The effects of blending ratios on soot formation remain unclear as sustainable aviation fuels (SAF) are introduced to replace fossil fuels and reduce particulate emissions. Small-Angle X-ray Scattering (SAXS) is used to investigate soot primary particles from ethylene, Jet A-1, and SAF blends in laminar diffusion flames. A Bayesian framework with physical constraints analyzes the SAXS data using a pair-correlation-based model, yielding spatially resolved primary particle size distributions. Results highlight the impact of replacing Jet A-1 with SAF on particle size distribution, Porod invariant (proportional to soot volume fraction), and surface-to-volume ratio.

The climatic impact of aviation is a subject of significant scientific scrutiny, encompassing effects beyond direct radiative forcing from carbon dioxide. A substantial component of the effective radiative forcing is attributable to non-CO2 effects, including the formation of contrail-cirrus clouds, for which non-volatile particulate matter (nvPM) emissions act as precursor nuclei. These emissions also degrade local air quality at airports. Therefore, the development of effective mitigation strategies is imperative. Empirical studies have demonstrated that Sustainable Aviation Fuels (SAF) represent a viable mitigation pathway, capable of significantly reducing nvPM mass and number emissions from jet engines.

Real-world emission data of aircrafts is essential for the development of realistic air quality models. In the present work, about 1600 single aircraft exhaust plumes were investigated during two measurement campaigns at Frankfurt Airport as part of the project SOURCE FFR (Study On Ultrafine Particles in the Frankfurt Airport Region). Based on these measurements emission indices for both total and non-volatile particle number as well as NO_x were obtained covering about 70 different aircraft engine types. This dataset provides a valuable source of input parameters for ongoing modelling efforts.

Aircraft operations emit significant particulate matter (PM) and ultrafine particles (UFP), impacting air quality near airports. The Appropriate project assessed emissions at Zürich Airport via laboratory studies, test cell measurements, and a month-long field campaign in 2022. A suite of advanced instruments, including LToF-AMS, EESI-TOF, and VOCUS PTR, quantified non-refractory PM components and volatile organic compounds. Preliminary LToF-AMS data revealed elevated oil-related organic markers (m/z 85/71 > 0.66), suggesting lubrication oil contributions. Coupled with molecular-level EESI and VOCUS data, measurements enable detailed source apportionment of primary and secondary aerosols, providing critical insights into aviation-related atmospheric chemistry and health impacts.

Here, the light absorption of wildfire-like Brown Carbon (BrC) emitted by wood combustion is elucidated using an integrated generation platform coupled with a real-time monitoring and time-integrated sampling instrumentation. The optical properties and particle size distribution of Brown Carbon (BrC) are controlled by varying the wood mass. The size fractionation of such wildfire-like BrC reveals that the PM_0.1-2.5 fraction absorbs up to five times more light compared to the PM_0.1 fraction. The size-resolved optical properties of BrC measured here can be interfaced with climate models to determine the contribution of wildfire PM to global warming.

Residential wood combustion (RWC) is a major source of light-absorbing particles into atmosphere. This study investigated how RWC aerosol optical properties are influenced by combustion conditions, novel emission control techniques and atmospheric aging. We found that an electrostatic precipitator (ESP) removed 71% of particle emissions, but considerably changed the particle size and composition, leading to increase in radiative forcing efficiency of the particles. Photochemical aging of emissions strongly decreased radiative forcing efficiency, but the particles still estimated cause a net warming effect. The results can be used to assess how efficiently new emission control technologies mitigate climate impacts of RWC.

Aerosol emissions, including polycyclic aromatic hydrocarbons (PAHs), from biomass combustion are extremely difficult to predict and to reproduce due to their complex nature and high sensitivity to the combustion conditions.

This study aimed to characterize fire emissions from commonly used wood-based construction materials during key combustion conditions, including well-ventilated, under-ventilated, and vitiated (reduced oxygen by nitrogen dilution) conditions with non-flaming smoldering combustion.

The results show that particle-phase PAH emissions were substantially increased with decreasing degree of ventilation. On the other hand, vitiated conditions did not result in similar PAH-rich emissions under the same heating conditions.

Condensable particulate matter (CPM) is a subset of primary particulate matter, formed through rapid condensation of vapors emitted from stacks to the atmosphere. CPM promotes new particle formation through homogeneous nucleation and particle growth through heterogeneous nucleation/condensation on the surface of filterable particulate matter (FPM). The effect of pre-existing particles and gaseous air pollutants around the stacks on the heterogeneous CPM formation has not been well understood. In this study, the effects of pre-existing particles and gaseous pollutants on the formation of heterogeneous CPM were investigated using the real-time CPM measurement system, PNU-CPM, developed by Pusan National University.

Sustainable energy transition aligns with UN Goal 7. Carbon-based fuel combustion emits CO₂, methane, and black carbon, worsening climate change. Contrasting hydrogen, ammonia (NH₃) is easier to store and transport but requires a pilot fuel for combustion because of bad ignition properties. In a dual-fuel engine study, replacing diesel with NH₃ reduced CO₂ emissions but increased N₂O and NOx. Nevertheless, at 80% diesel substitution, CO₂-equivalent greenhouse gas emissions dropped by 78%, while soot emissions also decreased. However, NH₃ and NOx emissions may enhance secondary aerosol formation, necessitating exhaust aftertreatment to mitigate environmental impacts for the low-carbon fuel alternative diesel/NH3.

