Abstract
Physical phenomena at the molecular level, such as van der walls interactions, can be used effectively for understanding and modeling drying relationships. Drying can be modeled utilizing fundamental phenomena, in contrast to most of the previous work in which these phenomena were used to explain empirical relationships.
New instruments and techniques provide an opportunity for advancing the knowledge of fundamental research in drying. The computer provides an opportunity for obtaining, storing, and analyzing a large quantity of data. Previously rather limited amounts of data were available from which analyses were made. New statistical and mathematical modeling approaches, a basis of much new fundamental research, need to be developed.
The two major developments make possible representing the drying relationship utilizing molecular building blocks to construct the product: newly-developed or about to be available instruments to measure and “see” the water molecule for a substrate (advanced electron microscopes), and high-speed, high-capacity computers (supercomputers).
The water molecule hp a diameter of 2 Å and a bond length of 0.9 Å. Water molecules are on a substrate which has a wide range of dimensions but much larger than water. As an example, hemoglobin protein with a molecular weight of 68,000 daltons has dimensions of 38 Å by 150 Å. Spectroscopy has been used to determine the presence of elements or molecules, such as water. During drying we are interested not only in the presence of water molecules but also the amount and movement of water. Hopefully, the observations and measurements during drying can be done without destroying the relationships between water and the substrate. A challenge for researchers is to utilize these techniques for nondestructive evaluation (NDE). The implications of the water molecule as a dipole and drying have not been explored--possibly another opportunity for fundamental research.
The scanning electron microscope (SEM) has a resolution of 100 to 200 Å; the transmission electron microscope (TEM), as low as 1–5 Å. and a scanning transmission electron microscope (STEM), combining the above with additional features, is expected to have a resolution of 0.5 Å. The photoelectron microscope (PEM) is presently used to survey the walls of cells. Further, the possibility of looking in three dimensions, to observe and characterize the movement, change of state, vaporization and condensation of water, offers new opportunities for research. The flow of water (liquid and gas) will be modeled as it moves through the products (fats, sugars, cellulose, proteins, minerals, etc.) in much the same way that the flow of electrons or ions can be represented as they move through metals. Likewise, the effect on elemental units of the product by browning, checking, splitting, or as represented by destruction of vitamins or stabilization of enzymes, can be related. These relationships can be utilized further to develop systems and equipment for drying. Admittedly, these measurement techniques have not been extensively developed for drying of biological products but offer considerable opportunities.
The supercomputer can be used to represent and model the drying phenomena from the most elemental component (electron, chemical, radical, atom, molecule) for which information is available and applied to the entire drying system.
The interaction of the water and substrate, energy involved, flow of water either as gas or liquid, and escape and measurement of water moving from the product (transcutaneous) can be used as parameters for the design of drying equipment. The components of the system can be modeled and the system can be represented with many parameters on the computer. The results of this approach using fundamental relationships can be used for several products and applications, providing results of a generic nature, while minimizing but not eliminating many of the time-consuming repetitive laboratory tests and empirical results from field tests.
This is a preview of subscription content, log in via an institution to check access.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Preview
Unable to display preview. Download preview PDF.
Similar content being viewed by others
References
Adams, Tom, “Acoustic Microscope Probes Materials,” High Technology, 2 (5): 78–81, Sept./Oct. 1982 ).
Anon., “Theory Predicts Thermal Decomposition Rates,” Chemical & Engineering News, 61(8): 24 (Feb. 21, 1983 ).
Anon., “Center Will Advance Electron Microscopy,” Industrial Research and Development, 25 (11): 41 (Nov. 1983).
Anon., “Electron Microscopy Goes 3-D,” Science News, 123(25):396 (June 18, 1983).
Anon., “Microscope Sees with Sound,” Science Digest, 91 (6): 27 (June 1983).
Anon., “New Methods Shed Light on Surface Chemistry,” Chemical and Engineering News, 61(37):30–32 (Sept. 12, 1983).
Anon., “New Scope Brings Atoms into Focus,” Science Digest, 91 (10): 35 (Oct. 1983).
Anon., “Positrons Useful in Probing Pores,” Chemical and Engineering News, 61(37):48 (Sept. 12, 1983).
Bash, Paul A., et al., “Van der Waals Surfaces in Molecular Modeling,” Science, 222:1325–1327 (Dec. 23, 1983 ).
Baum, Rudy, “Photoelectron Applied to Cells,” Chemical and Engineering News, 60 (50): 34 TDec. 13, 1982 ).
Baum, Rudy, “Zero-Field NMR Advances Molecular Structure Determinations,” Chemical and Engineering News, 61 (50): 23–24 Dec. 12, 1983 ).
Chandler, D., Weeks, J. D., and Andersen, H. C., “Van der Waals Picture of Liquids, Solids, and Phase Transformation,” Science, 220:787–794 (May 20, 1983 ).
Crewe, A. V., “High-Resolution Scanning Transmission Electron Microscopy,” Science, 221:325–330 (July 23, 1983 ).
Cromie, W. J., “High-Resolution Electron Microscopy Offers a View of the Atomic World,” Mosaic, 14(4):15–19 (July/August, 1983).
Derra, S., “Crewe Plans STEM to Resolve 0.5 Industrial Research and Development, 25 (3): 51–52 (March 1983).
