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Photonucleation of thriethylamine vapors in the air and argon
J. Aerosol Sci., Vol. 26. Suppl 1, pp. S329-$330, 1995 Elsevier Science Ltd Printed in Great Britain 0021-8502/95 $9.50 + 0.00
x~ D e r " a m o n
Photonucleation of thriethylamine vapors in the air and argon G.I. Skubnevskaya, E.N. Dul'tsev, S.N.Dubtsov Institute of Chemical Kinetics and Combustion, Siberian Division of RAS Instituskaya str.3, 630090, Novosibirsk, Russia The nanometer-sized aerosol particles formation resulting from thriethylamine (TEA) vapors photolysis in Ar or in the air were observed for the first time. The experimental set-up was similar to described in (Dubtsov, 1992). Aerosol formation and particles growth were estimated to take place only in irradiation zone. This suggests that aerosol formation in this system is initiated by short-living free radicals, as it was shown earlier for phenylhaloid ( PhHal ) vapors photolysis (Dubtsov, 1989, 1992). Free-radical mechanism for cluster formation from TEA photolysis products was proposed. The aerosol formation kinetics and particles size distribution were investigated. Figure 1 shows particles number concentration (Na) dependencies on irradiation time (r) for TEA photolysis in the air (2) and argon (2). The aerosol formation rate in the air is much higher than in inert gas. Small amount of the air being added to Ar (< 1%), increase Na significantly. Based on this experiments, it was suggested that oxygen takes part in chemical stages of TEA photonucleation. Such an 02 influence on photonucleation was observed earlier for PhHal photolysis (Dubtsov,1987). Mean diameters of aerosol particles, produced in Ar and in the air differ significantly. At equal T and irradiation intensity Io, aerosol particles formed in Ar approximately 10 times smaller than in the air. The aerosol formation rate was estimated to be nonlinearilly dependent on Io and 7-. This effect may be due to nonequivalent dependence of aerosol formation processes on ~- and Io at equal irradiation doze (Dp = 7- x Io). The experimental results for TEA photonucleation have much common $329
G . I . SKUBNEVSKAYA et al.
$330
×
p
5
g ~
o 0.00
1.00 Irradiation
2.00 time,
s
with PhHal photonucleation kinetics, typical for free-radical chemical mechanism of aerosol products formation. Acknowledgements
This work was supported by RFFI grant No. 94-03-08076. References
Dubtsov,S.N., Skubnevskaya,G.I. and Kutzenogii,K.P. (1987), Khimicheskaya fizika (in Russ.)., 6~ 1061. Dubtsov,S.N., Kondratjeva,L.N., Skubnevskaya,G.I. and Polukhina,I.A. (1989) Izv. Sib. Otd. Akad. Nauk, ser.khim. 5n Russ.) 2, 51 Dubtsov,S.N., Skubnevskaya,G.I. and Kutzenogii,K.P. (1992) J. Aerosol Sci., 23, 181.
x~ D e r " a m o n
Photonucleation of thriethylamine vapors in the air and argon G.I. Skubnevskaya, E.N. Dul'tsev, S.N.Dubtsov Institute of Chemical Kinetics and Combustion, Siberian Division of RAS Instituskaya str.3, 630090, Novosibirsk, Russia The nanometer-sized aerosol particles formation resulting from thriethylamine (TEA) vapors photolysis in Ar or in the air were observed for the first time. The experimental set-up was similar to described in (Dubtsov, 1992). Aerosol formation and particles growth were estimated to take place only in irradiation zone. This suggests that aerosol formation in this system is initiated by short-living free radicals, as it was shown earlier for phenylhaloid ( PhHal ) vapors photolysis (Dubtsov, 1989, 1992). Free-radical mechanism for cluster formation from TEA photolysis products was proposed. The aerosol formation kinetics and particles size distribution were investigated. Figure 1 shows particles number concentration (Na) dependencies on irradiation time (r) for TEA photolysis in the air (2) and argon (2). The aerosol formation rate in the air is much higher than in inert gas. Small amount of the air being added to Ar (< 1%), increase Na significantly. Based on this experiments, it was suggested that oxygen takes part in chemical stages of TEA photonucleation. Such an 02 influence on photonucleation was observed earlier for PhHal photolysis (Dubtsov,1987). Mean diameters of aerosol particles, produced in Ar and in the air differ significantly. At equal T and irradiation intensity Io, aerosol particles formed in Ar approximately 10 times smaller than in the air. The aerosol formation rate was estimated to be nonlinearilly dependent on Io and 7-. This effect may be due to nonequivalent dependence of aerosol formation processes on ~- and Io at equal irradiation doze (Dp = 7- x Io). The experimental results for TEA photonucleation have much common $329
G . I . SKUBNEVSKAYA et al.
$330
×
p
5
g ~
o 0.00
1.00 Irradiation
2.00 time,
s
with PhHal photonucleation kinetics, typical for free-radical chemical mechanism of aerosol products formation. Acknowledgements
This work was supported by RFFI grant No. 94-03-08076. References
Dubtsov,S.N., Skubnevskaya,G.I. and Kutzenogii,K.P. (1987), Khimicheskaya fizika (in Russ.)., 6~ 1061. Dubtsov,S.N., Kondratjeva,L.N., Skubnevskaya,G.I. and Polukhina,I.A. (1989) Izv. Sib. Otd. Akad. Nauk, ser.khim. 5n Russ.) 2, 51 Dubtsov,S.N., Skubnevskaya,G.I. and Kutzenogii,K.P. (1992) J. Aerosol Sci., 23, 181.