E-Locus - Institutional Repository of the University of Crete - Κινητική μελέτη των αντιδράσεων ριζών υδροξυλίου και ατόμων χλωρίυ με 2,2,2,-τριφθοροαιθανόλη στην αέρια φάση. Εξάρτηση από τη θερμοκρασία και την πίεση

Home Κινητική μελέτη των αντιδράσεων ριζών υδροξυλίου και ατόμων χλωρίυ με 2,2,2,-τριφθοροαιθανόλη στην αέρια φάση. Εξάρτηση από τη θερμοκρασία και την πίεση

Results - Details

[Add to Basket]

Identifier

000372709

Title

Κινητική μελέτη των αντιδράσεων ριζών υδροξυλίου και ατόμων χλωρίυ με 2,2,2,-τριφθοροαιθανόλη στην αέρια φάση. Εξάρτηση από τη θερμοκρασία και την πίεση

Alternative Title

Kinetic study of the gas phase reactions of 2,2,2-trifluoroethanol with clorine atoms and hydroxyl radicals, as a function of temperature and pressure

Author

Κουνενιδάκης Μιχάλης Μύρ.

Thesis advisor

Παπαγιαννακόπουλος, Πάνος

Abstract

The rate coefficients for the gas phase reactions of 2,2,2-Trifluoroethanol with chlorine atoms and hydroxyl radicals were determined as a function of temperature (258 - 363 K) and pressure (30 – 700 Torr), using the Thermostated PhotoChemical Reactor coupled with FTIR spectroscopy (TPCR-FTIR) method. Experiments were carried out in N2 bath gas, adding excess of O2, in order to efficiently remove primary alkyl-radical products and inhibit secondary chain reactions simulating the atmospheric conditions. The experimental results showed, that reaction rate coefficients, for the Cl reaction, were pressure-independent and very well represented by the Arrhenius expression k(T)=(1.68±0.47)×10^-11 exp(-1033.7±41.6/T) cm³ molecules-1 s-1, k(298 K) =(5.36 ±0.62) ×10^-13 cm³ molecules^-1 s^-1. The quoted uncertainties are at 95% level of confidence and include estimated systematic uncertainties of the measurements End-products analysis via quadrupole mass spectrometry and FTIR spectroscopy along with the non pressure dependence of the reaction rate coefficients observed in this work, provide with strong indications that the Cl atom reaction proceeds via direct hydrogen abtraction mechanism within the pressure range experiments performed. Moreover, OH reaction rate coefficient at temperature T=298 K and pressure P=700 Torr was determined to be k(298 K) =(1.04 ±0.1) ×1010^-13 cm³molecules^-1 s^-1. Finally, the infrared cross-section of CF₃CH₂OH was measured in order to evaluate its impact in atmospheric radiative forcing and to assess its effect on Global Warming and Climate Change.

Language

Greek

Subject

Climate change

Rate coefficient

Reference reaction

Relative rate measurment

Αντίδραση αναφοράς

Κλιματική αλλαγή

Συντελεστής ταχύτητας

Τεχνική μέτρησης συντελεστή σχετικής ταχύτητας

Issue date