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CO2 separation plays a crucial role in tackling the climate change induced by the greenhouse effects and improving the energy quality of natural gas and biogas. The efficient CO2 separation technology is highly required. Membrane separation technology is particularly attractive in CO2 separation processes owing to its advantages. However, the trade-off relationship limited the gas separation efficiency of polymeric membranes in gas separation processes. Therefore, it is necessary to prepare the high-performance membranes such as mixed matrix membranes (MMMs) for CO2 separation. This review mainly focuses on the preparation methods, the material properties and the CO2 separation efficiency of the MMMs containing various fillers such as modified ZIFs, MOFs, and GO, and the emerging MOF-based composites, 2D MOFs and 2D MXene. The modified fillers demonstrated higher compatibility with polymer matrix, resulting in enhanced mechanical stability and CO2 separation efficiency of MMMs. 2D materials could significantly enhance the CO2 separation efficiency of MMMs, owing to their layered structure and the effective regulation of gas transport ways. Finally, the future direction and conclusions of fillers and MMMs in gas separation processes are provided.

In this study, chemical deposition was used to synthesize structures of Ga2O3 -NW/SiO2/Si (NW—nanowire) at 348 K and SnO2-NW/SiO2/Si at 323 K in track templates SiO2/Si (either n- or p-type). The resulting crystalline nanowires were δ-Ga2O3 and orthorhombic SnO2. Computer modeling of the delta phase of gallium oxide yielded a lattice parameter of a = 9.287 Å, which closely matched the experimental range of 9.83–10.03 Å. The bandgap is indirect with an Eg = 5.5 eV. The photoluminescence spectra of both nanostructures exhibited a complex band when excited by light with λ = 5.16 eV, dominated by luminescence from vacancy-type defects. The current–voltage characteristics of δ-Ga2O3 NW/SiO2/Si-p showed one-way conductivity. This structure could be advantageous in devices where a reverse current is undesirable. The p-n junction with a complex structure was formed. This junction consists of a polycrystalline nanowire base exhibiting n-type conductivity and a monocrystalline Si substrate with p-type conductivity. The I–V characteristics of SnO2-NW/SiO2/Si suggested near-metallic conductivity due to the presence of metallic tin.

In this study the novel garnet-type Y2.47Na0.5Ln0.03Al5O12, Y2.97Ln0.03Al4.95V0.05O12, Y2.92Na0.05Ln0.03Al4.9833V0.0167O12 (Ln = Ce3+, Tb3+, Eu3+) phosphors were successfully synthesized by the sol-gel method for the first time. The structural, morphological and optical properties were characterized by using multiple characterization techniques. The XRD and FTIR results confirmed that all obtained phosphors are monophasic yttrium aluminium garnet compounds, i.e. the doping of Ce3+, Tb3+, Eu3+, Na+, V5+ ions does not induce any impurity phases, indicating the successful incorporation of these dopants into the YAG host. The formation of novel garnets was probed using 27Al, 51V, 23Na MAS NMR techniques. SEM micrographs revealed that almost in all cases, the surface of the obtained luminophores is porous and consists of homogeneously distributed irregular sphere-like shape particles, which tend to form larger agglomerates. The optical properties of obtained compounds were also investigated by recording their excitation and emission spectra and calculating the colour coordinates in the CIE 1931 colour space.

In the present work, iron–sillenite (Bi25FeO40) was synthesized using a simple solid-state reaction method and characterized. The effects of the synthesis conditions on the phase purity of Bi2O3/Fe3O4, morphological features, and possible application as an XRD/MRI dual-contrast agent were investigated. For the synthesis, the stoichiometric amounts of Bi2O3 and Fe3O4 were mixed and subsequently milled in a planetary ball mill for 10 min with a speed of 300 rpm. The milled mixture was calcined at various temperatures (550 °C, 700 °C, 750 °C, 800 °C, and 850 °C) for 1 h in air at a heating rate of 5 °C/min. For phase identification, powder X-ray diffraction (XRD) analysis was performed and infrared (FTIR) spectra were recorded. The surface morphology of synthesized samples was studied by field-emission scanning electron microscopy (FE-SEM). For the radiopacity measurements, iron–sillenite specimens were synthesized at different temperatures and mixed with different amounts of BaSO4 and Laponite solution. It was demonstrated that iron–sillenite Bi25FeO40 possessed sufficient radiopacity and could be a potential candidate to meet the requirements of its application as an XRD/MRI dual-contrast agent.

