Search

Methylammonium paradodecatungstate, (CH3NH3)10[H2W12O42] ⋅ nH2O, was prepared by the reaction of WO3 or H2WO4 in aqueous methylamine, followed by drying. The [H2W12O42]10− anion consists of two HW3O13 groups containing three edge-sharing WO6 octahedra and two W3O14 groups having two edge-sharing connections. On drying the produced material at 70 °C, some lattice water was released, but this did not affect the [H2W12O42]10− structure, although there was a decrease in the unit cell volume. By adding water, the loss of lattice water and structural changes were reversed. The existence of paradodecatungstate anions was confirmed by single-crystal and powder X-ray diffraction, Fourier transform infrared, Raman, 183W nuclear magnetic resonance, and ultraviolet-visible spectroscopy. When the methylammonium paradodecatungstate was heated to more than 150 °C, CH3NH2 and H2O were released, and amorphous WO3 was observed as an intermediate product and monoclinic WO3 as the final product. These results reveal the structure of methylammonium tungstate, which was first reported in 1909 and now is used as an important negative staining reagent for virus observation, is methylammonium paradodecatungstate., This study was supported by JSPS KAKENHI, Grant Number JP19H00843 (Grant-in-Aid for Scientific Research (A)), JST A-STEP Grant Number JPMJTM20RF, International Network on Polyoxometalate Science at Hiroshima University, and JSPS Core-to-Core program., Supporting information for this article is available on the WWW under https://doi.org/10.1002/zaac.202100219

Ceramifiable silicone composites have promising prospect due to their outstanding thermal protection performance. However, the indistinct thermal transformation process at various temperatures, may be an inevitable bottleneck for the improvement of mechanical strength. Herein, ceramifiable silicone composites (flexural strength over 8 Mpa at 1400 °C) were fabricated and their thermal transformation process was demonstrated by the analysis of composition evolution of the released gases and residual solids. Concretely, the ceramifiable silicone composites modified by octa-aminopropyl polyhedral oligosilsesquioxane (8AP-POSS) could reduce porosity and enhance mechanical properties by decreasing the release rate of gas. At high temperature, the phase composition evolution and microstructure change of formed ceramics did contribute to the adhesion of residues. Based on the above analysis of thermal transformation process from polysiloxane to silica polymorphs, a novel mechanism namely temperature-gradient phase evolution mechanism (TGPEM) was proposed. The research results contribute to the preparation of high-performance silicone composites.

The utilization of high-sulfur coal is becoming more urgent due to the excessive utilization of low-sulfur, high-quality coal resources, and sulfur removal from high-sulfur coal is the most important issue. This paper reviews the speciation, forms and distribution of sulfur in coal, the sulfur removal from raw coal, the thermal transformation of sulfur during coal pyrolysis, and the sulfur regulation during coal-blending coking of high organic-sulfur coals. It was suggested that the proper characterization of sulfur in coal cannot be obtained only by either chemical method or instrumental characterization, which raises the need of a combination of current or newly adopted characterization methods. Different from the removal of inorganic sulfur from coal, the organic sulfur can only be partly removed by chemical technologies; and the coal structure and property, particularly high-sulfur coking coals which have caking ability, may be altered and affected by the pretreatment processes. Based on the interactions among the sulfur radicals, sulfur-containing and hydrogen-containing fragments during coal pyrolysis and the reactions with minerals or nascent char, regulating the sulfur transformation behavior in the process of thermal conversion is the most effective way to utilize high organic-sulfur coals in the coke-making industry. An in-situ regulation approach of sulfur transformation during coal-blending coking has been suggested. That is, the high volatile coals with an appropriate releasing temperature range of CH4 overlapping well with that of H2S from high organic-sulfur coals is blended with high organic-sulfur coals, and the C–S/C–C bonds in some sulfur forms are catalytically broken and immediately hydrogenated by the hydrogen-containing radicals generated from high volatile coals. Wherein, the effect of mass transfer on sulfur regulation during the coking process should be considered for the larger-scale coking tests through optimizing the ratios of different coals in the coal blend.

Increasing the complexity of nanomaterials in terms of their structure and chemical composition has attracted significant attention, because it can yield unique scientific outcomes and considerable improvements for practical applications. Various approaches are being developed for the synthesis of nanostructured composites. Coordination polymers (CPs) emerged as new precursors in solid-state reactions for nanomaterials nearly two decades ago; the repetitively arranged inorganic and organic units can facilitate the production of nanoscale particles and porous carbon upon thermal decomposition. Metal-organic frameworks (MOFs), a subgroup of CPs featuring crystalline and porous structures, have subsequently become primary objects of interest in this field, as can be seen by the rapidly increasing number of reports on this topic. However, unique composite materials with increasingly complex nanostructures, which cannot be achieved via conventional methods, have been rarely realised, even though conventional MOF research has enabled the delicate control of structures at the molecular level and extensive applications as templates. In this regard, a comprehensive review of the fabrication strategies of MOF-based precursors and the thermal transformation into functional nanomaterials is provided herein, with a particular emphasis on the recent developments in nanocomposite research. We briefly introduce the roles and capabilities of MOFs in the synthesis of nanomaterials and subsequently discuss diverse synthetic routes for obtaining morphologically or compositionally advanced composite nanomaterials, based on our understanding of the MOF conversion mechanism.

