Chemical reaction condensation

Chemical reaction rate, see Rate of reaction Chemical reactions condensed phases, 42-46 enzymatic, see Enzymatic reactions gas phase, see Gas-phase reactions heterolytic bond cleavage, 46, 47, 51,... 

Micro structured wells (2 mm x 2 mm x 0.2 mm) on the catalyst quartz wafer were manufactured by sandblasting with alumina powder through steel masks [7]. Each well was filled with mg catalyst. This 16 x 16 array of micro reactors was supplied with reagents by a micro fabricated gas distribution wafer, which also acted as a pressure restriction. The products were trapped on an absorbent plate by chemical reaction, condensation or absorption. The absorbent array was removed from the reactor and sprayed with dye solution to obtain a color reaction, which was then used for the detection of active catalysts by a CCD camera. Alternatively, the analysis was also carried out with a scanning mass spectrometer. The above-described reactor configuration was used for the primary screening of the oxidative dehydrogenation of ethane to ethylene, the selective oxidation of ethane to acetic acid, and the selective ammonoxidation of propane to acrylonitrile. 

Cure — A process of changing the properties of a polymer by a chemical reaction (condensation, polymerization, or addition). In elastomers it means mainly cross-linking or vulcanization. 

Type V - Rigorous Model with Chemical Reaction Condenser =1 i = 1 to nr Total mass balance ... 

Schiff base. A class of compounds derived by chemical reaction (condensation) of aldehydes or ketones with primary amines. The general formula is RR X=NR". 

Accumulation mode particles in this mode originate from primary emissions as well as through gas-to-particle conversion, chemical reactions, condensation and coagulation. 

The scaleup of polymerization processes is conceptually identical to the scaleup of ordinary chemical reactions. The principal difference is that polymer systems are more likely to be highly viscous and in laminar flow. Although polymer melts can be markedly non-Newtonian, this is rarely a critical factor in the scaleup of polymer reaction and recovery systems. Vinyl polymerizations have strong exotherms so that parametric sensitivity and thermal runaways can be a problem, but so do many other chemical reactions. Condensation polymerizations tend to be equilibrium-limited, but so do many other chemical reactions. 

Ayers, P Morrison, R. C. Roy, R. K. Variational principles for describing chemical reactions Condensed reactivity indices. J. Chem. Phys. 2002,116, 8731. 

The physical chemist is very interested in kinetics—in the mechanisms of chemical reactions, the rates of adsorption, dissolution or evaporation, and generally, in time as a variable. As may be imagined, there is a wide spectrum of rate phenomena and in the sophistication achieved in dealing wifli them. In some cases changes in area or in amounts of phases are involved, as in rates of evaporation, condensation, dissolution, precipitation, flocculation, and adsorption and desorption. In other cases surface composition is changing as with reaction in monolayers. The field of catalysis is focused largely on the study of surface reaction mechanisms. Thus, throughout this book, the kinetic aspects of interfacial phenomena are discussed in concert with the associated thermodynamic properties. 

Harris A L, Berg M and Harris C B 1986 Studies of chemical reactivity in the condensed phase. I. The dynamics of iodine photodissociation and recombination on a picosecond time scale and comparison to theories for chemical reactions in solution J. Chem. Phys. 84 788... 

Grote R F and Hynes J T 1980 The stable states picture of chemical reactions. II. Rate constants for condensed and gas phase reaction models J. Chem. Phys. 73 2715-32... 

In order to segregate the theoretical issues of condensed phase effects in chemical reaction dynamics, it is usefiil to rewrite the exact classical rate constant in (A3.8.2) as [5, 6, 7, 8, 9,10 and U]... 

In this chapter many of the basic elements of condensed phase chemical reactions have been outlined. Clearly, the material presented here represents just an overview of the most important features of the problem. There is an extensive literature on all of the issues described herein and, more importantly, there is still much work to be done before a complete understanding of the effects of condensed phase enviromnents on chemical reactions can be achieved. The theorist and experimentalist alike can therefore look forward to many more years of exciting and challenging research in this important area of physical chemistry. 

Sprik M 1998 Density functional techniques for simulation of chemical reactions Classioal and Quantum Dynamios In Condensed Phase Simulations ed B J Berne, G Ciccotti and D F Coker (Singapore World Scientific) pp 285-309... 

Chemical reaction dynamics is an attempt to understand chemical reactions at tire level of individual quantum states. Much work has been done on isolated molecules in molecular beams, but it is unlikely tliat tliis infonnation can be used to understand condensed phase chemistry at tire same level [8]. In a batli, tire reacting solute s potential energy surface is altered by botli dynamic and static effects. The static effect is characterized by a potential of mean force. The dynamical effects are characterized by tire force-correlation fimction or tire frequency-dependent friction [8]. 

Bash, P.A., Field, M.J.,Karplus, M. Free energy perturbation method for chemical reactions in the condensed phase A dynamical approach baaed on a combined quantum and molecular dynamics potential. J. Am. Chem. Soc. 109 (1987) 8092-8094. 

On top of that, reaction databases can also be used to derive knowledge on chemical reactions which can then be used for reaction prediction, The huge amount of information in reaction databases can be processed by inductive learning methods in order to condense these individual pieces of information into essential features... 

In the last section we examined some of the categories into which polymers can be classified. Various aspects of molecular structure were used as the basis for classification in that section. Next we shall consider the chemical reactions that produce the molecules as a basis for classification. The objective of this discussion is simply to provide some orientation and to introduce some typical polymers. For this purpose a number of polymers may be classified as either addition or condensation polymers. Each of these classes of polymers are discussed in detail in Part II of this book, specifically Chaps. 5 and 6 for condensation and addition, respectively. Even though these categories are based on the reactions which produce the polymers, it should not be inferred that only two types of polymerization reactions exist. We have to start somewhere, and these two important categories are the usual place to begin. 

To see why the assumption of equal reactivity is so important to step-growth polymers, recall from Table 1.2 the kind of chemical reactions which produce typical condensation polymers ... 

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