Shipping is a significant source of light absorbing aerosols, i.e. black (BC) and brown carbon (BrC), which contribute to atmospheric warming. In 2020, the International Maritime Organization introduced a global regulation that reduced the maximum allowed sulfur content in fuels from 3.5 to 0.5% to mitigate sulfur pollution. We examined the light absorbing properties of fresh and aged aerosol emissions from a ship engine using fuels complying with the two major sulfur regulations. The results demonstrated that aerosol emissions from globally compliant LS-HFO can exhibit light-absorbing characteristics similar to SECA-compliant MGO, but with stronger overall absorption.

Brake wear particles, generated from the brake pad – brake disc contact, contribute significantly to particle emissions from vehicle transport. We use the pin on disc method to experimentally simulate mild and harsh braking using samples from comercial brake discs and brake pads. We find that BWP have substantial absorption at wavelengths spanning from UV to IR assessed with an aethalometer. The absorption is around 10% that of Black Carbon. We discuss the source of the absorbing material in BWP and the implications of the results on source apportionment of transport emissions.

A large waste treatment facility fire in Rusko, Tampere (November 2024) caused severe air pollution, with PM2.5 concentrations reaching 200 μg/m³ in nearby residential areas—almost 100 times the background level. Measurements using a mobile laboratory analyzed particle size, composition, and black carbon content. TEM analysis revealed diverse elements, including carbon, sulfur, and heavy metals. Despite high black carbon concentrations, organic compounds dominated. The smoke plume remained compact over long distances, worsening air quality. Findings highlight the severe impact of open waste burning on air pollution and health.

This study explores the toxicological effects of PM_0.3-2.5 and its organic extract (O-PM) on BEAS-2B cells, using two exposure models: classic submerged exposure and an air-liquid interface (ALI) system treated using the Vitrocell® Cloud alpha system. We report on the low deposition efficiency of airborne PM_0.3-2.5 sampled at an industrial site in northern France and the comparison of the effects of O-PM on cells at equal mass/surface concentrations in both exposure conditions. The importance of properly determining the deposition efficiency and comparing the effects by selecting the proper negative control is also highlighted.

This study investigates the oxidative potential (OP) of particulate matter (PM) emitted from a modern biomass combustion boiler with a nominal power of 15 kW (REKA HKRST-FSK-20 kW). Four biomasses for residential heating which are hardwood pellets, softwood pellets, hardwood chips, and softwood chips were tested. The sampled PM was analyzed by using two oxidative potential (OP) assays: ascorbic acid (AA) and dithiothreitol (DTT). By identifying the biomass fuels that produce PM with higher OP, this study provides critical insights for optimizing biomass selection and usage to minimize adverse health effects.

We developed an innovative technology for near real-time, autonomous detection of airborne viral particles using an optical detection system. The system leverages particle scattering spectra and machine-learning algorithms to identify and distinguish viral particles from common airborne particles. It was tested with air samples spiked with inactivated SARS-CoV-2 virus particles, showing strong correlation with digital PCR measurements. This technology enhances public health preparedness by providing quick warnings with minimal human intervention, making it suitable for indoor settings like airports, hospitals, and schools. It can increase our ability to respond to emerging viral threats.

The atmosphere transports microorganisms across ecosystems, with dust storms carrying large quantities over great distances. This study analyzed air samples from 13 dusty and 32 clear days in the Middle East, identifying facultative human and plant pathogens like Klebsiella pneumoniae and Fusarium poae. Pathogen abundance increased with dust storms and rising temperatures. Dust also carried up to 125 times more antibiotic resistance genes (ARGs) than clear air, some linked to mobile genetic elements, enabling resistance transfer. These findings highlight dust storms’ role in pathogen and ARG dispersal, stressing the need for continuous atmospheric microbiome monitoring for health and environmental risks.

Particulate matter concentration is employed in air quality guidelines. However, its oxidative potential has been suggested as an alternative. We propose a deep-learning method to estimate oxidative potential mean daily concentration from the combination of features extracted from surface reflectance images and meteorological variables. The proposed architecture comprises: a ResNet50, working on the images, and an MLP, which makes the prediction based on the concatenation of both information. We conducted preliminary experiments to predict PM10 concentration at three monitoring stations in Grenoble, and we obtained promising results to be exploited as baseline for the estimation of PM10’s OP daily average.

Monitoring CO2 levels is usually considered as a simple way to assess the renovation of indoor air. Moreover, COVID-19 pandemic generated an increased interest in enhancing the indoor air quality. To address these issues, the concentration of CO2 and PM were measured in the conference venue during the European Aerosol Conference (EAC2023) in Malaga (Spain). A balance equation is shown to fit well the CO2 measurements. Autoregressive average values for the PMs are also discussed. These CO2 and PM data are correlated to show the validity of CO2 measurements to evaluate the overall ventilation quality in a public indoor space.

In this study, we ran the FLEXPART-SOSAA model during and after a severe haze episode in Beijing. We found that as much as half of the particles originated outside of Beijing, and 5% of the primary mass and 8% of SOA mass originated in Xinjiang region in far western China. We also tested several scenarios related to potential emission control strategies that could mitigate the severity of haze episodes.