Atomically dispersed nickel sites complexed on nitrogen-doped carbon (Ni–N/C) have demonstrated considerable activity for the selective electrochemical carbon dioxide reduction reaction (CO2RR) to ...

Empty fruit bunches (EFB) are waste products in the palm oil industry. Upon pressing of EFB, a liquor is produced which contains low grade fats, oils, and greases (FOG). These are the least valuable products of palm oil production, and are often discarded as waste. It is shown here that the EFB pressed liquor can be thermally transformed at or below 350 &deg, C to produce a series of hydrocarbons in the range of kerosene and diesel fuel. This is distinctly different from other studies of biofuels from palm oil, which were based entirely on biodiesel (fatty acid methyl ester (FAME)) and biogas production. Furthermore, this transformation takes place without addition of an external catalyst, as was shown by comparison to reactions with the potential Lewis acid catalysts, ferric sulfate, and molecular sieves. The product distribution is similar to that obtained from brown grease, another waste FOG stream obtained from the sewage treatment industry, although the products from palm oil waste are less sensitive to reaction conditions.

“Fouling”, the unwanted deposition of solids, causes significant operational difficulties in petroleum producing and processing industries and is considered a billion dollar problem. There are two ...

Metal-organic frameworks (MOFs) are a class of distinctive porous crystalline materials constructed by metal ions/clusters and organic linkers. Owing to their structural diversity, functional adjustability, and high surface area, different types of MOF-based single metal sites are well exploited, including coordinately unsaturated metal sites from metal nodes and metallolinkers, as well as active metal species immobilized to MOFs. Furthermore, controllable thermal transformation of MOFs can upgrade them to nanomaterials functionalized with active single-atom catalysts (SACs). These unique features of MOFs and their derivatives enable them to serve as a highly versatile platform for catalysis, which has actually been becoming a rapidly developing interdisciplinary research area. In this review, we overview the recent developments of catalysis at single metal sites in MOF-based materials with emphasis on their structures and applications for thermocatalysis, electrocatalysis, and photocatalysis. We also compare the results and summarize the major insights gained from the works in this review, providing the challenges and prospects in this emerging field.

The thermolysis reactions of benzoazacyclodecatrienes under microwave irradiation conditions in toluene at 150 °C afforded complex azabenzo[a]cyclopropa[cd]azulene and (epiminomethano)cyclopenta[a]indene frameworks. Cyclopropanes were established as intermediates of the ultimate thermolysis products.

Ancient martian organic matter is likely to take the form of kerogen-like recalcitrant macromolecular organic matter (MOM), existing in close association with reactive mineral surfaces, especially iron oxides. Detecting and identifying a biological origin for martian MOM will therefore be of utmost importance for life detection efforts at Mars. We show that Type I and Type IV kerogens provide effective analogues for putative martian MOM of biological and abiological (meteoric) provenances respectively. We analyse the pyrolytic breakdown products when these kerogens are mixed with mineral matrices highly relevant for the search for life on Mars. We demonstrate that, using traditional thermal techniques as generally used by the Sample Analysis at Mars and Mars Organic Molecule Analyser instruments, even the breakdown products of highly recalcitrant MOM are transformed during analysis in the presence of reactive mineral surfaces, particularly iron. Analytical transformation reduces the diagnostic ability of this technique, as detected transformation products of both biological and abiological MOM may be identical (low molecular weight gas phases and benzene) and indistinguishable. The severity of transformational effects increased through: calcite < kaolinite < haematite < nontronite < magnetite < goethite. Due to their representation of various habitable aqueous environments and the preservation potential of organic matter by iron, it is not advisable to completely avoid iron-rich strata. We conclude that haematite-rich localities, with evidence of extensive aqueous alteration of originally reducing phases, such as the Vera Rubin Ridge, may be relatively promising targets for identifying martian biologically-sourced MOM.

—This paper presents a study of organomagnesiumoxaneyttroxanealumoxane oligomers soluble in organic solvents and exhibiting fiber-forming properties. We describe processes underlying the formation of modified alumina structures as a result of the thermal transformation of organoelement precursors into ceramic phases. The physicochemical properties of the organomagnesiumoxaneyttroxanealumoxanes and ceramic samples prepared from them have been studied by nuclear magnetic resonance, IR spectroscopy, scanning electron microscopy, thermogravimetric analysis, X-ray diffraction, and elemental analysis. Polymer fibers have been produced by melt-spinning the fiber-forming organomagnesiumoxaneyttroxanealumoxanes.

