Thermochemical interactions between calcium–magnesium–aluminosilicate (CMAS) glass and an environmental barrier coating of ytterbium disilicate (Yb2Si2O7) and ytterbium monosilicate (Yb2SiO5) were investigated. Top coats were deposited by plasma spray-physical vapor deposition onto silicon carbide substrates. CMAS powder was prepared as a glass and cast into a tape to yield a CMAS loading of ~29 mg/cm2. Samples were heat treated with CMAS at 1300 °C for 1–10 h or at 1400 °C for 1 h in air. Polished specimen cross-sections were characterized using scanning electron microscopy, X-ray diffraction, X-ray energy-dispersive spectroscopy, and transmission electron microscopy to evaluate resulting microstructures, phases, and compositions at CMAS/Yb2Si2O7 interfaces. Coatings exposed at 1300 °C—10 h and 1400 °C—1 h were fully infiltrated and compromised by CMAS. Dissolution of ytterbium silicate into molten CMAS followed by precipitation of cyclosilicate, silicocarnotite, and Yb2Si2O7 at 1300 °C and Yb2Si2O7 at 1400 °C enabled CMAS to effectively infiltrate top coats, rendering the predominantly Yb2Si2O7 coating ineffective at arresting molten CMAS degradation.

Air plasma sprayed thermal barrier coatings (TBCs) are used extensively throughout the gas turbine industry for both power and propulsion. As these engines push to higher temperatures, concern for failure from the melt infiltration of ingested siliceous debris [commonly called calcium–magnesium–alumino-silicate (CMAS)] arises, especially in aeroengines. 7 wt% yttria-stabilized zirconia is particularly prone to melt infiltration and stiffening-induced premature failure. Novel TBC materials such as gadolinium zirconate have been introduced for their infiltration-inhibiting CMAS reactions. Past academic work has utilized ideal laboratory furnace environments to study these phenomena. In this work, the influence of TBC microstructure and chemistry on impinging molten CMAS injected via a burner rig is studied. An observational study of the impacted surfaces and location-specific cross-sectional analysis is reported. Results point toward the critical role of surface microstructure on the mobility and reactivity of the molten CMAS.

Hydrogen is often touted as the fuel of the future, but hydrogen is already an important feedstock for the chemical industry. This review highlights current means for hydrogen production and use, and the importance of progressing R&D along key technologies and policies to drive a cost reduction in renewable hydrogen production and enable the transition of chemical manufacturing toward green hydrogen as a feedstock and fuel.

The chemical industry is at the core of what is considered a modern economy. It provides commodities and important materials, e.g., fertilizers, synthetic textiles, and drug precursors, supporting economies and more broadly our needs. The chemical sector is to become the major driver for oil production by 2030 as it entirely relies on sufficient oil supply. In this respect, renewable hydrogen has an important role to play beyond its use in the transport sector. Hydrogen not only has three times the energy density of natural gas and using hydrogen as a fuel could help decarbonize the entire chemical manufacturing, but also the use of green hydrogen as an essential reactant at the basis of many chemical products could facilitate the convergence toward virtuous circles. Enabling the production of green hydrogen at cost could not only enable new opportunities but also strengthen economies through a localized production and use of hydrogen. Herein, existing technologies for the production of renewable hydrogen including biomass and water electrolysis, and methods for the effective storage of hydrogen are reviewed with an emphasis on the need for mitigation strategies to enable such a transition.

Circular energy transformation of Turkey is essential to strengthen the national energy security. Turkey will benefit from moving towards a circular economy.

Circular economy (CE) has gained much attention due to global warming and climate change which are the most serious issues faced in the world. The United Nations has been struggling with the issues regarding sustainable development by releasing some programs and legislations, which are mostly supported by the EU. The EU's CE including both economy and energy within the scope of low-carbon world is binding for Turkey's energy transition. Among renewables, solar energy preserved the leading capacity expansion with an increase of 98 GW in 2019 in the world. Solar photovoltaic (PV) has become a mainstream energy source among renewables. Since the PV installation has been growing all around the world, several countries especially China, Germany, and the UK pay special attention to a sustainable PV waste management concept. We present the special case of Turkey within the global CE along with the current status of renewable energy in the global energy transformation. Turkey's energy outlook and the EU's targets are reviewed, and the significant role of solar energy in the CE transition process of Turkey has been revealed. We suggested adding a vision of “More Circular” to her new energy policy “More Domestic, More Renewable.”

The three generically accepted stages of glass corrosion are reviewed with focus on final stage termed alteration rate renewal (or resumption) stage when the glass may re-start corroding with the rate similar to that at the initial stage. It is emphasized that physical state and physical changes that occur in the near-surface layers can readily lead to an effective increase of leaching rate which is similar to alteration rate renewals. Experimental data on long-term (during few decades) corrosion of radioactive borosilicate glass K26 designed to immobilize high-sodium operational NPP radioactive waste evidence on resumption-like effects of radionuclides (137,134Cs) leaching. The cause of that was however related not to chemical changes in the leaching environment but rather to physical state of glass surface due to formation of small cracks and new pristine glass areas in contact with water.

