Structure-viscosity relationship

More recently, Yang and Thompson implemented this type of sensor in FI manifolds, which they consider ideal environments for relating the sensor s hydrodynamic response to the analyte s concentration-time profile produced by the dispersion behaviour of sample zones. Network analysis of the sensor generates multi-dimensional information on the bulk properties of the liquid sample and surface properties at the liquid/solid interface. The relationship between acoustic energy transmission and the interfacial structure, viscosity, density and dielectric constant of the analyte have been thoroughly studied by using this type of assembly [171]. 

There has been an increasing interest in liquid crystals containing fluorine atoms because fluorination produces important changes in the melting temperatures, viscosity, birefringence, dielectric anisotropy and mesophase stability. This why structure-mesomorphism relationship studies were carried out in mono- and... 

It is often difficult to make generahzations regarding the viscosity of epoxy resin components based on chemical structure. The relationships described below between structure and viscosity are based on unmodified epoxy resins and curing agents. However, one must be careful since there are many exceptions to these generalities. 

The aforementioned macroscopic physical constants of solvents have usually been determined experimentally. However, various attempts have been made to calculate bulk properties of Hquids from pure theory. By means of quantum chemical methods, it is possible to calculate some thermodynamic properties e.g. molar heat capacities and viscosities) of simple molecular Hquids without specific solvent/solvent interactions [207]. A quantitative structure-property relationship treatment of normal boiling points, using the so-called CODESS A technique i.e. comprehensive descriptors for structural and statistical analysis), leads to a four-parameter equation with physically significant molecular descriptors, allowing rather accurate predictions of the normal boiling points of structurally diverse organic liquids [208]. Based solely on the molecular structure of solvent molecules, a non-empirical solvent polarity index, called the first-order valence molecular connectivity index, has been proposed [137]. These purely calculated solvent polarity parameters correlate fairly well with some corresponding physical properties of the solvents [137]. 

Prediction models for ionic conductivity and viscosity of ILs using quantitative structure property relationships coupled with the descriptors of group contribution type were introduced [155], The polynomial expansion model based on the type of cation, length of side chain, and type of anion was applied to the expression of IL properties. Parameters of these polynomial expansion models were determined by means of a genetic algorithm. The reverse design of ILs was also tested [155],... 

Kauffman, G.W. and Jurs, P.C. (2001a) Prediction of surface tension, viscosity, and thermal conductivity for common organic solvents using quantitative structure-property relationships. J. Chem. Inf. Comput. Sci., 41, 408-418. 

The pharmaceutical industry has for many years developed mathematical models to explain the biological activity of drugs these are termed as quantitative structure-activity relationships (QSARs). These techniques may also be applied to the situations described herein, although more correctly we are often more interested in QPARs, where the P stands for property (which may refer to macroscopic properties such as density, melting point or viscosity, or to molecular or sub-molecular... 

This synthesis work was not only aimed at obtaining a better knowledge of the structure-properties relationships, but also at designing either polymers with reduced viscosity and improved response time, suitable for display applications, or polymers bearing in their side chains an electron donor-IT system-electron acceptor moiety for second order nonlinear optics. 

Rameshwaram et al. [6] investigated the structure-property relationships and the effects of a viscosity ratio on the rheological properties of polymer blends using oscillatory and steady shear rheometry and optical microscopy. 

Rameshwaram, J. K., Yang, Y.-S., and Jeon, H. S. 2005. Structure-property relationships of nanocomposite-like polymer blends with ultrahigh viscosity ratios. Polymer 46 5569-5579. 

E. coli and S. aureus Some quinuclidinium compounds were quite active in vitro with the most active XVIII having MIC values of 0.4 ug/ml for S. aureus and B. subtilis. A group of 68 N,N-dimethyl-N-alkyl-2-aryloxyethyl ammonium bromides were prepared and screened vs 8 common infectious organisms, and the best had alkyl groups of from 8-12 carbon atoms, with MIC values as low as 0.5 yg/ml. Bis-quaternary salts of ethylene and hexamethylene diamine of type XIX were active in vitro . The most active had R=CioH2i and the chloride had greater activity than the corresponding iodide. Another paper dealt with the structure-activity relationships of compounds of type XIX . Various physical properties such as pH, wettability, viscosity, surface tension, etc. were related to activity. 

By establishing structure property relationships one should be able to select polymers for specific technical applications. To give an example, we established a zero-shear-viscosity molecular weight - concentration relationship which is valid... 

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