We reported a new layered ZnCo1.5(OH)4.5Cl0.5·0.45H2O which crystallizes in two-dimensional (2D) nanosheets morphology in our previous work. Herein, two-dimensional hexagonal ZnCo2O4 nanosheets were synthesized by the thermal transformation of the ZnCo1.5(OH)4.5Cl0.5·0.45H2O precursor. Benefiting from this special hexagonal nanosheet morphology, the as-prepared ZnCo2O4 electrode has induced a pseudo-capacitance contribution, leading to a stable discharge capacity of 688 mAh g−1 (at 5.0 A g−1) over 1000 cycles. To the best of our knowledge, the rate performance of ZnCo2O4 for lithium ion batteries (LIBs) is superior to those of previously reported ZnCo2O4 electrodes. Further applied to sodium ion batteries, ZnCo2O4 electrode show fascinating performance with the specific capacity of 463 mAh g−1 after 60 cycles. This study provides a promising strategy for developing high-quality ZnCo2O4 nanosheet electrodes for long-cycle-life and high-power LIBs and sodium ion batteries (SIBs).

Two novel compounds, {[Cu(bpy)2]3H2W12O40}·3H2O (1) and {{[Cu(OH2)(bpy)][Cu(bpy)]2W6O21}·4H2O}n (2), were isolated under hydrothermal conditions. Compound 1 is an α-metatungstate Keggin unit decorated by three “{Cu(bpy)2}2+” fragments. Compound 2 is a thermodynamically stable 1D polymer built-up from an unusual hexatungstate moiety decorated by three Cu complexes. Compound 2 can be synthesized either from the starting reagents or via thermal transformation from crystals of 1 (180 °C, 7 d). The hexatungstate in 2 represents the first example containing a W–O bonding pattern with 13 terminal oxygen ligands, four μ2-Obridging, two μ3-Otriple-bridging, and two μ4-Ocorner, symbolizing the fourth W-hexamer geometry characterized so far. Compound 2 provides a rare example that withstands a water desorption–readsorption process (80–130 °C) and a subsequent reversible phase transition (190–230 °C). Both events appear accompanied by a unit-cell contraction, which occurs in the b and c directions involving the short...

Schwertmannite is a metastable mineral playing a crucial role in the immobilization of metal(oid)s in acid mine drainage (AMD) systems. High temperatures associated with wildfires could lead to a sudden schwertmannite transformation, changing the mobility of metal(oid)s. The objective of the present study was to examine the thermal transformation from schwertmannite to hematite, and the subsequent effect on the chromium partitioning. The immobilization of arsenate after thermal transformation and its implications on chromium mobility was also evaluated. Natural schwertmannite, with increasing contents of chromium, was thermally treated between 200 to 800 °C. Transformation products were characterized by solid-phase techniques and selective chemical extractions. Results indicated a transformation to hematite at temperatures above 400 °C. The presence of chromium barely affected the temperature at which the transformation occurred, although partitioning of chromium in the mineral changed with temperature. As the temperature increased from 25 °C to 400 °C, chromium was less mobile and less outcompeted by arsenic adsorption, suggesting a larger contribution of inner-sphere complexes with increasing temperature. At temperatures above 600 °C, non-mobile forms strongly associated with neo-formed hematite were found. Finally, neo-formation of hematite led to a decrease in arsenic adsorption, implying a potentially enhanced arsenic mobility in AMD systems upon wildfires.

The present study was conducted to qualitatively and quantitatively elucidate dynamic changes of ginsenosides in ginseng pulp steamed under different temperatures (100 or 120 °C) for different durations (1–6 h) through UPLC-QTOF-MS/MS and HPLC with the aid of as numerous as 18 authentic standards of ginsenosides. Results show that levels of eight polar ginsenosides (i.e., Rg1, Re, Rb1, Rc, Rb2, Rb3, F1, and Rd) declined but those of 10 less-polar ginsenosides [i.e., Rf, Rg2, 20(S)-Rh1, 20(R)-Rg2, F4, 20(S)-Rg3, 20(R)-Rg3, PPT, Rg5, and 20(R)-Rh2] elevated with increases of both steaming temperature and duration; the optimum steaming conditions for achieving the highest total ginsenosides were 100 °C for 1 h. Particular, 20(R)-Rg3, a representative less-polar ginsenoside with high bioactivity such as potent anti-cancer effect, increased sharply but Re, the most abundant polar ginsenoside in fresh ginseng pulp, decreased dramatically. More importantly, ginsenoside species enhanced from 18 to 42 after steaming, mainly due to transformation of polar into less-polar ginsenosides. Furthermore, four malonyl-ginsenosides were detected in fresh ginseng pulps and ten acetyl-ginsenosides were formed during steaming, demonstrating that demalonylation and acetylation of ginsenosides were the dominant underling mechanisms for transformation of polar into less-polar ginsenosides.

NaV3O8 nanobelts were successfully synthesized for Li/Na-ion batteries and rechargeable aqueous zinc-ion batteries (ZIBs) by a facile hydrothermal reaction and subsequent thermal transformation. Compared to the electrochemical performance of LIBs and NIBs, NaV3O8 nanobelt cathode materials in ZIBs have shown excellent electrochemical performance, including high specific capacity of 421 mA h g−1 at 100 mA g−1 and good cycle stability with a capacity retention of 94% over 500 cycles at 5 A g−1. The good diffusion coefficients and high surface capacity of NaV3O8 nanobelts in ZIBs were in favor of fast Zn2+ intercalation and long-term cycle stability.