The study applies the COSMO-MUSCAT model to analyse PM sources at sites in Germany and the Czech Republic. The model underestimates PM2.5 concentrations, possibly due to unaccounted emissions from Saharan dust intrusions and stagnant, cold weather conditions. A tagging method identifies emission sources by sector and country, highlighting domestic heating as a major winter contributor. Further sensitivity tests reveal underestimated SOA formation from aromatic VOCs during wood and coal combustion. Seasonal comparisons provide insight into model performance, with future improvements planned through the integration of a Heating Degree Day approach to better capture heating-related emission variations.

Is there a link between industrial-era air quality and contemporary socio-economic outcomes in German cities? Answering this question requires spatial data on urban air pollution at the end of the 19^th century. The regional chemistry-transport-model ICON-MUSCAT is used to model historical air quality in Germany using an improved emission dataset based on the emissions of the Community Emissions Data System (CEDS). Improvements of the spatial distribution of the sector-wise emissions are performed with the help of population data and historical maps that provide the location of factories etc. within the city, as well as the extent of populated areas.

The study assesses aerosol formation sources through chemical analysis and emission inventories, focusing on nanoparticle precursors using inverse modeling techniques. It examines five aerosol precursors in Estonia. SO2 is monitored at multiple stations, while H2SO4, HIO3, and two highly oxidized organic molecules (HOMs: C10H15NO8, C10H14O9) were measured at the SMEAR Estonia station from 2019 to 2023. Data from April to November 2019 are used in this research. The SILAM v5.7 model was used to detect aerosol precursor footprints, processed using a Time-Of-Flight mass spectrometer and TofTools software.

This study deals with aerosol synthesis of carbon nano onions (CNOs) containing TiO₂ with oxygen vacancies and investigation of their morphological and optical and photocatalytic features. The CNO composites were synthesized employing closed flame spray process and as obtained material was investigated using TEM, Raman spectroscopy, FTIR, Thermal optical carbon analyser, TGA and UV Vis absorption analysis. Results show that that CNOs exhibit concentric graphitic layered structures containing mixed phases TiO₂ with oxygen vacancies. Incorporation of TiO₂ leads to defects induced structure in CNOs and results in extended absorption in visible region, rendering promising material for photocatalytic and photochemical applications.

Flame spray pyrolysis (FSP) systems are getting an increasing level of attention because of their capacity to produce nanoparticles with well-defined characteristics for the production of innovative materials. To achieve good control of nanoparticles characteristics, a deep understanding of the processes governing their production in the flame is required. To this end, we have developed an experimental setup enabling us to study of TiO₂ synthesis in a laminar H₂/TTIP/air diffusion co-flow pre-vaporized flame. In this contribution, we will illustrate how to combine in-situ optical diagnostic, ex-situ measurements and detailed computational fluid dynamics to obtain new fundamental insights on flame synthesis.

Molecular dynamics (MD) simulations of air molecules accounting for their shape and force fields revealed recently that inelastic collisions are abundant. Here, fully atomistic MD simulations are conducted to assess the diffusivity of silica nanoparticles (NPs) in air. As NP size approaches that of air, NP diffusivity is increasingly affected by inelastic collisions, resulting in various collision patterns like grazing, head-on, and orbiting. The MD-derived diffusivities for sub-5 nm NPs were 50-60% smaller than those predicted by the Stokes-Cunningham-Millikan (SCM) equation. Additional simulations treating NPs and air as hard spheres yielded diffusivities that matched with the SCM equation.

We design a novel monolithic wall-flow reactor with optimized structure that can accommodate an unprecedented O(10) higher amount of catalytic particles (loaded via an aerosol process) vs washcoated technology and exhibit much lower overall flow resistance than a similar packed bed reactor. Prototype reactors loaded with catalytic powders are evaluated with respect to their flow resistance confirming their high potential. Employing rational approximations we obtain an analytical solution for the flow through the monolithic reactor and the dependance of the pressure drop on the parameters of the problem, which is shown to be in excellent agreement with the data.

This study presents an inlet system for extending the detection range of the SP-AMS with the added benefit of improved metal detection. The inlet uses Cab-O-Jet 300 particles produced by an atomizer and an agglomeration chamber for agglomerating sampled particles on the Cab-O-Jet 300 particles that can be transmitted into the SP-AMS. Due to higher vaporization temperatures associated with the SP-AMS laser, metals agglomerated on the particles can be measured and their relative ionization efficiencies can be calibrated.

We present a new method to measure the total scattering and extinction cross sections, and optical and mass spectrometry from a single micron sized particle in a touchless environment.

We present a drone-based aerosol sampling platform with fast, high resolution meteorological sensors and a pump-driven filter sampler. The system features streamlined data and power management, including real-time telemetry and remote pump control, ensuring operational integrity and efficiency. A field campaign in Gothenburg, Sweden demonstrated the systems capability in performing targeted aerosol sampling in relation to the development of the nocturnal boundary layer. Aerosl particles were analyzed semi-online using chemical ionization mass spectrometry (CIMS) with a filter inlet for gases and aerosols (FIGAERO). Mass spectrometry analysis revealed compositional differences in ground and aloft samples.

