Effect of Ni:Al blending ratio on porous structure of porous nickel aluminides fabricated through reactive synthesis with space holder particles were investigated. Fabricated porous nickel aluminides had large pores derived from NaCl space holder particles and small pores derived from reactions between Ni and Al. Porosity and size of the small pores increased with increasing Al content in the raw powder mixture. Compressive property of porous NiAl are also investigated. porous NiAl exhibited good energy-absorption properties with relatively high plateau stress, high plateau end strain, and relatively flat plateau stress. This study suggests the possibility of intermetallic-based porous materials as high-performance energy absorber.

Energy-savvy auto-combustion synthesis was used to form the porous BaLi2Ti6O14 titanate anode. It registered the lowest calcination temperature (800 °C) along with the shortest calcination duration (2 h). Rietveld analysis confirmed the purity of the orthorhombic (s.g. Cmca) product phase. The bond valence site energy analysis indicated a 1D ionic conduction along c axis with low activation energy and 2D pathways along (010) with high activation energy. AC conductivity analysis revealed a bulk conductivity of 2.41 × 10−4 S/cm (at 300 °C) with a moderate activation energy barrier (0.68 eV). From cyclic voltammetry, the Li+ diffusion coefficient was calculated to be 10−11–10−12 cm2/s. The as-synthesized BaLi2Ti6O14 reversibly intercalated ∼1.3 Li+ involving a 1.42 V Ti4+/Ti3+ redox activity delivering capacity ∼100 mA h/g with good cyclability over 100 cycles. Furthermore, BaLi2Ti6O14 was found to reversibly intercalate ∼0.89 Na+. With suitable diffusional and electrochemical performance, BaLi2Ti6O14 form a safe titanate anode for secondary batteries.

We report a rapid combustion synthesis method for producing band gap tunable gallium zinc oxynitrides, a material of interest for water splitting applications. By varying the ratio of zinc and gallium, we can tune the band gap from 2.22 to 2.8 eV. Furthermore, nitrogen can be incorporated up to nearly 50% via replacement of oxygen without the need for high temperatures or an additional ammonolysis step. X-ray photoelectron spectroscopy (XPS) and EDX analysis suggests a preferential segregation of Zn to the surface of the as-synthesized particles, though the surface Ga/Zn molar ratio in the as-synthesized particles is correlated with the Ga/Zn molar ratio of the precursor materials. Photoelectrochemical measurements show that the oxynitride powders are photoactive under both AM1.5 and visible-only (λ > 435 nm) irradiation. Hydrogen and oxygen were both evolved in half-reaction experiments under simulated AM1.5 irradiation without externally applied bias, although addition of an OER catalyst did not enhance the rate of oxygen formation, suggesting that intra- and interparticle recombination are significant.

Porous TiAl3 intermetallics were synthesized by the thermal explosion (TE) reaction from TiH2–75 at.% Al elemental powders combining with carbamide as the space holder. The results showed that the space holder particles were removed completely by dissolving in water before sintering and the violent exothermic reaction occurred from the temperature of 672–1193 °C within a few seconds. After TE, TiAl3 was the dominant phase in sintered products and the open porosity of 60.8% was obtained without space holder, while the porosity considerably increased to 81.4% with the addition of 60 vol% carbamide particles. The pore-forming mechanism can be concluded as follows: the sphere large pores replicated from carbamide particles and the small pores generated by the TE reaction. Moreover, porous TiAl3 intermetallics possess the excellent oxidation resistance at 650 °C in air, which enabled them good candidate materials for improving the service life and the accuracy of filtration under special conditions.

