Effects of Solvent and Temperature

From Eq. (3.1) to Eq. (3.3), surface tension, viscosity, and ambient temperature are parameters that will have an effect on the measured contact angle. While viscosity will primarily influence the rate of relaxation of 0d during wetting, surface tension will have effects on both the relaxation rate Eq. (3.2) and the final contact angle Eq. (3.1). Surface tension is a property of liquid caused by uneven attraction of liquid molecules (or surface cohesion) at or near the surface, the higher the surface tension, the larger the resistance for the liquid to wet. The effect of solvent on contact angle has been studied on many polymer surfaces, such as poly(tetrafluoroethylene), poly(vinylidene fluoride), poly(ethylene), poly(vinyl chloride), poly(vinylidene chloride), polystyrene, and the like and adsorbed monolayers from aliphatic fatty acids and perfluoro fatty acids. The subject was summarized well by Zisman [2]. The solvent effect is usually plotted as cos 0 versus /lv of the liquid. A typical plot 

This work demonstrates that care should be taken in interpreting the wetting data at different temperature. There are two components in liquid-solid interactions. While temperature certainly has effects on the surface tension and viscosity of the liquid, it may also have an effect on the morphology of the solid surface too. 

Young T (1805) An essay on the cohesion of fluids. Phil Trans R Soc London 95 65-87 

Zisman WA (1964) Relation of the equilibrium contact angle to liquid and solid constitution. In Fowkes F (ed) Contact angle, wettability, and adhesion, advances in chemistry. American Chemical Society, Washington, DC, pp 1-51 

Shuttleworth R, Bailey GJ (1948) The spreading of a liquid over a rough surface. Discuss Faraday Soc 3 16-22 

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Effect of Solvent and Temperature on Molecular Weights in Isobutylene Polymerizations... 

Yong Ju, Z. and Howar, L.R., Effects of solvent and temperature on pressurized liquid extraction of anthocyans and total phenolics from dried red grape skin, J. Agric. Food Chem., 51, 5207, 2003. 

Kleiman, Y. L., Morkovin, N. V., Ionin, B. I. Effect of Solvents and Temperature on Spin-Spin Interaction Constant 1 Jjjp in Dimethyl Hydrogen Phosphite. J. Gen. Chem. R. 37, 2661(1967). 

Perhaps the most important parameter involved in aqueous-organic mixtures is their effective protonic activity (denoted by pH or pan). This parameter has been measured for most commonly used buffers in all selected mixtures down to their freezing point (Hui Bon Hoa and Douzou, 1975 Douzou ei al., 1976). Values of pH depend on solvent and temperature in a way that varies for different buffers, but with the data available a medium of known pH under any desired condition may be prepared. An example of the effect of solvent and temperature is provided by Tris-HCl buffer a solution of this at pH 8.0 in water at 20 C will be pH 10.5 in 50% (v/v) ethanediol at -40 C (Douzou et al, 1976). On the other hand, neutral buffers such as phosphate undergo... 

Effect of solvent and temperature on intrinsic viscosity. Kurata, Utiyama, and Kamada (69) have compared the intrinsic viscosity of PTHF in several different solvents at the same temperature. Some of their results are shown in Table 11. 

Bailey, W. F. Brubaker, J. D. Jordan, K. P. Effect of solvent and temperature on the lithium-iodine exchange of primary alkyl iodides reaction of tBuLi with 1-iodooctane in heptane-ether mixtures./. Organomet. Chem. 

In the same fashion, the C15 side chain does not seem to have a great impact on the selectivity observed with G2. Compounds 74 (Scheme 2.28) and 76 (Scheme 2.29) are obtained as 66 34 and 69 31 mixtures of E/Z isomers, respectively, when treating dienes 73 and 75 with G2 in CH2C12 at ambient temperature. However, Maier and coworkers reported an example which seemingly shows some deviation from this behavior if a substrate very similar to 73 (with an extra methylene in the side chain) is reacted with G2 in toluene at 70 °C, the selectivity increases to 86 14 [58], However, in this example the effects of solvent and temperature cannot be ruled out. 

Effect of solvent and temperature on porphyrin-quinone electron transfer rates... 

In the case of charge-transfer emission (formally a bimolecular reation), Feldberg plots are also linear (e.g., [118]). The charge-transfer character of this emission, however, can be demonstrated by a correlation of emission energies of various ECL systems with the standard redox potential (e.g., correlation of the emission maxima with the oxidation potentials of the donor or with the reduction potentials of the acceptors [119]). The associated charge-transfer character can also be demonstrated by the effects of solvent and temperature on the emission energy and intensity (e.g., [120]). 

Both effects of solvent and temperature on the reaction of dibutylmagnesium with benzaldehyde in the presence of the lithium salt of 2a was examined and enhanced optical yield was exhibited at low temperature (entries 5, 6, 11, and 12 in Table 5) in toluene, in contrast with the preferred use of ethereal solvents observed in the same reaction using alkyllithiums (see Table 3)... 

V. EFFECTS OF SOLVENT AND TEMPERATURE ON THE ABSORPTION AND FLUORESCENCE EMISSION OF SYMMETRICAL SQUARAINES... 

The effects of solvent and temperature on the direction of the [4+2] cycloaddition of pyrrolidinocyclooctene to 4-methyl-l,2,3-triazine 86c have been studied. The ratio of products 138 and 139 changed while the total yields dropped with increasing temperature (Equation 51) <1988H(27)2213>. 

Table 2 Effects of solvent and temperature on site-selectivity in acylation of octyl p-D-glucopyranoside catalyzed by 8...

Kamiya, Y. Ingold, K. U. The Metal-Catalyzed Autoxidation of Tetralin. IV. The Effect of Solvent and Temperature. Can. J. Chem. 1964, 42, 2424-2433. Starks, C. M. Liotta, C. L. Halpem, M. Phase-Trantfer Catalysis Fundamentals, Applications, and Industrial Perspectives-, Chapman Hall New York, 195M. 

Hek, S.R., Chetry, S., Jayasree, V., Bhat, N. Effects of solvents and temperature on the critical miceUar concentration of sodium dodecyl sufate and cetylpyridin-ium chloride. J. Indian Chem Soc. 2000, 77(10), 478—481. 

Effect of solvents and temperature on generation of serratezomine A (40) and 97 from serratinine (83) through a modified Polonovski reaction 80). 

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