Thermogravimetric Analysis And Differential Scanning Calorimetry Research Articles

Enhanced photoreduction efficiency of Cr(VI) driven by visible light in a new Zr-based metal-organic framework modified by hydroxyl groups.

While metal-organic framework (MOF) photocatalysts have demonstrated a unique Cr(VI) photoreduction capability in recent decades, their performance is still insufficient for practical applications because of their low Cr(VI) uptake and poor visible light response. To cope with these drawbacks, a new OH-modified Zr-based MOF, termed HCMUE-1, was successfully prepared via a solvothermal method in this work. The complete characterization of HCMUE-1 was performed through various techniques, including powder X-ray diffraction (PXRD), Raman spectroscopy, Fourier transform infrared (FT-IR), thermogravimetric analysis and differential scanning calorimetry (TGA-DSC), scanning electron microscopy combined with energy-dispersive X-ray (SEM-EDX), and X-ray photoelectron spectroscopy (XPS). The obtained data exhibited the excellent Cr(VI) photoreduction efficiency of HCMUE-1, reaching up to 98% after 90 min and almost 100% after 120 min under visible light illumination in a low acidic medium. Noteworthily, HCMUE-1 retained the same Cr(VI) removal rate for at least seven cycles without considerable loss. Further experimental investigations demonstrated that the structural stability and surface morphology of HCMUE-1 were retained after photoreduction. Moreover, the photocatalytic reduction mechanism of Cr(VI) to Cr(III) was interpreted through a series of systematic experimental measurements. These results indicate that HCMUE-1 possesses potential as an efficient photocatalyst for reducing toxic Cr(VI) species from wastewater in real-life conditions.

Terahertz spectroscopy research on motion‐limited molecular chain of random polymethacrylate

AbstractIn this study, an innovative method was used to examine the impact of gamma‐ray irradiation on three specific monomers: methyl methacrylate (MMA), hexyl methacrylate (HMA), and lauryl methacrylate (LMA). The primary objective was to produce corresponding polymers—polymethyl methacrylate (PMMA), polyhexyl methacrylate (PHMA), and poly(lauryl methacrylate) (PLMA). The significance of the research was determined by conducting a thorough analysis of the thermal properties and structural characteristics of these polymers using advanced techniques, including thermogravimetric analysis and differential scanning calorimetry (TGA‐DSC), as well as Fourier transform infrared spectroscopy (FTIR). The results indicated that irradiation at a 30 kGy dose caused distinct decomposition of ester groups within the polymer matrices. Additionally, a clear trend was observed in the maximum exothermic temperature among the three polymers, with PMMA exhibiting the lowest temperature, followed by PLMA, and PHMA with the highest temperature. Surprisingly, when the radiation dose exceeded 30 kGy, PHMA's thermal stability peaked, demonstrating remarkable resistance to further changes. This highlights the crucial role of radiation dosage in adjusting polymer thermal properties. Furthermore, analysis of infrared characteristic peaks identified a critical radiation dose range between 15 and 30 kGy, where polymerization was efficiently promoted without generating extra by‐products, showcasing experimental ingenuity. Lastly, optical properties of the synthesized polymers were explored using THz time‐domain spectroscopy. Results showed intriguing changes in refractive indices following 30 kGy dose irradiation. Specifically, MMA and HMA exhibited moderate refractive index increases, while LMA displayed a significant decrease. Notably, PHMA demonstrated substantial absorption reduction beyond 15 kGy doses, with minimal further changes, highlighting the potential to customize polymer optical properties through controlled irradiation.

Preparation of High-Ductility Cement-Calcined Coal-Gangue-Powder-Composite-Based Rapid Repair Material.

