Professor Diosady’s research interests include vegetable oil processing, edible-oil refining and catalytic hydrogenation, extrusion, protein extraction by membrane processes, advanced separation processes, micronutrient fortification of food and meat curing. He is the author of over 120 publications in refereed journals, and presented the results of the group’s research at some 80 international scientific meetings in Canada and abroad. His research has resulted in patents for a nitrite-free meat-curing system, and for a novel approach to canola processing. The rapeseed extraction process developed by Professors Diosady and Rubin received a Canada Award for Business Excellence in the “Inventions” category in 1987. In 1990 their nitrite-free meat-curing system was selected by the Institute of Food Technologists as one of the ten best food products or processes for 1989.
For the past ten years he has been active in developing techniques for fortifying salt with iron and iodine for the prevention of micronutrient deficiency diseases, which adversely affect some 2 billion people. Tests in Ghana with 5000 subjects demonstrated that replacement of household salt with double-fortified salt resulted in a 30% decrease in anemia in children after eight months. The technology has now been tested on a small scale in India, Morocco, Ivory Coast, Ghana and Kenya. Large scale tests with 250,000 subjects are planned for next year in Nigeria and Kenya, by the Micronutrient Initiative and UNICEF. He is now working on triple fortification with Vitamin A, iron and iodine.
Dr. Diosady is a member of the Expert Committee on Food Engineering, and is a past member of the Canada Committee on Food, Expert Committee on Refrigeration and Preservation Technologies and past-Chairman of the Expert Subcommittee on Energy, all of Agriculture Canada, and a member of the Expert Committee on Food, Expert Committee on Grains and Oilseeds, Ontario Ministry of Agriculture Food and Rural Affairs. He was a member of the panel that established the criteria for bio-engineering for PEO, and is on the review panel for food engineering for CEQB.
He has been an active member of several scientific societies, including the Canadian Institute of Food Science and Technology, Institute of Food Technologists (U.S.A.), American Oil Chemists’ Society, the Canadian Society of Chemical Engineering and he is a Fellow of the Chemical Institute of Canada. He is the past president of the Canadian Section of the American Oil Chemists’ Society, and the Food Engineering Section, Canadian Institute of Food Science and Technology. He serves on the editorial board of two scientific journals in Taiwan and Hungary.
In addition to his academic activities, Dr. Diosady continues to consult in the areas of food processing, trace organic analysis, laboratory planning, and R & D management. He is the President of Food BioTek Corporation and a Director of Chemical Engineering Research Consultants Limited. He represented the academic sector on the Board of Directors of SGS-ICS, a firm specializing in certification of manufacturing operations to the ISO 9000 series of standards. Dr. Diosady is active in the cultural activities of the Hungarian-Canadian community: he is a founding director and Secretary Treasurer of the Hungarian Research Institute of Canada, a research ancillary of the University of Toronto; a founding director and executive director of the Rákóczi Foundation, Vice President of a non-profit housing corporation and past president of the Hungarian-Canadian Engineers’ Association.
Enzyme technology; bioreactors and bioprocesses; industrial applications of enzymes; alternative energy sources; pulp and paper, reactor design and kinetics
Consulting Activity
Bioprocess technology, reactor design and kinetics, occupational health and safety.
About
Brad Saville is a Professor in the Department of Chemical Engineering and Applied Chemistry at the University of Toronto, and is the Faculty Coordinator for Occupational Health and Safety. He obtained his B.Sc. (1985) and Ph.D. (1989) degrees in Chemical Engineering at the University of Alberta, specializing in bioreactors, drug metabolism, and bioprocessing.
Professor Saville is interested in bioprocess technology, with particular emphasis on the performance, characteristics and applications of enzymes to biofuels, in starch processing, and in pulp and paper. He holds several patents related to enzyme technology and the industrial application of biocatalysts. In addition, he has published several articles related to the kinetics and mechanistic aspects of enzyme function, including pharmacokinetics, and is the co-author of “An Introduction of Chemical Reaction Engineering and Kinetics”, published by John Wiley and Sons in 1999.
Professor Saville provides advice on issues related to occupational health and safety, bio/enzymatic processing, general chemical engineering process technology, and technical/process analysis in support of insurance claims and litigation.
