Decomposition Of Nitrate Research Articles

One-step aromatic acids assisted synthesis of γ-Fe2O3 nanoparticles with large surface area by thermal decomposition of ferric nitrate

Maghemite (γ-Fe2O3) has attracted much attention due to its variety of applications in many areas. However, the current preparation methods of γ-Fe2O3 still involve complicated processes and a high cost, thereby needing improvement. In this study, a novel and facile one-step solid-state method for the preparation of γ-Fe2O3 nanoparticles (NPs) is performed through the thermal decomposition of ferric nitrate (Fe(NO3)3⋅9H2O) and the addition of aromatic acids. Three aromatic acids that have different numbers of carboxyl groups (i.e., benzoic acid, phthalic acid, and trimesic acid) are used as additives and their effects on the formation of γ-Fe2O3 NPs are investigated. Furthermore, the influence of the aromatic acid/Fe(NO3)3⋅9H2O mass ratio and calcination temperature on the structural properties of the products are investigated. The structural properties, morphology, and magnetic properties of the products are analyzed through X-ray diffraction, transmission electron microscopy, scanning electron microscopy, nitrogen adsorption/desorption measurements, and magnetic measurements. The results show that the addition of aromatic acids to Fe(NO3)3⋅9H2O leads to the formation of γ-Fe2O3 NPs, and has a significant influence on the morphology of γ-Fe2O3 NPs. When the aromatic acid/Fe(NO3)3⋅9H2O mass ratio is greater than 0.5, the addition of the three aromatic acids leads to the formation of pure γ-Fe2O3. The γ-Fe2O3 NPs obtained from benzoic acid/Fe(NO3)3⋅9H2O and phthalic acid/Fe(NO3)3⋅9H2O systems do not show a well-defined morphology. In contrast, the γ-Fe2O3 NPs obtained from the trimesic acid/Fe(NO3)3⋅9H2O system are composed of a porous three-dimensional hierarchical structure and have the largest Brunauer−Emmett−Teller surface area (100.0 m2 g−1).

Elucidating the Significance of Copper and Nitrate Speciation in Cu-SSZ-13 for N2O Formation during NH3-SCR

Unwanted N2O formation is a problem that has been noted in selective catalytic reduction (SCR) where copper zeolite catalysts are utilized. With its immense global warming potential and long-term stability, elevated atmospheric N2O has already been identified as a future challenge in the war on climate change. This paper explores the phenomenon of N2O formation during NH3-SCR over Cu-SSZ-13 catalysts, which are currently commercialized in automotive emissions control systems, and proposes a link between N2O production and the local copper environment found within the zeolite. To achieve this, a comparison is made between two Cu-SSZ-13 samples with different copper co-ordinations produced via different synthesis methods. A combination of synchrotron X-ray absorption near-edge spectroscopy, UV–vis, Raman, and density functional theory (DFT) is used to characterize the nature of copper species present within each sample. Synchrotron IR microspectroscopy is then used to compare their behavior during SCR under operando conditions and monitor the evolution of nitrate intermediates, which, along with further DFT, informs a mechanistic model for nitrate decomposition pathways. Increased N2O production is seen in the Cu-SSZ-13 sample postulated to contain a linear Cu species, providing an important correlation between the catalytic behavior of Cu-zeolites and the nature of their metal ion loading and speciation.

Radiation-thermal stability of hydrazine nitrate in nitric acid solutions

The effect of temperature, HNO3 concentration and radiation dose rate on the decomposition of hydrazine nitrate in aqueous nitric acid solutions has been studied. Kinetic characteristics have been obtained for evaluating the yields of the main decomposition products of hydrazine nitrate - hydrazoic acid and ammonium nitrate. The results of the study are important for analyzing the explosion safety of technological processes with nitric acid solutions containing hydrazine nitrate.

Catalysis of the Thermal Decomposition of Transition Metal Nitrate Hydrates by Poly(vinylidene difluoride).