Abstract Seafood farming is heralded for its economic opportunities and its potential to reduce the greenhouse gas emissions associated with food production. Yet the persistent lack of awareness among the US public about these potential benefits of seafood farming is often cited as a barrier to social acceptance and industry growth. We employed two exploratory online surveys of residents of western and northeastern US coastal states and a unique message‐testing approach to explore: (1) how existing opinions about seafood farming vary across sociodemographic attributes, geography, and prior familiarity with aquaculture; (2) the malleability of opinions about seafood farming; and (3) what benefits of marine aquaculture broadly and of seaweed farming specifically were viewed as the strongest reasons to support industry expansion, and what messengers are most trusted to share that information. We found that baseline attitudes about seafood farming strongly correlate with prior familiarity and that opinions about both marine aquaculture and seaweed farming were highly malleable, at least in the short term. If confirmed by further studies, our results suggest that messages emphasizing benefits in terms of environmental sustainability, as opposed to economic benefits or social benefits, may be an important tool to better engage residents of western and northeastern US coastal states with seafood farming expansion.

This work presents a rapid and facile way to access the cell wall of wood with magnetic nanoparticles (NPs), providing insights into a method of wood modification to prepare hybrid bio-based functional materials. Diffusion-driven infiltration into Scots pine (Pinus sylvestris L.) sapwood was achieved using colloidal Fe3O4 nanoparticles. Optical microscopy, scanning electron microscopy/energy-dispersive X-ray spectroscopy, transmission electron microscopy, and X-ray powder diffraction analyses were used to detect and assess the accessibility of the cell wall to Fe3O4. The structural changes, filling of tracheids (cell lumina), and NP infiltration depth were further evaluated by performing X-ray microcomputed tomography analysis. Fourier transform infrared spectroscopy was used to assess the chemical changes in Scots pine induced by the interaction of the wood with the solvent. The thermal stability of Fe3O4-modified wood was studied by thermogravimetric analysis. Successful infiltration of the Fe3O4 NPs was confirmed by measuring the magnetic properties of cross-sectioned layers of the modified wood. The results indicate the feasibility of creating multiple functionalities that may lead to many future applications, including structural nanomaterials with desirable thermal properties, magnetic devices, and sensors.

The mechanisms of formation of induced intrinsic and impurity radiative states, which consist of intrinsic and impurity electron–hole-trapping center states in irradiated Ca2P2O7−Mn and Ca2P2O7 phosphates, were investigated using thermoactivation and vacuum-ultraviolet spectroscopy methods. These centers are excited at photon energies of 4.0 eV and 4.5 eV, which are within the matrix’s transparency region. New radiative-induced states at 3.06 eV and 2.92 eV are demonstrated to be generated upon the excitation of anions by photons with energies of 5.0 and 5.64 eV. This process is due to charge transfer from the ion to the impurities, specifically Mn2+(O2−−Mn2+) and the neighboring ion O 2−−(P2O7)4−. Furthermore, upon the excitation of matrix anions with photon energies exceeding the band gap (8.0–8.25 eV), electron-trapping by impurities such as Mn2+ and (P2O7)4− ions results.

Abstract In the present work, three different Mn2+-doped calcium pyrophosphate (CPP, Ca2P2O7) polymorphs were synthesized by wet co-precipitation method followed by annealing at different temperatures. The crystal structure and purity were studied by powder X-ray diffraction (XRD), Fourier-transform infrared (FTIR), solid-state nuclear magnetic resonance (SS-NMR), and electron paramagnetic resonance (EPR) spectroscopies. Scanning electron microscopy (SEM) was used to investigate the morphological features of the synthesized products. Optical properties were investigated using photoluminescence measurements. Excitation spectra, emission spectra, and photoluminescence decay curves of the samples were studied. All Mn-doped polymorphs exhibited a broadband emission ranging from approximately 500 to 730 nm. The emission maximum was host-dependent and centered at around 580, 570, and 595 nm for γ-, β-, and α-CPP, respectively.