The increasing production and usage of chlorinated paraffins (CPs) correspondently increase the amount of CPs that experience thermal processes. Our previous study revealed that a significant amount of medium-chain chlorinated paraffins (MCCPs), short-chain chlorinated paraffins (SCCPs) as well as aromatic and chlorinated polycyclic aromatic hydrocarbons (Cl-PAHs) were formed synergistically during the thermal decomposition of CP-52 (a class of CP products). However, the transformation mechanisms of CP-52 to these compounds are still not very clear. This article presents a mechanistic analysis on the decomposition of CP-52 experimentally and theoretically. It was found that CP-52 initially undergoes dehydrochlorination and carbon chain cleavage and it transformed into chlorinated and unsaturated hydrocarbons. Cyclization and aromatization were the most accessible pathways at low temperatures (200–400°C), both of which produce mostly aromatic hydrocarbons. As the temperature exceeds 400°C, the hydrocarbons could decompose into small molecules, and the subsequent radical-induced reactions become the predominant pathways, leading to the formation of Cl-PAHs. The decomposition of CP-52 was investigated by using density functional theory and calculations demonstrating the feasibility and rationality of PCB and PCN formation from chlorobenzene. The results improve the understanding of the transformation processes from CP-52 to SCCPs and Cl-PAHs as well as provide data for reducing their emissions during thermal-related processes.

Metallized plastic, a sandwiched multilayered combination of polymers and aluminum, is widely used in the packaging industry attributed to their lower cost and superior barrier properties. Accordin...

The increases in the volumes of electronic waste have become an aggravating environmental, economic, and social health issue in recent times. This study investigates the conversion of e-waste plastics into hydrocarbon oils via noncatalytic thermal transformation followed by an in-depth characterization of these oils using diverse analytical techniques such as gas chromatography–mass spectrometry (GC–MS), Fourier transform infrared (FTIR) spectroscopy, and nuclear magnetic resonance (NMR) spectroscopy. In particular, NMR spectroscopy is a key analytical tool utilized in this study to gain a comprehensive insight into the chemical nature of the resultant oils along with a semiquantitative investigation of the changes in their composition over a temperature range of 800–1200 °C. The one-dimensional (1D) 1H and two-dimensional (2D) heteronuclear single-quantum correlation spectra were acquired for the oils, wherein the 2D NMR spectrum provided improved resolution of peaks to address the overlaps encountered in the 1D spectrum. The experimental results obtained from GC–MS, FTIR spectroscopy, and NMR spectroscopy were found to align well with each other. The oils produced in this study have a high calorific value of 38.27 MJ/kg and thus may find use in several applications. A detailed mechanism for the thermal degradation of styrene acrylonitrile plastics and the formation of major products is elucidated in this study.

A new uranium fluoride phosphate, UFPO4, was synthesized via a mild hydrothermal route and characterized optically, thermally, and magnetically. Two thermal transformation products, U2O(PO4)2 and U...

Semiconductor photocatalysis has become the focus of recent research on antibiotic treatment because it is a green and efficient technology. In this study, α-GaOOH with several novel microstructures has been synthesized at a low temperature and its subsequent thermal transformation. The influence of pH on the synthesis of α-GaOOH is studied, and the results indicate that pH played an important role in the microstructures of α-GaOOH and β-Ga2O3. All Ga2O3 samples possess macro-mesoporous network structures and exhibits a remarkable photocatalytic activity for antibiotic degradation. The photoelectron chemical tests show that the separation efficiency of photogenerated charge carriers of Ga2O3-7.0 is higher than that of other Ga2O3. The enhanced photocatalytic activity of Ga2O3-7.0 is mainly ascribed to its morphology and oxygen vacancy. The active species trapping and photoluminescence measurement experiments indicate that OH and O2- are the major active species contributing to the photocatalytic process. This study will bring about the potential application in treatment of the antibiotic pollutants.

The review consists of four parts. Part I is about the thermal transformation in clay minerals under firing and about the properties of fired clay. The transformations in the clay are expressed quantitatively with the extent of conversion, α, which is the function of two parameters of firing process, time t and temperature T: α = f(t, T). Part II is about the estimation of firing temperature after the analysis of the products of firing clays. All the estimations are speculative, without mathematical equations. It is impossible to derive the value of only one variable T from α = f(t,T), the function of two variables. Part III is about the long-term inverse transformation in fired ceramic paste under ambient conditions. The mass gain as a function of time is used for the evaluation of the time elapsed from the ancient firing, t. Part IV is about the visualization of the extent of conversion of the clay in the paste after all direct and reverse reactions, i.e., α.

