Physical solutions

A classic in its field, giving a splendid survey of solution physical chemistry from a chemist s point of view. While seriously out of date, it nevertheless provides physical insight into how molecules "behave" in mixtures. 

Graessley W W 1993 Viscoelasticity and flow in polymer melts and concentrated solutions Physical Properties of Polymers ed J E Mark et al (Washington, DC ACS) pp 97- 143... 

Rocha, E. R. P. Nobrega, J. A. Effects of Solution Physical Properties on Copper and Chromium Signals in Plame Atomic Absorption Spectrometry, /. Chem. Educ. 1996, 73, 982-984. 

Physica.1 Absorption. Whereas chemical absorption rehes on solvent reactions to hold acid gas components in solution, physical absorption exploits gas—hquid solubiUties. The amount of absorption for these solvents is direcdy proportional to the partial pressure of the acid gas components. Thus these processes are most appHcable in situations involving high pressure feed streams containing significant concentrations of acid gas components. To favor absorption, lower temperatures are often employed. Some processes require refrigeration. 

Horvath, A. L., Handbook of Aqueous Electrolyte Solutions, Physical Properties, Estimation and Correlation Methods, Ellis Horwood, Chichester, 1985. 

We follow the analysis of Frank-Kamenetskii [3] of a slab of half-thickness, rG, heated by convection with a constant convective heat transfer coefficient, h, from an ambient of Too. The initial temperature is 7j < 7 ,XJ however, we consider no solution over time. We only examine the steady state solution, and look for conditions where it is not valid. If we return to the analysis for autoignition, under a uniform temperature state (see the Semenov model in Section 4.3) we saw that a critical state exists that was just on the fringe of valid steady solutions. Physically, this means that as the self-heating proceeds, there is a state of relatively low temperature where a steady condition is sustained. This is like the warm bag of mulch where the interior is a slightly higher temperature than the ambient. The exothermiscity is exactly balanced by the heat conducted away from the interior. However, under some critical condition of size (rG) or ambient heating (h and Too), we might leave the content world of steady state and a dynamic condition will... 

Ethylene oxide aqueous solutions, physical properties of, 20 635t Ethylene oxide catalysts, 20 648-649 Ethylene oxide hydrolysis, rate constants for, 20 638t... 

Nitric acid solutions, physical properties of, 17 172t... 

Mediators can exist free in solution physically entrapped behind a membrane - immobilized in a matrix along with the biocatalyst or covalently bound to a surface or polymer network, wherein the polymer can be conductive or insulating. - Detailed discussion of the various formats is outside scope of this review paper. However, selected immobilization chemistries reported in relation to enzymatic biofuel cells are reviewed in the sections below. 

Greenfield ef. ai.l l) observed a reduction of signal intensity that correlates with sample intake effects from the modified solution viscosity and/or surface tension of mineral acids. This, coupled with peristaltic pumping of solutions into the nebulizer, considerably reduces physical interferences. Increased salt concentration also has an effect on solution physical properties. In the experience of these authors, the high levels of salt in the matrix also increases the noise from the nebulizer system. This degradation of nebulizer performance, which is not necessarily accompanied by a proportional reduction in sensitivity, is the cause of the observed deterioration of detection limits in real samples as opposed to ideal solutions. 

It is important to state the difference between particles and particulate films at the onset of this section. Particles are separate nanometer- to micron-sized colloids dispersed in solution. Physically interconnected colloidal metal particles constitute a particulate film which may be supported by a monolayer floating on an aqueous subphase or be deposited on a solid substrate. 

To prepare the developing solution (physical developer), weigh 100 mg of L4 emulsion (silver donor) into a watch glass, and add 2 5 mL of the freshly pre-... 

Physical development. The developer used in this process contains a soluble silver salt, and the developed image is obtained by reduction of this salt. The process is chemical, but the term is retained for historical reasons. Development by the same mechanism can occur when silver ions from silver halide grains pass into solution and are subsequently reduced at latent image centers or developed silver. This process is termed solution-physical development. 

Typically, a solvent that is chemically similar to the target solute or that reacts with it will provide high solubility. Water is often used for polar and acidic solutes (e.g., HCl), oils for light hydrocarbons, and special chemical solvents for acid gases such as C02, S02, and H2S. Solvents are classified as physical and chemical. A chemical solvent forms complexes or chemical compounds with the solute, while physical solvents have only weaker interactions with the solute. Physical and chemical solvents are compared and contrasted by examining the solubility of C02 in propylene carbonate (representative physical solvent) and aqueous monoethanolamine (MEA representative chemical solvent). 

In adsorption from solution, physical adsorption is far more common than chemisorption. However, chemisorption is sometimes possible for example, fatty acids are chemisorbed from benzene solutions on nickel and platinum catalysts. 

If a solution containing approximately 4 mole percent sodium in ammonia is cooled below -42°C (231 K) a remarkable liquid-liquid phase separation occurs (33, 155). The solution physically separates into two distinct layers—a low-density, bronze metallic phase that floats out on top of a more dense, less concentrated dark-blue phase. The first experimental observation of this striking phenomenon in sodium-ammonia solutions was made by Kraus (109, 110) in 1907 more recent studies have mapped out the phase coexistence curves for a variety of alkali and alkaline earth metals in liquid ammonia, and these are delineated and discussed elsewhere (164). 

Burgess, J., Ions in Solution, Wiley, Nfew York, 1988. A very readable account of complexation reactions from tlie point of view of solution physical chemistry, emphasizing molecular mechanisms. 

The size and shape of macromolecules in solution can be studied using two techniques termed equilibrium and velocity ultracentrifugation. These techniques use an ultracentrifuge to rotate solutions of macromolecules and place them under a centrifugal force to study their physical properties. The size and shape of the macromolecules can then be determined from the solution physical properties. The ultracentrifuge is equipped for direct measurement of the solution as it spins at high speed. 

History—Occurrence—Formation—Preparation—Concentration of Solutions— Physical Properties — Chemical Properties — Catalytic Decomposition — Decomposition with Self-reduction—Oxidation Processes—Applications. 

Non-Cross-Linked Linear Polymer Solutions (Physical Gels)... 

Seidel, J., Grafstrom, S., and Eng, L. (2005) Stimulated Emission of Surface Plasmons at the Interface between a Silver Film and an Optically Pumped Dye Solution. Physical Review Letters 94 177401. 

Diffusion transfer development is a photographic processing system which involves both chemical development and solution physical development. Diffusion transfer... 

It must be possible to completely remove excess oxidant or reductant by selective reaction in solution, physical separation of phases, or other means such as dilution or cooling. 

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