Статья «COMPUTER SIMULATION OF HIGH-FREQUENCY HEATING OF A PROTONATED POLY(ETHYLENE OXIDE) CHAIN IN A VACUUM, "Высокомолекулярные соединения. Серия А"»

Heating of an isolated protonated poly(ethylene oxide) chain by high-frequency electric field was simulated using molecular dynamics. Simulations were performed at the field strength of about 10 V/m and frequencies from 1 to 100 GHz. At initial temperature (500 K), the chain is a globule. Absorption of the field energy heats the chain and leads to a growth in its size. In some frequency ranges, the field causes the chain to rotate as a whole. The rotation leads to a sharp increase in the heating rate and the rate of stretching the chain. The rotating chain has larger size than its non rotating counterpart at the same temperature. Contrary to the non rotating chain, this chain can be in a two-phase state in which the globular and the stretched microphases coexist. The absorption spectrum of the chain is temperature dependent and, at high temperatures, contains two distinctly expressed peaks. In the vicinity of these peaks, the chain rotates with a frequency equal to the field frequency or about half the field frequency. The results obtained are explained using the model of a spatial damped oscillator in which, together with the usual resonance, the subharmonic resonances typical for nonlinear systems arise.