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•Improved spirulina-based ingredients were produced by spray-drying.•Maltodextrin and maltodextrin crosslinked with citric acid were used.•The novel ingredients offer advantages over ...the direct use of spirulina.•The best solution is based on maltodextrin crosslinked with citric acid.
The consumption of foods functionalized with spirulina might have positive health effects. However, spirulina-based food products are usually associated with unpleasant flavor and odor, and can present non-homogeneous appearance, impairing consumers’ acceptance. Moreover, it is important to assure bioactivity maintenance. To develop a novel food ingredient, spirulina was chemically characterized, and spray-dried using two encapsulating materials: i) maltodextrin and ii) maltodextrin crosslinked with citric acid. Thereafter, free and encapsulated spirulina were evaluated for their bioactive properties. Microencapsulated spirulina presented higher thermal stability than the base materials, while showing better anti-inflammatory activity without exerting cytotoxicity. Free and encapsulated spirulina were further added to yogurts to validate their suitability as functionalizing agents. Yogurts added with encapsulated spirulina presented a more homogeneous appearance, and the best solution was spirulina encapsulated in maltodextrin crosslinked with citric acid, considering the nutritional profile, attractive color, and improved antioxidant activity throughout storage time.
Recently, entropy stabilized catalytic systems have been raised great concerns due to the urgent demand for functional materials aiming to realize chemical catalysis. As one of the significant ...groups, high entropy oxides (HEOs) with variable structure, controllable chemical composition, and rich functional properties have become the research hotspots. This review briefly introduces the advantages of HEOs in the catalytic system brought by their structural characteristics and fully summarizes recent applications of HEOs in thermal/electro/photo-catalysis and supports. Finally, the future prospects of HEOs in environmental catalysis, such as visible light catalysis, catalytic wet air oxidation (CWAO), and single-atom catalyst supports are proposed, which will provide a general direction for the development and breakthrough of HEOs in related fields.
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•The applications of HEOs in catalysis and support were summarized.•The active sites of HEOs in catalysis and support were analyzed.•The prospects of HEOs in environmental catalysis were provided.
A series of 20 coal samples were subjected to sequential leaching with ammonium acetate, hydrochloric acid, hydrofluoric acid, and nitric acid to quantify the modes of occurrence of about 42 ...elements. The results indicate that within a coal rank the leaching behavior of many elements are broadly similar. However, the behavior of many elements varies between bituminous and subbituminous coals. While the leaching behavior of most elements is consistent with previous mode of occurrence interpretations there were a number of unanticipated results. About 75% of the arsenic in bituminous coals appears to be associated with sulfides, probably pyrite, however only 40% of the arsenic in the low rank coals appears to be associated with pyrite. In the bituminous coals we interpret that about 60% of the beryllium is associated with silicates, but in the low rank coals only 30% is silicate associated. In the bituminous coals 25% of the magnesium is associated with carbonates, but in the low rank coals 75% of the magnesium is in the carbonates. Fifty-five percent of the molybdenum was associated with the sulfides in the bituminous coals and in the low rank coals 65% was in the silicates. In the bituminous coals the rare earth elements (REE) are predominantly in the phosphate minerals (70% for the light REE and 50% for the heavy REE) but in the low rank coals the REE (50–60%) are associated with the clays. Sodium is predominantly (80%) associated with silicates in the bituminous coals and with the organics (65%) in the low rank coals. Titanium appears to occur more in the clays (65% bituminous, 70% low rank) than in oxides (35% bituminous, 15% low rank). Tungsten is in the sulfides (50%) in the bituminous coals but in the clays (60%) in the low rank coals. Uranium is associated with the silicates (40%) and insoluble phases such as zircon (30%) in the bituminous coals, but is associated with the organics (55%) in the low rank coals. Many of these rank differences reflect a higher detrital input and greater sulfide mineralization of the bituminous coals.