DeYoung, H. G., “Biosensors, the Meeting of Biology and Electronics,” High Technology, 3 (11): 41–49 (Nov. 1983).
Eckert, E. R. G., and Pfender, E., “Heat and Mass Transfer in Porous Media,” Proceedings of Sixth International Heat Transfer Conference, Toronto, Canada, 6: 1–12 (1978)
Eisenberg, D., and Kauzman, W., The Structure and Properties of Water, Oxford University Press, Oxford, England (1969).
Faghri, M., and Eckert, E. R. G., “Moisture Migration Caused by Periodic Temperature Fluctuations in an Unsaturated Porous Medium,” Warme- und Stoffubertragung, 14: 217–223 (1980).
Fendler, J. H., “Membrane Mimetic Chemistry,” Chemical and Engineering News, 62(1):25–38 (Jan. 2, 1984 )
Franks, Felix (editor), Water, A Comprehensive Treatise, 6 volumes, Vol. 1, The Physics and Physical Chemistry of Water, Plenum Press, New York, N.Y., 596 p. (1972)
Giddings, J. Calvin, “Basic Approaches to Separation, Analysis and Classification of Methods According to Underlying Transport Characteristics,” Separation Science and Technology, 13 (1): 3–24 (1978).
Gregg, S. J., and Singh, K. S. W., Adsorption Surface Area and Porosity, Academic Press, Inc., New York, N.Y., 340 p. (1982).
Griffith, J. D., Electron Microscopy in Biology, Wiley-Interscience, New York, N.Y., 296 p. (1981).
Halle, J. M., and Mansoori, G. A., Molecular-Based Study of Fluids, American Chemical Society, Washington, D.C., 524 p. (1983).
Harris, J. E., Electron Microscopy of Proteins, Academic Press, Inc., New York, N.Y., 362 p. (1981).
Hasted, J. B., Aqueous Dielectrics, Chapman and Hall, London, England, 302 p. (1973).
Hillman, G. C., et al., “Determination of Thermal Histories orArcheological Cereal Grains with Spin Resonance Spectroscopy,” Science, 222:1235–1236 (Dec. 16, 1983 ).
Johnson, Roger S., “It Makes One Dandy Package–Even if It’s Only Skin Deep,” Smithsonian, 13 (12): 151–154 (March 1983).
Jorgenson, J. W., and Lukacs, K. D., “Capillary Zone Electrophoresis,” Science, 222: 266–272 (1983).
Jortner, J., and Pullman, B., Intramolecular Dynamics, D. Reidel Publishing Co., New York, N.Y. (1982).
Khanna, S. K., and Lambe, J., “Inelastic Electron Tunneling Spectroscopy,” Science, 220:1345–1353 (June 24, 1983 ).
Kihara, T., and Ichimaru, S., Intermolecular Forces, J. Wiley and Sons, New York, N.Y., 182 p. (1976).
Levine, R. D., and Bernstein, R. B., Molecular Reaction Dynamics, Oxford University Press, Oxford, England, 205 p. (1974).
Levine, R. D., and Jortner, J. (editors), Molecular Energy Transfer, J. Wiley and Sons, New York, N.Y., 310 p. (1976).
March, N. H. (editor), Orbital Theories of Molecules and Solids, Clarendon Press, Oxford, England (1974).
Marx, J. L., “Organizing the Cytoplasm,” Science, 222:1109–1111 (Dec. 9, 1983 ).
Ogniewicz, Y., and Tien, C. L., “Analysis of Condensation in Porous Insulation,” International Journal of Heat and Mass Transfer, 24 (3): 421–429 (1981).
Rawls, R., “Penning Spectroscopy Studies Molecules,” Chemical and Engineering News, 61(31):20 (Aug. 1, 1983).
Reese, K. M., “The Coming of Age of NMR,” Mosaic, 14 (5): 14–19 (1983).
Robinson, A. L., “IBM Images Surfaces by Electron Tunneling,” Science, 220:43 April 1, 1983 ).
Shah, D. J., Ramsey, J. W., and Wang, M, M., “An Experimental Determination of the Heat and Mass Transfer Coefficients in Moist, Unsaturated Soils,” International Journal of Heat and Mass Transfer, to appear in 1984.
Speakman, J. C., Molecules, McGraw Hill Book Co., New York, N.Y., 158 p. (1966).
Tucker, J. B., “Designing Molecules by Computer,” High Technology, 4 (1): 52–59 (Jan. 1984).
Wolfenden, R, R., “Waterlogged Molecules,” Science, 222:1087–1093 (Dec. 9, 1983 ).
Author information
Authors and Affiliations
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 1985 Springer-Verlag Berlin Heidelberg
About this paper
Cite this paper
Hall, C.W. (1985). Opportunities for Fundamental Research in Drying. In: Toei, R., Mujumdar, A.S. (eds) Drying ’85. Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-662-21830-3_1
Download citation
DOI: https://doi.org/10.1007/978-3-662-21830-3_1
Publisher Name: Springer, Berlin, Heidelberg
Print ISBN: 978-3-662-21832-7
Online ISBN: 978-3-662-21830-3
eBook Packages: Springer Book Archive