The development of efficient water oxidation catalyst is a major path to realize water splitting systems, which could benefit high performance and cost-effective metal-air batteries, fuel cells and solar energy conversion. To date, the rare crustal abundant platinum group metals rule this sector with Pt-alloys being the best for oxygen reduction reaction (ORR) and ruthenium oxides for oxygen evolution reaction (OER) in acidic solution. However, they show poor stability and are too expensive for large scale applications. Moreover, oxygen reduction in basic solutions can otherwise be catalysed by metal oxide with non-precious earth abundant transition metals (e.g. Fe, Co, Ni). Hence, there is a massive demand to explore noble metal free bifunctional electrocatalysts. In this work, we present the electrocatalytic activity of three cobalt based sodium phosphates namely NaCoPO4 (with one phosphate), Na2CoP2O7 (with two phosphate) NaFe2Co(PO4)3 (with three phosphate). Synthesized by solution combustion route, all these phosphates confirmed phase purity. NaCoPO4 and Na2CoP2O7 adopted orthorhombic structure with Pnma and Pna21 space group respectively; whereas NaFe2Co(PO4)3 crystallized in monoclinic (C2/c) framework. Electrocatalytic activity of these cobalt phosphates were inspected by linear sweep voltammetry with rotating disk electrode (RDE). All three showed promising bifunctional activity. In fact, the ORR activities of both orthorhombic cobalt phosphates are comparable to Vulcan carbon and Pt/C. OER activity of Na2CoP2O7 overrode other phosphates. The bifunctional activity and good stability of these sodium cobalt phosphates stem from cobalt ions and stabilization of the catalytic centres by the phosphate frameworks. The present work builds a detail structure-property correlation in these phosphate systems and also demonstrates the possibility of utilizing these sodium cobalt phosphates as alternate cost-effective, novel electrocatalysts for efficient OER/ORR activity in alkaline solution.

The oxidation behavior of nonstoichiometric Ti2AlC x (x = 0.69) powders synthesized by combustion synthesis was investigated in flowing air by means of simultaneous thermal gravimetric analysis-differential thermal analysis, X-ray diffraction, X-ray photoelectron spectroscopy, and scanning electron microscope/energy dispersive spectroscopy, with an effect of powder size. The oxidation of the fine Ti2AlC powders with the size of about 1 μm starts at 300 °C and completes at 980 °C, while with increasing the powder size around 10 μm the corresponding temperature increases to 400 and 1040 °C, respectively. The oxidation of nonstoichiometric Ti2AlC x (x = 0.69) powders is controlled by surface reaction in 400–600 °C, and mainly diffusion in 600–900 °C, with the corresponding oxidation activation energy of 2.35 eV and 0.12 eV, respectively. In other words, the critical temperature of changing oxidation controlling step is around 600 °C. The oxidation products were mainly rutile-TiO2 and α-Al2O3. The tiny white flocculent particles of α-Al2O3 appeared on the surface of fine Ti2AlC powders and increased with increasing the oxidation temperature.

This contribution reports the synthesis and characterization of La-based perovskites which can be used for the production of syngas via solar thermochemical splitting of H2O/CO2. The La-based perovskites were synthesized using a solution combustion synthesis approach. The derived perovskites were analyzed using powder X-ray diffractometer (PXRD), BET surface area analyzer (BET), and scanning/transmission electron microscope (SEM/TEM). The results associated with the synthesis and characterization of La-based perovskites is reported in detail.

In the present study, we have attempted to produce the porous Ti–Al intermetallic based alloys by pressure-sintering of the elemental powders of Ti and Al through a combustion reaction, with a NaCl space holder to achieve the development of a highly porous structure. The powders of Ti (particle size: <45 μm) and Al (particle size: <45 μm) were mixed to various total compositions of Ti–0-40 Al (at.%), and NaCl (particle size: 300-400 μm) was mixed with the Ti/Al powder to give a highly porous structure. The mixed powder was sintered at 700 oC under a constant pressure of 30 MPa to form cylindrical specimens with a diameter of 20 mm. The soaking of the specimens in pure water allows for the removal of NaCl (with a volume fraction of 60 %) and the formation of the pores to achieve a controlled relative density of 0.4. The present process can produce porous Ti–Al alloys with various compositions. In as-sintered Ti–Al specimens, an inhomogeneous microstructure consisting of Ti particles surrounded by the a Ti–Al alloy layer (various Ti–Al intermetallic phases) was observed. The as-sintered specimens exhibited the brittle behavior under compression, which is independent of their Al content. However, in a Ti–20Al alloy heat-treated at 1300 °C, a nearly Ti3Al single-phase microstructure appeared in the porous specimen. The heat-treated porous Ti–20Al alloy shows both a high plateau-strength level of approximately 100 MPa and a high plateau-end strain over 50%, resulting in a high absorption energy. The present results demonstrate that controlling the microstructure for the formation of the Ti3Al single-phase would be an effective method to achieve high energy absorption capacity of the porous Ti–Al alloy.

