Temperature Effects on Optical Properties and Chemical Composition of Secondary Organic Aerosol Derived from <i>n</i>-Dodecane

Abstract

Abstract. Environmental temperature plays a vital role in controlling chemical transformations that lead to the formation of secondary organic aerosol (SOA), and ultimately impact composition and optical properties of the aerosol particles. In this study, we investigate optical properties of n-dodecane secondary organic aerosol under two temperature conditions: 5 °C and 25 °C. It is shown that low temperature can enhance the real part of refractive index (RI) of the SOA at the wavelengths of 532 nm and 375 nm. Mass spectrometry analysis reveals that molecular composition of n-dodecane SOA is significantly modified by temperature: a large amount of oligomers are formed under low temperature condition, which lead to higher RI values. These findings will help improve our understanding of the chemical composition and optical properties of SOA under different temperature conditions, and provide another possible explanation of the low visibility during winter.

Effects of OH radical and SO2 concentrations on photochemical reactions of mixed anthropogenic organic gases

“…For the same precursor, under similar VOC / NO x conditions, the lower the temperature, the higher the mass of particulate matter. Lower temperatures can affect the partitioning process of organic vapour and facilitate the formation of particles, which in turn increases the particle mass concentration in the reaction system, and this is consistent with previous experimental reports (Ding et al, 2017;Li et al, 2020;Sheehan and Bowman, 2001;Takekawa et al, 2003;Warren et al, 2009). Meanwhile, with the increase in the VOC/NO x ratio value, the particle mass concentration increases (S. .…”

“…Studies of single long-chain alkanes (e.g. n-decane, n-undecane, n-dodecane, n-tridecane, 2,6,10trimethyl dodecane, nonyl-cyclohexane) include reaction kinetics (Lamkaddam et al, 2019;Shi et al, 2019a, b), reaction mechanisms (Li et al, 2020(Li et al, , 2021a, analysis of gas phase and particle phase products (Fahnestock et al, 2015;Lamkaddam et al, 2020), quantification of particle yield (Docherty et al, 2021;Loza et al, 2014), and particle physicochemical properties (J. Li et al, 2020Li et al, , 2021a.…”

“…n-decane, n-undecane, n-dodecane, n-tridecane, 2,6,10trimethyl dodecane, nonyl-cyclohexane) include reaction kinetics (Lamkaddam et al, 2019;Shi et al, 2019a, b), reaction mechanisms (Li et al, 2020(Li et al, , 2021a, analysis of gas phase and particle phase products (Fahnestock et al, 2015;Lamkaddam et al, 2020), quantification of particle yield (Docherty et al, 2021;Loza et al, 2014), and particle physicochemical properties (J. Li et al, 2020Li et al, , 2021a. For the mixture of various precursors including long-chain alkanes, studies are mainly focused on the chemical composition of the mixture gases, the properties of total organic carbon, the amount of SOA generated, and the effect of semi-volatile and intermediate-volatility organic compounds (S/IVOCs) on the formation of SOA contribution (Qi et al, 2019(Qi et al, , 2021Hu et al, 2021;Cai et al, 2019;Deng et al, 2017;K.…”

A large-scale outdoor atmospheric simulation smog chamber for studying atmospheric photochemical processes: Characterization and preliminary application

“…A series of photochemical simulation experiments of hydrocarbons and NOx were designed and conducted according to the atmospheric conditions in Lanzhou and Beijing (Zhang and Li, 1998). Then a serious environmental issues were studied based on the smog chambers constructed with various size in the past decades, including the mechanism of photochemical reaction (Liu et al, 2017;Wang et al, 2014;Wu et al, 2007), ozone and SOA formation (Li et al, 2018a;Ma et al, 2018;Wang et al, 2015), biomass burning reactions (Zhang et al, 2011), the photochemical process of the gasoline and diesel (Chen et al, 2019a;Chen et al, 2019b;Kamens et al, 2011), physicochemical properties of SOA formed under various conditions (Li et al, 2017a;Li et al, 2020;Li et al, 2018b;Peng et al, 2018;Zhang et al, 2020), et al However, most of the chambers constructed in China were indoor smog chambers, establishment large-scale outdoor smog chambers in China was limited. In order to study the atmospheric pollution process close to China's actual atmospheric environment, it was necessary to build a large outdoor smog chamber in China.…”

Modeling the influence of chain length on secondary organic aerosol (SOA) formation via multiphase reactions of alkanes

“…A scanning mobility particle sizer (SMPS 3080, TSI Inc., USA) was used to measure the size distribution of particles within the chamber. Previous studies that have measured the density of alkane SOA have found a range from 1 to 1.4 g cm −3 (Li et al, 2020(Li et al, , 2022Lim and Ziemann, 2009;Loza et al, 2014). Aerosols from each alkane experiment in this study were assumed to have a density of 1.2 g cm −3 .…”