Plastic-derived materials have become persistent ecological contaminants since their industrial introduction in the mid-20th century. In that context, nanoplastics (NPs) have been discussed as an emerging, ubiquitous plastic-derived pollutant with unique physicochemical properties. Their increased surface-to-volume ratio enhances their adsorption, reactivity, and cellular penetration, driving distinct ecotoxicological behaviours when compared to larger plastic particles. In this study, we identify direct NP-induced DNA mutagenesis in Salmonella enterica. Using a combination of biochemical and biophysical studies, as well as mutagenicity assays, we show that functionalized and non-functionalized NPs induce mutations, depending on the energy state of the bacteria and the NP surface chemistry, by disrupting base-stacking and base-pairing - an intrinsic property of all DNA. Whole-genome analysis revealed that exposure to NPs alters the mutational spectrum and mutation frequency, while circular dichroism spectroscopy demonstrated NP-induced helical flipping from B- to non-B DNA conformations. These motifs preferentially adopt Z-like or A/B-hybrid structures associated with localized mutagenesis through DNA destabilization. Our combined data reveal that NP-mediated mutagenesis is based on surface chemistry and DNA topology, linking surface chemistry on nanoplastics to genomic instability in vivo. The proposed mechanism redefines the current perspective on nanoplastic toxicity shifting it from an indirect stress to direct macromolecular interactions. This mechanism provides a molecular framework for understanding how NPs could impose mutation bias, environmental selection pressure, and potential genomic risk across biological systems.

Polyolefins are the main building blocks for consumer products. Here, chitosan, a biopolymer that can be derived from abundant fishery waste, is shaped as a microspheroidal support using spray drying to facilitate ethylene polymerization. Definitive screening design was used to optimize synthesis steps efficiently. The generated catalysts were tested for ethylene polymerization, and the effects of MAO loading and generated porosity were assessed using a variety of micro- and spectroscopic techniques.

Studies on the catalyst restructuring during the electrochemical CO2 reduction reaction (eCO2RR) are limited and mostly focused on Cu (001) or (111) single crystals as model systems. A comprehensive overview of the dynamic restructuring of different Cu facets is lacking. Here, we first reveal the facet-dependent restructuring of polycrystalline Cu electrodes through electron backscatter diffraction (EBSD) and identical grain atomic force microscopy (AFM). This combined analysis provides new insights into the evolution of crystal domains (EBSD) and surface topography (AFM) at varying conditions (e.g., applied potential and oxidative-reductive pulses). The statistic slope distribution function was applied to study the restructuring asymmetry on five Cu facets (i.e., planar vs. atom stepped). We find that planar Cu (001) shows a square-shaped morphology after eCO2RR with 4-fold asymmetry restructuring behavior, while triangular features dominate on Cu (111), evidenced by surface changes with 3-fold asymmetry. 2-fold restructuring is observed for Cu (114), (212), and (124) with atom steps, resulting in forming elongated structures. Therefore, the surface restructuring is dominated by the asymmetry of its facet lattice structure (i.e., planar vs. atom-stepped). This work underscores the potential of combining techniques to elucidate the relationship between surface restructuring and crystal facets on different length scales.

BackgroundMicro- and nanoplastics (MNPs) are emerging pollutants of concern with ubiquitous presence in global ecosystems. MNPs pose potential implications for human health; however, the health impacts of MNP exposures are not yet understood. Recent evidence suggests that MNPs can cross the placental barrier, underlying the urgent need to understand their impact on reproductive health and development. ObjectiveThe Actionable eUropean ROadmap for early-life health Risk Assessment of micro- and nanoplastics (AURORA) project will investigate MNP exposures and their biological and health effects during pregnancy and early life, which are critical periods due to heightened vulnerability to environmental stressors. The AURORA project will enhance exposure assessment capabilities for measuring MNPs, MNP-associated chemicals, and plastic additives in human tissues, including placenta and blood. MethodsIn this interdisciplinary project, we will advance methods for in-depth characterization and scalable chemical analytical strategies, enabling high-resolution and large-scale toxicological, exposure assessment, and epidemiological studies. The AURORA project performs observational studies to investigate determinants and health impacts of MNPs by including 800 mother-child pairs from 2 existing birth cohorts and 110 women of reproductive age from a newly established cohort. This will be complemented by toxicological studies using a tiered-testing approach and epidemiological investigations to evaluate associations between maternal and prenatal MNP exposures and health perturbations, such as placental function, immune-inflammatory responses, oxidative stress, accelerated aging, endocrine disruption, and child growth and development. The ultimate goal of the AURORA project is to create an MNP risk assessment framework and identify the remaining knowledge gaps and priorities needed to comprehensively assess the impact of MNPs on early-life health. ResultsIn the first 3 years of this 5-year project (2021-2026), progress was made toward all objectives. This includes completion of recruitment and data collection for new and existing cohorts, development of analytical methodological protocols, and initiation of the toxicological tiered assessments. As of September 2024, data analysis is ongoing and results are expected to be published starting in 2025. ConclusionsAs plastic pollution increases globally, it is imperative to understand the impact of MNPs on human health, particularly during vulnerable developmental stages such as early life. The contributions of the AURORA project will inform future risk assessment. International Registered Report Identifier (IRRID)DERR1-10.2196/63176