Despite recent progress in the chemistry of frustrated Lewis pairs (FLPs), direct FLP‐catalyzed hydrogenation of CO2 remains elusive. From a near‐infinite array of plausible Lewis pairs, it is ...challenging to identify individual combinations that are appropriate for catalyzing this reaction. To this end, we propose a mapping of the chemical composition of FLPs to their activity towards direct catalytic hydrogenation of CO2 into formate. The maps, built upon linear scaling relationships, pinpoint specific FLP combinations with the proper complementary acidity and basicity to optimally balance the energetics of the catalytic cycle. One such combination was experimentally validated to achieve hitherto unreported catalytic turnover for this transformation.
The chemical composition of frustrated Lewis pairs is mapped to their performance in catalytic direct hydrogenation of CO2 to formate using linear scaling relationships. This map highlights the need for appropriately balancing the acidity and basicity of the components for enhanced activity, which led to the demonstration of hitherto unreported catalytic turnover for this transformation.
In this study, the initial reaction of lignin pyrolysis was explored in depth with light gas emission combined with liquid bio-oil composition and physical-chemical structure of solid bio-char. The ...result reveals that lignin pyrolysis undergoes a complex initial reaction between 160 and 330 °C with significant mass loss (about 20%). Lignin molecular network begins to crack down with lignin monomer linkage breaking and light gas molecular (CO2 and CO) formation as temperature reaching 160 °C. Also, polymerization reaction involving forming larger molecular weight lignin pieces took place between 160 and 200 °C. After that (200–330 °C), lignin cracking reaction is the main reaction with lignin molecular accelerating to form heavy (dimers and trimers) and light units (monomers) in bio-oil and causing more mass loss. At the same temperature range, lignin soften reaction happens and results in lignin surface adhesion, microscopic surface structure changing and functional group evolution. As temperature over 330 °C, lignin initial pyrolysis stage finished and entered intense pyrolysis stage, with more oxygen contained functional group cracking and light lignin pieces formed.
MXenes, as a novel kind of two-dimensional (2D) materials, were first discovered by Gogotsi
et al.
in 2011. Owing to their multifarious chemical compositions and outstanding physicochemical ...properties, the novel types of 2D materials have attracted intensive research interest for potential applications in various fields such as energy storage and conversion, environmental remediation, catalysis, and biomedicine. Although many achievements have been made in recent years, there still remains a lack of reviews to summarize these recent advances of MXenes, especially in biomedical fields. Understanding the current status of surface modification, biomedical applications and toxicity of MXenes and related materials will give some inspiration to the development of novel methods for the preparation of multifunctional MXene-based materials and promote the practical biomedical applications of MXenes and related materials. In this review, we present the recent developments in the surface modification of MXenes and the biomedical applications of MXene-based materials. In the first section, some typical surface modification strategies were introduced and the related issues were also discussed. Then, the potential biomedical applications (such as biosensor, biological imaging, photothermal therapy, drug delivery, theranostic nanoplatforms, and antibacterial agents) of MXenes and related materials were summarized and highlighted in the following sections. In the last section, the toxicity and biocompatibility of MXenes
in vitro
were mentioned. Finally, the development, future directions and challenges about the surface modification of MXene-based materials for biomedical applications were discussed. We believe that this review article will attract great interest from the scientists in materials, chemistry, biomedicine and related fields and promote the development of MXenes and related materials for biomedical applications.
MXenes, as a novel kind of two-dimensional (2D) materials, were first discovered by Gogotsi
et al.
in 2011.