Coal gangue is a kind of solid waste. A high-ductility cement-calcined coal-gangue-powder-composite-based rapid repair material (HD-RRM) was prepared by partially replacing cement with calcined coal gangue powder (CCGP) for achieving high ductility and rapid hardening and conforming to the strength requirements of pavement layers. First, the physical and chemical properties and the reactivity of the CCGP were investigated. Second, HD-RRM material was prepared, and its tensile performance characteristic parameters were investigated. Lastly, the hydration products and microstructure of HD-RRM were characterized through tests (e.g., non-evaporable water content, scanning electron microscopy (SEM), X-ray diffraction (XRD), and comprehensive thermogravimetric analysis and differential scanning calorimetry (TG-DSC)). As indicated by the experimental results, the CCGP with a particle size of 1250 mesh exhibited the maximum potential reactivity. The optimal mixing ratio for HD-RRM in the experiments comprised a water-cement ratio of 0.27, a sand-cement ratio of 0.3, a fiber volume fraction of 2%, a cement content of 70%, a CCGP content of 20%, a fly ash (FA) content of 10%, and a superplasticizer content of 0.1%. Using the abovementioned mix design, the prepared HD-RRM was endowed with a 6 h ultimate elongation of 2.75%, an ultimate tensile strength of 7.58 MPa, a compressive strength of 45.4 MPa, and an average crack width of 125.53 μm, which meets the requirements of repair materials and provides a design method for CCGP resource utilization and asphalt concrete road and bridge deck repair.

Comparative analysis of natural fibres characteristics as composite reinforcement

Due to environmental concerns, natural fibre development is essential, and its utilization has recently attracted more attention. The use of jute, hemp, linen, sisal, and banana fibres in textile production is widespread around the world. Additionally, these fibres are widely accessible in many countries, including Pakistan, India, China, Turkey, and the United States. The objective of this study is to compare the physio-mechanical characteristics of the aforementioned natural fibres. All of these fibres were obtained locally. Scanning electron microscopy was used to examine the surface morphology of these natural fibres, and the results revealed that banana and sisal fibres are hollow in comparison to other fibres. A single fibre tensile testing apparatus was used to evaluate the mechanical characteristics. Banana and sisal fibres demonstrated the highest breaking strength and elongation, respectively. Fourier transform infrared spectroscopy was used to investigate the functional groups of these natural fibres. Differential scanning calorimetry and thermogravimetric analysis were used to investigate their thermal behaviour. Energy Dispersive X-Ray Analysis and Raman analysis were also carried out to ascertain the chemical composition.

Thermal Decomposition of Siderite and Characterization of the Decomposition Products under O2 and CO2 Atmospheres

Siderite (FeCO3) is an iron-bearing carbonate mineral that is the most abundant sedimentary iron formation on Earth. Mineralogical alteration of four siderite samples annealed at temperatures 200 °C, 300 °C, 400 °C, 500 °C, 750 °C, and 1000 °C in an O2 and a CO2 atmosphere were investigated using such tools as X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), the X-ray fluorescence (XRF) method, differential scanning calorimetry and thermogravimetric analysis (DSC/TGA), and Mössbauer spectroscopy measurements. The decomposition of three siderite samples with similar iron content in the oxygen atmosphere took place in the temperature range of 340–607 °C. This process begins at approximately ~100 °C higher under a reducing atmosphere, but it is completed just above 600 °C, which is a temperature comparable to decomposition in an oxidizing atmosphere. These processes are shifted toward higher temperatures for the fourth sample with the lowest iron but the highest magnesium content. Magnetite, hematite, and maghemite are products of siderite decomposition after annealing in the oxygen atmosphere in the temperature range 300–500 °C, whereas hematite is the main component of the sample detected after annealing at 750 °C and 1000 °C. Magnetite is the main product of siderite decomposition under the CO2 atmosphere. However, hematite, maghemite, wüstite, and olivine were also present in the samples after annealing above 500 °C in this atmosphere.

Catalytic Design of Matrix-Isolated Ni-Polymer Composites for Methane Catalytic Decomposition.