Although biomass-based alternatives for the manufacturing of bioplastic films are an important aspect of a more sustainable future, their physicochemical properties need to be able to compete with the existing market to establish them as a viable alternative. One important factor that is often neglected is the long-term stability of renewables-based functional materials, as they should neither degrade after a day or week, nor last forever. One material showing high potential in this regard, also due to its intrinsic biodegradability and antibacterial properties, is chitosan, which can form stable, self-standing films. We previously showed that green additives introduce a broad tunability of the chitosan-based material properties. In this work, we investigate the long-term stability and related degradation processes of chitosan-based bioplastics by assessing their physicochemical properties over 400 days. It was found that the film properties change similarly for samples stored in the fridge (4 °C, dark) as at ambient conditions (20 °C, light/dark cycles of the day). Additives with high vapor pressure, such as glycerol, evaporate and degrade, causing both brittleness and discoloration. In contrast, films with the addition of crosslinking additives, such as citric acid, show high stability also over a long time, bearing great preconditions for practical applications. This knowledge serves as a stepping-stone to utilizing chitosan as an alternative material for renewable-resourced bioplastic products.

Although plastic pollution and exposure to plastic-related compounds have received worldwide attention, health risks associated with micro- and nanoplastics (MNPs) are largely unknown. Emerging evidence suggests MNPs are present in human biofluids and tissue, including blood, breast milk, stool, lung tissue, and placenta; however, exposure assessment is limited and the extent of human exposure to MNPs is not well known. While there is a critical need to establish robust and scalable biomonitoring strategies to assess human exposure to MNPs and plastic-related chemicals, over 10,000 chemicals have been linked to plastic manufacturing with no existing standardized approaches to account for even a fraction of these exposures. This review provides an overview of the status of methods for measuring MNPs and associated plastic-related chemicals in humans, with a focus on approaches that could be adapted for population-wide biomonitoring and integration with biological response measures to develop hypotheses on potential health effects of plastic exposures. We also examine the exposure risks associated with the widespread use of chemical additives in plastics. Despite advancements in analytical techniques, there remains a pressing need for standardized measurement protocols and untargeted, high-throughput analysis methods to enable comprehensive MNP biomonitoring to identify key MNP exposures in human populations. This review aims to merge insights into the toxicological effects of MNPs and plastic additives with an evaluation of analytical challenges, advocating for enhanced research methods to fully assess, understand, and mitigate the public health implications of MNPs.

The strong metal–support interaction (SMSI) is a phenomenon observed in supported metal catalyst systems in which reducible metal oxide supports can form overlayers over the surface of active metal nanoparticles (NPs) under a hydrogen (H2) environment at elevated temperatures. SMSI has been shown to affect catalyst performance in many reactions by changing the type and number of active sites on the catalyst surface. Laboratory methods for the analysis of SMSI at the nanoparticle-ensemble level are lacking and mostly based on indirect evidence, such as gas chemisorption. Here, we demonstrate the possibility to detect and characterize SMSIs in Co/TiO x model catalysts using the laboratory X-ray standing wave (XSW) technique for a large ensemble of NPs at the bulk scale. We designed a thermally stable MoN x /SiN x periodic multilayer to retain XSW generation after reduction with H2 gas at 600°C. The model catalyst system was synthesized here by deposition of a thin TiO x layer on top of the periodic multilayer, followed by Co NP deposition via spare ablation. A partial encapsulation of Co NPs by TiO x was identified by analyzing the change in Ti atomic distribution. This novel methodological approach can be extended to observe surface restructuring of model catalysts in situ at high temperature (up to 1000°C) and pressure (≤3 mbar), and can also be relevant for fundamental studies in the thermal stability of membranes, as well as metallurgy.