Salt cake radioactive waste is a remnant solid salt concentrate after deep evaporation of radioactive evaporator concentrate at WWER NPP’s. The traditional cementing of borate-containing liquid radioactive waste, to which the salt cake belongs, leads to a significant increase in the volume of the final product. This work describes borosilicate vitreous wasteforms developed to immobilize radioactive salt cake waste and comprises data on both glass synthesis and characterization. The composition of glass selected for the purpose of immobilisation of the salt cake radioactive waste allows to include up to 40 wt. % of the oxides contained in the salt cake and to reduce the volume of the final product by more than 2 times compared with the cement compound. The batches were melted in a cold crucible melter at 1200 °C. The normalized cesium leaching rate of the vitrified wasteform product was within range 3.0·10-5 – 3.7·10-6 g/(cm2·day).

The sustainable integration of human activities into the global ecosystem is discussed, pointing out fatal anthropogenic heat as a major ecological problem and proposing global technical and economical solutions.

For human sake, we must get out of the “thermal age” and implement the “electroprotonic era” as soon as possible. Contrary to thermal power, electroprotonic is sustainable and can be produced by photoenzymatic systems, a cheap way to produce hydrogen (H2) or ammonia (NH3). We can accelerate the advent of this new era if we re-integrate external costs generated by thermal energies into their final prices. The author is leading the H2GREEN project in Belgium as an entrepreneur for more than a decade, which develops the photoenzymatic production of dihydrogen from water. The aim of the H2GREEN project is to contribute to the launch of a low-cost, renewable Hydrogen-based local economy as an energy carrier. Among the difficulties of this launch, the most important is certainly the lack of competitiveness due to the unfair competition of carbon products that externalizes their costs (CO2, oil spills, lethal pollution, armed conflicts, political oppression, foreign dependence, etc.).

More than 1 million tons of oil is inadvertently spilled each year. The economic and environmental costs of these spills are enormous and compel further development of environmentally friendly sorbent materials. Here, we demonstrate a vapor-phase modification approach to create a new class of oil sorbents composed of cellulosic materials (cotton) coated with a subnanometer layer of inorganic oxide. This new cellulosic sorbent remains buoyant in water indefinitely and achieves a selective oil sorption capacity (23 g/g or 1.05 g/cm3) that is at least 35 times better than untreated cellulose in aqueous environments. This new sorbent particularly excels under “realistic” conditions such as continuous agitation (e.g., simulated waves) and presoaking in water (e.g., rain or forced immersion). When sorption performance is compared on a per-volume basis—which better captures use conditions than a per-mass basis—this modified natural product becomes comparable to the best sorbents reported in the literature.

State policymakers and regulators should consider how to respond to the emergence of new storage technologies while observing the regulatory and legal proceedings that will draw the line between state and federal jurisdiction over matters related to storage.

The emergence of new energy storage is challenging traditional jurisdictional lines and giving state policy makers new things to consider. This article discusses conflicts in jurisdiction and offers options for policy makers to consider with regard to storage technologies.

According to the UNEP, mercury pollution is one of the main contamination problems of the world. The UN showed that more than 1,870 tons of this metal are released into the environment annually. This material arrives to water bodies where fish consume it and then reaches humans, producing negative effects on their health. The hydroxyapatite is one of the main components of bones and has proven itself to be useful in the removal of mercury from polluted sources. The aim of this research project is to synthesize and characterize different formulations of this substance and to determine which is the best selective formulation to remove mercury in water. Currently, twenty-one formulations have been produced. The experimental variables examined are the pH, the temperature and the time of calcination. These variables are characterized with Infrared Spectrophotometry (IR), Scanning Electron Microscope (SEM) and X-ray diffraction (XRD). Before calcination the samples contained 70% of hydroxyapatite. This concentration increased in some of them after calcination. The analysis of the results allowed to test the efficiency of these formulations at removing mercury from water. These materials will also be combined, in future stages of the research, with other substances such as activated carbon and organic fibers to improve their performance. The material will be used to coat a filter so that it can become a piping accessory to remove mercury from polluted waters as it is being recirculated.

