Thermalization of vibrational excess energy in liquid chloroform

Graener, H.; Zürl, R.; Bartel, Markus; Seifert, G.

doi:10.1016/s0167-7322(99)00175-0

Cited by 8 publications

(2 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In this context, the speed of intermolecular and intramolecular transport of vibrational energy, the directed energy flow in complex biosystems, and even solitonic energy transport are discussed 3, 4. It has been shown that in polyatomic molecules in solution at room temperature the excitation of specific vibrational modes decays on the time scale of picoseconds 5–11. In larger molecular systems, e.g., dye molecules, intramolecular redistribution of vibrational energy takes a few picoseconds.…”

Section: Introductionmentioning

confidence: 99%

Following the energy transfer in and out of a polyproline–peptide

et al. 2013

View full text Add to dashboard Cite

The intramolecular and intermolecular vibrational energy flow in a polyproline peptide with a total number of nine amino acids in the solvent dimethyl sulfoxide is investigated using time-resolved infrared (IR) spectroscopy. Azobenzene covalently bound to a proline sequence containing nitrophenylalanine as a local sensor for vibrational excess energy serves as a heat source. Information on through-space distances in the polyproline peptides is obtained by independent Förster resonance energy transfer measurements. Photoexcitation of the azobenzene and subsequent internal conversion yield strong vibrational excitation of the molecule acting as a local heat source. The relaxation of excess heat, its transfer along the peptide and to the solvent is monitored by the response of the nitro-group in nitrophenylalanine acting as internal thermometer. After optical excitation, vibrational excess energy is observed via changes in the IR absorption spectra of the peptide. The nitrophenylalanine bands reveal that the vibrational excess energy flows in the peptide over distances of more than 20 Å and arrives delayed by up to 7 ps at the outer positions of the peptide. The vibrational excess energy is transferred to the surrounding solvent on a time scale of 10-20 ps. The experimental observations are analyzed by different heat conduction models. Isotropic heat conduction in three dimensions away from the azobenzene heat source is not able to describe the observations. One-dimensional heat dissipation along the polyproline peptide combined with a slower transversal heat transfer to the solvent surrounding well reproduces the observations.

show abstract

Section: Introductionmentioning

confidence: 99%

Following the energy transfer in and out of a polyproline–peptide

et al. 2013

View full text Add to dashboard Cite

show abstract

“…For a laser macropulse of 4 µs, the energy of the FEL is thermalized in a time scale of ∼100 ps. 92 Therefore, applying a temperature rise model to the frozen solvent matrix system should explain the ablation characteristics seen for the different resonance modes.…”

Section: Mechanisms Of High-power Laser Absorption In Solvent Matricesmentioning

confidence: 99%

Mechanisms of Resonant Infrared Matrix-Assisted Pulsed Laser Evaporation

Torres

Johnson

Haglund

et al. 2011

Critical Reviews in Solid State and Materials Sciences

View full text Add to dashboard Cite

For the last decade, a variant of pulsed laser ablation, Resonant-Infrared Matrix-Assisted Pulsed Laser Evaporation (RIR-MAPLE), has been studied as a deposition technique for organic and polymeric materials. RIR-MAPLE minimizes photochemical damage from direct interaction with the intense laser beam by encapsulating the polymer in a high infrared-absorption solvent matrix. This review critically examines the thermally-induced ablation mechanisms resulting from irradiation of cryogenic solvent matrices by a tunable free electron laser (FEL). A semi-empirical model is used to calculate temperatures as a function of time in the focal volume and determine heating rates for different resonant modes in two model solvents, based on the thermodynamics and kinetics of the phase transitions induced in the solvent matrices.Three principal ablation mechanisms are discussed, namely normal vaporization at the surface, normal boiling, and phase explosion. Normal vaporization is a highly inefficient polymer deposition mechanism as it relies on collective collisions with evaporating solvent molecules. Diffusion length calculations for heterogeneously nucleated vapor bubbles show that normal boiling is kinetically limited. During high-power pulsed-FEL irradiation, phase explosion is shown to be the most significant contribution to polymer deposition in RIR-MAPLE. Phase explosion occurs when the target is rapidly heated (10 8 to 10 10 K/s) and the solvent matrix approaches its critical temperature. Spontaneous density stratification (spinodal decay) within the condensed metastable phase leads to rapid homogeneous nucleation of vapor bubbles. As these vapor bubbles interconnect, large pressures build up within the condensed phase, leading to target explosions and recoil-induced ejections of polymer to a near substrate. Phase explosion is a temperature (fluence) threshold-limited process, while surface evaporation can occur even at very low fluences.

show abstract