Papin’s digester

Papin s digester, 177 Partial pressures, lawr of, 171, 265, 274 Pascal s law, 40 Passive resistances, 91 Path, 44... 

A solvothermal process is one in which a material is either recrystallized or chemically synthesized from solution in a sealed container above ambient temperature and pressure. The recrystallization process was discussed in Section 1.5.1. In the present chapter we consider synthesis. The first solvothermal syntheses were carried out by Robert Wilhelm Bunsen (1811-1899) in 1839 at the University of Marburg. Bunsen grew barium carbonate and strontium carbonate at temperatures above 200°C and pressures above 100 bar (Laudise, 1987). In 1845, C. E. Shafhautl observed tiny quartz crystals upon transformation of freshly precipitated silicic acid in a Papin s digester or pressure cooker (Rabenau, 1985). Often, the name solvothermal is replaced with a term to more closely refer to the solvent used. For example, solvothermal becomes hydrothermal if an aqueous solution is used as the solvent, or ammothermal if ammonia is used. In extreme cases, solvothermal synthesis takes place at or over the supercritical point of the solvent. But in most cases, the pressures and temperatures are in the subcritical realm, where the physical properties of the solvent (e.g., density, viscosity, dielectric constant) can be controlled as a function of temperature and pressure. By far, most syntheses have taken place in the subcritical realm of water. Therefore, we focus our discussion of the materials synthesis on the hydrothermal process. 

Panchenkov s viscosity formula, 89 paper chromatography, 182 Papin s digester, 276 parabola, 421 paraboloid, 429, 430 parachor, 144, 159 atomic, 144 bibliography on, 148 and bond-type, 147 constitutional effect on, 144 and coordinate link, 144 and dipole moment, 146 and entropy, 147 and latent heat of evaporation, 323 and latent heat of fusion, 146 and magnetic susceptibility, 147 for mixtures, 145 negative, 147 and refractivity, 146-7 in solution, 145 and space-filling fraction, 146 and space-filling, 146 ... 

I introduced into a small Papin s digester, built from the end of a thick-walled gun barrel, a certain quantity of alcohol at 36 degrees and a marble or sphere of flint the liquid occupied nearly a third of the interior capacity of the apparatus. Having observed the kind of noise that the marble produced upon my making it roll in the barrel at first cold, and then heated little by little over a fire, I arrived at a point where the marble seemed to bounce at each collision, as if the liquid no longer existed inside the barrel [69]. 

I prepared a lime soap by double decomposition, by. pouring a Bolntion of chloride of calcium into an aqueous solution of commercial soap. The precipitate, when well washed, was introduced into a small Papin s digester, with nearly its own weight of water and 40 per cent- of olive oil. The vessel was kept for nearly three hours in an oil bath at a temperature of from 311 to 329° F. The water above the precipitate was evaporated, and left a syrupy residue presenting all the properties of glycerine. 

British physicist and chemist Robert Boyle (r.) and Denis Papin (I.) inspect Papin s steam digester. 

The wide diversity and the large number of apparatuses used for investigations and processing of reactions in SCFs make a systematization difficult. They have been developed during the time from the first digester by Denys Papin in 1680 to Ipatiev s high-pressure bomb [198] and up to the first... 

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