Aerosol droplets are unique microcompartments containing microscopic amounts of material and exhibiting remarkable chemical reactivity. In this presentation, we describe a novel approach for mass spectrometric analysis of individual aqueous picolitre droplets (∼1–180 pL, or ~5-100 µm radius) containing down to ∼1 pg analyte mass per droplet. Individual droplets are generated using a microdroplet dispenser, imparted a small amount of net charge, and guided to the inlet of a high-resolution mass spectrometer using a linear quadrupole-electrodynamic balance. We will characterise the sensitivity of the approach and will discuss experiments investigating accelerated chemical reactions in aerosol droplets.

Processes on the earth-atmosphere interface influence the source-sink dynamics of airborne microplastics (MPs), yet we lack understanding and quantification. Monthly atmospheric deposition over one year (08/2024-07/2025) at four study sites located less than 700 meters apart at the Ecological-Botanical Garden at the University of Bayreuth, Germany were collected and analyzed for number, size, shape, and polymer type using micro-Fourier transform infrared spectroscopy. We evaluated the relative importance of wet and dry depositions in the scavenging of airborne MPs and explored its spatial and temporal variability.

This study examines airborne nano- and microplastics (NMPs) in an urban environment, focusing on their concentration, size distribution, and chemical composition. Using aerosol samples collected over two weeks, the current study analysed synthetic polymers in different particulate matter (PM) fractions: PM₁₀, PM_2.5 (fine microplastics), and PM_10-2.5 (coarse microplastics). Tire wear particles accounted for ~65% of total NMPs, with car tire tread as the dominant. Strong correlations were observed among fine microplastics, indicating common sources. Associations with carbonaceous species suggest shared emissions and secondary formation processes. Findings emphasize the need for extended monitoring and regulatory measures to address airborne NMP pollution.

Micro- and nano-plastics (MNPs) are emerging pollutants due to their widespread presence, however, identifying airborne MNPs is challenging due to their small size. Mechanical recycling, essential for a circular economy, can generate MNPs during energy-intensive processes like shredding and washing. Understanding MNP formation in recycling facilities is crucial for emission reduction strategies. This study tracked polypropylene (PP) emissions during recycling, using real-time and offline particulate matter sampling methods. Results showed increased airborne particles during shredding and significant PP emissions during washing. These findings can help develop protocols for monitoring and reducing airborne MNPs in recycling processes.

Inhalation is the primary route of exposure to micro- and nanoplastics (MNP) for workers, especially in workplaces involving plastic materials. Indoor MNP concentrations can be much higher than outdoors, but limited data and lack of standard methods hinder exposure assessment. The INAIL BRiC CELLOPHAN project aims to develop multi-technique sampling and analytical methods to characterize airborne MNP in the particulate matter (PM) of indoor workplaces. Three plants were investigated (a water bottling plant, a tyre fixing/car repair shop and a textile factory) by different co-located samplers (PM, VOC) and direct-reading instruments. First-year results are presented and discussed in this contribution

This study explores whether microplastics, including polypropylene, polyethylene, polyethylene terephthalate, and tire wear particles can influence cloud formation by promoting ice formation. Laboratory experiments show that some microplastics can act as ice-nucleating particles and initiate freezing in mimicked cloud droplets at higher temperatures than the water background. Simulated atmospheric aging had either no effect or decreased the freezing temperatures. These findings suggest that microplastics may impact cloud freezing processes if present in high concentrations. In addition, their atmospheric lifetime may be impacted by ice nucleation followed by precipitation, with implications for their transport pathways.

Microplastics (MPs) have been detected in various environmental, as well as biological, contexts and their presence has attracted the attention of the scientific community, which has classified them as new emerging contaminants. Airborne MPs are a relatively new topic and research has to largely focus on indoor environments, as most people, on average, spend around 90% of their time in homes and workplaces.

Consequently, the aim of this innovative study, performed within the BRIC ID-14 CELLOPHAN project, is to investigate the exposure levels of MPs in workplaces, specifically by characterizing them using a combination of spectroscopic and microscopic techniques.

In this study, we investigate the spatial distribution and dynamics of neutral gold atoms (Au I) immediately following spark generation using a structured two-photon laser-induced fluorescence (TALIF) technique, dubbed Light Amplitude Control (LAC). Ultrashort laser pulses with tailored spectral and spatial profiles excite gold’s atomic transitions, with fluorescence signals processed via multi-dimensional lock-in detection. The research examines spark ablation for nanoparticle synthesis by linking gold vapor cloud evolution with SDG parameters. Experiments using Au and Cu electrodes, high-speed imaging, and SMPS measurements reveal how spark energy, repetition frequency, gas composition, and flow rates critically govern early nucleation and particle growth.

This study examines the oxidation mechanism of Co-Ni nanoparticles synthesized via spark ablation to optimize NiCo₂O₄ for catalytic applications. A spark discharge generator (SDG) produced three precursor structures in air, nitrogen, and nitrogen/hydrogen. X-ray diffraction (XRD) confirmed the formation of NiCo₂ in metallic and oxide phases but not NiCo₂O₄. Annealing at 450°C converted these precursors into NiCo₂O₄ with structural variations. In-situ environmental TEM (ETEM) provided real-time insights into oxidation, revealing void formation that increases surface area and enhances catalytic performance. Understanding these mechanisms helps refine synthesis conditions for improved material properties.