Targeted synthesis of C/composite Ni-based material was carried out by the method of matrix isolation. The composite was formed with regard to the features of the reaction of catalytic decomposition of methane. The morphology and physicochemical properties of these materials have been characterized using a number of methods: elemental analysis, scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, temperature programmed reduction (TPR-H2), specific surface areas (SSA), thermogravimetric analysis, and differential scanning calorimetry (TGA/DSC). It was shown by FTIR spectroscopy that nickel ions are immobilized on the polymer molecule of polyvinyl alcohol, and during heat treatment, polycondensation sites are formed on the surface of the polymer molecule. By the method of Raman spectroscopy, it was shown that already at a temperature of 250 °C, a developed conjugation system with sp2-hybridized carbon atoms begins to form. The SSA method shows that the formation of the composite material resulted in a matrix with a developed specific surface area of 20 to 214 m2/g. The XRD method shows that nanoparticles are essentially characterized by Ni, NiO reflexes. The composite material was established by microscopy methods to be a layered structure with uniformly distributed nickel-containing particles 5-10 nm in size. The XPS method determined that metallic nickel was present on the surface of the material. A high specific activity was found in the process of catalytic decomposition of methane-from 0.9 to 1.4 gH2/gcat/h, XCH4, from 33 to 45% at a reaction temperature of 750 °C without the stage of catalyst preliminary activation. During the reaction, the formation of multi-walled carbon nanotubes occurs.

Impact of biochemical composition on the pyrolysis products of cork oak (Quercus suber) samples

The impact of biochemical composition (cellulose, hemicelluloses, lignin, and suberin) on the products of pyrolysis of lignocellulosic biomass was investigated. A comparative study using double-shot pyrolysis of cork, branches and leaves of cork oak (Quercus suber) was conducted. Differential scanning calorimetry and thermogravimetric analysis (DSC-TGA) demonstrated 350 °C and 550 °C to be the optimal temperatures for the two shots. Leaves and branches released mainly polysaccharide derivatives in the first shot and produced phenols in the second shot, while cork mainly released ketones in the first shot and produced aliphatic hydrocarbons in the second shot. Higher selectivities in high added-value chemicals, such as benzofurans (20.3 %) and ketones (26.5 %) were respectively achieved for leaves and branches at 350 °C whereas aliphatic hydrocarbons (48.8 %) were mainly obtained from cork at 550 °C.

Enhanced up-conversion emission of fluoride phosphor in the dual-fuel system under 1550 nm excitation

A 1.5 μm multi-component fluoride nanocrystal PbxNay-nLinYzF2x+y+3z+3m: Er3+m was synthesized by the low temperature combustion synthesis (LCS) method. On the basis of the orthogonal experiment and optimization experiment, Li+ ion was introduced into the matrix and the dual-fuel system was established, and the up-conversion luminescence intensity was enhanced by changing the matrix composition and improving the process methods. The results show that when the concentration of Li+ ion is 2.07 mol%, the fuel consumption in the dual-fuel system is 2.2 stoi., 0.7 stoi., the up-conversion luminescence intensity is obviously improved. The structure and morphology of samples were analyzed by the X-ray diffraction (XRD) and scanning electron microscopy (SEM), and a schematic model of physical mechanism for the luminescence intensity of Li+ ion enhanced materials was confirmed. The exothermic characteristics of the dual-fuel system were analyzed by the differential scanning calorimetry and thermogravimetric analysis (DSC-TGA). The influence of the introduction of Li+ ion and the dual-fuel system on the luminescence intensity was discussed in detail.

