Transport and Interfacial Properties

Transport and interfacial properties are often neglected in favor of research and development efforts directed to phase equilibrium properties. Even less attention has been devoted to such properties for electrolytes and polymers. In industrial practice, the needs for transport and interfacial properties are numerous, i.e., detailed design of heat exchangers, and distillation column tray and packing sizing calculations. Both predictive and correlative models are needed for liquid viscosity, thermal conductivity, surface tension, diffusion coefficients, etc. 

Some recent works on polymer viscosity and electrolyte viscosity are very promising. The simplicity and accuracy of these models make them particularly attractive for engineering applications. However, extensive successful industrial applications are essential if any of these models are to become accepted in the industry. 

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Matthew V. Tirrell (Co-Chair) is Dean of the College of Engineering at the University of California at Santa Barbara. He was previously Professor and Head of the Department of Chemical Engineering and Materials Science at the University of Minnesota, where he served as Director of its Biomedical Engineering Institute. He received a B.S. from Northwestern University and a Ph.D. from University of Massachusetts. His interests are in transport and interfacial properties of polymers, with particular emphasis on molecular-scale mechanical measurements, bioadhesion, and new materials development. He is a member of the National Academy of Engineering. 

Taketani, Y. Matsuura, T. Sourirajan, S. Proceedings of the Symposium on Ion Exchange Transport and Interfacial Properties. 158th Electrochemical Society Meeting, Hollywood, Florida, Oct 5-10, 1980 p 88. 

C. Heitner-Wirguin, in Ion Exchange Transport and Interfacial Properties, Ed. by R. S. Yeo and R. P. Buck, The Electrochemical Society Softbound Proceedings Series, Pennington, N.J., 1981, p. 249. 

R.L. Dotson, R.W. Lynch, and G.E. Hillard, Transport of Water Molecules and Sodium Ions Through Nafion Ion Exchange Membranes, In R.S. Yeo and R.P. Buck (eds), Ion-Exchange Transport and Interfacial Properties, PV 81-2, The Electrochemcial Society, Pennington, NJ, (1981), p. 268. 

Appetecchi, G.B., Croce, F., Persi, L., Ronci, F., Scrosati, B. (2000) Transport and interfacial properties of composite polymer electrolytes. Electrochimica Acta, 45, 1481-1490. 

There is a need to better understand the physical, chemical, and mechanical behaviors when modeling HE materials from fundamental theoretical principles. Among the quantities of interest in PBXs, for example, are thermodynamic stabilities, reaction kinetics, equilibrium transport coefficients, mechanical moduli, and interfacial properties between HE materials and the... 

Surfactants may spend long periods of time being transported in the reservoir before interacting to alter the wettability of pore surfaces. The surfactant must maintain its chemical structure and interfacial properties during that time. The long term stability of surfactants at elevated temperatures in an appropriate brine can be monitored in the laboratory from cloud point and interfacial tension measurements [63]. 

Poly (ethylene oxide) (PEO) - LiX complexes appear to be the most suitable electrolytes for lithium polymer batteries, however, the local relaxation and segmental motion of the polymer chains remain a problem area (Armand et al., 1997). Therefore, the PEO-based electrolytes show an appreciable ionic conductivity only above 100°C (Gorecki et al., 1986). This is, of course, a drawback for applications in the consumer electronic market. On the other hand, the gel polymer electrolytes although offer high ionic conductivity and appreciable lithiiun transport properties it suffers from poor mechanical strength and interfacial properties (Croce et al., 1998 Gray et al., 1986 Kelly et al., 1985 Weston et al., 1982). Recent studies reveal that the nanocomposite polymer electrolytes alone can offer safe and reliable lithium batteries (Appetecchi... 

Atmospheric Reaeration. Interfacial properties and phenomena that govern oxygen concentrations in river systems include 1) oxygen solubility (temperature, partial pressure and surface dependency), 2) rate of dissolution of oxygen (saturation level, temperature and surface thin film dependency, i.e., ice, wind), and 3) transport of oxygen via mixing and molecular diffusion. A number of field and empirically derived mathematical relationships have been developed to describe these processes and phenomena, the most common of which is (32) ... 

The interfacial rheologic properties are extremely sensitive parameters toward the chemical composition of immiscible formation liquids [1053]. Therefore comparison and interpretation of the interfacial rheologic properties may contribute significantly to extension of the spectrum of the reservoir characterization, better understanding of the displacement mechanism, development of more profitable enhanced and improved oil-recovery methods, intensification of the surface technologies, optimization of the pipe line transportation, and improvement of the refinery operations [1056]. 

The low efficiencies could be due to lack of intimate contact (interface) between the sensitizer (which is hydrophilic) and the spirobifluorene (which is hydrophobic). Moreover, the surface charge also plays a significant role in the regeneration of the dye by the electrolyte.98 In an effort to reduce the charge of the sensitizer and improve the interfacial properties between the surface-bound sensitizer and the spirobifluorene hole-carrier, amphiphilic heteroleptic ruthenium(II) complexes ((48)-(53)) have been used as sensitizers. These complexes show excellent stability and good interfacial properties with hole-transport materials, resulting in improved efficiencies for the solar cells. 

Experimental studies of the thermodynamic, spectroscopic and transport properties of mineral/water interfaces have been extensive, albeit conflicting at times (4-10). Ambiguous terms such as "hydration forces", "hydrophobic interactions", and "structured water" have arisen to describe interfacial properties which have been difficult to quantify and explain. A detailed statistical-mechanical description of the forces, energies and properties of water at mineral surfaces is clearly desirable. 

The results in Table V illustrate that MD studies, compared to the MC results in Table IV, facilitate the investigation of transport and time-dependent properties. Also, they show that use of the MCY potential leads to very large density oscillations and increasing water density near the surfaces. This appears to be a serious drawback to the use of the MCY potential in simulations of interfacial water. Results from the investigations using the ST2 potential show that interfacial water density is approximately 1.0 g/cc, with a tendency for decreased density and hydrogen bonding near the surfaces. As in the MC simulations, orientations of the water dipole moment are affected by the presence of a solid/liquid interface, and an... 

Lord, D.L., Hayes, K.F., Demond, A.H., and Salehzadeh, A. Inflnence of organic acid solntion chemistry on snbsnrface transport properties. 1. Surface and interfacial tension. Environ. Sci Technol, 31(7) 2045-2051, 1997. 

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