This study investigates the composition evolution of Cu-Zn nanoparticles (NPs) produced via spark ablation, challenging the assumption that NPs retain the feedstock’s composition when produced using alloyed feedstocks. Preliminary findings reveal depletion of Zn in the feedstock surface, indicating compositional shifts in the generated NPs—likely driven by differences in melting point and vapor pressure between Cu and Zn.
Using time-resolved x-ray fluorescence, ICP-MS, and optical emission spectroscopy, we analyze NPs from Cu-Zn alloys and pure elements. These results provide new insights into spark ablation dynamics, enabling better control over bimetallic NP synthesis, of great improtance in catalysis and sensing applications.

Antennas are primarily designed to receive and transmit electromagnetic (EM) waves, spurring widespread applications in communications, radars, and radios. However, traditional nanofabrication techniques generally suffer from 2D flat patterns. This not only increases energy dissipation but also eliminates the possibility for three-dimensional control. To resolve that, we used our homemade printer for fabricating 3D plasmonic nanoantennas with various material combinations (Au, Ag, and their hybrids) and dimensional flexibilities, showcasing tunable responses to visible light.

Circular economies require the use of sustainable pathways for processing of advanced materials. While significant advances have been made in discovery and processing of novel materials that have innovative functionalities, rarely is attention provided to a holistic analysis to ensure these processes are sustainable. An aerosol process to produce carbon nanomaterials is described. Comprehensive models that account for particle formation and growth are used to develop scale up methodologies. Comprehensive life cycle assessment of a continuous, single step aerosol approach are compared to the conventional batch pyrolysis techniques for synthesis of high surface area porous nano-carbon materials.

The calibration of CPCs and DMAs needs monodisperse, singly charged, spherical particles. A common way to generate these using silver is the evaporation-condensation method with subsequent sintering to obtain spherical particles. The sintering process reduces particle size drastically, limiting the maximum obtainable particle diameter. An alternative approach to generating spherical particles is the seeded growth using heterogeneous condensation. A Silver Particle Generator (SPG) feeds seed particles into a second SPG, where silver vapor condenses heterogeneously onto the seed particles. Temperature and flow rate combinations of the two SPGs are investigated to achieve spherical silver particles larger than 100 nm.

Magnetic nanoparticles (NPs), particularly superparamagnetic iron oxide nanoparticles (Fe₃O₄), have gained significant attention due to their unique properties and wide-ranging applications. This study presents the synthesis of magnetite nanoparticles coated with polyethylenimine (PEI) via the co-precipitation method to enhance their stability and prevent agglomeration. Further encapsulation of these PEI-coated nanoparticles in organic matrices such as tetraethyl orthosilicate (TEOS) and (3-aminopropyl) triethoxysilane (APTES) was performed to facilitate surface functionalization. Aerosol Spray Pyrolysis (ASP) techniques were utilized to ensure the formation of spherical nanoparticles, which are more suitable for drug delivery applications.

This study presents the complex acousto-hydrodynamics associated with surface acoustic wave (SAW) aerosol generation, i.e. investigations of the SAW interactions with a microscale liquid film, comprising acoustic fluid patterning and pattern stabilization, and the liquid breakup mechanisms from the developed spatially arranged liquid micro-domes. The liquid atomization zone on the piezoelectric substrate, i.e., the zone of SAW-fluid interaction and the aerosol origin on a straightforward SAW atomization chip is optically visualized by an ultra-high-speed camera. As one of the aerosol generation mechanisms, we demonstrate the presence of micro-cavitation driven by a SAW at a frequency of 43 MHz.

As technology advances, the demand for compact, high-efficiency electronic devices grows, especially those with power converters like powder core inductors (PCIs). FeNi-based materials are ideal for PCIs due to their high permeability and low coercivity. This study focuses on the aerosol synthesis of dense FeNi particles and silica-coated FeNi (FeNi@SiO₂) particles, using a swirler connector-assisted spray pyrolysis method. The tuned process controls particle quality, minimizes carbon impurities, and determined silica coating. Results show that low impurities, and uniform silica shells are essential for improving PCI performance, efficiency, and stability, particularly regarding DC bias, core loss, and breakdown voltage.

In this study, we explore a combustion-aerosol process designed to systematically capture a high-temperature phase and stabilize it at room temperature, as demonstrated with CoCu₂O₃. Using a combination of ex situ and in situ X-ray diffraction, electron microscopy, and real-time flame characterization, we investigate the synthesis and thermal stability of CoCu₂O₃ nanocrystals, along with the formation of thermodynamically stable phases and cluster structures. This work establishes general thermodynamic-process relationships to regulate phase composition as a function of flame-aerosol engineering parameters, including precursor concentration, temperature profile, and high-temperature residence time.

The rising threat of air pollution has accelerated advancements in gas-sensing technologies, particularly those utilizing carbon-based materials like activated carbons (ACs). This study explores an innovative approach to fabricating noble metal-carbonaceous films from recycled e-waste for next-generation gas sensors. Noble metals are selectively recovered via hydrometallurgical leaching and adsorbed onto AC substrates. Using electrospray deposition, these metal-loaded ACs form thin films with tunable morphology and surface properties. The resulting films are evaluated for sensing applications, emphasizing sustainability and circular economy principles. This research bridges nanomaterial fabrication with eco-friendly resource recovery, enhancing sensor performance while minimizing environmental impact.

