Publication Date:
2015-02-07
Description:
Nucleation of particles with sulfuric acid, water, and nitrogeneous bases was studied in a flow reactor. Sulfuric acid and water levels were set by flows over sulfuric acid and water reservoirs, respectively, and the base concentrations were determined from measured permeation rates and flow dilution ratios. Particle number distributions were measured with a nano- differential mobility analyzer system. Results indicate that the nucleation capability of NH 3 , methyl-, dimethyl-, and trimethyl- amines with sulfuric acid increases from NH 3 as the weakest, methyl amine next, and dimethyl amine and trimethyl amine the strongest. Three other bases were studied and experiments with triethyl amine showed that it is less effective than methyl amine, and experiments with urea and acetamide showed that their capabilities are much lower than the amines with acetamide having basically no effect. When both NH 3 and an amine were present, nucleation was more strongly enhanced than with just the amine present. Comparisons of nucleation rates to predictions and previous experimental work are discussed and the sulfuric acid - base nucleation rates measured here are extrapolated to atmospheric conditions. The measurements suggest that atmospheric nucleation rates are significantly affected by synergistic interactions between ammonia and amines.
Print ISSN:
0148-0227
Topics:
Geosciences
,
Physics
