LaMer model

Figure 3. (a) LaMer model describing nucleation and growth of crystallites versus time for a... 

Figure 8.5. The development of supersaturation in a solution that nucleates and grows monosized particles according to the LaMer model. When the solution gets oversaturated there is a short period in which nucleation occurs. The burst of nucleation lowers the concentration to a value where no more nuclei form but all the existing ones start to grow simultaneously.

The mechanism of assembly of the formed gold atoms to gold clusters can be explained by the LaMer model (Figure 11.3) [19, 20]. (i) With time on stream, the concentration of gold atoms increases, (ii) Once the concentration of gold... 

LaMer, Monomer Addition Growth Model. Most of the recent publications (13,18,37,43-45) concerning the Stober silica precipitation describe a first-order hydrolysis of TEOS as the rate-limiting process in the silica particle precipitation. The second reaction step, the condensation reaction, was found to be faster by at least a... 

For several decades, Ostwald s work was the foundation of crystallization theory. In 1950, an American chemist, Victor Kuhn LaMer (1895-1966), advanced our understanding of crystallization of colloidal sols. LaMer assumed that crystallization was a diffusion-driven process (LaMer, 1952 Boistelle and Astier, 1988), as described in previous chapters. LaMer s model is described in three steps, presented in Figure 4.1. In the initial steps of the reaction, the concentration of the molecular materials builds until a critical concentration is reached. This critical concentration, called supersaturation, can be written as... 

This dilemma led us to investigate the feasibility of a nonlinear extrapolation for the evaluation of E°. For the sake of brevity, we will not reproduce here the detailed mathematical derivations of Gronwall, LaMer, and Sandved s extended terms of the Debye-Hlickel theory. One can find these derivations in their original paper (4) or in Hamed and Owens classic monograph. For a description of the basic assumptions and the physical model of the interionic attraction theory one should consult Hamed and Owens monograph as well as the work of Gurney (8,9). 

VoUley, A., Lamer, C., Dubois, O., Feuillat, M. (1990). Influence of macromolecules and treatments on the behaviour of aroma compounds in a model wine. J. Agric. Food Chem., 38, 248-251. 

A general model of floe structure has been proposerd by Sutherland (289), who assumed that coagulation occurs with addition of single particles to doublets, trip lets, and larger aggregates and also that aggregates can collide and become joined. The theory of flocculate density and ease of filtration has been developed by Smellie and LaMer (290). 

Even the concept of molecular switch is an important topic from a variety of perspectives ranging from the modelling of biological processes to the design of devices for molecular electronics. The idea of switching directly the NLO properties has recently been envisioned [151]. Lamere et al. have reported on the synthesis and characterization of a boronate chromophore built up from two push-pull NLO sub-units in a quasi-free rotation around a chemical axis. They discussed on the possibility to use such a system as a molecular NLO switch induced by an electric field [152]. 

If the reduction rate is high enough to keep the monomer concentration higher than supersaturation, as described by LaMer s model, numerous tiny nuclei will form and few monomers will be left for further growth. These liny nuclei tend to... 

The majority of the carbohydrate chemists in this country have accepted the multibranched model for glycogen and amylopectin as the one representing a closer approximation to the true structure. Nevertheless, the Haworth and Hirst laminated model has been seriously considered as a possibility, inasmuch as it is consistent with practically all the data upon which Meyer and Bemfeld base their multibranched structure. Most of the experimental results can be interpreted so as to fit either model. By submitting glycogen and amylopectin to separate and consecutive action of phosphorylase and amylo-l,6-glucosidase, Lamer et oi. were able to examine the inner stmcture of these polysaccharides in... 

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