Poly(vinylidene difluoride) (PVDF) doped with transition metal nitrate hydrates are cast into thin films giving a high β-phase content. Analysis of the thermal behavior of the doped PVDF shows that the decomposition of the metal (II) nitrate hydrates to metal (II) oxides is catalyzed by the PVDF, as evidenced by reduction in the decomposition temperature by as much as 170 °C compared to the pure metal salts. In contrast, there is little to no apparent catalysis for the decomposition of the metal (III) nitrate hydrates. The FTIR spectra of the gas phase decomposition products show H2O and NO2 are the major components for both PVDF-doped material and the pure metal nitrate hydrates. A mechanism for the role of PVDF is proposed that uses the internal electric field of the ferroelectric phase to orient the nitrate ions and polarize the N–O bonds.

Construction of core-shell structured Co7Fe3@C nanocapsules with strong wideband microwave absorption at ultra-thin thickness

Constructing magnetic/dielectric composites with core-shell structure is an effective strategy for the development of high-efficiency microwave absorbers owing to the synergistic effect of multiple attenuation mechanisms. In this work, FeCo2O4 nanoparticles of 8 nm prepared by the nitrate decomposition method were used as the precursor, and the core-shell structured Co7Fe3@C nanocapsules with an average particle size of only 30 nm were fabricated through subsequent carbonization-reduction process. The Co7Fe3@C nanocapsules exhibit high-efficient microwave absorption performance. At an ultra-thin thickness of 1.6 mm, the minimum reflection loss (RL) value reaches up to −117.4 dB at 11.9 GHz. Notably, at the same thickness, the effective absorption bandwidth (RL ≤ −10 dB) is as wide as 9.2 GHz (8.8–18 GHz), covering almost the whole X and Ku bands. Moreover, the microwave absorption mechanism is revealed in detail through in-depth analysis of electromagnetic parameters. The outstanding microwave absorption capability is ascribed to the synergetic effect of strong magnetic loss of Co7Fe3 alloy cores and strong dielectric loss of amorphous carbon shells, as well as the superior impedance matching. It is believed that the core-shell structured Co7Fe3@C nanocapsules should be promising as high-efficiency microwave absorbers with thin thickness, strong absorption strength and broad absorption bandwidth.

Расчетно-аналитическое обоснование предельных значений массы аммиачной селитры при хранении на складах и терминалах

On the basis of theory of stationary thermal explosion of A.D. Frank-Kamenetsky, depending on the temperature of the critical size of the ammonium nitrate embankment, the calculations were performed, which show that it can be stored in the large volumes at the temperatures up to 30 °C. On the contrary, at the temperatures above 100 °C (for example, at 200 °C), the decomposition of nitrate occurs with acceleration and can lead to an explosion. Based on the studies performed, it is shown that the changes and additions to the fire safety requirements for ammonium nitrate storage in the buildings and structures should be determined by the requirements for fire resistance of buildings (at least II degree of fire resistance), for the purity of the product and its packaging, for the exclusion of contacts with organic substances and materials, storage conditions. Additional fire safety requirements were developed for inclusion in the normative document regarding ammonium nitrate storage. Ammonium nitrate is allowed to be stored in one-story warehouse buildings of at least II degree of fire resistance, structural fire hazard class C0. The floor area within the fire compartment should not exceed 10 500 m2. Between the fire-fighting walls of the 1st type, it is allowed to store no more than 25 000 tons of nitrite in bulk or in the special bags, as well as in the soft specialized containers for bulk products in accordance with GOST 2—2013.The conditions for placing ammonium nitrate in the stacks should be accepted in accordance with the requirements of SP 92.13330.2012. Temperature in the storage room of ammonium nitrate should not exceed 30 °C with a relative humidity of not more than 60 %. Warehouses for storing ammonium nitrate should be equipped with general exchange supply and exhaust and (or) emergency ventilation, in order to exclude the formation of a fire and explosion hazardous environment in the room during the decomposition of ammonium nitrate. Warehouses for storing ammonium nitrate in an amount of not more than 5 thousand tons may be separated from other premises, including from the warehouses for fertilizers and pesticides, by solid (without openings) type 2 fire walls.

