Characterization of Nano-Sized Particles for Propulsion Applications

2003 ◽  
Vol 800 ◽  
Author(s):  
Grant A. Risha ◽  
Eric Boyer ◽  
Brian Evans ◽  
Kenneth K. Kuo ◽  
Rafaat Malek
Keyword(s):  
Surface Area ◽  
Rapid Development ◽  
Particle Diameter ◽  
Nano Particles ◽  
Bet Surface Area ◽  
Solid Fuels ◽  
Average Particle ◽  
Hybrid Rocket ◽  
Combustion Properties ◽  
Active Content

ABSTRACTEnergetic nano-sized particles have been shown to have a great potential for use in the aerospace propulsion applications. Some of the unique combustion properties of nano-particles such as very rapid ignition and short combustion times make them particularly valuable for propulsion systems; they can be included in solid fuels, solid propellants, or even as energetic gellant in liquid systems. However, due to the novelty of the application and rapid development of production techniques, there is no comprehensive understanding of what characteristics of a nano-sized particle are important in contributing to desirable performance and ease of processing into a final usable form. Previous studies have shown that HTPB-based solid fuels containing various types of nano-sized particles showed differing performance results when tested in the same hybrid rocket motor under identical conditions. Many of these particles have data available only on the basic composition (aluminum, boron, boron carbide, etc.), average diameter, and/or BET surface area. In order to better understand and correlate observed combustion behavior with intrinsic material properties, the particles of interest need to be better characterized. A variety of standard particle characterization techniques were applied to the fifteen types of particles examined in this study and the results tabulated. Some of the parameters measured were average particle diameter, specific surface area, amount of active content, and oxide layer thickness. Trends in propulsion performance measured using a parameter of great interest to the hybrid rocket community (fuel mass burning rate) in general matched trends in particle characteristics (i.e. active content, surface area), but there were some noticeable exceptions. This study indicates that there is still much more to learn about the correlation between physical and chemical properties and measured combustion performance. Other parameters that should be examined in the future include particle size distribution, degree of agglomeration, reactivity and thermal effects (oxidation rate, onset temperature for oxidation exotherm, heat release associated with any excess stored energy), etc.

scholarly journals Synthesis of Mesoporous MWCNT/HKUST-1 Composite for Wastewater Treatment

2019 ◽  
Vol 9 (20) ◽  
pp. 4407 ◽  
Author(s):  
Rasidi Sule ◽  
Ajay K. Mishra
Keyword(s):  
Carbon Nanotubes ◽  
Surface Area ◽  
Multiwalled Carbon Nanotubes ◽  
Particle Diameter ◽  
Pollutant Removal ◽  
Bet Surface Area ◽  
Maximum Adsorption Capacity ◽  
Average Particle ◽  
Multiwalled Carbon ◽  
Composite Surface

Metal–organic frameworks (MOFs) (Hong Kong University of Science and Technology (HKUST)-1) have been widely studied using the hydrothermal method. Recently, efforts have also been geared toward the incorporation of multiwalled carbon nanotubes (MWCNTs) into the HKUST-1 MOF to advance its applications for gas storage as well as pollutant removal in wastewater. However, a significant reduction in the MWCNT/HKUST-1 composite surface area has limited its applications. We therefore synthesized HKUST-1 and HKUST-1 impregnated with acid-treated multiwalled carbon nanotubes (FMWCNTs). A large surface area of 1131.2 m2g−1 was obtained after acid treatment of the as-received MWCNTs. HKUST-1 was found to have an average particle diameter of 6.5 to 8 µm with a BET surface area of 1176.66 m2g−1. The FMWCNT/HKUST-1 composites had a BET surface area of 1108.85 m2/g. The addition of FMWCNTs was found to increase the parent MOF pore volume from 0.76 to 1.93 cm3g−1. A BJH desorption cumulative pore size of 6.97 nm was obtained in a composite sample. The maximum adsorption capacity of the composites was found to be greater than 100 mg/g at 298 K. The results obtained indicate that FMWCNT/HKUST-1 nanocomposites are a potential adsorbent for methylene blue (MB) removal in dye synthetic water.

scholarly journals SiO2:MgMnO3: An Efficient Heterogeneous Catalyst for One Pot Synthesis of 1H-Pyrazolo[1,2-b]phthalazine-5,10-dione Derivatives

2020 ◽  
Vol 32 (10) ◽  
pp. 2489-2494
Author(s):  
S.S. Sagar ◽  
R.P. Chavan
Keyword(s):  
Surface Area ◽  
Average Particle Size ◽  
Bet Surface Area ◽  
High Yield ◽  
Average Particle ◽  
One Pot ◽  
Short Reaction Time ◽  
Investigative Techniques ◽  
Current Procedure ◽  
Efficient Heterogeneous Catalyst

The present study deals with hydrothermal synthesis of SiO2 composite MgMnO3 catalyst. The obtained polycrystalline product was analyzed by using physical investigative techniques including XRD, SEM, EDAX, TEM, SAED and BET surface area. The product corresponded to average particle size of 100 nm by TEM images. The BET surface area was found 234.38 cm2/g for SiO2 composite MgMnO3 catalyst which indicates a good catalytic property. The synthesized catalyst was applied for the synthesis of 1H-pyrazolo[1,2-b]-phthalazine-5,10-dione in presence of ethanol as a solvent at 80 ºC. The current procedure and catalyst offers the gains of clean reaction, short reaction time, high yield, easy purification and financial availability of the catalyst.

