Viscosity future research

Transport phenomena and other dynamic processes in lyotropic liquid crystals have received relatively little research attention. However, they can be quite important in practice because relatively long times are often required to reach equilibrium when a liquid crystal is present. Moreover, understanding of equilibrium behavior seems to have reached a point where additional work on dynamic phenomena would be productive. Accordingly, the available information on such phenomena is reviewed. It consists mainly of measurements of viscosity, diffusivity, electrical conductivity, and chemical reaction rates in liquid crystalline materials. Some possible areas for future research are identified and discussed briefly. 

In summary, research reported in this chapter illustrates not only the complexity of surfactant enhanced remediation of hydrophobic NAPLs, but also demonstrates the ability of properly designed surfactant systems to effectively remediate these hydrophobic oils (EACN of 10-20). Future research will further evaluate this area, including field studies. This research also explored surfactant systems for attacking even more hydrophobic, low viscosity NAPLs (EACNs)20). Addressing the highly hydrophobic oils (EACNs))20) and highly viscous oils may require combined approaches, (i.e., surfactants plus alcohols/solvents and/or temperature) such will also be the focus of future research. 

Nousiainen, R, Future research and development in viscose fibres. Kemira Communications, Kemira Fibres, Sateri, 1992. 

When multiphase feeds are atomized, stresses occurring in atomization result in an oil drop breakup, following theoretical considerations for emulsification. Ca number and viscosity ratio allow for understanding oil drop breakup. At higher disperse phase contents oil drops coalesce within the spray. The exact location of oil drop breakup and coalescence should be investigated in future research, in order to control these effects in atomization. 

The viscosity shows a shght dependence on the fibre length at low shear rates, which is disappearing at higher shear rates. A more detailed investigation of these effects as well as the influence of fibre content will be subjects of oin future research interest. 

The structures of the solid-melt interface and the melt confined within a narrow gap are of great significance in diverse areas of research such as lubrication, adhesion, or in future nanometer science. It is well recognized that the melt of n-alkanes, and other simple molecules show anomalous oscillations in density, viscosity, etc. vs. depth from the surface showing the presence of marked layer structures in the melt [40]. Even in polymer melts similar layering phenomena were suggested near the solid surface [41], but no pronounced ordering or the onset of crystallization were reported. 

Eisenthal s reports that the solvent dependence of the kinetics of the LE/CT interconversion of DMABN should be attributed predominantly to polarity-induced barrier height changes rather than viscosity (friction) changes, has received a lot of recent attention. Su and Simon have explored the role of intramolecular vibrational fluctuations in the LE/CT kinetics of DMABN [80]. This mechanism is outlined in the following subsection, where the same mechanism has been invoked to understand the photodynamics of bis-(N,N-dimethylaminophenyl)-sulfone. Research on the DMABN class of molecules continues to the very active. It will be interesting to see how the various mechanisms and apparently contradictory arguments are reconciled in the future. 

Other relevant parameters, such as viscosity raise and crystallization rate,which are currently explored by other research groups (13.15). will be the subject of future studies on our experimental system, in the presence of various added substances. 

In this chapter, we will review the principles of acoustic measurement techniques and describe, in detail, acoustic flowmeters for solid/liquid and solid/gas pipe flows. Because field engineers who work with solid/liquid flows find it important to monitor liquid viscosity, we also describe the use of ultrasound to monitor. To conclude the chapter, we enumerate future sensor research needs. 

---