Decomposition of Hydroxylammonium Nitrate Solution Over Nanoporous CuO Supported on Honeycomb.

We investigated the influence of a copper loading strategy over a honeycomb structure on the catalytic performance during the decomposition of a hydroxylammonium nitrate (HAN) aqueous solution. Copper was supported on the honeycomb surface by means of a metal coating method (MC), i.e., a method of directly coating a metal, and a metal alumina coating method (MAC), i.e., a method of coating a mixture of metal and alumina. The properties of the catalysts were analyzed by N₂ adsorption, X-ray diffraction (XRD), and scanning electron microscopy (SEM). The Cu(16.8)/honeycomb-MC catalyst showed a lower decomposition onset temperature during the decomposition of the HAN aqueous solution compared to that over the Cu(7.0)/honeycomb- MAC catalyst, an outcome ascribed to the higher copper loading and the higher dispersion of copper in the Cu(16.8)/honeycomb-MC catalyst compared to that in the other catalyst. The Cu(16.8)/honeycomb-MC catalyst was confirmed to have both excellent activity and heat resistance during the decomposition of a HAN aqueous solution.

One‐Step Synthesis of Carbon‐Protected Co3O4 Nanoparticles toward Long‐Term Water Oxidation in Acidic Media

The design and development of highly efficient and stable oxygen evolution reaction (OER) electrocatalysts in acid media are important for various renewable technologies. Herein, an advanced Co3O4 electrocatalyst supported on a mesoporous hydrophobic carbon paper (Co/29BC) is formed via a simple one‐step thermal decomposition of cobalt nitrate. Through this novel approach, the amorphous carbon layer resulting from the thermal decomposition of carbon‐containing species in the mesoporous layer provides enhanced electronic conduction and protection against corrosion to the Co3O4 nanoparticles. Equally important, the OER performance is found to be correlated with the morphology and surface composition of Co3O4. With optimized Co3+ active sites and oxygen vacancies at the metal oxide surface, the Co3O4 catalyst shows superior OER performance and durability in a proton exchange membrane (PEM) water electrolyzer, with a small overpotential (350 mV) at a constant current density of 10 mA cm−1 for over 50 h. Accordingly, this work provides new insights toward the design of high‐performance and highly stable OER electrocatalysts in corrosive acidic environments.

Chemical looping conversion of ethane to ethanol via photo-assisted nitration of ethane

Ethane is an abundant and cheap hydrocarbon. Selective conversion of ethane to ethanol has economic value but is difficult to achieve due to overoxidation. Here, we report a chemical looping strategy established to selectively convert ethane (C 2 H 6 ) to ethanol (C 2 H 5 OH) using molecular oxygen (O 2 ) as the end oxidant and nitrogen dioxide (NO 2 ) as a relay oxidant. Visible light is used to excite NO 2 to drive a radical reaction with C 2 H 6 to produce ethyl nitrate (C 2 H 5 ONO 2 ) at −10°C with a selectivity of >80% and an ethane conversion of >90%. C 2 H 5 ONO 2 is hydrolyzed to generate C 2 H 5 OH and nitric acid (HNO 3 ), thus completing a chemical loop for the conversion of ethane to ethanol. DFT calculations show that the introduction of light overcomes the barrier of ethane activation at a relatively low temperature and thus avoids ethyl nitrate decomposition and overoxidation, leading to the high selectivity of ethyl nitrate. A chemical looping is proposed to convert ethane to ethanol Selective nitration of ethane produces ethylnitrate in high yields Atmospheric reaction is used for preparative synthesis Photocatalysis is used to activate inert C–H bond at mild conditions The activation of the inert C–H bonds in ethane, an abundant hydrocarbon gas, is an important step in alkane upgrading. He et al. put forward a chemical looping strategy to convert ethane to ethanol via selective photoactivated nitration under mild conditions.

