Problem 14.1. Drying Time Calculation

Determine the total time to dry a 1.0 cm spherical green body with void fraction 40% formed from an aqueous Z1O2 paste with polymer at 

TABLE 14.2 Evaporative Drying of Spherical Green Body, by Heat Transfer Controlling Steps 

This time is long and shows precisely the problem in drying large green bodies. If the green body were 10 cm in diameter rather than 

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Theories neglect that catalysts usually have limited turnover numbers due to destructive side reactions. This may not be so obvious in analytical experiments but it has severe consequences for large scale applications. A simple calculation can illustrate this problem if a redox polymer with a monomer molecular weight of 400 Da and a density of 1 g cm " is considered with all redox centers addressable from the electrode and accessible to the substrate with a turnover number of 1000, then, to react 1 nunol of substrate at a 1 cm electrode surface, at least 5 pmol of active catalyst centers corresponding to 2 mg of polymer, or a dry film thickness of 20 pm are required. This is 20 times more than the calculated optimum film thickness for rather favorable conditions... 

There are four broad reasons why the FORTRAN program fails to converge or calculate properly at times. These include mathematical limitations, complete drying of the solution, oscillatory convergence problems, and poor coding. 

Problem 6.22 Weighed amounts of styrene (M) and -butyl mercaptan (S) in sealed glass ampoules were heated at 60° C for different periods of time. The polymers were then precipitated in methanol, dried in oven, and degrees of polymerization evaluated by intrinsic viscosity measurements. From.the data given below calculate the chain transfer constant (Cs) for the st5Tene/dodecyl mercaptan system at 60°C. 

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