Summary Metal-organic frameworks (MOFs) are excellent supports for metal nanoparticles (NPs), but the interactions between metal NPs and inorganic nodes of MOFs are weak because of the presence of organic ligands. Here, we present a strategy for strengthening the metal-NP/MOF interactions through controlled deligandation of the metal/MOF composites by thermal transformation. The controlled deligandation of MOF results in the formation of a "quasi-MOF," which has a transition-state structure between the porous MOF and metal oxide. The obtained metal/quasi-MOF composites not only retain a porous structure but also achieve a strong interaction between the metal NPs (i.e., Au) and the inorganic nodes (i.e., Cr–O) of the quasi-MOF, leading to dramatically enhanced catalytic performance in the low-temperature oxidation of carbon monoxide (CO). The present findings could open new avenues for the design of superior heterogeneous catalysts.

This contribution is devoted to thermoanalytical investigation of the mechanism of the formation of solid solutions of Li1+xCrxZr2−x(PO4)3. The samples were prepared by high-temperature solid-state reaction in the reaction mixtures of (0.5 + x/2)Li2CO3–(2 − x)ZrOCl2·8H2O–(x/2)Cr2O3–3(NH4)2HPO4. Thermal behaviour of the mixtures was characterised using STA analysis (RT-1200 °C); evolution of the phase composition during heating was analysed using powder XRD analysis. It is shown that with increase in substitution degree x from 0 to 2, the mechanism of the formation of the solid solutions changes dramatically. In general, it is influenced by the content of ZrOCl2·8H2O because its interaction with (NH4)2HPO4 is the dominant feature of the thermal transformation of the mixtures. However, with decrease in ZrOCl2·8H2O content and the corresponding increase in x, the indicated process becomes less dominant. On the other hand, unreacted amount of (NH4)2HPO4 is increased and the corresponding effect of elimination of its ammonia becomes more and more prominent. The mixture with x = 2 can be characterised with typical behaviour of the mixtures of (NH4)2HPO4 with oxides or carbonates. In general, the formation of solid solutions required calcination at 1200 °C during 6–12 h.

This study investigates, verifies and determines the optimal parameters for the selective thermal transformation of problematic electronic waste (e-waste) to produce value-added copper-tin (Cu-Sn) based alloys; thereby demonstrating a novel new pathway for the cost-effective recovery of resources from one of the world's fastest growing and most challenging waste streams. Using outdated computer printed circuit boards (PCBs), a ubiquitous component of e-waste, we investigated transformations across a range of temperatures and time frames. Results indicate a two-step heat treatment process, using a low temperature step followed by a high temperature step, can be used to produce and separate off, first, a lead (Pb) based alloy and, subsequently, a Cu-Sn based alloy. We also found a single-step heat treatment process at a moderate temperature of 900 °C can be used to directly transform old PCBs to produce a Cu-Sn based alloy, while capturing the Pb and antimony (Sb) as alloying elements to prevent the emission of these low melting point elements. These results demonstrate old computer PCBs, large volumes of which are already within global waste stockpiles, can be considered a potential source of value-added metal alloys, opening up a new opportunity for utilizing e-waste to produce metal alloys in local micro-factories.

A series of Сu–Cr–Co/Al2O3/Al catalysts were synthesized under conditions of both traditional heat treatment and action of UHF field, with determination of the thermal transformation properties and degree of radiation penetration into the catalyst bulk. The performance of the catalysts in joint deep oxidation of n-butane and carbon monoxide, stimulated by microwave radiation, was evaluated. The use of the generalized Harrington desirability function reflecting the whole set of definite different-dimension partial responses facilitates the visualization of the expert evaluation of the results and can be recommended for preparing heterogeneous catalysts for related reactions, stimulated by microwave radiation, and for ranking them with respect to performance.

Morphology controllable fabrication of electrode materials is of great significance but is still a major challenge for constructing advanced Li ion batteries. Herein, we propose a novel space constraint assembly approach to tune the morphology of Mn(terephthalic acid) (PTA)-MOF, in which benzonic acid was employed as a modulator to adjust the available MOF assembly directions. As a result, Mn(PTA)-MOFs with microquadrangulars, microflakes, and spindle-like microrods morphologies have been achieved. MnO/C hybrids with preserved morphologies were further obtained by self-sacrificial and thermal transformation of Mn(PTA)-MOFs. As anodes for Li ion batteries, these morphologies showed great influence on the electrochemical properties. Owing to the abundant porous structure and unique architecture, the MnO/C spindle-like microrods demonstrated superior electrochemical properties with a high reversible capacity of 1165 mAh g–1 at 0.3 A g–1, excellent rate capability of 580 mAh g–1 at 3 A g–1, and no considerabl...

Negative Poisson’s ratio of polymeric foam can be obtained by using the thermal transformation method to convert cell shape from convex to reentrant ones. In this work, the large-deformation finite element analysis is performed to quantify the magnitudes of compression and temperature for subsequent heat treatment to reduce elastic recovery, such that the reentrant shape can be maintained when the compression is removed. The amount of compression and temperature for heat treatment that can produce NPR foam can be used as a guide for experimental investigations, instead of trial-and-error methods to determine manufacturing parameters.