Effects of elevated temperature on the mechanical properties of concrete with aggregate of waste porcelain tile

The waste porcelain tile can be used as recycled aggregate in concrete, which will reduce the environmental pollution and alleviate the shortage of natural aggregate. The effects of waste porcelain tile of the mechanical properties of concrete at room temperature were positive. However, the properties of concrete with waste porcelain tile exposed to elevated temperature were unclear. In this experimental study, 45 groups of 100mm × 100mm × 100 mm and 15 groups of 100mm × 100mm × 300 mm specimens were prepared, and 180 specimens of concrete were heated to the target temperature. Variables included aggregate substitution rate (0%, 50%), aggregate categories (coarse and fine aggregate), and exposure temperature (25, 200, 400, 600, and 800 °C). Combining X-ray fluorescence spectrometry (XRF), X-ray diffractometry (XRD), scanning electron microscopy (SEM), and thermogravimetric analysis and differential scanning calorimetry (TGA-DSC), the effects of high temperature on the concrete properties with waste porcelain tile recycled aggregate were investigated. The results showed that the mass loss of concrete with porcelain tile aggregate increased with increasing temperature. The compressive strength of concrete with porcelain tile coarse aggregate gradually decreased with rising temperature. The compressive strength of concrete with porcelain tile fine aggregate increased by 0.8% after being heated at 200 °C. The reduction in splitting tensile strength of concrete with porcelain tile aggregate was slight after exposure temperature below 200 °C. The elastic modulus of porcelain tile coarse and fine aggregate concrete decreased with rising temperature. After being heated at 600 °C, the elastic modulus of porcelain tile coarse and fine aggregate concrete decreased by 90.5% and 89.6%, respectively, compared with room temperature. It is recommended that waste porcelain tile fine aggregate should be used in recycled concrete in preference to porcelain tile coarse aggregate.

Extraction of Gold from the Leachate of Copper Anode Slime by Quaternary Ammonium Rice Husk Lignin

ABSTRACT Extraction of gold by adsorption is being concerned because of easy operation, low cost and non-pollution for the present. Lignin and its derivatives are considered to be the most promising adsorbent due to abundance and environmental friendliness. In this work, gold was extracted from the leachate of copper anode slime by quaternary ammonium rice husk lignin (QARHL). QARHL was synthesized and characterized by Fourier Transform Infrared Spectrometry (FTIR), Scanning Electron Microscope-Energy Dispersive Spectrometer (SEM-EDS) and Thermogravimetric Analysis and Differential Scanning Calorimetry (TG-DSC). The influence of adsorption time, dosage of adsorbent and temperature on adsorption were investigated. The adsorption mechanism of QARHL for gold was explored by Scanning Electron Microscope (SEM), FTIR and X-ray Diffractometry (XRD). The results showed that QARHL had excellent thermostability and contained a large number of quaternary ammonium groups and hydroxyl groups. The saturated adsorption capacity reached 220.70 mg•g-1 and the time of equilibrium was 120 min. The adsorption was easy to occur spontaneously and obeyed the models of pseudo-second order and Langmuir. AuCl4- was reduced to Au(0) by phenolic hydroxyl after ion exchange. The new process could be used to recovery gold from gold-containing raw materials without pretreatment. It is possible to extract gold effectively, economically and environmentally friendly.

PH and pCl Operational Parameters in Some Metallic Ions Separation with Composite Chitosan/Sulfonated Polyether Ether Ketone/Polypropylene Hollow Fibers Membranes.