Effect of Fe-based organic metal framework on the thermal decomposition of potassium nitrate and its application to the composite solid propellants

This research focuses on the MIL-100(Fe) organometallic framework (MOF) promoting the thermal decomposition of potassium nitrate. A conventional MOF, MIL-100(Fe), is a chemical compound with a three-dimensional architecture composed of iron clusters and coordinating organic ligands. In the present study, MIL-100(Fe) was manufactured and dopped into potassium nitrate for thermogravimetric analysis to delineate the thermal decomposition behaviors of potassium nitrate. According to the thermal decomposition results, it shows that MIL-100(Fe) could promote potassium nitrate to reach the highest mass loss rate effectively at lower temperature conditions. Moreover, The results also delineate that the activation energy of thermal decomposition of potassium nitrate could be reduced by adding MIL-100(Fe) in potassium nitrate. On the other hand, the solid composite propellant composed of epoxy and potassium nitrate was also prepared as an example of the burning velocity test. The results show that the burning velocity could be enhanced by adding MIL-100(Fe) and also suggest the potential combustion catalyst for composite solid propellant.

La2Zr2O7 Nanoparticle-Mediated Synthesis of Porous Al-Doped Li7La3Zr2O12 Garnet.

In this work, we modified the reaction pathway to quickly (minutes) incorporate lithium and stabilize the ionic conducting garnet phase by decoupling the formation of a La-Zr-O network from the addition of lithium. To do this, we synthesized La2Zr2O7 (LZO) nanoparticles to which LiNO3 was added. This method is a departure from typical solid-state synthesis methods that require high-energy milling to promote mixing and intimate particle-particle contact and from sol-gel syntheses as a unique porous microstructure is obtained. We show that the reaction time is limited by the rate of nitrate decomposition and that this method produces a porous high-Li-ion-conducting cubic phase, within an hour, that may be used as a starting structure for a composite electrolyte.

Fabrication of molten nitrate/nitrite dual-phase four-channel hollow fiber membranes for nitrogen oxides separation

Molten salt-ceramic dual-phase membranes have great prospects in the selective separation of nitrogen oxides. A gas-tight KNO3–Ba0.5Sr0·5Co0·8Fe0·2O3-δ (KNO3-BSCF) four-channel hollow fiber membrane was developed in this study. A wide operating temperature window of 350–500 °C with high nitrogen oxides permeance was achieved. The maximum nitrogen oxides permeance reached 9.2 × 10−9 mol m−2 s−1 Pa−1 under the condition of 1% NO2, 1% CO2 and 20% O2 at 500 °C. The presence of nitrogen oxides was able to suppress the reaction of BSCF oxide with CO2 to form carbonates. Insights on the transport mechanism of nitrogen oxides transport were provided and the existence of nitrite route for nitrogen oxides transport was firstly demonstrated by experiments. An 1800 h long-term nitrogen oxides permeation was running on the KNO3-BSCF hollow fiber membrane while the permeance increased by a factor of ~40 (5.2 × 10−10 mol m−2 s−1 Pa−1 to 2.2 × 10−8 mol m−2 s−1 Pa−1 at 450 °C) due to the partial decomposition of nitrate into nitrite. This nitrite route was also verified in KNO3/KNO2-BSCF hollow fiber membrane constructed by preloading 30 wt% nitrite in molten salt.

Study of the effect of flow rate and decomposition temperature on sensing of ammonium nitrate by carbon nanotubes

Abstract The role of flow rate of carrier gas and decomposition temperature in sensing mechanism of pristine single walled carbon nanotubes (SWCNT) with ammonium nitrate vapor has been studied. For this purpose, sensing studies were carried out at 10 sccm, 25 sccm and 50 sccm flow rates. Three decomposer temperatures (70 °C, 170 °C and 230 °C) were taken while varying the bubbler temperature from 70 °C–120 °C. It was found that both flow rates and decomposition temperature play a vital role in affecting the interaction mechanism between SWCNT and ammonium nitrate vapors. Low decomposition temperature favors the ammonia sensing and higher decomposition temperatures (170 °C and 230 °C) lead to dominance of NOx vapors on account of strong decomposition of ammonium nitrate. These trends were observed irrespective of vapor pressure and concentration of ammonium nitrate vapors. This highlights the significant role of flow rate of carrier gas and decomposition temperature in determining the sensing behavior of ammonium nitrate.