Mixed catalysts are scarcely used because of the present a lack of scalable synthesis methods. Catalysts based on atomic clusters are presently not used because of their strong mobility on surfaces. Very recently introduced flexible aerosol synthesis principles for (mixed) nanoparticulate and atomic cluster catalysts are reviewed. Spark ablation plus Artificial Intelligence, DFT, XRD and XPS correctly predict the composition of improved catalysts. A heteroatom doped carbonaceous support enables very stable immobilization of the atomic clusters. Ag atoms stabilize Cu atomic clusters. The Cu-Ag atomic clusters on the carbonaceous layer exhibit electrochemical conversion of CO2 to acetaldehyde with 92% selectivity.

Surface enhanced Raman spectroscopy (SERS) is a highly specific spectroscopic technique, which utilizes the plasmonic enhancement provided by metallic nanostructures. Such SERS substrates can be produced by depositing nanoparticles produced during spark ablation to a filter. The properties of the substrate can be adjusted through the parameters of the fabrication method, such as the frequency of the sparking, the temperature of the particle compaction, or the type of filter used. We investigated the effects these parameters have on the SERS enhancement and also applied the optimal substrate in thiram sensing, where 1.2 ppm thiram was found to be directly detectable.

I present an overview of flame aerosol deposition (FAD) as a scalable technique for fabricating functional nanostructured films with tailored properties. In biosensing, FAD enables the creation of highly porous films that enhance sensor sensitivity, supporting plasmonic sensing via surface-enhanced Raman scattering or colorimetric detection. Additionally, tunable plasmonic films extend photothermal responses for surface disinfection and microneedle fabrication. In biomedical applications, FAD-derived antibacterial and antifouling coatings prevent bacterial adhesion, while photocatalytic films achieve visible-light disinfection. These advances highlight FAD’s potential for next-generation biomedical coatings, with future research focusing on improved deposition strategies and functionalization approaches.

This study presents a novel approach using bipolar electrospray for synthesizing TiO₂/Ag heteroaggregates, ensuring stable and efficient nanostructure formation. The method leverages electrohydrodynamic atomization to generate charged droplets, allowing precise control over particle formation. A detailed investigation into process stability includes current-voltage (I/V) analyses, optimizing parameters such as voltage, flow rate, and solution properties. Additionally, an advanced microscopy system is introduced to capture high-resolution images of droplet interactions, providing insights into coagulation mechanisms. This research highlights the potential of bipolar electrospray and advanced imaging for optimizing nanomaterial synthesis, particularly for photocatalytic applications.

The fragmentation of liquid jets by a gas stream plays a critical role in advanced materials production due to its high efficiency. Pneumatic techniques, such as Flow Blurring (FB), promote droplet formation by inducing microscale mixing. This approach has been successfully adapted for viscous liquids, enabling the generation of droplets, micro- and nanoparticles, and fibrous materials. Recent advancements combine FB atomization with electric charging, facilitating the synthesis of polymer fibers embedded with nanomaterials like carbon nanotubes and graphene oxide. Current research efforts focus on developing an FB device with integrated high-voltage electrodes to enhance atomization efficiency and optimize material collection.

We introduce a model of the field emission of small ions from a cloud of evaporating electrospray nanodroplets of a salty solution.

Effective inhalation therapy requires precise aerosol size and distribution for targeted lung delivery. Electrospray (EHDA) generates uniform micro- and nanodroplets, improving drug delivery. Gilbert b.v. is developing an EHDA-based inhaler for complex lung conditions. This study investigates droplet neutralization and electrospray control in a soft mist inhaler using a multi-nozzle system and corona discharge. A stable cone-jet region was mapped, and optimal neutralization voltage was identified for ethanol-based solutions. Future research will focus on spray stability with reduced ethanol content and its impact on droplet size and drug delivery efficiency.

Quantifying exhaled aerosol and factors that govern the airborne survival of pathogens are crucial steps in improving our understanding of airborne disease transmission. We will present data from a longitudinal study of the amount of aerosol exhaled by individuals and the correlation with exhaled carbon dioxide. We will show that carbon dioxide in an indoor environment does not necessarily reflect the amount of airborne aerosol and pathogen. In addition, we will show the level of carbon dioxide can impact on the survival of airborne pathogens. Both factors must be considered when implementing effective mitigations to reduce airborne viral transmission.

This research investigated the collection efficiency of small bioaerosols which is Bacillus globigii (B.G.) and environmental DNA (eDNA) of B.G using a novel, wearable membrane-based aerosol sampling device called the Compact Personal Aerosol Sampler (CPAS). Aerosolised bacterial spores and eDNA were collected inside a miniature chamber for the capture, recovery, and quantification of DNA.

Pseudomonas syringae is a common plant pathogen, posing a significant threat to the global crop production. Some strains of P. syrinage can cause frost injuries on plants and influence cloud properties and precipitation through ice nucleating proteins (INpro). The study investigated the mechanisms driving aerosolization and INpro production in the model organism P. syringae R10.79. Aerosolization by bubble-bursting resulted in a higher fraction of INpro-bearing cells after aerosolization (33.2%) compared to before (10.7%). A significant positive correlation between the fraction of viable cells and the increase in INpro-bearing cells after aerosolization indicates that INpro are synthesized de novo.