The development of new composite membranes is required to separate chemical species from aggressive environments without using corrective reagents. One such case is represented by the high hydrochloric acid mixture (very low pH and pCl) that contains mixed metal ions, or that of copper, cadmium, zinc and lead ions in a binary mixture (Cu–Zn and Cd–Pb) or quaternary mixture. This paper presents the obtaining of a composite membrane chitosan (Chi)–sulfonated poly (ether ether ketone) (sPEEK)–polypropylene hollow fiber (Chi/sPEEK/PPHF) and its use in the separation of binary or quaternary mixtures of copper, cadmium, zinc, and lead ions by nanofiltration and pertraction. The obtained membranes were morphologically and structurally characterized using scanning electron microscopy (SEM), high resolution SEM (HR–SEM), energy dispersive spectroscopy analysis (EDAX), Fourier Transform InfraRed (FTIR) spectroscopy, thermogravimetric analysis, and differential scanning calorimetry (TGA-DSC), but also used in preliminary separation tests. Using the ion solutions in hydrochloric acid 3 mol/L, the separation of copper and zinc or cadmium and lead ions from binary mixtures was performed. The pertraction results were superior to those obtained by nanofiltration, both in terms of extraction efficiency and because at pertraction, the separate cation was simultaneously concentrated by an order of magnitude. The mixture of the four cations was separated by nanofiltration (at 5 bars, using a membrane of a 1 m2 active area) by varying two operational parameters: pH and pCl. Cation retention could reach 95% when adequate values of operational parameters were selected. The paper makes some recommendations for the use of composite membranes, chitosan (Chi)–sulfonated poly (ether ether ketone) (sPEEK)–polypropylene hollow fiber (Chi/sPEEK/PPHF), so as to obtain the maximum possible retention of the target cation.

Spontaneous combustion of wheat straw residue at different cooling temperatures: Combined effect of water sorption and air oxidation

Self-heating and spontaneous combustion of torrefied biomass are direct hazards related to the production, storage and transport of torrefied biomass. In this study, we investigated the effect of combined air oxidation and water sorption on self-heating of torrefied agricultural residue biomass at 60, 120 and 180 °C cooling temperatures by measuring weight change and heat flow using thermogravimetric analysis and differential scanning calorimetry (TGA/DSC). Our results showed that the effect of water adsorption predominated at 60 °C. When the gas stream was changed from nitrogen to humid nitrogen, the weight of the torrefied biomass increased rapidly associated with heat generation. Conversely, at 180 °C, the effect of air oxidation predominated and the torrefied biomass decreased rapidly when it was exposed to dry air associated with heat generation. The effect of water adsorption decreased with an increase in the cooling temperature whereas the effect of air oxidation increased with an increase in temperature. The higher torrefaction severity increases the self-heating propensity. The air oxidation and water adsorption may lead to the self-heating of torrefied biomass.

Mechanistic Study on the Impact of the Occurrence of Various Basic Mineral Species on Spontaneous Combustion Propensity of Alkali‐Rich Low‐Rank Coal

AbstractSpontaneous combustion of low‐rank coal, especially alkali‐rich coal, is a key issue that determines the safety of storage and transportation. To understand the role of different forms of Alkali and alkaline earth metals (AAEMs) on coal spontaneous combustion, AAEMs in raw coal were sequentially eluted by water, ammonium acetate (NH4OAc) and hydrochloric acid (HCl) solution. The occurrence forms and mineralogical characteristics of AAEMs in raw coal and its derived coal samples were investigated. Further, the spontaneous combustion tendency of raw coal and derived coal samples was measured by programmed heating process and the chemical structure parameters were characterized by thermogravimetric analysis and differential scanning calorimetry (TGA‐DSC) and in situ infrared spectroscopy. The results show that demineralization mitigates the spontaneous combustion tendency by the increasing the ignition temperature, confirming the enhancement of inherent mineral on low‐temperature oxidation. In situ infrared spectroscopy results suggest that acid‐soluble and ion‐exchangeable AAEMs have greater catalytic impact on the oxidation reaction of coal than water‐soluble AAEMs. Specifically, the complete removal of AAEMs by acid‐washing treatment has the most obvious effect on the change of oxygen‐containing functional groups, which greatly reduces the generation rate of carboxylic acid, ester and anhydride groups during the low temperature oxidation. Moreover, calcium elements including ion‐exchangeable calcium and HCl‐soluble calcium can promote the oxidation capacity of coal at low‐temperature, which were verified by loaded coal samples.

