The application of Electrospray and Electrosonic Spray Ionization Mass Spectrometry (ESI-MS ESSI-MS) to study accelerated reaction kinetics in droplets is examined using numerical models, new experimental data, prior literature.

Abstract. A systematic study of black carbon (BC) vertical profiles measured at high-resolution over three Italian basin valleys (Terni Valley, Po Valley and Passiria Valley) is presented. BC are scarcely available in literature. The campaign lasted 45 days resulted 120 profiles. Besides the mass concentration, measurements along also included aerosol size distributions optical particle counter range, chemical analysis filter samples a full set meteorological parameters. Using collected...

Using a comparative evaporation kinetics approach, we describe new and accurate method for determining the equilibrium hygroscopic growth of aerosol droplets. The time-evolving size an aqueous droplet, as it evaporates to steady composition that is in with gas phase relative humidity, used determine time-dependent mass flux water, yielding information on vapor pressure water above droplet surface at every instant time. Accurate characterization humidity provided from control measurement...

Surfaces play a critical role in accelerating reaction rates micro-compartments.

Abstract. Hygroscopicity data for 36 organic compounds, including amino acids, alcohols and sugars, are determined using a comparative kinetics electrodynamic balance (CK-EDB). The CK-EDB applies an electric field to trap-charged aqueous droplets in chamber with controlled temperature relative humidity (RH). dual micro dispenser set-up allows sequential trapping of probe sample accurate determination droplet water activities from 0.45 > 0.99. Here, we validate benchmark the homologous...

Abstract. Information on the rate of diffusion organic molecules within secondary aerosol (SOA) is needed to accurately predict effects SOA climate and air quality. Diffusion can be important for predicting growth, evaporation, reaction rates under certain atmospheric conditions. Often, researchers have predicted using measurements viscosity Stokes–Einstein relation (D∝1/η, where D coefficient η viscosity). However, accuracy this in remains uncertain. Using rectangular area fluorescence...

Measurements of the water activity-dependent viscosity aerosol particles from two techniques are compared, specifically coalescence droplets in holographic optical tweezers (HOT) and poke-and-flow experiments on deposited onto a glass substrate. These new data also compared with fitting dimer coagulation, isolation, (DCIC) measurements. The system considered this work ternary mixtures sucrose-citric acid-water sucrose-NaNO3-water, at varying solute mass ratios. Results HOT excellent...

A Dimer Coagulation, Isolation and Coalescence (DCIC) technique is used to probe the phase behaviour glass transition temperatures of ternary aerosol mixtures. The DCIC perform temperature relative humidity dependent viscosity measurements at viscosities near 5 × 106 Pa s. Measurements include organic-organic organic-inorganic mixtures composed sucrose-citric acid sucrose-sodium nitrate. data reported here add additional insight into wide discrepancies in for pure sodium diagram model work...

Representing the physicochemical properties of aerosol particles complex composition is crucial importance for understanding and predicting thermodynamic, kinetic, optical processes interpreting comparing analysis methods. Here, we consider representations density refractive index aqueous-organic with a particular focus on dependence these relative humidity water content, including an examination solution droplets existing at supersaturated solute concentrations. Using bulk phase...

The physical, chemical, and biological properties of an aerosol droplet/particle are dependent on the morphology itself; for example, a liquid droplet will be processed by oxidants in gas phase fundamentally different way than solid particle. Additionally, given their small size, droplets may change over timescales order milliseconds (e.g., deliquescence or crystallisation). Thus, ability to rapidly easily estimate is critical, especially interpretation complex processes such as spray drying...

Organic aerosol can adopt a wide range of viscosities, from liquid to glass, depending on the local humidity. In highly viscous droplets, evaporation rates organic components are suppressed varying degrees, yet water remains fast. Here, we examine coevaporation semivolatile compounds (SVOCs), along with their solvating water, particles levitated in humidity-controlled environment. To better replicate composition secondary aerosol, nonvolatile organics were also present, creating...

Two droplets, individually levitated in an electrodynamic balance, are allowed to collide produce a pH jump the merged droplet, which starts bimolecular reaction.

Abstract. Alkylaminium sulfates originate from the neutralisation reaction between short-chained amines and sulfuric acid have been detected in atmospheric aerosol particles. Their physicochemical behaviour is less well characterised than their inorganic equivalent, ammonium sulfate, even though they play a role processes such as nucleation growth of new particles cloud droplet formation. In this work, comparative evaporation kinetics experimental technique using cylindrical electrodynamic...

Laboratory studies can provide important insights into the processes that occur at scale of individual particles in ambient aerosol. We examine accuracies measurements core physicochemical properties aerosols be made single particle and explore impact these on microscopic Presenting new measurements, we here refinements our understanding aerosol hygroscopicity, surface tension, viscosity optical gained from detailed laboratory for complex mixtures through to surrogates secondary organic...

The validation of approaches to predict the hygroscopicity complex mixtures organic components in aerosol is important for understanding hygroscopic response atmosphere. We report new measurements dicarboxylic acids and amino using a comparative kinetic electrodynamic balance (CK-EDB) approach, inferring equilibrium water content from close saturation relative humidity (100%) down 80%. show that solution densities refractive indices can be estimated with an accuracy better than ±2% molar...

Responding to changes in the surrounding environment, aerosol particles can grow by water condensation changing rapidly composition and dramatically viscosity. The timescale for growth is important establish undergoing hydration processes atmosphere or during inhalation. Using an electrodynamic balance, we report direct measurements at −7.5, 0, 20 °C of timescales hygroscopic condensational on a range model systems. These extend from viscous containing single saccharide solute (sucrose,...

Single droplet levitation provides contactless access to the microphysical and chemical properties of micrometer-sized samples. Most applications biological systems use nondestructive optical techniques probe properties. To provide improved specificity, we coupled a multicompartment quadrupole electrodynamic trap (QET) with single mass spectrometry. Our QET continuously traps monodisperse population (tens hundreds droplets) allows for simultaneous sizing using its Mie scattering pattern....

The energy demands of data centers (DCs) worldwide are rapidly increasing, as their environmental and economic costs. This paper presents a study conducted at Sannazzaro de' Burgondi (Po Valley), Italy, specifically aimed optimizing the operating conditions DC designed for Italian Oil Gas Company (Eni) (5200 m(2) Information Technology installed, 30 MW) based on direct free cooling (DFC) system. aim was to save largest possible quantity energy, while same time preventing aerosol corrosion....

Climate and pollution can lead to materials weathering. In this study, an innovative method is employed evaluate the hazard for heritage stone substrates induced by synergic effect of particulate matter (PM) climate. respect, two indicators were determined: time wetness number dissolution crystallization cycles. The computed coupling experimental measurements PM deliquescence relative humidity with climatic data. For first time, these estimated based on hygroscopic properties, considering...

Abstract. Gas-particle equilibrium partitioning is a fundamental concept used to describe the growth and loss of secondary organic aerosol (SOA). However, recent literature has suggested that gas-particle may be kinetically limited, preventing volatilization from phase as result physical state (e.g. glassy, viscous). Experimental measurements diffusion constants within viscous are limited do not represent complex chemical composition observed in SOA (i.e. multicomponent mixtures). Motivated...