Bioaerosols, including fungal spores, bacteria, and pollen, impact air quality, health, and climate but are difficult to characterize. To address this, we developed a mass spectrometry-based method combining AMS for bulk composition and EESI-Orbitrap-MS for molecular identification. Laboratory experiments confirmed its ability to distinguish bioaerosols, leading to the development of a mass-spectral library to support field measurements in Switzerland for tracing emission sources and seasonal trends.

This study assessed children's exposure to particulate matter (PM1, PM2.5, PM10), ultrafine particles (UFP), and black carbon (BC) in indoor and outdoor environments (schools, homes, and gymnasium) in Lisbon. PM2.5 exposure was higher during the cold season, likely due to increased outdoor pollution and poor ventilation. In schools, PM2.5 levels increased during class hours and cleaning activities, while in homes, peaks occurred during cooking and cleaning. Indoor concentrations often exceeded outdoor levels, highlighting the significant impact of indoor activities on daily exposure to air pollution.

Air pollution impacts children's health, with ultrafine particles (UFPs) posing significant risks. As part of the InChildHealth project, monitoring campaigns in elementary schools across seven European cities assessed indoor air quality and children's exposure. This study presents data from Athens, Lisbon, and Essex, where real-time UFP number concentration and size distribution were measured inside five classrooms per city using Partector 2 Pro. Concurrent outdoor monitoring was performed. Initial results showed strong indoor-outdoor correlations, with ventilation and indoor activities influencing UFP levels. Indoor and outdoor UFP size distributions were analyzed to investigate mechanisms and indoor activities associated with increased UFP levels.

Raising awareness among businesses and institutions on the topic of indoor air quality requires scientific data and analysis models of a dual nature: 1) epidemiological and 2) economic.

The work quantifies the reduction in time spent in good health due to indoor pollution an turns it into the economic impact in terms of external costs.

Considering all the costs over the whole Italy, the indoor air PM pollution in schools and hospitals ranged between 54-106 billion of € accounting up to 5% of the Italian Gross Domestic Product (GDP). Therefore, treating indoor air means drastically reducing these costs.

Climate change affects indoor air quality through changes in ambient temperatures and pollutant concentrations, indoor chemical reactions and occupant behavior. This work applied the IAQCC model to examine the long- and short-term indoor particle concentrations in a German residence under the SSP5-8.5 scenario by 2100. Results show that temperature rise leads to increased formation of secondary organic aerosols via the limonene ozone reaction. However, this increase is compensated by future decreases in outdoor PM_2.5 levels. Ozone events and Sahara dust storms can significantly increase indoor particle concentrations. Preventive measures are needed to reduce indoor air pollution risks.

Current understanding suggests that the intrinsic properties of freshly nucleated particles critically determine their early growth behavior and potential to reach sizes where they can serve as cloud droplet formation seeds. In this contribution, we present our recent work of theoretically exploring the growth and hydration mechanisms of atmospheric clusters. Sulfuric acid and ammonia clusters will be focused, as they are established as the most prevalent drivers of NPF in many regions due to their strong binding properties and high atmospheric concentrations.

Better understanding of atmospheric sulphur chemistry is key to better modelling and predictions of new particle formation. This presentation will discuss the use of ab initio (DFT) calculations paired with metadynamics simulations to understand reactions in systems of SO₃, H₂O and atmospheric acids, in particular the branching fraction between production of sulphuric acid versus other organosulphates which have been recently measured experimentally. We also hypothesize the formation of new, hitherto unexamined complex organosulphates in the atmosphere.

In our study, we employ semi-empirical molecular dynamics (SEMD) at the GFN1-xTB level to investigate monomers sticking onto freshly nucleated particles, including combinations of sulfuric acid and various amines. Our results reveal that neglecting long-range interactions underestimates the number of collisions leading to sticking. By comparing SEMD and all-atom force field simulations, we find similar enhancement factors, although discrepancies appear at lower collision velocities. For systems with larger effective masses, where such velocities are more prevalent, we would expect the two methods to diverge.

Atmospheric aerosols contain diverse organic compounds, the majority of which remain uninvestigated. Quantifying their effect on aerosol processes depends on properties like the glass transition temperature (T_g). Molecular Dynamics (MD) simulations were carried out to predict T_g for various compounds, considering carbon and oxygen content, functional groups (-COOH > -OH > -CO), and molecular architecture (cyclic vs. linear). T_g increased with carbon number and was consistently higher in cyclic structures. A parameterization was developed based on the MD predictions and was evaluated against experimental measurements. A leave-one-out evaluation approach was utilized, providing insights into the contributions of various molecular features.

Aromatic hydrocarbons are prolific contributors to secondary organic aerosol (SOA). It is known that this contribution is multi-generational, where every oxidation step produces more reactive aromatics, each with successively larger contribution to SOA. However, our understanding of the underlying autoxidation mechanisms that produce low-volatility products is limited, preventing us from quantifying this SOA contribution. This work resolves this using quantum chemical calculations and targetted experiments. We show that a previously unknown geminal diol intermediate plays a key role in the autoxidation of multi-generation aromatic products. This mechanism will significantly reduce the current uncertainties in the contribution of aromatics to SOA.

I present an overview of new computational/theoretical results concerning branching points in the gas-phase oxidation chemistry leading from precursors (hydrocarbons and other VOCs emited to the air) to polytunctional low-volatility products relevant to aerosol formation.