In this study, chemical deposition was used to synthesize structures of Ga2O3 -NW/SiO2/Si (NW—nanowire) at 348 K and SnO2-NW/SiO2/Si at 323 K in track templates SiO2/Si (either n- or p-type). The resulting crystalline nanowires were δ-Ga2O3 and orthorhombic SnO2. Computer modeling of the delta phase of gallium oxide yielded a lattice parameter of a = 9.287 Å, which closely matched the experimental range of 9.83–10.03 Å. The bandgap is indirect with an Eg = 5.5 eV. The photoluminescence spectra of both nanostructures exhibited a complex band when excited by light with λ = 5.16 eV, dominated by luminescence from vacancy-type defects. The current–voltage characteristics of δ-Ga2O3 NW/SiO2/Si-p showed one-way conductivity. This structure could be advantageous in devices where a reverse current is undesirable. The p-n junction with a complex structure was formed. This junction consists of a polycrystalline nanowire base exhibiting n-type conductivity and a monocrystalline Si substrate with p-type conductivity. The I–V characteristics of SnO2-NW/SiO2/Si suggested near-metallic conductivity due to the presence of metallic tin. [ABSTRACT FROM AUTHOR]

The photochromic properties and charge transfer processes were studied in novel Eu-doped M3MgSi2O8 (M = Ca, Sr, Ba) compounds. These materials exhibit vivid color changes upon irradiation with UV light, resulting in orange, reddish-pink, and green colors. The introduction of europium ions enhances photochromic efficiency and shifts excitation peaks to lower energy ranges. Analysis of diffuse reflectance and electron paramagnetic resonance spectra reveals the formation of both paramagnetic and non-paramagnetic defects, with the dominant signals attributed to electron centers, likely F+-type centers. The Eu2+ → Eu3+ charge transfer during irradiation indicates that Eu2+ acts as a hole center. These findings contribute to a better understanding of the mechanisms underlying photochromism in these materials and highlight their potential for practical applications. [ABSTRACT FROM AUTHOR]

The possibility of controlling physical properties via chemical doping is particularly important when considering the formation of both electrical and magnetic orderings in the same compounds, which are commonly referred as multiferroics [...]

Recently, layered double hydroxides (LDHs) have attracted substantial attention due to their wide range of important application areas, e [...]

Government funding accounts for a large proportion of conservation and environmental improvements, and is often the result of citizen votes on state ballot measures. A key concern surrounding public investments in the environment is whether that funding serves lower-income communities, which are often the communities of greatest need. We applied three statistical methods to analyze the spatial distribution of conservation funding derived from Californias Proposition 84, which distributed nearly $4 billion across California between 2006 and 2015. First, we used hurdle models to ask if income, population density, urban coverage, or pollution could explain receipt of grants or magnitude of funding. Second, we compared the income levels of funded and unfunded communities for each chapter of the proposition. Finally, we examine two sections of the proposition that were intended to fund parks around the state and compare the attributes of funded and unfunded communities. Proposition 84 offers lessons for environmental legislation and future research. While there were general tendencies for more funding to flow to poor areas and areas with pollution problems, the language in Proposition 84 as a whole was vague with respect to the funding of disadvantaged areas, and as a result the targeting of these areas overall was at best modest. However, when enabling legislation (AB 31) defined specific metrics of disadvantage that had to be met by communities to receive funds from some sections of Proposition 84, the funds did flow much more selectively to poorer communities. This suggests that future ballot measures should be very explicit in their language if they want to promote equity in conservation investments, and that future research should investigate the extent to which technical workshops and outreach could further increase the number of funded grant proposals from low-income communities.