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Green synthesis of silver iodide nanoparticles (AgI-NPs) using carboxymethyl β-glucan from Kluyveromyces marxianus M59 was conducted to produce environmentally friendly and stable nanomaterials. The AgI-NPs had particle sizes ranging from 29 to 100 nm, exhibited a crystalline structure confirmed by X-ray diffraction, and and showed a characteristic absorption peak at 450 nm. Biological evaluations revealed low antibacterial activity against Listeria monocytogenes (maximum inhibition zone: 1.70 mm at 5 mg/mL), strong antibiofilm activity (66.9% reduction at 5 mg/mL), and significant antioxidant capacity, with the highest 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity of 58.9% at 5 mg/mL. Cytotoxicity assays showed selective toxicity toward A549 lung cancer cells (IC50: 23.95 µg/mL at 24 h and 19.13 µg/mL at 48 h) compared to normal L929 fibroblasts (IC50: 130.37 µg/mL at 24 h and 73.69 µg/mL at 48 h). These findings highlight the multifunctional potential of AgI-NPs, emphasizing their antibiofilm, antioxidant, and anticancer activities, and provide a foundation for further investigations into their molecular mechanisms and sustainable applications.

AgI and ZnI2 nanocrystals are key components for AgI-ZnI2-SiO2 hybrid powders (HPs), which could be potentially important for atmospheric artificial precipitation technology. HPs were created by the “Hydrothermal template cocondensation” method (“HTC” method). Mesoporous silica dioxide (MCM48, MCM41, SBA15, SBA16), silver iodides, and zinc iodides were simultaneously grown under specific conditions. The influence of silica dioxide on AgI and ZnI2 nanocrystals characteristics (phase, size, and thermal stability) were studied using various physicochemical analysis methods. In addition to crystal features, some structural and textural properties of the AgI-ZnI2-SiO2 hybrid as an individual agglomerate and its morphology were determined. This showed that nanocrystal features were dependent on synthesis condition. The influence of the nature of the reagent, which is pH-forming, was manifested at the initial stage of the process, and the morphology of the silica dioxide matrix controlled the crystal properties during the post-synthesis phase. It was established that the thermal stability of AgI and ZnI2 nanocrystals increased due to the protective shielding function of that SiO2 matrix.

Part I of this paper presents the results from a series of plume-tracing flights over the Medicine Bow and Sierra Madre Ranges in south-central Wyoming. These flights, conducted during February and early March of 2011, were part of the Wyoming Weather Modification Pilot Project. Effective targeting of ground-based silver iodide plumes to supercooled clouds has long been a problem for winter orographic cloud-seeding projects. Surface-based ice nucleus (IN) measurements made at a fixed location near the Medicine Bow Range target area had confirmed the effective transport of IN plumes in many cases, but not all. Airborne plume tracing, undertaken to further illuminate the processes involved, provided additional insight into the plume behavior while providing physical measurements that were later compared with large-eddy-simulation modeling (Part II). It was found that the plumes were most often encountered along the flight paths set out in the experimental designs and, in the absence of convection, appear to be mostly confined to the lowest 600 m above the highest terrain. All passes above 600 m above ground level revealed IN concentrations greater than background levels, however. An estimate of IN flux measured over the Medicine Bow Range was approximately 85% of that produced by the five ground-based IN generators active at the time.

The conditions needed to form a complex of polyacrylic acid with silver ions (Ag + ) in aqueous solution were investigated. Ag + formed a complex with the dissociated carboxyl units of polyacrylic acid. It was found that the complex of polyacrylic acid with silver ions formed by disproportionation of Ag + on polyacrylic acid macromolecules. When Ag + and H + coexisted in solution, the negatively charged carboxyl groups of polyacrylic acid preferentially interacted with H + . The size characteristics of the polyacrylic acid macromolecular coils and polyacrylic acid–silver complex and their volume ratio were investigated in solution. Silver iodide nanoparticles were synthesized under conditions where Ag + formed a complex with polyacrylic acid, and when they were dispersed in bulk solution. The products were characterized by transmission electronic microscopy. The presence of the polyelectrolyte–silver complex as a precursor yielded silver iodide nanoparticles of smaller size and narrower size distribution, than those formed in the absence of the polyelectrolyte–silver complex.

