Bio-based and bio-degradable plastics such as polybutylene succinate (PBS) have the potential to become sustainable alternatives to petrochemical-based plastics. Polybutylene succinate can be produced from bio-based succinic acid and 1,4-butanediol using first-generation (1G) or secondgeneration (2G) sugars. A cradle-to-grave environmental assessment was performed for PBS products in Europe to investigate the non-renewable energy use (NREU) and greenhouse gas (GHG) impacts. The products investigated are single-use trays and agricultural film, with incineration, industrial composting and degradation on agricultural land as end-of-life scenarios. Both end products manufactured from fully bio-based PBS and from partly bio-based PBS (made from bio-based succinic acid and fossil fuel-based 1,4 butanediol) were analysed. We examine corn (1G) as well as corn stover, wheat straw, miscanthus and hardwood as 2G feedstocks. For the cradle-to-grave system, 1G fully bio-based PBS plastic products were found to have environmental impacts comparable with their petrochemical incumbents, while 2G fully bio-based PBS plastic products allow to reduce NREU and GHG by around one third under the condition of avoidance of concentration of sugars and energy integration of the pretreatment process with monomer production. Without energy integration and with concentration of Modeling and Analysis: NREU and GHG balance of succinic acid-based PBS products made from lignocellulosic biomass MK Patel et al.sugars (i.e., separate production), the impacts of 2G fully bio-based PBS products are approximately 15-20% lower than those of 1G fully bio-based PBS products. The environmental analysis of PBS products supports the value proposition related to PBS products while also pointing out areas requiring further research and development.

Cadmium-containing quantum dot (QD) nanoparticles are integrated into electronic displays because of their ability to efficiently convert colors. There are conflicting accounts as to whether these particles present a hazard to the environment, as they have been studied either as (1) embedded QDs in display screen films or (2) as model QDs with small, hydrophilic ligands. Both approaches have limitations that we addressed by synthesizing QDs featuring the core–shell structure and the thick polymer coating present in commercial devices to probe the dissolution of QDs in response to two environmental factors (pH and dissolved oxygen) over 1 day and 6 months. Results show that QDs were chemically stable at circumneutral pH (0% Cd dissolution after 6 months), but low pH initiated rapid dissolution under both aerobic and anaerobic conditions (up to 100% Cd dissolution after 6 months). In addition to the presence of a capping polymer, the QD shell structure led to more chemically stable nanoparticles compared to nonshelled QDs, as the presence of ZnS shells decreased Cd dissolution by 75%. The dense aggregation of QDs into structures of ∼100 nm diameter over time was observed as well, which could lead to decreased bioavailability. To test this, we used liver cells to compare the toxicity of pristine QDs to those subjected to acid dissolution. Our results reveal that low-pH-exposed QDs separated from dissolved ions are less toxic than pristine QDs (half maximal inhibitory concentration, IC50, of 290 and 150 mg/L, respectively) and suggest a key role of dissolved ions and capping polymers for QD toxicity. These findings highlight the use of a commercially relevant nanoparticle structure to demonstrate fate and toxicity.

Thanks to an accelerating voltage in the range of 30 to 300 kV, an electron beam can pass through a thin specimen and form an image with sub-Ångström spatial resolution. When impinging on a thin crystalline specimen, the fast electrons scatter and diffract. The transmitted electron pattern depends on the local thickness, density, crystal structure, and chemical nature of the sample. The transmission electron microscope (TEM) shapes the incoming electron beam using magnetic lenses onto the specimen and, using a different set of magnetic lenses, focuses the projected electron pattern to a camera. The final image magnification and contrast are controlled using the parameters from the electron gun, apertures positioned along the optical path, and magnetic lenses. With this combination of lens and aperture, TEM offers two possible modes of operation: (a) imaging, including high-resolution electron microscopy to reveal the size, shape, crystallinity, and morphology of materials; and (b) diffraction, to determine the crystalline nature of a region of interest of a thin film, particle, or collection of particles. Chemical engineers have taken advantage of both of these modes to analyze their samples and inform their research. A bibliometric study conducted using the WoS database places TEM as one of the preferred microscopy tools to study advanced materials such as thin films, nanomaterials, and composites used in particular for the development of applications related to energy storage and conversion (catalysis, photocatalysis, electrochemistry, and batteries) and environment (adsorption, waste-water treatment, and filtration). K E Y W O R D Selectron diffraction, interfaces, metrology, nanomaterials, transmission electron microscopy