Production of 5-Hydroxymethylfurfural from glucose using Al2O3-TiO2-ZrO2 ternary catalysts

In this work, mixed oxides Al2O3-TiO2-ZrO2 were evaluated varying their composition (% w/w) for the conversion of monosaccharides (fructose and glucose) to 5-hydroxymethylfural (HMF). Materials were characterized using Thermogravimetric Analysis and Differential Scanning Calorimetry (TGA-DSC), Nitrogen Physisorption (N2), X-ray Diffraction (XRD), RAMAN Spectroscopy, DRS UV-Vis Spectroscopy, Infrared Spectroscopy (FTIR), SEM, TEM, FTIR-Pyridine and Temperature Programmed Desorption of CO2 (TPD-CO2). The reactions were carried out at 175 °C and 30 bar of Ar pressure in a biphasic system (THF/H2O) for 3 h, obtaining a 78% maximum yield of HMF from the glucose and 63% yield from fructose. The materials studied carried out a direct dehydration of the monosaccharides to HMF in 30 min of reaction and were obtained as intermediates to dehydrate levulinic acid (LA) and formic acid (FA), these intermediates were analyzed and eluted using 1H NMR technique.

Mineralogy and geochemistry of clay fractions in soils developed from different parent rocks in Limpopo Province, South Africa

This study investigates the mineralogical and geochemical characteristics of clay fractions in soils developed from different parent rocks in Limpopo Province, South Africa using the X-ray diffraction (XRD), X-ray Fluorescence (XRF) Spectrometry, Laser Ablation – Inductively Coupled Plasma – Mass Spectrometry (LA-ICP-MS), Fourier Transform Infrared (FTIR) Spectrophotometry, Thermogravimetric Analysis and Differential Scanning Calorimetry (TGA-DSC) analytical techniques. Health risk associated with the presence of some trace elements was also investigated. The results revealed that the clay fractions had kaolinite as the dominant clay component occurring with other weatherable minerals. The crystallinity based on FTIR for the soil kaolinites correspond to partially - poorly ordered structures. The geochemical data showed appreciable accumulation of trace elements in the clay fractions. The absence of negative Ce anomaly in the chrondrite-normalised rare earth elements (REE) pattern in the clay fractions suggest the alteration of the primary minerals took place under suboxic conditions. The average non-carcinogenic hazard index (HI) were 1.52, 1.08, and 2.01 for children and 0.18, 0.13, and 0.24 for adults in the clay fractions from basalt, granite, and arkosic sandstone, respectively. The HI > 1 for children suggest non-carcinogenic health risk to children with ingestion pathway contributing the highest. The average carcinogenic risk index values were >10−3 for children and adults with respect to Cr, Ni, and Pb in the clay fractions. This suggests very high carcinogenic risk to children and adult population in decreasing order from clay fractions in arkosic sandsone > basalt > granite, respectively.

Synthesis, Characterization, and Properties of Rivaroxaban New Crystalline Forms

AbstractIn this paper, two new Rivaroxaban crystalline forms are reported and characterized by the single‐crystal X‐ray diffraction (SXRD), powder X‐ray diffraction (PXRD), thermogravimetric analysis, and differential scanning calorimetry (TGA/DSC), which are synthesized with formic acid and acetic acid, named as forms F and G, respectively. The intermolecular forces for forms F and G are analyzed by Hirshfeld surface analysis method, showing that the force of O···H is significantly stronger than that of H···H. Furthermore, the stability, solubility, and bioavailability of the two crystal forms are also studied. The clinical experiments show that form F is more effective than other reported crystal forms in inhibiting the activity of thrombin and thrombosis, which is expected to replace the marketed crystalline forms in clinical application.

