HAJIME AKIMOTO is a Guest Scientist at the National Institute for Environmental Studies, Japan. JUN HIROKAWA is Associate Professor at Hokkaido University, Japan.

• Preface xiii1 Historical Background of Atmospheric Secondary Aerosol Research 11.1 Introduction 11.2 Secondary Inorganic Aerosols 11.2.1 Sulfate 21.2.2 Nitrate 31.3 Secondary Organic Aerosols 41.3.1 Photochemical Smog 51.3.2 Blue Haze 6References 72 Fundamentals of Multiphase Chemical Reactions 132.1 Introduction 132.2 Gas–Liquid Phase Equilibrium and Equilibrium in Liquid Phase 132.2.1 Fundamentals of Thermodynamics 142.2.1.1 Internal Energy and Enthalpy 142.2.1.2 Entropy 162.2.1.3 Gibbs Energy 182.2.1.4 Chemical Potential 192.2.2 Chemical Equilibrium and Equilibrium Constant 212.2.2.1 Chemical Equilibrium 212.2.2.2 Equilibrium Constant of Gas-Phase Reaction 222.2.2.3 Equilibrium Constant of Liquid-Phase Reaction 242.2.2.4 Temperature Dependence of Equilibrium Constant 262.2.3 Gas–Liquid Equilibrium and Henry’s Law Constant 292.2.4 Hydration of Carbonyl Compounds and Effective Henry’s Law Constant 312.2.5 pH and Equilibrium in the Aqueous Solution 322.2.5.1 Dissociation Equilibrium of Pure Water and pH 322.2.5.2 Ion Dissociation and Equilibrium in Aqueous Solution 332.3 Reactions in the Liquid Phase 352.3.1 Thermodynamics and Activity Coefficients of Nonideal Solutions 352.3.1.1 Salting-in, Salting-out 382.3.2 Chemical Kinetics of Aqueous-Phase Reaction 392.3.2.1 Diffusion Process and Chemical Reaction Kinetics 392.3.2.2 Transition State Theory of Solution Reaction and Thermodynamic Expression 422.3.3 Cage Effect and Aqueous-Phase Solvent Effect 462.3.3.1 Cage Effect 462.3.3.2 Solvent Effect in the Aqueous Phase 482.4 Uptake Coefficient and Resistance Model 512.4.1 Accommodation Coefficient and Uptake Coefficient 522.4.2 Resistance Model 542.5 Physical Chemistry of Interface Reaction 562.5.1 Langmuir-Hinshelwood Mechanism and Eley-Rideal Mechanism 562.5.2 Resistance Model Including Interface Reaction 592.5.3 Surface Tension of Air–Water Interface and Thermodynamics of Accommodation Coefficient 652.5.3.1 Surface Tension 652.5.3.2 Thermodynamics of Accommodation Coefficient at Air–Water Interface 682.6 Chemical Compositions and Physical Characters of Particles 712.6.1 Elemental and Molecular Composition of Particles 722.6.1.1 Inorganic Elements and Compounds 722.6.1.2 Organic Compounds 742.6.1.3 van Krevelen Diagram 772.6.2 Molecular Composition and Vapor Pressure 782.6.3 Gas-Particle Partitioning and Volatility Basis Set Model 842.6.3.1 Gas-Particle Partitioning and SOA Formation Yield 842.6.3.2 Volatility Basis Set Model 882.6.3.3 Gas-Aqueous Phase Partitioning of Hydrophilic Compounds 902.6.4 Phase State of Particles and Mass Transfer 93References 953 Gas-Phase Reactions Related to Secondary Organic Aerosols 1073.1 Introduction 1073.2 Ozone Reactions 1073.2.1 Properties and Reactions of Criegee Intermediates 1083.2.1.1 Direct Detection of Criegee Intermediate and Molecular Structure 1103.2.1.2 Formation of CH2OO in Ozone-Ethene Reaction 1153.2.1.3 Formation of syn- and anti-CH3CHOO in Ozone-Alkene Reactions 1183.2.2 Alkenes and Dialkenes 1303.2.2.1 Ethene 1303.2.2.2 >C3 Alkenes 1323.2.2.3 1,3-Butadiene 1343.2.3 Isoprene 1353.2.4 Cycloalkenes 1393.2.4.1 Cyclohexene 1393.2.4.2 1-Methylcyclohexene 1413.2.4.3 Methylenecyclohexane 1443.2.5 Monoterpenes 1443.2.5.1 α-Pinene 1453.2.5.2 β-Pinene 1483.2.5.3 Limonene 1503.2.6 Sesquiterpenes 1553.3 OH Radical-Induced Oxidation Reactions 1603.3.1 Alkanes 1603.3.1.1 Reactions of Alkyl Peroxy Radicals 1653.3.1.2 Reactions of Alkoxy