In the present world scenario the demand for fresh water and clean energy is driving the need to convert a microbial fuel cell (MFC) into an algal-based microbial desalination cell (MDC) that can support algal growth along with desalination of saline water. In this study, the performance of a five-chambered MDC fed with saline water having two different salt concentrations, namely 2.5 g/L and 5.0 g/L in desalination chamber, as well as MDC operated without algae in catholyte was investigated. The algal-based MDC operated with 5 g/L of total dissolved solid (TDS) in desalination chamber exhibited the best performance results among all other combinations giving a maximum power density of 45.52 mW/m2 and a desalination efficiency of 71 ± 2 %. Also, a chemical oxygen demand (COD) removal efficiency of 78 % and coulombic efficiency of 12.24 % was achieved with 5 g/L NaCl concentration in desalination chamber. Based on this experimental performance evaluation, it can be inferred that algal-based MDC can provide a promising and sustainable approach for wastewater treatment with the capability of simultaneous desalination, algal production and electrical energy recovery.

In this study, 3 types of zwitterionic phospholipid biosurfactants LDP(S), CDP(S) and CTDP(S) were prepared from 3 different raw materials such as rapeseed oil, coconut oil and cottonseed oil respectively. The structure of the resulting phospholipid biosurfactants was elucidated by FT-IR, 1H NMR and 13C NMR spectroscopies and their interfacial properties have been examined such as CMC, static surface tension, wetting property, solution stability, and foam property. Interfacial property measurement and prescription test in cosmetic formulation prepared with the newly synthesized biosurfactants revealed that CDP(S) biosurfactant possesses excellent mildness and superior interfacial properties, indicating the potential applicability in cosmetic product formulations.

The piezoelectric properties of lead-free ferroelectric materials have been dramatically improved over the past two decades. For some limited applications, their properties have reached the same levels or have even surpassed the properties of the benchmark lead-based material Pb(Zr,Ti)O3 (PZT). Initial commercial lead-free products, including powders, ceramic components, films, and devices (e.g., ultrasonic cleaner, knocking sensor), are now available on the market. Several prototype devices, such as inkjet printheads, ultrasonic motors, angular sensors, and energy harvesters, have been developed. Their overall performance is still inferior to that of PZT-based devices; however, these prototypes and products point the way for future applications. Here, we provide an overview of recent industrial developments in the field and discuss the main advantages and disadvantages of lead-free piezoceramics for individual applications.

Activation of persulfate (PS) by ultraviolet light or transition metal catalysts has been extensively studied. However, little is known about the activation of PS by iron oxychloride (FeOCl) in the presence of visible light irradiation. Herein, the catalytic activity of FeOCl was developed for oxidative degradation of rhodamine B (RhB) with the FeOCl/PS/Vis process. The characterization of FeOCl for reaction kinetics, degradation mechanism, and catalyst stability was investigated. It is found that the redox cycle of iron species and photoinduced electrons formed on the FeOCl catalyst surface can effectively activate PS, to generate radicals. Based on quenching experiments and electron paramagnetic resonance, the photogenerated holes (h+) and sulfate radicals (SO4−•) are the predominant reactive oxidants for RhB decolorization, while superoxide radicals (•O2−) and hydroxyl radicals (•OH) are also involved. Moreover, FeOCl shows good catalytic performance in a wide range of pH values (pH = 3–10) and excellent reusability and stability, as well.

Novel cerium-loaded MnTiOx/attapulgite (Ce/MnTiOx/ATP) and cerium-doped MnTiOx/attapulgite (Ce–MnTiOx/ATP) catalysts for low-temperature selective catalytic reduction of nitrogen oxides (NOx) with ammonia (NH3-SCR) were synthesized by co-precipitation methods. The results of catalytic activity testing for the as-prepared Ce–MnTiOx/ATP and Ce/MnTiOx/ATP indicated that the Ce–MnTiOx/ATP catalyst exhibited better catalytic performance with over 80% NOx conversion within a wide temperature window between 170 and 350°, and the highest NOx conversion attained for the Ce–MnTiOx/ATP catalyst was 97.5%. A series of characterization illustrated that the Ce–MnTiOx/ATP catalyst exhibited a higher specific surface area, oxygen vacancy, redox ability, and acid site as compared to that of the Ce/MnTiOx/ATP catalyst. The performance tests showed that the Ce–MnTiOx/ATP catalyst exhibited not only better SO2 & H2O resistance but also higher N2 selectivity and good stability. Therefore, the Ce–MnTiOx/ATP catalyst was testified to be a promising catalyst for NH3-SCR.

Coupling oxidation type semiconductors is a feasible strategy to improve the photocatalytic activity of reduction type g-C3N4 photocatalysts. In this work, Bi2O3 was used as an oxidation type semiconductor to construct direct Z-scheme Bi2O3/g-C3N4 photocatalysts by a one-step calcination method. The obtained Bi2O3/g-C3N4 composites exhibited excellent photocatalytic activity and stability toward methylene blue degradation under visible light irradiation. The composite with 1% weight content of Bi2O3 to g-C3N4 exhibited the highest photocatalytic activity with an apparent rate constant of 0.063 min−1, which was 3.0 and 3.7 times higher than that of pure Bi2O3 and g-C3N4, respectively. The enhanced photocatalytic activity of the Bi2O3/g-C3N4 composite was mainly attributed to the improved charge separation efficiency and stronger redox ability. This work gave a new insight in developing g-C3N4-based Z-scheme heterojunction photocatalysts with enhanced photocatalytic activity.