Red and blue wavelengths affect the morphology, energy use efficiency and nutritional content of lettuce (Lactuca sativa L.)

Since red (R) and blue (B) LED light has different quantum efficiency and photoelectric conversion efficiency, mixed RB with different proportions of R and B results in varied energy consumption. In order to improve the energy use efficiency of the closed-type plant production systems, the effects of R and B proportions on the electric use efficiency (EUE), light use efficiency (LUE) as well as the quality of butter leaf lettuce were evaluated in this study. Lettuce seedlings were cultivated in a plant factory with artificial lighting (PFAL) and subjected to eleven combinations of R and B (100%R, 90%R, 80%R, 70%R, 60%R, 50%R, 40%R, 30%R, 20%R, 10%R, 0%R; the rest of the photons in each treatment were B) with the same total photosynthetic photon flux density (PPFD) and photoperiod (200 ± 3 μmol·m−2·s−1, 16 h) for 35 days. The results showed that palpable petiole distortion appeared when R proportion was more than 70% and the distortion was aggravated with the increase of R proportion. The highest EUE and LUE were both detected in lettuce under 90%R treatment, which were respectively 3.64% and 1.20%. The least number of photons and the least electricity amount required to produce 1 g dry weight of lettuce was respectively 2.92 mol and 1.67 MJ, which were both detected in lettuce treated with 90%R. The sucrose content in lettuce treated with more than 50%R was significantly higher than those treated with less than 50%R (50%R included). Lettuce treated with 80%R possessed the highest soluble sugar content as well as the lowest crude fiber and nitrate content (not significantly different with the minimum values). R proportion exceeding 50% in mixed RB light was beneficial to the accumulation of hexose and sucrose, as well as the decomposition of nitrate in lettuce. The vitamin C content in lettuce treated with 100%R was significantly higher than that in lettuce under other treatments in the study. On the whole, the study indicated that the proportions of R and B affected the energy use efficiency and quality of lettuce in closed plant factory, however the responses of plants to the proportions of R and B varied according to different indexes. Thus, some indexes of top priority should be determined before choosing the optimal proportions of R and B.

Investigation of the Thermal Aging Behavior of Pyrotechnic Tracer Composition by Spectroscopic Techniques Coupled with Principal Component Analysis

AbstractThis work aims to investigate the aging behavior related to heat of a pyrotechnic tracer composition (PTC) sample composed of strontium nitrate as an oxidizer and dual‐fuel of Mg and Mg−Al alloy. Fresh and thermally aged samples were examined using nondestructive spectroscopic techniques, namely Raman spectroscopy, scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and X‐ray diffraction (XRD). The obtained results showed that aging for 20, 40, and 60 days at 65 °C does not provoke noticeable chemical or structural changes, whereas, after 60 days, the changes are visible, and become more obvious after aging for 120 days. These changes are caused by the partial decomposition of strontium nitrate and the oxidation of magnesium, which are followed by the generation of degradation products such as Sr(NO2)2, MgO, and Mg(OH)2. On the other hand, the applicability of FTIR and XRD associated with a chemometric tool, the principal component analysis, as a simple and useful technique has been also assessed to discriminate the spectra of the aged samples. It has been revealed that these combined approaches can be effectively used to recognize the main compositional and structural changes within the pyrotechnic tracer composition affected by the thermal degradation process.

