Absorption spectra of irradiated films of polyvinyl chloride coated with perylene.
The visible and UV spectra γ-irradiated films of polyvinyl chloride doped or coated with perylene were recorded. These films were irradiated either under a vacuum, in N2 O or in NH3. In the case of...
Inter and Intramolecular Charge and Excitation Transfer Observed in Irradiated Polyvinyl Chloride Particles with Surface-coated Additives
Particles of polyvinyl chloride were coated with small amounts of various aromatic compounds from benzene solutions and were then irradiated in a vaccum. The ESR spectra of the specimen thus obtained were recorded. Though the amount of the coated additives, in the ratio of 1 molecule for 100 monomer units of PVC, was small, strong effects on the ESR spectra were observed. The additives coated on the surface affect the ESR spectra in two ways. They cause a decrease in the total ESR absorption intensity; this was observed with all the additives studied. They also often transform the ESR spectrum; this was observed with several additive compounds, such as p-benzoquinone, tetramethylphenylenediamine-2·HCl, chrysene, hydroquinone, nitrosonaphthol, perylene, and diphenylpicrylhydrazine. Only the conduction of the excitations, holes and electrons formed in the bulk particles, to the surface of the particle can explain these results. On the surface of the particle, the excitation or the electric charge is transfe...
Modeling of chemical reactors—XXIX mixing-cell model for packed bed reactors. Steady state considerations. Problems of multiplicity
Abstract The axial heat and mass transfer in tubular catalytic reactors may be described by mixing-cell model and diffusion model as well. The diffusion description yields for a strong exothermic reaction and adiabatic conditions three steady state profiles, on the other hand the mixing-cell model gives rise to more than three steady states. A simple numerical and graphical analysis for mixing-cell model is presented.