Hygroscopicity measurement of sodium carbonate,β-alanine and internally mixed β-alanine/Na2CO3 particles by ATR-FTIR

作     者：Ping Yang Hui Yang Na Wang Chunyun Du Shufeng Pang Yunhong Zhang Ping Yang;Hui Yang;Na Wang;Chunyun Du;Shufeng Pang;Yunhong Zhang

作者机构：School of Chemistry and Chemical EngineeringBeijing Institute of Technology 

出 版 物：《Journal of Environmental Sciences》 (环境科学学报（英文版）)

年 卷 期：2020年第32卷第1期

页      面：250-259页

核心收录：

学科分类：07[理学] 070602[理学-大气物理学与大气环境] 0706[理学-大气科学] 

基　　金：supported by the National Natural Science Foundation of China(Nos.91644101 91544223 and 21373026) 

主　　题：Sodium carbonate β-Alanine Hygroscopicity Crystallization Immune effects Deliquescence 

摘      要：Water-uptakes of pure sodium carbonate(Na2CO3),pureβ-alanine and internally mixedβ-alanine/Na2CO3 aerosol particles with different mole ratios are first monitored using attenuated total reflectance Fourier transform infrared spectroscopy(ATR-FTIR)*** pure Na2CO3 aerosol particles,combining the absorptions at 877 and 1422 cm-1 with abrupt water loss shows the efflorescence relative humidity(ERH)of 62.9%–51.9%.Upon humidifying,solid Na2CO3 firstly absorbs water to from Na2CO3·H2O crystal at 72.0%RH and then deliquesces at 84.5%RH(DRH).As for pureβ-alanine particles,the crystallization takes place in the range of 42.4%–33.2%RH and becomes droplets at^88.2%***β-alanine is mixed with Na2CO3 at various mole ratios,it shows no efflorescence of Na2CO3 whenβ-alanine to Na2CO3 mole ratio(OIR)is 2:*** 1:1 and 1:2β-alanine/Na2CO3 aerosols,the ERHs of Na2CO3 are 51.8%–42.3%and 57.1%–42.3%,***β-alanine crystal appears from 62.7%RH for 2:1 and 59.4%RH for both 1:1 and 1:2 particles and lasts to driest *** hydration,the DRH is 44.7%–75.2%for Na2CO3 with the OIR of 1:1 and 44.7%–69.0%for 1:2 mixture,and those of β-alanine are 74.8% for 2:1 mixture and 68.9%for two *** the first dehumidification–humidification,all the water contents decrease despite of constituent *** at^92%RH,the remaining water contents are 92%,89%and 82%at^92%RH,corresponding to OIR of 2:1,1:1 and 1:2 mixed system,respectively.