Light emissive organics and inorganic nanoparticles are substance classes competing for applications in displays in the form of organic light emitting diodes (OLEDs) and quantum LEDs (QLEDs), respectively. Upcoming substance classes, perovskites and Q-OLED displays, also contain novel nanomaterials and organics for these applications. However, the safety and viability of these emissive substances is difficult to assess quickly and broadly because of their complexity, their inherently different structures, and their rapid evolution in the literature. We propose the use of an alternatives assessment focusing on hazard, cost, and performance, so as to compare these possible substitute substances, with incombent cadmium-containing quantum dots. This assessment type is used in industry and government to inform chemical substitution. It uses available information, while pointing out important data gaps for decision-making. The cost assessment highlights competitiveness of OLEDs because of the low amounts needed in their application for display, but performance assessments do not identify a preferred alternative. The hazard results indicate that there is no clear alternative either, with each novel nanomaterial or organic substance having different negative aspects. These results identify the need for a low-hazard highperforming alternative substance, and the assessment provides a framework for researchers to evaluate their own novel substances.

Chemicals and materials with essential and functional uses are central to economic and social well-being. However, the development and application of such items may be challenged when sustainability factors are considered. These are further challenged by disciplinary gaps and concerns over reproducible and responsible research. Here, we detail a checklist for early career researchers on how “to do” research on chemicals, materials, processes, and products in a manner that is safe and sustainable by design. The checklist contains 20 items that are organized into five interconnected sections: (1) think broad and big, (2) set a clear research foundation, (3) focus on quality and reproducibility, (4) flag safe and sustainability issues, and (5) communicate, listen, and learn. Each item can be self-scored on 0–3 scale. This checklist is meant to be a fast tool to help researchers better “think and do” things so that outcomes and outputs may help address societal grand challenges.

Commercially used quantum dots (QDs) exemplify complex nanomaterials with multiple components, though little is known about the type of interactions between these components in determining the overall toxicity of this material. We synthesized and characterized a functional QD (CdSe/ZnS_P&E) that was identical in structure and composition to a patented and commercially applied QD and the combinations of its components (CdSe, CdSe/ZnS, ZnS, CdSe_P&E, ZnS_P&E, and P&E). Cells exposed to incremental concentrations of these materials were investigated for cell viability and cellular perturbations, contributing to a final common pathway of cell death using high-content screening assays in model human intestinal epithelial cells (HIEC-6). The concentrations that resulted in a loss of 20% cell viability (EC20 values) for each tested component were used for estimating the combination index (CI) to evaluate synergistic or antagonistic effects between the components. Complete QD (core/shell-polymer) showed the highest toxic potential due to synergistic interactions between core and surface functional groups. The cationic polymer coating enhanced cellular uptake of the QD, ensuing lysosome acidification and release of heavy metal ions to the intracellular milieu, and caused oxidative stress and cytotoxicity. Overall, this study advances our understanding of the collective contribution of individual components of a functional QD toward its toxic potential and emphasizes the need to study multilayered nanomaterials in their entirety for hazard characterization.

Cadmium-containing quantum dot nanoparticles (QDs) are integrated into electronic displays because of their ability to efficiently convert colors. There are conflicting accounts as to whether these particles present a hazard to the environment, as they have been chloroform. Samples were run on Bruker AVIIIHD 500 MHz NMR spectrometer.

Light emissive organics and inorganic nanoparticles are substance classes competing for applications in displays in the form of organic LEDs (OLEDs) and quantum LEDs (QLEDs), respectively.Upcoming substance classes (perovskites) and Q-OLED displays also contain novel nanomaterials and organics for these applications. However, the sustainability of these emissive substances is difficult to assess quickly and broadly because of their complexity, their inherently different structures, and their rapid evolution in the literature. We propose the use of an alternatives assessment to compare the hazard, cost, and performance of these competing substances, with a focus on replacing cadmiumcontaining quantum dots. The cost assessment highlights competitiveness of OLEDs because of their low amounts needed per display, but performance assessments do not identify a preferred alternative. The hazard results indicate there is no clear alternative either, with each novel nanomaterial or organic substance having different negative aspects. These results identify the need for a low-hazard highperforming alternative substance, and the assessment provides a framework for researchers to evaluate their own novel substances.