Micro- and nanoplastics (MNPs) are ubiquitous environmental pollutants representing a concern for human health. MNPs have been detected in human placentas, indicating that during pregnancy maternal exposure may lead to placental transfer and foetal exposure, with potential for adverse effects on early-life development. However, a comprehensive risk assessment (RA) framework, specific to early-life is lacking. Here, we propose a novel roadmap to assist the development of an early-life health RA of MNPs. This roadmap is designed based on established chemical, mixture, particle, and MNP assessment strategies aligned with standard RA components (problem formulation, hazard identification, hazard characterisation, exposure assessment, risk characterisation). We systematically work through these stages to identify what is needed to progress a RA for the early-life impacts of MNPs, including what information is missing, and what may be used in the interim. While challenges such as complex physicochemical properties of MNPs, limited toxicity data at relevant exposure levels, and uncertainties related to characterising complex exposures have been described elsewhere, our work discusses how these challenges specifically impact early-life stages such as the significance of MNP presence in biological samples and factors influencing bioaccumulation and placental transfer. Additionally, we introduce the development of new technology readiness levels for methods used in the detection of MNPs in complex matrices. Importantly, this review integrates a broad scope of relevant information into one comprehensive document, providing a unified resource. We highlight specific requirements and areas for targeted research, including the development of dose-response relationships specific to early-life stages and novel strategies for assessing bioaccumulation and placental transfer of MNPs. By addressing these gaps, our roadmap aims to advance the development of a robust framework, ultimately enhancing the understanding and mitigation of risks associated with early-life exposure to MNPs.

Turning waste into valuable products is one of the main challenges of the chemical industry. In this work, chitosan (CS), an abundant, low-cost, and non-toxic biopolymer derived from chitin, was reshaped into beads of ~3 mm. Their suitability as a support material for active phase catalyst materials was tested for a zirconium-based Metal-Organic Framework (MOF) with incorporated Pt, namely UiO-67-Pt. Its incorporation was investigated via two procedures: a one-pot synthesis (OPS) and a post-synthetic functionalization (PSF) synthesis method. Scanning electron microscopy (SEM) images show good UiO-67-Pt dispersion throughout the CS beads for the one-pot synthesized material (UiO-67-Pt-OPS@CS). However, this uniform dispersion was not observed for the post-synthetically functionalized material (UiO-67-Pt-PSF@CS). The success of the implementation of UiO-67-Pt was evaluated with ultraviolet-visible and infrared spectroscopy for both composite materials. Thermogravimetric analysis (TGA) reveals higher thermal stabilities for UiO-67-Pt-OPS@CS composite beads in comparison to pure CS beads, but not for UiO-67-Pt-PSF@CS. The study provides valuable insights into the potential of chitosan as a green, bead-shaped support material for MOFs, offering flexibility in their incorporation through different synthesis routes. It further contributes to the broader goal of the sustainable and eco-friendly design of a new generation of catalysts made from waste materials, which will be the topic of future studies.

Spectroscopy on metal–organic framework (MOF) films and the molecular phenomena associated to them is mostly limited to grazing incidence methods. To allow for transmission‐based characterization and highlight the applicability of MOFs on transparent substrates, UiO‐67, UU‐1, and ZIF‐8 MOFs are synthesized on CaF 2 windows. It is revealed that the growth of the UiO‐67 MOF follows a Volmer–Weber mechanism using scanning electron microscopy (SEM). This growth is assisted by growing seeds in solution, which anchor on the film and become part of the intergrown film itself. UU‐1, a copper‐based MOF, is formed after spin coating the Cu‐BTC precursors, showing its characteristic fiber‐like morphology and resulting inter‐fiber macroporosity. ZIF‐8 is formed using a “flash”‐synthesis, and it is shown that this approach resembles a Volmer–Weber growth mode as well. Last, CO probe molecule adsorption FT‐IR spectroscopy is utilized to study the effect of methanol exposure. UiO‐67 becomes inaccessible toward CO, due to the formation of methoxy species, whereas UU‐1 undergoes a topotactic transformation to HKUST‐1. ZIF‐8 is the most stable as methanol only removes impurities from the framework. This approach opens the venue for other film materials to be studied in situ synthesis, sorption, or catalysis using transmission‐based spectroscopy.

Metal nanoparticles (NPs) encapsulated within Zr-based UiO-67 metal-organic frameworks (MOFs) have increased selectivity toward methanol in CO2 reduction reactions. However, the reduction mechanism in these systems remains unclear. We built upon prior work examining the synergistic interaction between Pt nanoparticles and Zr6O4(OH)(4) clusters in UiO-67 and developed five distinct models representing the possible active sites in the Pt subset of MOF system. Density functional theory (DFT) calculations were employed to elucidate the CO2 reduction mechanism toward methanol, methane, and CO formation. Our findings support previous evidence showing that the interface between the Zr6O4(OH)(4) cluster and platinum nanoparticles plays a crucial role in the activation of CO2 to CO or formate intermediates and its further reduction to methane and methanol, respectively. Furthermore, we found different CO2 hydrogenation mechanisms for interfaces involving Pt-flat terraces and Pt-edges. On Pt terraces and interfaces near Pt terraces, the reaction goes via CO, which can be desorbed as CO(g) or be further reduced to methane. On interfaces near Pt-edges, the reaction proceeds via formate and preferably forms methanol over methane. We designed experiments to validate our computational insights involving large and small Pt nanoparticles interacting with Zr6O4(OH)(4) clusters. These experiments showed that only CO and methanol were formed when smaller nanoparticles were present. Notably, methane formed with CO and methanol in the presence of larger nanoparticles, highlighting the need for flat platinum surfaces at the interfaces for methane formation. We could also associate the IR signals corresponding to CO and bidentate formate with platinum nanoparticles and Zr6O4(OH)(4) clusters, respectively. Theoretical models and experimental data provided us with insights into the complexity of the reaction mechanism and emphasized the significance of understanding both the individual components of the catalytic system and their interactions in enhancing catalytic activity