Radicals 1653.3.2 Alkynes 1703.3.3 Alkenes, Dialkenes, and Cycloalkenes 1713.3.3.1 Alkenes 1713.3.3.2 1,3-Butadiene 1733.3.3.3 Cycloalkenes and Methylene cyclohexane 1743.3.4 Isoprene 1753.3.4.1 Fundamental Processes of OH-Induced Oxidation Reaction 1753.3.4.2 HOx Radicals Regeneration Reaction 1783.3.4.3 Formation of Isoprene Hydroxy Hydroperoxide (ISOPOOH) and Isoprene Epoxydiol (IEPOX) 1793.3.4.4 Formation of Hydroxy Isoprene Nitrates 1803.3.4.5 Reactions of Methyl Vinyl Ketone and Methacrolein 1823.3.5 Monoterpenes 1833.3.5.1 α-Pinene 1833.3.5.2 β-Pinene 1853.3.5.3 Limonene 1873.3.6 Monocyclic Aromatic Hydrocarbons 1893.3.6.1 Benzene 1893.3.6.2 Toluene 1923.3.7 Polycyclic Aromatic Hydrocarbons 1953.3.7.1 Naphthalene 1963.3.7.2 Other Polycyclic Aromatic Hydrocarbons 1983.3.8 Carbonyl Compounds: OH Radical Reactions and Photolysis 1993.3.8.1 Glyoxal 1993.3.8.2 Methylglyoxal 2023.3.8.3 Glycolaldehyde 2043.3.8.4 Hydroxyacetone 2073.4 NO3 Oxidation Reactions 2093.4.1 Isoprene 2093.4.2 Monoterpenes 2133.4.2.1 α-Pinene 2133.4.2.2 β-Pinene 2143.4.2.3 Limonene 2153.4.3 Monocyclic and Polycyclic Aromatic Hydrocarbons 2173.4.3.1 Phenol, and Cresol 2173.4.3.2 Naphthalene 2183.4.3.3 Other Polycyclic Aromatic Hydrocarbons 219References 2194 Aqueous-Phase Reactions Related to Secondary Organic Aerosols 2454.1 Introduction 2454.2 OH Radical Reactions 2464.2.1 UV Absorption Spectrum of OH Radicals in Aqueous Solution 2464.2.2 Formation of OH Radicals in Cloud/Fog Droplets and Deliquescent Aerosols 2484.2.3 Reaction Rate Constants of OH Radicals in the Aqueous Phase 2544.2.4 Reactions of Formaldehyde and OH Radical Chain Reaction 2574.2.5 OH Radical Reactions and Photolysis of ≥C2 Carbonyl Compounds 2624.2.5.1 Glyoxal and Glyoxylic Acid 2624.2.5.2 Methylglyoxal, Pyruvic Acid, and Acetic Acid 2644.2.5.3 Glycolaldehyde and Glycolic Acid 2674.2.5.4 Methacrolein and Methyl Vinyl Ketone 2684.2.6 Oligomer Formation Reactions from ≥C2 Carbonyl Compounds 2704.2.6.1 Glyoxal and Methylglyoxal 2724.2.6.2 Methyl Vinyl Ketone and Methacrolein 2734.3 Nonradical Reactions 2754.3.1 Diels-Alder Reaction 2764.3.2 Hemiacetal and Acetal Formation Reactions 2774.3.2.1 Glyoxal 2794.3.2.2 Methylglyoxal 2804.3.2.3 1,4-Hydroxycarbonyl Compounds 2814.3.3 Aldol Reaction 2814.3.3.1 Acetaldehyde 2824.3.3.2 Methylglyoxal 2834.3.3.3 Methyl Vinyl Ketone and Methacrolein 2844.3.4 Esterification Reactions 2854.4 Formation Reactions of Organic Sulfates 2874.4.1 C2 and C3 Carbonyl Compounds 2874.4.2 Monoterpenes 2884.4.3 Isoprene 2914.4.4 Monocyclic and Polycyclic Aromatic Hydrocarbons 2914.5 Formation Reactions of Organic Nitrogen Compounds 2924.5.1 Organic Nitrates 2924.5.2 Imidazoles 293References 2955 Heterogeneous Oxidation Reactions at Organic Aerosol Surfaces 3095.1 Introduction 3095.2 Aging of Organic Aerosols in the Atmosphere 3095.3 Reactions of Ozone 3135.3.1 Oleic Acid and Unsaturated Long-Chain Carboxylic Acids 3145.3.2 Squalene 3165.3.3 Polycyclic Aromatic Hydrocarbons 3185.4 Reactions of OH Radicals 3205.4.1 Squalane and Long-Chain Alkanes 3205.4.2 Levoglucosan, Erythritol, and Hopane 3255.4.3 Saturated Dicarboxylic Acids 3265.4.4 Squalene and Long-Chain Unsaturated Carboxylic Acids 3285.4.5 Polycyclic Aromatic Hydrocarbons 3305.5 Reactions of NO3 Radicals 3325.5.1 Levoglucosan, Squalane, Long-Chain Alkane, and Alkanoic Acid 3325.5.2 Squalene and Oleic Acid 3345.5.3 Polycyclic Aromatic Hydrocarbons 334References 3366 Reactions at the Air–Water and Air–Solid Particle Interface 3436.1 Introduction 3436.2 Molecular Pictures and Reactions at the Air–Water Interface 3446.2.1 