A nanoscale and pure, olivine-structured LiFePO4 was synthesized at ∼300 °C using an organic–inorganic steric entrapment method. Normally, when calcined and crystallized in air, this method leads to the synthesis of compounds where the cations are in their highest oxidation state. However, in this study, we found a way to produce compounds having lower oxidation states (e.g., compounds containing Fe2+), which may have wider applications in the synthesis of other compounds with complex chemistry that have variable oxidation states and, therefore, potential applications in electronic ceramics. The resulting LiFePO4 or (Li2O·2FeO·P2O5) was characterized by thermogravimetric analysis/differential thermal analysis, x-ray diffractometry, scanning electron microscopy, transmission electron microscopy, inductively coupled plasma emission spectroscopy, specific surface area by Brunauer–Emmett–Teller nitrogen absorption, and particle size analysis.

In this work we produce atomically thin carbon nanostructures which have a disk-like shape when deposited on a substrate. These nanostructures have intermediate characteristics between a graphene island and a molecular compound and have the potentiality to be used either as they are, or to become building blocks for functional materials or to be manipulated and engineered into composite layered structures.

The carbon nanostructures are produced in a premixed ethylene/air flame with a slight excess of fuel with respect to the stoichiometric value. The size distribution of the produced compounds in aerosol phase has been measured on line by means of a differential mobility analyzer (DMA) and topographic images of the structures deposited on mica disks were obtained by Atomic Force Microscopy. Raman spectroscopy and XPS have been used to characterize their structure and the electronic and optical properties were obtained combining on-line photoionization measurements with Cyclic Voltammetry, light absorption and photoluminescence.

When deposited on the mica substrate the carbon compounds assume the shape of an atomically thin disk with in plane diameter of about 20 nm. Carbon nano-disks consist of a network of small aromatic island with in plane length, La, of about 1 nm. Raman spectra evidence a significant amount of disorder which is in a large part due to the quantum confinement in the aromatic islands. Nano-disks contain small percentage of sp3 and the O/C ratio is lower than 6%. They furthermore present interesting UV and visible photoluminescence properties.

Laser-induced vibrational excitation of ethylene molecules was integrated to the CVD diamond deposition process for an in-depth understanding of the energy coupling path in chemical reactions and an alternative method to enhance the diamond deposition. On- and off-resonance excitations of ethylene molecules were achieved via tuning the incident laser wavelengths centered at 10.532 µm. With the same amount of laser power absorbed, the chemical reaction is highly accelerated with on-resonance vibrational excitation whereas energy coupling with off-resonance excitations was less efficient in influencing the combustion process. The diamond deposition rate was enhanced by a factor of 5.7 accompanied with an improvement of diamond quality index with the on-resonance excitation at 10.532 μm. The measured flame temperature demonstrated that the resonant vibrational excitation was an efficient route for coupling energy into the reactant molecules and steering the combustion process.

Nano-sized SiOx/C composite was successfully prepared by drip combustion in a fluidized bed reactor. A mixture of tetraethyl orthosilicate (TEOS) ant kerosene at a 2:3 volume ratio was used as a precursor solution. The synthesis was carried out between 600 °C and 900 °C. The as-prepared powder (600 °C) consists of SiOx and carbon particles which are approximately ranged from 30 to 80 nm. For the nano-sized SiOx/C composite sample, the heat treatment process was introduced to remove incomplete combustion materials and the dry ball milling was performed to homogenize the distribution of carbon inside the sample. The final sample (nano-sized SiOx/C nanocomposite) was used as an electrode active material and then electrochemical testing was performed. The cell exhibited discharge and charge capacities of 1158 and 533 mAh g-1, respectively, at current density of 50 mAh g-1 in the voltage range between 0.01-3 V versus Li/Li+.

We present the first quantitative assessment of combustion dynamics of on-chip porous silicon (PS) energetic material using sulfur and nitrate-based oxidizers with potential for improved moisture stability and/or minimized environmental impact compared to sodium perchlorate (NaClO4). Material properties of the PS films were characterized using gas adsorption porosimetry, and profilometry to calculate specific surface area, porosity and etch depth. The PS/sulfur energetic composite was formed using three pore loading techniques, where the combustion speeds ranged from 2.9 – 290 m/s. The nitrate-based oxidizers were solution-deposited using different compatible solvents, and depending on the metal-nitrate yielded combustion speeds of 3.1 – 21 m/s. Additionally, the combustion enthalpies from bomb calorimetry experiments are reported for the alternative PS/oxidizer systems in both nitrogen and oxygen environments.

