Quantifying how atmospheric particles interact with water vapor is critical for understanding the effects of aerosols on climate. We present a novel method to measure the mass-based hygroscopicity of particles while characterizing their elemental and carbon functional group compositions. Since mass-based hygroscopicity is insensitive to particle geometry, it is advantageous for probing the hygroscopic behavior of atmospheric particles, which can have irregular morphologies. Combining scanning electron microscopy with energy dispersive X-ray analysis (SEM/EDX), scanning transmission X-ray microscopy (STXM) analysis, and in situ STXM humidification experiments, this method was validated using laboratory-generated, atmospherically relevant particles. Then, the hygroscopicity and elemental composition of 15 complex atmospheric particles were analyzed by leveraging quantification of C, N, and O from STXM, and complementary elemental quantification from SEM/EDX. We found three types of hygroscopic responses, and correlated high hygroscopicity with Na and Cl content. The mixing state of 158 other particles from the sample broadly agreed with those of the humidified particles, indicating the potential to infer atmospheric hygroscopic behavior from a selected subset of particles. These methods offer unique quantitative capabilities to characterize and correlate the hygroscopicity and chemistry of individual submicrometer atmospheric particles.
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http://dx.doi.org/10.1021/acs.est.6b00793 | DOI Listing |
J Phys Chem Lett
January 2025
Department of Chemistry, Yonsei University, Wonju, Gangwon 26493, Korea.
Understanding the environment-dependent stability and photoluminescence (PL) properties of advanced perovskite materials remains a challenge with conflicting views. Herein, we investigated the influence of the host matrix (poly(methyl methacrylate) (PMMA) and polystyrene (PS)) and atmospheric conditions (ambient and N) on the PL properties of a CsPbBr perovskite quantum dot (PQD) using single-particle spectroscopy. Despite the same PL blinking mechanism, the PL properties of the PQD were considerably affected by the environmental conditions.
View Article and Find Full Text PDFSci Rep
January 2025
Department of Pediatric Dentistry Faculty of Dental Medicine, University of Damascus, Damascus, Syria.
This in vitro study aims to evaluate various surface treatments on the shear bond strength and failure mode of CAD/CAM PMMA teeth to the heat-polymerized acrylic denture base. The study sample consisted of 100 teeth that were divided equally into five groups: Group 1: denture artificial teeth (control), Group 2: PMMA teeth without surface treatment, Group 3: PMMA teeth with MMA etching, Group 4: PMMA teeth with sandblasting (aluminum oxide particles), and Group 5: PMMA teeth with perpendicular grooves. The shear bond strength test was performed using a universal testing machine and the failure mode was recorded.
View Article and Find Full Text PDFFood Res Int
January 2025
State Key Laboratory of Crop Stress Adaptation and Improvement, College of Agriculture, Henan University, Kaifeng 475004, China; Food Laboratory of Zhongyuan, Luohe 462300, China. Electronic address:
Hydrothermal treatment is a physical modification technology to alter starch structures for the production of resistant starch (RS). However, the underlying regulation mechanism of the multiscale structure and digestive properties of starch by dual hydrothermal synergistic treatment remains unclear. To solve this problem, A- and B-type wheat starch granules (AWS and BWS) were separated and subjected to toughening and heat-moisture synergistic treatment (THT) with various moisture content (10 %, 15 %, 20 %, 25 %).
View Article and Find Full Text PDFMar Pollut Bull
January 2025
Environmental Research Institute, University of the Highlands and Islands, Thurso, UK.
We evaluate global microplastics particle density distribution using field data from 1972 to 2022, made available by the NOAA (National Oceanic and Atmospheric Administration) NCEI (National Centers for Environmental Information) global marine microplastics database. We resampled the measured microplastics density data from NOAA NCEI into a regularly spaced 1° × 1° grid and applied ordinary block kriging on a 1° × 1° mask map of the global oceans to spatially interpolate the gridded data. Climate data were retrieved from the Climate Data Store of the Copernicus Climate Change Service.
View Article and Find Full Text PDFEnviron Sci Technol
January 2025
Xi'an AMS Center, State Key Laboratory of Loess Science, Shaanxi Key Laboratory of Accelerator Mass Spectrometry Technology and Application, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an 710061, P. R. China.
There has been a sharp rise in the extent and scale of human activities since the mid-20th century, termed the "Great Acceleration", and nuclear activities are one of the defining technological processes for this period. Pu released by atmospheric nuclear weapons tests provides an ideal chronostratigraphic marker for labeling this change due to its global fallout feature, temporal mutation, and long half-lives. However, the accumulation dynamics of plutonium from atmospheric deposition to preservation in the sediment is still controversial.
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