Effect of the synthesis method on the morphology, textural properties and catalytic performance of La-hexaaluminates in the dry reforming of methane

This work describes the synthesis of nickel/lanthanum hexaaluminates (NiO/LHA), optimizing the LHA synthesis method, as well as their performance in terms of stability and catalytic activity in the dry reforming of methane (DRM). The synthesis methods studied include co-precipitation, nitrate decomposition and freeze drying, using a La/Al molar ratio of 1:11 in all methods. Drying methods, namely oven drying (4 h at 353 K), vacuum drying (8 h at 353 K) + oven drying (2 h at 423 K) and heat treatment (12 h at 473 K) + oven drying (2 h at 373 K), were also optimized during selection of the final catalyst support. After calcination at 1473 K for 2 h, the presence of lanthanum aluminate (LaAlO3) and traces of LHA were found in all cases. Specific surface areas of 50, 32 and 30 m2/g were obtained for the samples AD1 (nitrate decomposition), FD1 (freeze drying), CP1 (co-precipitation).The nitrate decomposition method was selected and optimized to obtain the LHA structure at low temperature in the presence of Ni(II), using a La/Al/Ni molar ratio of 1/15/0.2. The results showed the formation of pure-phase hexaaluminate at 1473 K. The solids obtained were used as supports for nickel catalysts (10 wt%) for DRM at 973 K. The supports and catalysts were characterized by X-ray diffraction (XRD), N2 adsorption at 77 K, temperature-programmed reduction (TPR), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The simulation of the TPR patterns of the catalysts allowed determining the type of metal support interaction and the activation energy of the system as well as the rest of the kinetic parameters. A cumulative mean activation energy of 100.7 kJ/mol was determined for the catalysts. The metallic morphologies, dispersion and distribution of NiO on the surface of the LHA support were analyzed considering a theoretical simulation of the reduction profiles, obtaining an average growth factor of 1.4, which indicates that the metallic phase is growing in one and two dimensions. The NiO/LHA catalysts synthesized were found to be active and very stable in the DRM reaction after 20 h of reaction with an average selectivity H2/CO upper than 0.90. The differences observed can be related to the textural properties developed during the optimized nitrate decomposition method.The characterization analysis by simulation, TPR, XRD, TEM, SEM allowed us to establish the effect of the textural properties, the metal interaction, the growth of the nickel grains and their distribution in the support on the catalytic performance in DRM. The better performance was obtained with the catalysts with higher porosity and greater support metal interaction, which allowed obtaining a better distribution of the metallic phase, thus generating less harmful carbonaceous species for the activity of the catalyst and therefore showing the best values of catalytic stability and conversion.Finally, three types of coke were identified from HR-TEM and EDS analysis: graphitic, filamentous and CNT, showing different effects on the catalytic behavior deactivation being the presence of graphitic more aggressive than the other two species.

Octyltrimethylammonium bromide-assisted synthesis of maghemite powder by thermal decomposition of ferric nitrate and its properties

Maghemite (γ-Fe2O3) powder was prepared by one-step thermal decomposition of ferric nitrate (Fe(NO3)3⋅9H2O) with the aid of octyltrimethylammonium bromide (OTAB). The effect of OTAB on the formation of γ-Fe2O3, structural properties and magnetic properties of the γ-Fe2O3 powder has been studied by X-ray powder diffraction, thermogravimetric analysis, scanning electron microscopy, transmission electron microscopy, magnetic measurements and nitrogen adsorption–desorption. It is found that OTAB has a great influence on the thermal decomposition products of Fe(NO3)3⋅9H2O. With no OTAB addition, the thermal decomposition of Fe(NO3)3⋅9H2O produces only hematite (α-Fe2O3). In contrast, when OTAB is added to Fe(NO3)3⋅9H2O, a pure γ-Fe2O3 is formed, and its crystallite size can be controlled from 7.4 to 27.8 nm by varying the calcination temperature. Magnetic properties of γ-Fe2O3 powder are found to be strongly dependent on the calcination temperature. The saturation magnetization of γ-Fe2O3 powder increases from 28.6 to 67.5 emu g−1, when the calcination temperature increases from 160 to 200 °C. The sample obtained at 200 °C is nearly flake-like in shape and possesses a mesoporous structure with a Brunauer–Emmett–Teller surface area of 121.3 m2 g−1.