Kinetically formed metastable molecular assemblies have attracted increasing interest especially in the field of supramolecular polymers. In most cases, metastable assemblies are ensemblies of aggregates based on the same supramolecular motif but with different lengths or sizes, and therefore their kinetic stabilities are experimentally indistinguishable. Herein, we demonstrate a topological effect on kinetic stabilities in a complex mixture of metastable supramolecular polymers. Our azobenzene-incorporated monomer upon heating in nonpolar solvent at ambient temperature kinetically forms complex mixtures of supramolecular polymers with cyclized and open-ended randomly coiled topologies. Upon further heating, we obtained thermodynamically stable twisted fibrils organizing into crystalline fibers. Through the direct visualization of the complex supramolecular polymer mixtures by atomic force microscopy, we demonstrate that the cyclized supramolecular polymer has superior kinetic stability compared to the open-ended species toward the thermal transformation into twisted fibrils. Since the superior kinetic stability of the cyclized species can be attributed to the absence of aggregate termini, we could convert them fully into the thermodynamic species through photoinduced opening of the cyclized structures.

Organic crystals are easily cracked into pieces or powders under applied stress because of their intrinsic brittle nature. This undesired mechanical property directly limits their application in flexible optical and optoelectronic devices. Herein, we developed a compact single-benzene molecule dimethyl 2,5-bis((2-hydroxyethyl)amino)terephthalate, which was easily crystallized to form two polymorphs, A and B. Featuring a single-benzene π-system, both polymorphs A and B display red fluorescence in crystals. More importantly, crystals of polymorph A are flexible and can be elastically bent under mechanical force. Given these advantages, a flexible optical waveguide has been realized in the crystal of polymorph A with a bent shape, highlighting its potential application in flexible devices. In addition, the thermal transformation of crystals from polymorph A to polymorph B, which was accompanied by the change of optical property as well as mechanical elasticity, has been observed.

Hierarchical NaV6O15 flower-like structures were successfully synthesized via a facile hydrothermal reaction combined with subsequent thermal transformation. The as-prepared NaV6O15 microflowers are composed of many nanoneedles with a width of about 200 nm and a length of several micrometers. The electrochemical performance of NaV6O15 microflowers as cathodes for both lithium and sodium ion batteries are investigated. High first discharge capacities of 255 mA h g−1 (vs. Li+/Li) and 130 mA h g−1 (vs. Na+/Na) are observed and the capacity retention reaches 105% and 64% after 50 cycles under 4–1.5 V at a current density of 100 mA g−1 and 50 mA g−1, respectively. High lithium/sodium ion diffusion coefficients play an important role in improving the electrochemical performance of NaV6O15 microflowers.

Magnetic and structural properties of Sn-substituted Mn 2 Sb were investigated. A first-order magnetic transition (FOMT) from a ferrimagnetic (FRI) to an antiferromagnetic state occurred between 100 and 200 K, which was accompanied by an iso-structural transformation. Upon cooling in 5 T, the residual FRI phase was observed even at 10 K, and the residual FRI phase slightly decreased with increasing time. The results indicate that the FOMT of Mn 2 Sb 0.9 Sn 0.1 is arrested by applying a magnetic field.

Hellenistic ceramics and a clay sample from the archaeological site of Qizlar Qal'eh in Gorgan plain, northeastern Iran were examined through microchemical, mineralogical and thermogravimetric–differential thermal analyses to characterize the provenance and thermal behavior of the ceramics from Seleucid and early Parthian periods (2268 ± 111BP, thermo-luminance date). Microstructural and mineralogical characteristics of the ceramics were also compared to the raw clay sample heated at two different heating rates. Thermal transformation of minerals and weight loss during firing indicate that the ceramic samples were locally produced and fired at different thermal stages at 718.1 °C and 1023.8 °C, 1047.7 °C which can be related to mineral decomposition, new-crystallization, partial sintering and sintering.

This work investigates the effect of clinoptilolite, a natural zeolite, as filler on the mechanical performance and heavy metal's adsorption capacity of the metakaolin-based geopolymers. Clinoptilolite was chosen as an inexpensive additive with high adsorption capacity, replacing metakaolin (0, 25, 50 and 75%) in the synthesis of four different geopolymers (MK100, MK75, MK50 and MK25, respectively). To produce geopolymers with low environmental impact, during the geopolymerization processes the SiO2/Al2O3 and Na2O/Al2O3 molar ratios were kept constant at 1, to reduce sodium silicate and sodium hydroxide to a minimum. The final products were studied by powder X-ray diffraction, Al-27 and Si-29 solid-state NMR and Scanning electron microscopy. Moreover, strength parameters and heavy metals Pb2+, Zn2+, Cu2+, Cd2+ and Cr3+ adsorption tests were performed. The results show that geopolymerization in the presence of zeolite leads to an increase of the compressive strength of all blended geopolymers, with an optimal metakaolin precursor/zeolite filler ratio of 50:50, affording the highest strength (8.8 MPa at 28 days). The adsorption of metal cations on geopolymers was well fitted using the Langmuir model (0.97 < R-2 < 0.99). The geopolymers adsorbed heavy metals in the order Pb2+ > Cd2+ > Zn2+, Cu2+ > Cr3+ The maximum adsorption capacity of Cu2+ and Cr3+ was highest for geopolymer with 100% of metakaolin (MK100), while for Pb2+, Cd2+ and Zn2+ the highest adsorption capacity is for geopolymers with 75% of metakaolin (MK75), indicating that 25% zeolite addition to geopolymers has efficiently improved the adsorption capacity. (C) 2016 Elsevier B.V. All rights reserved.

