Temperature effects on sulfuric acid aerosol nucleation and growth: initial results from the TANGENT study

Abstract

Abstract. New particle formation (NPF) consists of two steps: nucleation and subsequent growth. At present, chemical and physical mechanisms that govern these two processes are not well understood. Here, we report initial results obtained from the TANGENT (Tandem Aerosol Nucleation and Growth Environment Tube) experiments. The TANGENT apparatus enables us to study these two processes independently. The present study focuses on the effects of temperature on sulfuric acid nucleation and further growth. Our results show that lower temperatures enhance both the nucleation and growth rate. However, under temperatures below 268 K the effects of temperature on the nucleation rate become less significant and the nucleation rate becomes less dependent on relative humidity, indicating that particle formation in the conditions of our flow tube takes place via barrierless nucleation at lower temperatures. We also examined the growth of newly formed particles under differing temperature conditions for nucleation and further growth. Our results show that newly nucleated clusters formed at low temperatures can indeed survive evaporation and grow in a warmer environment in the presence of SO2 and ozone and potentially other contaminant vapors. These results imply that some heterogeneous reactions involving nanoparticles affect nucleation and growth of newly formed particles.

Formation and growth of sub-3-nm aerosol particles in experimental chambers

“…Particle wall losses become important in the case of turbulent flows, high residence times or large surface-to-volume ratios of the flow tube (e.g., due to small inner diameters). Ideally, one can assume that the particle wall loss rate is of first order and determine it experimentally by introducing particles of a certain size into the flow tube and measuring their concentrations at different positions Benson et al 61 , Young et al 63 , Benson et al 71 , Tiszenkel et al 204 , Benson et al 205 , Erupe et al 206 University Ball et al 52 Zollner et al 73 , Glasoe et al 78 Jen et al 76 , Jen et al 81 University 196 . c Detection efficiency estimated to be <1% for 3-nm particles due to sampling losses.…”

Evaluation of optical particulate matter sensors under realistic conditions of strong and mild urban pollution

“…4are not known a priori. That explains why it is difficult to calibrate OPS for realistic ambient PM concentration measurements: any laboratory calibration may or may not be applicable to the changing outdoor conditions (Tryner et al, 2020;Crilley et al, 2020).…”

“…Grimm 11-R per-formed well, while both OPC-N2 and PMS7003 (which is a miniaturized version of PMS5003) produced mediocre performance with heavy low bias. PurpleAir (PMS5003) was tested in Tryner et al (2020) using laboratory and field tests. High bias of PMS5003 was observed.…”

Carbon dioxide and propane nucleation: the emergence of a nucleation barrier

“…However, in the limiting case of extremely high supersaturation, nucleation can become barrierless. [18][19][20][21] Extremely high supersaturations can be achieved either by strongly increasing the concentration of the nucleating species or by substantially lowering the temperature. Alternatively, the energy barrier can also be modified by introducing another substance that provides an alternative nucleation pathway.…”