This research discussed how to synthesize submicrometer-sized TiC particulate reinforcement in the molten aluminum melt at low temperature via combustion synthesis by using in situ casting technique. A high temperature preheating treatment of Al–Ti–C pellets was carried out, by which the thermal explosion reaction of the pellets could take place in the pure aluminum melt at 750 °C. The synthesizing temperature of TiC particles was reduced by at least 150 °C compared with the conventional methods. In situ formed TiC particles were spherical in shape and were smaller than 1 µm in size due to the low melting temperature. The emergence of liquid aluminum phase led to the generation and accumulation of plenty of heat in the pellet in a short time due to the reactive diffusion of Al(l)–Ti(s). The formation mechanism of the submicrometer-sized TiC particles in the molten aluminum at low temperature was discussed in this research.

In this paper, the authors have reported the structural and photoluminescence (PL) studies of pure and nickel (Ni) doped zinc oxide (ZnO) nanoparticles synthesized by the solution combustion method. The structural, morphological and optical studies are carried out by powder x-ray diffraction (XRD), field emission-scanning electron microscopy (FE-SEM) and PL spectra, respectively. The XRD pattern indicates that the prepared particles are in hexagonal wurtzite structure with the average crystalline size is around 35-50nm. Room temperature PL shows the near band edge related emission and the results are related several intrinsic defects in the ZnO nanoparticles.

Calcium phosphates (CaPs) are major chemical constituents of mammalian bone. Their osteoconductivity in vitro and in vivo has encouraged their use in biomaterial applications such as implant materials and drug delivery. High aspect ratio nanoparticles are attractive for many biomedical applications; however, precise control of the phase and morphology is challenging. The impact of fuel-to-oxidant ratio, pH, and cation chemistry on morphology and phase was studied for CaP-based compositions by microwave-assisted solution combustion synthesis (MASCS) in a urea–nitrate (fuel–oxidant) system. An initial calcium to phosphate ratio of 1.5 was used. Highly crystalline hydroxyapatite (HA) and biphasic CaP nanoparticle compositions were produced as confirmed by x-ray diffraction, scanning electron microscopy, and transmission electron microscopy. MASCS was capable of synthesizing high aspect ratio (∼5 to 20) single and biphasic CaP nanoparticles with diameters ranging from 250 to 500 nm and lengths between 2 and 10 μm.

Powder X-ray diffraction data for cubic La0.3Sr0.7CoO3−δ, perovskite prepared by a combustion method, using metal-EDTA complexes are reported. The cubic cell parameter is: ac = 3.8323(9)Å.

Standardized X-ray powder diffraction data for orthorhombic LaCo0.4Fe0.6O3 prepared by calcination of a glycine-nitrate combustion-synthesized precursor are reported. Orthorhombic unit cell parameters: a = 5.4688 (2), b = 5.5100 (2), c = 7.7462 (3) Å. The reference intensity ratio, I/Icor,= 6.12.

Due to its outstanding properties, diamond is considered as an ideal material for mechanical and electric applications at high temperatures, voltages, radiation, etc. It is known that femtosecond lasers exhibit extremely high precision and minimized thermal effect in material processing. In this study, a seed-free diamond pattern growth method was developed by patterning silicon substrates using a femtosecond laser before diamond deposition through laser-assisted combustion flame synthesis. The resolution of the diamond patterns reaches micro scales. Peak position, full width at half maximum (FWHM), and diamond quality parameter were calculated from Raman spectra. The mechanism of the seed-free diamond growth based on the femtosecond laser patterning was discussed. The influence of substrates surface roughness on the diamond nucleation and subsequent growth was studied, indicating that the nucleation density is proportional to the surface roughness.

nGimat has commercialized a number of nanotech applications based on its core competence of creating low cost high quality nanomaterials. It offers a wide range of nanomaterials as coatings and nanopowders including dispersion form. While being successful in obtaining government R&D funding, nGimat has more than half of revenues from its private industry customers and is profitable. As an example, based on the DOE and DOD SBIR funding, nGimat has successfully developed high performance superhydrophobic coatings on various substrates. The superhydrophobic coatings show high transparency and high durability in addition to high contact angle and low rolling angle. Due to the excellent performance, nGimat signed a license agreement with a major automobile manufacturer to commercialize the superhydrophobic coatings for automobile applications. A few of other applications are also covered, including various nanopowders (including Li-battery based) and nGisulateTM high temperature thin wire coatings.

The CCVD (coating NanoSpraySM Combustion process) can be easily scaled up to large substrates and integrated into an existing production line, thus enabling a license business model. The CCVC (nanopowder NanoSpraySM Combustion process) is above 50kg/day capability and will soon yield 100kg/day production rates. Even higher production rates are readily achievable as demand is required. A manufacturing business model is being used for these nanopowder based products and should be internationally competitive even when made in the USA as the market matures