Proliferation of nanoparticles (NPs) as aqueous pollutants is a matter of growing concern today. The aggregation kinetics of colloidal bare silver (Ag, 20.5 nm) and silver iodide (AgI, 15.3 nm) NPs were investigated during ozone/ultraviolet (O 3 /UV) oxidation. Dynamic light scattering was applied to monitor the aggregation of NPs, and the z -average of treated samples was considered aggregate diameter. The effect of temperature, pH, and initial concentration of NPs was investigated on the aggregation rate constant and stability ratio. At a short oxidation period of approximately 1 min, the lower stability ratio was achieved for Ag NPs (< 50) than AgI NPs (> 100). Under acidic conditions, the negative surface charge of both NPs was neutralized that resulted in faster aggregation. In contrast, the impact of temperature and initial concentration of NPs on the aggregation rate was different for both NPs, which was due to the type of O 3 /UV interaction with the surface of NPs and the thickness of the electrical double layer surrounding the NPs. The aggregation behavior of Ag NPs obeyed diffusion-limited regime, while an intermediate regime between diffusion- and reaction-limited was observed for AgI NP aggregation. The resulting aggregate morphologies showed that the clusters were ramified for Ag and compressed for AgI NPs. Applying the O 3 /UV oxidation process for water treatment purposes leads to a significant reduction in aggregation time for inherently unstable Ag and stable AgI toxic NPs from several hours or days to several minutes. Graphical Abstract

Considering sustainable development factors such as element abundance, cost, environmental friendliness, and stability, the research and development of novel inorganic non‐lead perovskites are very significant. Copper‐silver‐bismuth iodide (CABI) is a promising solar cell material with halide perovskite genes, possessing eco‐friendly, element‐rich, and cost‐effective characteristics. The fabrication of high‐quality CABI films with tailored compositions still poses a substantial hurdle. We developed a CuAgBi2I8 material that effectively reduced the bandgap to 1.69 eV by optimizing Bi distribution to create an environment conducive to in‐situ redox reactions of Bi with I2, Cu, and Ag via vapor‐phase synthesis. This strategy proved highly effective in synthesizing high‐quality CuAgBi2I8 compound, accompanied by significant improvements in film quality, including enhanced crystallinity, minimized defects, and reduced non‐radiative recombination. The crystal structure of CuAgBi2I8 and mechanisms of elemental reactions and diffusion are discussed. Devices featuring the structure FTO/c‐TiO2/m‐TiO2/CuAgBi2I8/CuI/Spiro‐OMeTAD/carbon achieved a champion efficiency of 3.21%, the highest for CABI solar cells. This work provides a novel idea and approach to governing the gas–solid element diffusion and reaction for high‐quality CABI and related halide perovskite films. CuAgBi2I8 of high quality, featuring a resolved cubic close packed crystal structure and a direct bandgap of 1.69 eV, was in situ synthesized by tailoring the distribution of Bi in vapor‐phase redox reactions. Employing this novel approach, the efficiency of CuAgBi2I8 solar cells reached 3.21%, which is the highest reported to date.

Throughout the western United States and other semiarid mountainous regions across the globe, water supplies are fed primarily through the melting of snowpack. Growing populations place higher demands on water, while warmer winters and earlier springs reduce its supply. Water managers are tantalized by the prospect of cloud seeding as a way to increase winter snowfall, thereby shifting the balance between water supply and demand. Little direct scientific evidence exists that confirms even the basic physical hypothesis upon which cloud seeding relies. The intent of glaciogenic seeding of orographic clouds is to introduce aerosol into a cloud to alter the natural development of cloud particles and enhance wintertime precipitation in a targeted region. The hypothesized chain of events begins with the introduction of silver iodide aerosol into cloud regions containing supercooled liquid water, leading to the nucleation of ice crystals, followed by ice particle growth to sizes sufficiently large such that snow falls to the ground. Despite numerous experiments spanning several decades, no direct observations of this process exist. Here, measurements from radars and aircraft-mounted cloud physics probes are presented that together show the initiation, growth, and fallout to the mountain surface of ice crystals resulting from glaciogenic seeding. These data, by themselves, do not address the question of cloud seeding efficacy, but rather form a critical set of observations necessary for such investigations. These observations are unambiguous and provide details of the physical chain of events following the introduction of glaciogenic cloud seeding aerosol into supercooled liquid orographic clouds.