Characterization of Aluminum Powders: IV. Effect of Nanometals on the Combustion of Aluminized Ammonium Nitrate‐Based Solid Propellants

AbstractThis study is devoted to the investigation of the energetic properties of two types of aluminized solid propellants with inert and active binders modified by additives of six different metal nanopowders. The substitution of an inert binder for the active one resulted in significant improvement of energetic properties. However, burning rate regulation become more complicated because the pressure exponent in burning rate law was increased as well. The DSC analysis revealed that the most significant catalytic effects were observed while using Zn, Cu, and Mo powders. Combustion of compositions based on an inert combustible binder and ammonium nitrate was studied in the pressure range 0.1–10.0 MPa. Due to the low combustion rate, no dispersion of burning aluminum particles was observed. During combustion, a single agglomerate of aluminum particles was formed, the mass of which was about 96 % of the initial aluminum mass in the formulation. A comparative analysis of nanosized metal additive effect on the propellant's combustion process was performed. It had been found that the activity of the metal nanopowders depends on the propellant formulation. It had been shown that Al and Zn did not affect the combustion rate of propellant with inert binder but they were effective in compositions with an active binder. Cu and Ni were found to be a good catalyst for the ammonium nitrate and active binder decomposition.

Low-temperature synthesis of dense garnet-type Li6.5La3Zr1.5Ta0.5O12 layered structures using fluorite-type precursor oxide

We have fabricated a dense garnet-type Li-ion conductor at low temperature (700 °C) by allowing the dense precursor oxide La0.6Zr0.3Ta0.1O1.75 to react with the lithium vapor generated from the thermal decomposition of lithium nitrate. The obtained garnet-type Li6.5La3Zr1.5Ta0.5O12 electrolyte layer had a columnar structure and its thickness was controlled within the range of 14 ~ 500 µm by adjusting the reaction temperature and time. The fabricated sample (500 µm) exhibited a total Li-ion conductivity of 5.1 × 10−4 S·cm−1 at 25 °C and the temperature dependence of the Li-ion conductivity of the garnet-type Li-ion conductor was also investigated. Moreover, we were able to fabricate 30 µm thick dense free-standing Li6.5La3Zr1.5Ta0.5O12 sheets using this precursor method.

Nano Calcium Oxide Incorporated Hydrocolloid Dressings for Wound Care

The study aimed to formulate hydrocolloid dressings incorporated with nano calcium oxide for effective wound healing. Hydrocolloid dressings create an insulated, moist environment in the wound bed for controlling the exudate and promoting autolytic debridement. Calcium ions play an important role in wound response and are considered to be an initial trigger in our immune response to healing, and research has shown that Ca2+ in the external medium is essential for wound repair. Seventy five parts per million of nano calcium oxide (NCO) obtained by thermal decomposition of calcium nitrate at 450 °C was used in the preparation of hydrocolloid dressings along with varying concentrations of micronized xanthan gum and HPMC. The dressings were evaluated for their surface characteristics, thickness, mechanical properties, folding endurance, pH, viscosity, swelling studies, water vapor transmission, and in vivo wound healing activity. The average particle size of NCO was found to be 307.8 nm. The SEM (scanning electron microscopy) analysis of the dressing revealed a porous surface and EDX (energy dispersive X-ray spectroscopy) characterization showed intense peaks of calcium and oxygen. The formulated dressings possessed uniform thickness, flexibility, and mechanical strength. The percentage of wound contraction was higher in wounds treated with formulated hydrocolloid dressings in comparison to standard commercial product (DuoDERM® hydrocolloid dressing) and control (untreated) group. The wound healing properties of hydrocolloid dressings were confirmed by histopathological analysis. Nano calcium incorporated hydrocolloid dressings with enhanced wound healing activity were developed successfully.