Environment-friendly ceramic capacitors with outstanding energy storage properties (ESPs) are greatly desired for advanced pulsed power systems. However, it is still a great challenge to develop ...lead-free dielectric materials with simultaneous excellent recoverable energy storage density (Wrec) and energy storage efficiency (η). In the present work, a synergistic optimization strategy with regard to ferroelectric domain and band structures is applied to NaNbO3 (NN)-based ceramics, where the introduction of Bi3+ induces elongated ferroelectric P–E loops due to nanodomain formation, and the further modification of the Ta doping content remarkably reduces the grain size and widens the band gap (Eg), leading to a high breakdown strength. As a result, the involved Na0.7Bi0.1Nb0.9Ta0.1O3 ceramics exhibit excellent comprehensive ESP (Wrec = 7.33 J cm−3, η = 83.68%, Eb = 530 kV cm−1) and good stability. Moreover, an ultrafast discharge time of 60 ns and high power density of 320.21 MW cm−3 are also achieved. Na0.7Bi0.1Nb0.9Ta0.1O3 ceramics with an uncomplicated chemical composition and prominent properties demonstrate promising applications in pulsed power systems and the synergistic optimization strategy in this study offers an important reference for future lead-free ceramic capacitors.
Double-atom catalysts (DACs) have gained more and more attention to achieve efficient catalysts for the electrocatalytic nitrogen reduction reaction (NRR). It is expected that heteronuclear members ...could play an important role in the development of DACs, due to which the vast possible combinations of two different transition metal (TM) elements provide a large chemical composition space for the DAC design. Herein, to screen for efficient NRR DACs and, in particular, to further explore the synergetic effect as well as the TM combination pattern conductive to the NRR in the heteronuclear DACs, we have theoretically studied the NRR on TM dimer embedded N-doped porous graphene (TM = V, Cr, Mn, Fe, Co, Ni, and Cu), denoted as M1M2@NG, and both homonuclear and heteronuclear DACs have been considered. Our results indicate that most of the M1M2@NG systems exhibit comparable or better intrinsic NRR activity than the stepped Ru(0001) surface in terms of the calculated limiting potential. In particular, the heteronuclear DAC VCr@NG exhibiting metallic conductivity and high stability has an ultralow limiting potential of −0.24 V for the NRR and a strong capability of suppressing the competing hydrogen evolution reaction. Moreover, the synergetic effect for the heteronuclear DACs compared with the homonuclear counterparts has been studied in terms of energy and electronic structures. Based on this, we propose that combining a highly chemically active TM element (often the early TM) with another TM to form heteronuclear TM dimers on an appropriate substrate can help achieve efficient heteronuclear DACs for the NRR. Our studies not only highlight the important role of heteronuclear members in the application of DACs, but further provide a promising strategy to design efficient heteronuclear DACs for the NRR from the large chemical composition space.
Present studies highlight the important role of the heteronuclear members for the development of the double-atom catalysts, and further provide a strategy to design efficient heteronuclear double-atom catalysts from the large chemical composition space for the electrocatalytic NRR.
Nanoparticles have become a vital part of a vast number of established processes and products; they are used as catalysts, in cosmetics, and even by the pharmaceutical industry. Despite this, ...however, the reliable and reproducible production of functional nanoparticles for specific applications remains a great challenge. In this respect, reticular chemistry provides methods for connecting molecular building blocks to nanoparticles whose chemical composition, structure, porosity, and functionality can be controlled and tuned with atomic precision. Thus, reticular chemistry allows for the translation of the green chemistry principle of atom economy to functional nanomaterials, giving rise to the multifunctional efficiency concept. This principle encourages the design of highly active nanomaterials by maximizing the number of integrated functional units while minimizing the number of inactive components. State‐of‐the‐art research on reticular nanoparticles—metal‐organic frameworks, zeolitic imidazolate frameworks, and covalent organic frameworks—is critically assessed and the beneficial features and particular challenges that set reticular chemistry apart from other nanoparticle material classes are highlighted. Reviewing the power of reticular chemistry, it is suggested that the unique possibility to efficiently and straightforwardly synthesize multifunctional nanoparticles should guide the synthesis of customized nanoparticles in the future.
The discovery of reticular chemistry has unexpectedly shifted the focus of functional nanoparticle design away from size, shape, and surface characteristics toward straightforward direct integration of functional building units into the nanomaterial. The realization of this potential together with systematic material characterization can revolutionize nanoscience to enable groundbreaking advances in different areas of the life sciences and catalysis.
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