Catalyst fragmentation behavior and polymer particle morphology evolution are two critical factors for obtaining high-quality polyethylene (PE). However, for metal-organic frameworks (MOFs), emerging catalysts for ethylene polymerization, systematic studies related to their fragmentation behavior and PE morphology evolution from early stages are still missing. Here, we provide a strategy by using MOF thin films as 2D model catalysts to elucidate PE growth and fragmentation behavior of MOFs in ethylene polymerization. The morphological evolution and particle expansion processes of the formed PE are observed as a function of polymerization time, which is linked to the morphology of MOFs and the crystallinity of produced PE. Moreover, the fragmentation process is visualized, revealing a combination of layer-by-layer and bisectioning fragmentation modes at very early stages and a dominant bisectioning fragmentation later. The desirable fragmentation behavior of MIL-101 (Cr) and PE growth and morphology indicate the potential of MOFs in ethylene polymerization.

To switch to alternatives for fossil-fuel-based polymer materials, renewable raw materials from green resources should be utilized. Chitosan is such a material that is a strong, but workable derivative from chitin, obtained from crustaceans. However, various applications ask for specific plastic properties, such as certain flexibility, hardness and transparency. With different additives, also obtainable from green resources, chitosan-based composites in the form of self-supporting films, ranging from very hard and brittle to soft and flexible were successfully produced. The additives turned out to belong to one of three categories, namely linear, non-linear, or crosslinking additives. The non-linear additives could only be taken up to a certain relative amount, whereas the uptake of linear additives was not limited within the range of our experiments. Additives with multiple functional groups tend to crosslink chitosan even at room temperature in an acidic medium. Finally, it was shown that dissolving the chitosan in acetic acid and subsequently drying the matrix as a film results in reacetylation compared to the starting chitosan source, resulting in a harder material. With these findings, it is possible to tune the properties of chitosan-based polymer materials, making a big step towards application of this renewable polymer within consumer goods.

Nanoplastics (NPs), small (<1 μm) polymer particles formed from bulk plastics, are a potential threat to human health and the environment. Orders of magnitude smaller than microplastics (MPs), they might behave differently due to their larger surface area and small size, which allows them to diffuse through organic barriers. However, detecting NPs in the environment and organic matrices has proven to be difficult, as their chemical nature is similar to these matrices. Furthermore, as their size is smaller than the (spatial) detection limit of common analytical tools, they are hard to find and quantify. We highlight different micro-spectroscopic techniques utilized for NP detection and argue that an analysis procedure should involve both particle imaging and correlative or direct chemical characterization of the same particles or samples. Finally, we highlight methods that can do both simultaneously, but with the downside that large particle numbers and statistics cannot be obtained.

Angewandte Chemie International EditionVolume 61, Issue 5 e202280511 Graphical AbstractFree Access Graphical Abstract: Angew. Chem. Int. Ed. 5/2022 First published: 18 January 2022 https://doi.org/10.1002/anie.202280511Citations: 1AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Volume61, Issue5January 26, 2022e202280511 RelatedInformation

Polyolefin catalysts are characterized by their hierarchically complex nature, which complicates studies on the interplay between the catalyst and formed polymer phases. Here, the missing link in the morphology gap between planar model systems and industrially relevant spherical catalyst particles is introduced through the use of a spherical cap Ziegler-type catalyst model system for the polymerization of ethylene. More specifically, a moisture-stable LaOCl framework with enhanced imaging contrast has been designed to support the TiCl 4 pre-active site, which could mimic the behaviour of the highly hygroscopic and industrially used MgCl 2 framework. As a function of polymerization time, the fragmentation behaviour of the LaOCl framework changed from a mixture of the shrinking core (i.e., peeling off small polyethylene fragments at the surface) and continuous bisection (i.e., internal cleavage of the framework) into dominantly a continuous bisection model, which is linked to the evolution of the estimated polyethylene volume and the fraction of crystalline polyethylene formed. The combination of the spherical cap model system and the used advanced micro-spectroscopy toolbox, opens the route for high-throughput screening of catalyst functions with industrially relevant morphologies on the nano-scale.