Zinc hydroxide chloride, Zn5(OH)8Cl2·H2O, belongs to a special group of layered materials which are used in a wide variety of commercial applications. During the heating, Zn5(OH)8Cl2·H2O undergoes a complex transformation which involves several overlapping stages and highly depends on the experimental conditions. Although it is well established that the thermal transformation of Zn5(OH)8Cl2·H2O leads to the formation of ZnO as final product, there is still no generally accepted mechanism explaining the intermediate stages of this process. This review provides a summary of the studies devoted to this topic complemented by critical data assessment and generalisation of the established information. We hope that the review conveys to the reader state of the art of this problem and provides baseline knowledge required for complete understanding of thermal behaviour of this material.

New quaternary A2MSn3S8 (A ​= ​alkali metals; M ​= ​Zn, Cd) sulfides were synthesized and characterized by X-ray diffraction and spectroscopic methods. α-Cs2ZnSn3S8(1), α-Rb2ZnSn3S8(2) and α-Cs2CdSn3S8(3) have layered tetrahedral [MSn3S8]2- frameworks, in which Zn2+, Cd2+ and Sn4+ ions are ordered. No such ordering is present in three-dimensional tetrahedral [MSn3S8]2- framework of β-Cs2ZnSn3S8(4), β-Rb2ZnSn3S8(5), β-Cs2CdSn3S8(6) and β-Rb2CdSn3S8(7) compounds. The β-modifications undergo thermal transformation to α–modifications. K2CdSn3S8(8) and Na2CdSn3S8(9) have a new type of layered structure, in which Cd2+ and Sn4+ ions are octahedrally coordinated and disordered in [CdSn3S8]2- framework. Their potassium and sodium ions undergo facile ion-exchange with mono-, di- and trivalent cations at room temperature. The Raman spectra and band gap values of compounds 1–9 corroborate their structural differences.

Summary Two main types of the Bazhenov suite are distinguished, differing by the degree of catagenetic transformation. The first type is common in low-temperature areas and is characterized by weak thermal transformation, and the second, on the contrary, occurs in high-temperature areas exposed to tectono-hydrothermal effects, and therefore the organic matter that is part of the Bazhenov suite is here thermally transformed and metamorphosed to various degrees metamorphosed bitumen. Various ways of developing the Bazhenov suite in low-temperature and high-temperature areas are proposed.

The evolution of the core structure and change of the Peierls stress with temperature are investigated for the 1 2 ⟨ 110 ⟩ { 111 } screw dislocation in aluminum using the fully discrete Peierls theory. It is found that there are two different core structures and the core structure may be thermally transformed from one to the other. The critical temperature for transformation is about T ∼ 700 K. The Peierls stress at the critical temperature has the minimum σ p ∼ 0.6 MPa, which is much smaller than σ p ∼ 3 MPa at room temperature.

As plasticizers and flame retardants, highly chlorinated paraffin (CP70) and related products will experience thermal processes during their lifecycle stages. However, the thermal transformation data for CP70 is limited. In this study, we investigated the release and transformation of chlorinated and unchlorinated products during the thermal decomposition of CP70. Large quantities of short- and medium-chain chlorinated paraffins (SCCPs and MCCPs) and unsaturated analogues (Cl-polyenes or chlorinated olefins) as well as toxic chlorinated aromatic hydrocarbons were formed synergistically under different thermal conditions. The yield of SCCPs increased gradually in the gas phase, while it decreased in the residue at 200–400 °C. SCCPs can be transformed further and generated mostly polychlorinated biphenyls (PCBs). Oxygen promoted the thermal transformation of SCCPs and MCCPs and decreased the yield in the gas phase at >400–500 °C. In contrast, the yield of both SCCPs and MCCPs increased notably under N2 at 8...

Research in smart textiles and garments has mostly focused on integrating sensing technology. In order to make garments that are truly interactive it is also essential to develop technologies for actuating smart garments and textiles. This paper introduces ShapeTex, a thermal shape changing fabric that uses laminate thermal expansion to actuate textiles. We present the design process and rationale for ShapeTex; we explain the fabrication process we have developed for making ShapeTex accessible to fashion designers and interaction designers. Based on co-creation sessions with designers we discuss requirements derived from this material. Finally we present a number of concept prototypes created to explore and illustrate the potential applications of ShapeTex.

The Co 3 O 4 nanosheets electrode have been fabricated on Ni foam by a facile synthesis process including the electrodeposition of Co(OH) 2 precursor followed by subsequent thermal transformation of precursor to Co 3 O 4 . The resulting Co 3 O 4 nanosheets electrode exhibits an ultrahigh specific capacitance of 6469 F g −1 at a current density of 5 mA cm −2 , exceeding their theoretical value. Moreover, at density of 15 mA cm −2 , the specific capacitance maintains 4127 F g −1 , with 81.6% retention after 2000 charge-discharge cycles. The work confirms the promising application of Co 3 O 4 nanosheets as an efficient electrode for supercapacitors, and also offers a facile strategy to design and synthesis Co 3 O 4 electrode with enhanced specific capacitance.

