Fluorescence lifetimes of formaldehyde (H2CO) in the A1A2 --> X1A2 band system at elevated temperatures and pressures.
Fluorescence lifetimes of formaldehyde excited by picosecond laser radiation with a wavelength of 355 nm were determined in nitrogen gas in a cell using time-resolved laser-induced fluorescence spectroscopy. The measurements were conducted at temperatures between 295 and 770 K and pressures up to 10 bar (1 MPa). Detection was broadband in most cases. Temperature and pressure were found to have a quenching effect on the fluorescence. At 295 K and pressures between 1 and 5 bar, decay rates between 0.03 and 0.04 ns(-1) were observed. At 770 K, the decay rates increased from 0.11 to 0.17 ns(-1) as the pressure was raised from 1 to 10 bar. The dependence on pressure was not linear at 1 bar. At 10 bar the linearity is unclear. The dependence on temperature appeared to be exponential.
Metz
Thomas
T
Division of Combustion Physics, Lund Institute of Technology, P.O. Box 118, SE-221 00 Lund, Sweden.
Bai
Xiao
X
Ossler
Frederik
F
Aldén
Marcus
M
D005557:Formaldehyde / Q000737:chemistry*; D007834:Lasers; D009584:Nitrogen / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry*; D011312:Pressure; D013050:Spectrometry, Fluorescence / Q000379:methods*; D013053:Spectrophotometry / Q000295:instrumentation* / Q000379:methods*; D013696:Temperature; D013997:Time Factors
D011108:Polymers; D005557:Formaldehyde; D009584:Nitrogen; C003043:paraform