Degradation of Plasticized Poly(1-chloroethylene) Waterproofing Membranes used as a Building Material

In the present work, both unused plasticized poly(1-chloroethylene) membranes and membranes taken from a flat roof area were comprehensively analysed. First, tensile strength and elongation at breaking points were determined, followed by measurements of wettability. Secondly, morphological changes were analysed using scanning electron microscopy (SEM). To study chemical changes in aged membranes, Fourier transform infrared spectroscopy (FTIR) analysis in the attenuated total reflection mode (ATR) was used. Finally, thermogravimetric analysis and differential scanning calorimetry (TGA-DSC) were performed simultaneously to study thermal degradation. The results show obvious changes in the mechanical, physical and chemical properties of membranes caused by plasticizer loss. Surface microstructure becomes stiffer, which leads to contractions and the prevalence of voids. In cross-sectional area, average thickness values decrease. Due to the degradation of the plasticized waterproofing membranes, the roofing area had to be completely replaced.

Thermal Stability of Mg/TeO2 Priming Compositions

The insensitive ignitors with magnesium/tellurium dioxide (Mg/TeO2) priming composition installed on the spacecraft will experience a harsh thermal environment. Therefore, it is necessary to verify their availability at extreme temperatures. Differential Scanning Calorimetry and Thermogravimetric Analysis (DSC-TGA) were used to analyze the reaction process of the Mg/TeO2 priming composition. The morphology change of the Mg/TeO2 priming composition after -70 ℃6d, room temperature, 165 ℃6d were analyze by digital cameras, scanning electron microscope (SEM), as well as the output pressure, ignition time, function time and firing sensitivity of the Mg/TeO2 priming composition under three temperature conditions were tested. The results show that in a temperature range of -70 ℃ ~ 165 ℃, the temperature conditions have an effect on the output pressure less than 5%, the influence of high temperature conditions on ignition/ function time and sensitivity is greater than low temperature. It can be used as a priming composition for insensitive ignitors at -70 ℃ ~ 165 ℃.

Synthesis, Polymorphism and Thermal Decomposition Process of (n-C4H9)4NRE(BH4)4 for RE = Ho, Tm and Yb.

In total, three novel organic derivatives of lanthanide borohydrides, n-But4NRE(BH4)4 (TBAREB), RE = Ho, Tm, Yb, have been prepared utilizing mechanochemical synthesis and purified via solvent extraction. Studies by single crystal and powder X-ray diffraction (SC-XRD and PXRD) revealed that they crystalize in two polymorphic forms, α- and β-TBAREB, adopting monoclinic (P21/c) and orthorhombic (Pnna) unit cells, previously found in TBAYB and TBAScB, respectively. Thermal decomposition of these compounds has been investigated using thermogravimetric analysis and differential scanning calorimetry (TGA/DSC) measurements, along with the analysis of the gaseous products with mass spectrometry (MS) and with analysis of the solid decomposition products with PXRD. TBAHoB and TBAYbB melt around 75 °C, which renders them new ionic liquids with relatively low melting points among borohydrides.

Fabrication and electrochemical property of La0.8Sr0.2MnO3 and (ZrO2)0.92(Y2O3)0.08 interface for trace alcohols sensor

Abstract A mixed potential type alcohols gas sensor based on an yttrium stabilized zirconia (YSZ) electrolyte and an La0.8Sr0.2MnO3 (LSM) sensing electrode was fabricated. The influences of YSZ-LSM interface on sensing performance were studied by multiple methods including X-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive spectroscopy (EDS), thermogravimetric analysis and differential scanning calorimetry (TG-DSC) and electrochemical impendence spectroscopy (EIS). The sensor with 1150 °C-sintered interface showed an ultralow detection limit of 50 ppb alcohols (methanol and ethanol) at 500 °C in air. The response voltage was independent of water, CO, CO2 and NOx. The sensor exhibited a reasonable selectivity towards alcohols under the existence of several kinds of volatile organic compounds. Meanwhile, the sensor showed a good repeatability and a suitable long-term stability. Based on the polarization curves and EIS results, a mixed potential mechanism was proposed. These results demonstrate the promising potential of using the LSM-based sensor for human exhale test.