Cloud seeding is considered a practical but unproved method to enhance precipitation or suppress hail, due to insufficient knowledge of ice formation and evolution after seeding clouds with ice nucleating particles. This study investigates the size effects on the immersion freezing of aerosol produced from commercial silver iodide (AgI) containing flares at mixed‐phase cloud temperatures from 243 to 267 K. Flare‐generated aerosol exhibited comparable ice nucleation ability (INA) to pure AgI particles in the size range of 200 and 400 nm. Non‐AgI impurities reduced the INA of flare‐generated particles ≤90 nm, which is lower than pure AgI particles ≤40 nm. The critical mass ice‐active site density of the generated aerosols (critical‐nm) was derived, indicating the minimum mass of AgI particles required for efficient ice nucleation. The new parameterization to predict critical‐nm can serve as a reference to optimize the effectiveness of cloud‐seeding materials for practical use. Plain Language Summary Ice‐forming aerosol is commonly added to clouds, expecting precipitation enhancement via promotion of ice production. In this work, silver iodide (AgI) containing aerosol was generated from commercial cloud‐seeding products under different wind speed conditions. Its ice‐forming ability was studied at mixed‐phase cloud temperatures. The lower size limit for effective ice‐forming ability of the cloud‐seeding particles (90 nm) is higher than that of pure AgI particles (40 nm). The non‐AgI components produced by cloud‐seeding products are hypothesized to decrease the ice‐forming ability of smaller particles, as the mass fraction of ice‐nucleating AgI decreases. To estimate the minimum mass of AgI in a particle required for efficient ice nucleation under cloud‐seeding relevant conditions, we derived the critical ice‐activated mass fraction of the generated aerosols. These findings provide valuable insights into the optimization of cloud‐seeding practices for enhanced precipitation. Key Points Silver iodide (AgI) containing cloud‐seeding aerosols exhibit comparable ice‐forming abilities to pure AgI at sizes of 200 and 400 nm Non‐AgI impurities produced from flare burning decrease the ice nucleation ability of particles smaller than 90 nm A new parameterization is presented to estimate the minimum mass of AgI particles required to maximize glaciogenic seeding

Pathogenic microorganisms and dyes are the main sources of water pollution. These pollutants are extremely hazardous and may harm aquatic life and human health. As a result, removing these pollutants is critical in assessing contamination risks and mitigating potential health hazards. To effectively remove pathogenic microorganisms and dyes from wastewater, an efficient multi-functional material was designed based on AgI, Ag NPs, and Ag NPs@AgI immobilized on bamboo fabrics as a support substrate. The water disinfection aptitude of the modified bamboo fabrics was evaluated against different microorganisms. The results showed that the Ag NPs@AgI@bamboo showed excellent antibacterial activity against S. aureus (88%) and E. coli (90%) as well as perfect antifungal activity against C. albicans (82%). Methylene blue (MB) was used as a pollutant model to test the catalytic and photocatalytic activity of modified bamboo fabrics. The results show that Ag NPs@AgI@bamboo was highly efficient in removing the MB dye via reduction (90%) after 60 min or photodegradation (93%) after 6 h of UV light irradiation. The pseudo-first-order kinetic study shows that Ag NPs@AgI@bamboo possessed outstanding catalytic reduction and photocatalytic degradation activities toward MB.

AgI is one of the best-investigated ice-nucleating substances. It has relevance for the atmosphere since it is used for glaciogenic cloud seeding. Theoretical and experimental studies over the last 60 years provide a complex picture of silver iodide as an ice-nucleating agent with conflicting and inconsistent results. This review compares experimental ice nucleation studies in order to analyze the factors that influence the ice nucleation ability of AgI. The following picture emerges from this analysis: the ice nucleation ability of AgI seems to be enhanced when the AgI particle is on the surface of a droplet, which is indeed the position that a particle takes when it can freely move in a droplet. The ice nucleation by particles with surfaces exposed to air depends on water adsorption. AgI surfaces seem to be most efficient at nucleating ice when they are exposed to relative humidity at or even above water saturation. For AgI particles that are completely immersed in water, the freezing temperature increases with increasing AgI surface area. Higher threshold freezing temperatures seem to correlate with improved lattice matches as can be seen for AgI–AgCl solid solutions and 3AgI·NH4I·6H2O, which have slightly better lattice matches with ice than AgI and also higher threshold freezing temperatures. However, the effect of a good lattice match is annihilated when the surfaces have charges. Also, the ice nucleation ability seems to decrease during dissolution of AgI particles. This introduces an additional history and time dependence for ice nucleation in cloud chambers with short residence times.