Pregledni rad

How to Tailor Polymers with the Help of Quantum Theory?

János Ladik ; Chair for Theoretical Chemistry, Friedrich-Alexander University Erlangen-Nürnberg, Egerlandstr. 3, 8520 Erlangen, Germany

Sažetak

In the case of industrial and other practical applications, one usually needs certain polymers with several optimized prescribed unrelated properties. To predict such systems, it is still much cheaper to calculate the band structures of a larger number of polymers at a high level of approximation (aò initio Hartree-Fock HF + correlation corrected band structure) and from them compute the required properties than to snythetize the corresponding polymers and measure their properties.
First, the paper shortly reviews the method for correcting the band structure for correlation and the so-called negative factor counting (NFC) method which provides a very good approximation for the density of states (DOS).
After that, the ground state properties of an (SN)X, chain, the vibrational spectra of a number of polymers and the results obtained for the fundamental gap are discussed. In a short form, also the exciton spectra of different polymers, the calculation of primary jump rate of aperiodic polypeptides and the bulk modulus of polyethylene are mentioned. Finally, the paper gives at least the most important references for the calculation of the effect of static and time-dependent electric (static and dynamic polarizabilities and hyperpolarizabilities) and magnetic field on the band structure of a periodic polymer as well as for the effect of laser light on a polymer. All these theoretical developments are very important for an understanding of the non-linear properties of polymers.

Ključne riječi

Hrčak ID:

137106

URI

https://hrcak.srce.hr/137106

Datum izdavanja:

1.6.1993.

Posjeta: 767 *