Although water-soluble OC (WSOC) and ON (WSON) constitute a substantial fraction of aerosols, particularly in urban areas affected by agricultural, biogenic, and biomass burning emissions, there remains a paucity of information regarding the size-segregated levels, sources, and seasonality of these parameters. The primary objective of this study is to determine the levels, seasonality, and sources of WSOC and WSON in size-segregated aerosol samples collected at a ground-based station (40.73° N, 31.60º E, 743 m asl) in Bolu (Türkiye) between April 2021 and April 2022.

This study examines the chemical composition and sources of aerosols during severe winter pollution episodes in Ioannina, Greece. Using data from an ACSM, a PTR-MS and an aethalometer, biomass burning was identified as the dominant pollution source, significantly contributing to organic aerosols (OA) and brown carbon absorption. Combined aerosol acidity and liquid water content lead to enhanced secondary aerosol formation through aqueous phase processing. Concurrently, PMF showed that 58% of OA originates from biomass burning. Not least, Ioannina’s basin location and temperature inversions lead to pollutant accumulation, highlighting the urgent need for targeted air quality policies in southeastern European cities.

This work focuses on wildfire events, in the climate sensitive area of the Eastern Mediterranean and especially in Greece. The analysis focuses on three intense wildfire events that occurred in the proximity of Athens during the first half of August 2021 (August 3–10: Varympompi and Euboea forest fires; August 17–19: Vilia forest fire), following a prolonged and intense heatwave. The study assesses the impact of transported smoke from forest fires on urban air quality and aerosol optical, physical and chemical properties.

This work combines chamber experiments and field measurements to determine the contribution of different secondary organic aerosol precursors into the organic carbon observed at urban and forested areas of Paris. Organic carbon measurements and molecular scale analyses using HRMS, LC-MS and GC-MS highlight the contribution of anthropogenic sources into the aerosol composition, which predominates for both environments.

Domestic wood burning is a major source of particulate matter (PM) emissions in the UK, exceeding road traffic emissions. Despite mitigation efforts like 'EcoDesign' stoves, emissions have risen over two decades. UK estimates rely on lab tests that may not reflect real-world conditions, especially during transient phases like ignition and reloading. A new test facility at the University of Manchester used real-time analysers, including EESI mass spectrometry, to monitor emissions under varied conditions. Findings reveal significant chemical variations across burn phases, with oxidised gases peaking early and nitrogen-containing aerosols increasing during smouldering, highlighting the impact of combustion conditions

Our study presents a novel methodology that integrates multiple high-dimensional imaging techniques to enhance the characterization of air pollution particles. By combining SEM-EDX and ToF-SIMS data with multiway analysis, we address the challenges posed by heterogeneous particle composition and evolving pollution sources. This approach enables more precise source apportionment and a deeper understanding of PM characteristics, particularly in the context of changing vehicle emissions and urban air quality. The results demonstrate the potential of multiway techniques to unlock new insights into air pollution dynamics, paving the way for improved regulatory strategies and pollution mitigation efforts

This study investigated the optical properties of soluble BrC and its impact on climate. Fluorescence analysis was used to obtain the structural characteristics of soluble BrC, contributing to a deeper insight into its composition in urban areas. The findings provide valuable information to support future atmospheric research utilizing fluorescence analysis. Furthermore, this study will employ the PMF model to apportion emission sources and assess their relationship with BrC optical properties. This approach aims to improve our understanding of the contributions of various urban emission sources to climate change.

Biological aerosol particles, or bioaerosols, represent a significant portion of atmospheric particulate matter (PM) and can profoundly affect the chemical and physical properties of atmospheric aerosols. Interest in atmospheric bioaerosols has increased recently because of the effects bioaerosols have on global climate and human health. In the present study, extracts of common bioaerosols were aged with an oxidation flow reactor (OFR) and with H₂O₂ under UV-Vis light. The chemical analysis of organic species in fresh and aged bioaerosol samples was performed using Liquid Chromatography Mass Spectrometry (LC-MS) and Nuclear Magnetic Resonance Spectroscopy (¹H-NMR).

This study presents the first NMR-based seasonal analysis of organic aerosols in Mumbai, a tropical coastal megacity. PM₁₀, EC-OC, and NMR-derived functional groups were analyzed using high-resolution diurnal sampling. PM₁₀ peaked in winter afternoons due to meteorological factors, while summer recorded the lowest levels. EC-OC trends indicated biomass burning and secondary aerosol formation. NMR analysis revealed higher hydrocarbons in winter, with aliphatics dominating year-round. Oxygenated species peaked in winter, linked to stagnant conditions. Strong correlations between functional groups and EC-OC suggest seasonal variations in sources and processes. Advanced NMR analysis is ongoing for further insights

We characterize the chemical composition of particles from five wildfire plumes that reached the Jungfraujoch in 2023, using TOF-ACSM, AE33 and MAAP measurements. Organic aerosol (OA) dominated all biomass burning (BB) plumes, and the contribution to OA of m/z 60, a levoglucosan tracer, increases for these plumes. We also observe that the contribution of the m/z range 135-200 to OA increases during the BB plumes. A preliminary PMF source apportionment hints at a wildfire-specific BBOA factor in summer. Further work will focus on better separating the air masses and, consolidating the PMF and investigating more BB plumes.