We live at present with a largely linear materials economy. Our use of natural resources is characterized by the sequence “take – make – use – dispose” as materials progress from mine, through product, to landfill. Increasing population, rising affluence and the limited capacity for the planet to provide resources and absorb waste argue for a transition towards a more circular way of using materials (F. Blomsma, and G. Brennan, J. Industrial Ecology 21, 603 (2017); W. McDonough and M. Braungart, Cradle to cradle, remaking the way we make things, (North Point Press, New York, 2002)).

When products come to the end of their lives the materials they contain are still there. Repair, reuse and recycling (the three “Rs”) can return these to active use creating a technological cycle that, in some ways, parallels the carbon, nitrogen cycle and hydrological cycles of the biosphere. Repair, reuse and recycling are not new ideas; they have been used for centuries to recirculate materials and, in less-developed economies, they still are. But in developed nations they dwindled as the cost of materials fell and that of labor rose over time, making all three Rs less attractive. This and the complexity of current products has led to loss reparability and, therefore, reuse. So, what is novel about the contemporary idea of a circular materials economy? Haven’t we been there before?

Over the last decade, the idea of deploying rather than consuming materials, has gained economic as well as environmental appeal. Governments now sign up to programs to foster circular economic ideas and mechanisms begin to appear to advance them. Here we examine the background, the successes and the challenges of implementing a circular materials economy and the degree to which it can deliver the ultimate goal – that of reducing the drain on non-renewable natural resources to as close to zero as possible.

Circular economy (CE) is closely linked with the ideas of a low-carbon economy, management of supply risks, value generation through the service-based economy and efficient resource management. CE implies a design that focusses on material legacy, creating an economy that retains or regenerates materials over many life cycles, hence not consuming but using materials.

Granta Design has a history of involvement with material circularity, through collaborative develop of tools to aid teaching of engineering and design courses and industrial decision-making. The paper concludes with a brief discussion of these.

It is common knowledge that chromophore aggregation usually quenches light emission. The concept of aggregation-induced emission (AIE) changes this general belief and provides a new stage for the exploration of practical luminescent materials. The weak emission of AIE fluorogens (AIEgens) as molecular species and their bright fluorescence as nanoscopic aggregates distinguishes them from conventional organic luminophores and inorganic nanoparticles, making them ideal candidates for high-tech applications. This article summarizes the impact of AIEgens in biomedical applications.

In this work, o-phenylenediamine-m-phenylenediamine copolymer dots (omCPs) with designed surface groups are synthesized and characterized. Here, we explored a simple, rapid semiquantitative detection system for Cu2+ with a wide detection range (5–7 orders of magnitude) based on the fluorescence in the solid state of omCPs and their tunable detection limits. The construction and application of the rapid semiquantitative detection system for Cu2+ are developed and demonstrated for the practical applications. What’s more, the detection limit can be modulated easily by adjusting the surface groups of these dots through the monomer dose control before the co-polymerization. Moreover, we demonstrated that this new technological approach is suitable for the semiquantitative determination of other ions pollutants (i.e., Na+, K+, Cu2+, Pb2+, Hg2+, and NO2 −) in environmental water.

This comparative study on two interdisciplinary artistic practices aims to improve public perception of scientific research and to facilitate informed decision making regarding climate change and how it affects everyday life. It also hopes to break down (or bridge?) the isolated silos of Art and Science, by emphasizing the role of imagination as a tool of creation and innovation in the new economies of the 21st century. Notwithstanding the ephemeral appearance of the super-light nanomaterial silica aerogel used by Ioannis Michaloudis (Michalous) in his sculptures, the longevity of some of his art seems guaranteed: two works, Bottled Nymph and Noli Me Tangere have been selected to be rocketed to the moon as part of the MoonArk sculpture. The sculptures will be aboard a Space X Falcon 9 rocket launched in 2018 from Cape Kennedy in an Astrobotic Robotic Lunar Mission, and will remain on the moon, potentially, for billions of years. Spirited Skies is a project where we experience by touching other forms of longevity of the ephemeral silica aerogel. Filling double jacketed borosilicate glass vials with aerogel skies and clouds in a unique way, Michaloudis transforms every day’s life trivial objects into art. And whilst Michaloudis is seeding the heavens and landing his artwork onto the moon, a Masters student under his supervision, Matthew van Roden is waxing and waning back here on earth. Van Roden’s material of choice is wax, which he pushes through various artistic disciplines to extrapolate its flesh like qualities.