The influence of carbon additives with different texture on the thermal transformation of coal pitch is studied. The additives considered are Kemerit carbon nanomaterial, Taunit M nanotubes, AG-3 active coal, and graphite foam. All the additives increase the yield of solid residue and reduce the emissions of volatiles from pitch destruction, including carcinogens. The greatest increase in yield of the solid residue (up to 15%, rel.) is obtained with Kemerit carbon nanomaterial. However, the carbon material formed is more disordered than for individual pitch. Adding 5% of crystalline carbon (graphite foam) catalyzes the formation of graphite structures in the thermal destruction of pitch; their content in pitch carbonized at 900°C may be as much as 30%. At the same time, adding graphite foam reduces the content of carcinogens in the volatile destruction products of the pitch more effectively than adding amorphous carbon additives.

Three different kaolins (K1, K2, K3) from sources in Cameroon were applied for producing geopolymer cements. The kaolins differ significantly in their gibbsite and quartz contents. Thermal transformation (700 °C, 4 h) into their metakaolins MK1, MK2, MK3 shows the total loss of crystalline kaolinite and reveal the typically rather broad bump in the X-ray pattern. Gibbsite becomes dehydrated into γ and χ-Al 2 O 3 . Geopolymer cements (GP1, GP2, GP3) were obtained using freshly prepared sodium silicate solutions (NWG) with a ratio NWG/MK = 0.87. It could be observed that the initial (60/80/90 min) and final (90/140/160 min) setting time increases and their 28 day compressive strength (49/39/30 MPa) decreases in the course GP1/GP2/GP3. It is discussed that the higher content of quartz in K1 (up to 22 wt.%), compared to K2 (10 wt.%) and K3 (8 wt.%) promotes higher strength values and decreased setting times. Gibbsite was not present in K1, but up to 11 wt.% in K2 and 28 wt.% in K3, transformed in its dehydrated forms remains unreacted during geopolymerization. Therefore, the higher content of gibbsite in the kaolinite could be related to a lower strength. The reacted volumes and compositions of the geopolymer become almost the same in all three cases. A content of 30–50% of unreacted metakaolin was proved in all cases.

Gadolinium tartrate (Gd 2 (C 4 H 4 O 6 ) 3 ⋅6H 2 O) complexes with microrods morphology have been synthesized by direct precipitation in solution at room temperature. The structure of Gd 2 (C 4 H 4 O 6 ) 3 ⋅6H 2 O was determined by XRD, EDS, FT-IR, and TGA–DSC analysis. The morphology was characterized by SEM method. The solvent-dependent morphological evolution and the formation mechanism of the Gd 2 (C 4 H 4 O 6 ) 3 ⋅6H 2 O microrods were investigated in detail. Furthermore, the Gd 2 O 3 and Eu 3+ -doped Gd 2 O 3 microrods, which inherit their parents’ morphology, were obtained through annealing gadolinium tartrate in air. Both Gd 2 (C 4 H 4 O 6 ) 3 ⋅6H 2 O:Eu 3+ and Gd 2 O 3 :Eu 3+ exhibit strong red emission corresponding to the 5 D 0 → 7 F 2 transition of the Eu 3+ ions under UV light excitation. This general and facile method may be of significance in the synthesis of many other oxides with one dimensional morphology.

The monograph addresses the development of the theoretical foundations for the improvement of thermal transformation technologies for their competitive implementation in the designed and modernized heat and cold supply systems. Modern methods of thermo-economic analysis and optimization of thermal transformers are widely used in the work, the synthesis of their technological schemes is considered. Original methods have been developed for testing the thermodynamic perfection of modern refrigeration machines and heat pumps, as well as evaluating their technical, economic, and environmental indicators when working in heat and cold supply systems. Methods of thermo-economic optimization of steam compressor thermo-transformers using substances of natural origin as a refrigerant are proposed. The book is designed for engineers and scientists in the field of energy and low-temperature technology, and is of interest to graduate students and students of relevant specialties.

Novel chrysanthemum-like 3D hierarchical magnetic γ-Fe2O3 and Fe3O4 superstructures self-assembled by nanobelts have been successfully synthesized through a simple one-pot solvothermal route without using structure-directing additives. The morphology and structure of the sample depend strongly on the reaction time. γ-Fe2O3 and Fe3O4 with superparamagnetic properties were obtained by thermal transformation of the precursor without changing the overall architectures. A possible formation mechanism of the chrysanthemum-like 3D hierarchical precursor was proposed. The BET surface area and the magnetic properties of the prepared γ-Fe2O3 and Fe3O4 were investigated. In addition, the adsorption capacity of the as-prepared magnetic iron oxide for organic pollutants was also determined by using 2,4-dichlorophenol and 2,4,6-trichlorophenol as probe pollutants.