Thermodynamics of Adsorption 3456.2.1.1 OH, HO2, and O3 3466.2.1.2 Organic and Inorganic Compounds 3486.2.2 Microscopic Picture of Molecules 3496.2.2.1 Air–Pure Water Interface 3506.2.2.2 Hydrophilic Organic Compounds 3526.2.2.3 Amphiphilic Organic Compounds (Surfactants) 3566.2.2.4 Hydrophobic Organic Compounds 3576.2.2.5 NH3 and SO2 3586.2.3 Reactions of O3 and Organic Compounds 3596.2.3.1 Oleic Acid 3606.2.3.2 Sesquiterpene Criegee Intermediates 3606.2.3.3 Polycyclic Aromatic Hydrocarbons 3616.2.4 Reactions of OH Radicals and Organic Compounds 3626.2.4.1 Carboxylic and Dicarboxylic Acids 3626.2.4.2 Organic Sulfur Compounds 3646.3 Air–Sea Salt Particle, Seawater, and Sulfate/Nitrate Aerosol Interface 3656.3.1 Microscopic View of Interface of Air and Alkaline Halide Aqueous Solution 3666.3.2 Reactions at the Interface of Sea Salt and Alkali Halide Aqueous Solution 3686.3.2.1 Reaction with O3 3696.3.2.2 Reaction with OH Radicals 3716.3.2.3 Uptake of HO2 Radicals 3726.3.2.4 Reaction with N2O5 3726.3.2.5 Reaction with HNO3 3736.3.3 Reactions of Organic Compounds at the Air–Seawater and Air–Sea Salt Interface 3756.3.4 Microscopic View of the Interface of Air and Sulfate/Nitrate Aqueous Solution 3776.3.4.1 Sulfate Ion (SO4 2−) 3776.3.4.2 Nitrate Ion (NO3 −) 3786.4 Reactions on Snow/Ice Surface 3796.4.1 Formation of NOy in the Photochemical Reaction of NO3 − 3796.4.2 Formation of Inorganic Halogens on the Snow Ice and Sea Ice Surface 3826.4.2.1 Reaction with O3 3826.4.2.2 Reaction with OH Radicals 3836.4.2.3 Reactions with N2O5 3846.5 Interface of Water and Mineral Dust, Quartz, and Metal Oxide Surface 3856.5.1 Microscopic View of Adsorbed Water on Mineral Surface 3866.5.2 HONO Formation Reaction from NO2 on the Mineral Surface 3906.5.2.1 Dark Reaction 3906.5.2.2 Photochemical Reaction 3926.5.3 Reaction of Organic Monolayer on Mineral Surface 394References 3967 Atmospheric New Particle Formation and Cloud Condensation Nuclei 4157.1 Introduction 4157.2 Classical Homogeneous Nucleation Theory 4157.2.1 Homogeneous Nucleation in One-Component Systems 4157.2.2 Homogeneous Nucleation in Two-Component Systems 4197.3 Atmospheric New Particle Formation 4227.3.1 New Particle Formation Rate and Growth Rate 4227.3.2 Sulfuric Acid in New Particle Formation 4257.3.3 Basic Substances in New Particle Formation 4277.3.4 Organic Species in New Particle Formation 4307.3.5 Other Species in New Particle Formation 4337.3.5.1 Iodine Oxides 4337.3.5.2 Atmospheric Ions 4347.3.6 Field Observation of Nanoclusters 4357.4 Aerosol Hygroscopicity and Cloud Condensation Nuclei 4367.4.1 Köhler Theory 4367.4.2 Nonideality of Solution in a Droplet 4417.4.3 Hygroscopicity Parameter, 𝜅 442References 4468 Field Observations of Secondary Organic Aerosols 4538.1 Introduction 4538.2 Global Budget of Aerosols 4538.3 Analysis Methods of Ambient Aerosol Compositions 4588.3.1 Positive Matrix Factorization 4588.3.2 Mass Spectrum Peak Intensity and Elemental Ratio 4598.3.3 Elemental Composition 4608.4 Marine Air 4618.5 Forest Air 4658.5.1 Amazon Tropical Forest 4658.5.2 Finland Boreal Forest 4698.6 Urban/Rural Air 4728.6.1 Characterization of Ambient Aerosols 4728.6.1.1 PMF Analysis 4728.6.1.2 Mass Signal Intensity Ratio and Elemental Ratio 4748.6.1.3 Particle Size Distribution 4778.6.1.4 Elemental Composition 4788.6.2 Molecular Composition 4798.6.2.1 Dicarboxylic Acid 4808.6.2.2 Plant Origin VOC Tracers 4818.6.2.3 Anthropogenic VOC Tracer 4848.6.2.4 Organic Sulfate 4858.6.2.5 Organic Nitrates and Imidazoles 4868.6.2.6 High-Molecular-Weight Compounds and Oligomers 489References 493Index 509