Mathematical Simulation of the Synthesis of cis-1,4-Polybutadiene on a Cobalt-Containing Catalyst in the Presence of Ethylene

Based on an analysis of experimental results and published data, the main elementary steps of the anionic coordination polymerization of butadiene rubber on a cobalt-containing catalyst in the presence of ethylene were found, and a mathematical model of the periodic process at an optimum water content was developed. The molecular-weight characteristics of the process depending on ethylene concentration were studied with the use of this model.     

New nanomaterials for control of the luminescence of polycyclic aromatic hydrocarbons

New nanomaterials (ordered structures) have been proposed for control of the luminescence of polycyclic aromatic hydrocarbons by solubilization of the latter into ordered structures. These structures are formed by hydrophilic silver nanoparticles adsorbed on a cellulose matrix—filter paper—through their self organization and by molecules of a cationic surfactant—cetyltrimethylammonium bromide—in concentrations exceeding the critical micelle concentration. The observed enhancement of luminescence of solubilized pyrene molecules in the violet spectral range is due to the resonance of the electronic transitions of monomeric pyrene molecules in this range with a plasmon vibrations in silver nanoparticles.     

Equations of three-dimensional deformation of linear viscoelastic media

An equation is proposed relating the stress and strain tensors in time for the three-dimensional deformation of linear viscoelastic media whose properties are determined by four parameters. A method is indicated for determining these parameters based on simple creep or relaxation tests. Values of the parameters are given for certain polymer materials. For such materials, there is an upper limit of the stress state below which an equilibrium limit state is possible. A creep kernel is proposed for the case of no equilibrium limit state, and a resolvent constructed with account for the variation of stress and strain in time.Mekhanika Polimerov, Vol. 1, No. 4, pp. 35–42, 1965     

Fluorescence of pyrene in the presence of silver nanoparticles on cellulose modified by surface-active substances

Luminescent properties of pyrene in the ordered structure formed by the molecules of a surface-active substance represented by cetyltrimethylammonium bromide on a cellulose matrix preliminarily modified with silver nanoparticles are studied. Elevated intensity of fluorescence in the violet range of the spectrum of pyrene molecules solubilized in these structures is observed. This phenomenon is rationalized by the resonance of electron transitions of monomeric pyrene molecules in this range with plasmonic vibrations in silver nanoparticles.