Biodiesel Preparation from Styrax Confusus Hemsl. Oil Catalyzed by Magnetic Catalyst S2O82--ZrO2/Fe3O4

2013 ◽  
Vol 805-806 ◽  
pp. 247-250
Author(s):  
Zhen Xing Liu ◽  
Xiao An Nie ◽  
Yi Gang Wang
Keyword(s):  
Particle Diameter ◽  
Magnetic Core ◽  
Raw Material ◽  
Bet Surface Area ◽  
Precipitation Method ◽  
Molar Ratio ◽  
Solid Catalyst ◽  
Average Particle ◽  
Magnetic Catalyst ◽  
Catalyst Carrier

Styrax confusus Hemsl., a promising energy plant, was used as raw material for biodiesel preparation in this paper. The transesterification was catalyzed by magnetic catalyst S2O82--ZrO2/Fe3O4, prepared by chemical co-precipitation method. TEM images indicat that the average particle diameter of magnetic core Fe3O4 and catalyst carrier ZrO2/Fe3O4 are 5-20 nm and 30-50 nm respectively. Because of its unique porous structure the BET surface area could up to 140.75 m2/g. The results show that a best catalytic activity is obtained when the solid catalyst impregnated in 2.5 mol·L-1 (NH4)2S2O8, calcined at 400 °C for 3 h, and a high methyl ester yield could be obtained under the optimal reaction conditions of catalyst amount 4.5 % (wt/wt oil), molar ratio of methanol/oil 6:1, reaction temperature 65 °C and time 2.0 h.

scholarly journals High-quality mesoporous SiO2 nanospheres via a confined jet impingement continuous microchannel reactor

2021 ◽  
Author(s):  
Qiang Chen ◽  
Kai Chen ◽  
Feng Yu ◽  
Aixia Guo ◽  
Siqing Zou ◽  
...  
Keyword(s):  
Mesoporous Silica ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Particle Diameter ◽  
Jet Impingement ◽  
High Specific Surface Area ◽  
Lithium Silicate ◽  
Average Particle ◽  
Microchannel Reactor

Abstract High surface area mesoporous silica (SiO2) nanospheres has been considered an ideal material for the catalytic, adsorption and drug delivery. However, synthesis of ultra-high specific surface area mesoporous silica nanoparticles with well-defined sphere structure and small particle size (< 200 nm) is still challenging. Here, a two-stream confined jet impingement continuous microchannel reactor is proposed to produce novel mesoporous silica nanospheres (MSNs) with ultra-high specific surface area (SSA) and abundant worm-like meso-porosity. The as-obtained MSNs with worm-like mesoporous structure were produced with average particle diameter of 142 ~ 207 nm, high SSA of 1347 ~ 1854 m2/g, total pore volume of 0.86 ~ 1.23 cm3/g and pore diameter of 2.6 ~ 3.3nm. Moreover, the shear force field in the microchannel reactor on the mesoscopic structure of MSNs was simulated by mesoscopic kinetics. Additionally, MSNs was used as the silicon source to synthesize lithium silicate (Li4SiO4), which enhanced carbon dioxide (CO2) adsorption of 27.18 wt% at 650 ℃.

Development of Heterostructured Ferroelectric SrZrO3/CdS Photocatalysts with Enhanced Surface Area and Photocatalytic Activity

2020 ◽  
Vol 20 (6) ◽  
pp. 3770-3779 ◽  
Author(s):  
Umar Farooq ◽  
Farheen Naz ◽  
Ruby Phul ◽  
Nayeem Ahmad Pandit ◽  
Sapan Kumar Jain ◽  
...  
Keyword(s):  
Particle Size ◽  
Dielectric Constant ◽  
Photocatalytic Activity ◽  
Surface Area ◽  
Room Temperature ◽  
Average Particle Size ◽  
Chemical Deposition ◽  
Bet Surface Area ◽  
Cds Nanoparticles ◽  
Average Particle

This paper reports the attempt to develop an efficient heterostructure photocatalyst by employing SrZrO3 as ferroelectric substrate with deposited nanostructured CdS semiconductor on the surface. Primarily bare SrZrO3 and CdS nanoparticles were synthesized by using polymeric citrate precursor and co-precipitation routes, respectively. The chemical deposition technique was used to develop the CdS over the surface of the pre-synthesized SrZrO3 nanoparticles. The synthesized bare nanoparticles and their heterostructure were characterized by XRD which shows the formation of orthorhombic and face centred cubic (FCC) phases of SrZrO3 and CdS, respectively. TEM was used to estimate the morphology and particle size of as-synthesized nanoparticles, which shows the average particle size of 14, 24 and 25 nm for SrZrO3, CdS and SrZrO3/CdS, respectively. The BET surface area of SrZrO3, CdS and SrZrO3/CdS samples was found to be 299, 304 and 312 m2/g respectively. Methylene blue was used as model pollutant to determine the photocatalytic activity of the synthesized nanomaterials. The heterostructure shows an enhanced activity as compared to bare nanoparticles. Dielectric constant and dielectric loss of the nanoparticles was investigated as a function of frequency at room temperature and as a function of temperature at 500 kHz. The room temperature dielectric constant for SrZrO3, CdS and SrZrO3/CdS was found to be 13.2, 17.8 and 25.5 respectively at 100 kHz.

scholarly journals The Characterization of Heterogeneous Nanocatalyst of Biohydroxyapatite-Lithium and its Application for Converting Malapari Seed Oil (Milletia pinnata L.) to Biodiesel

2018 ◽  
Vol 34 (4) ◽  
pp. 1817-1823
Author(s):  
I. Nengah Simpen ◽  
I. Made Sutha Negara ◽  
Ni Made Puspawati
Keyword(s):  
Particle Size ◽  
Surface Area ◽  
Seed Oil ◽  
Surface Acidity ◽  
Average Particle Size ◽  
Bet Surface Area ◽  
Average Particle ◽  
Bovine Bone ◽  
Heterogeneous Nanocatalyst ◽  
Surface Basicity

Heterogeneous nanocatalyst of biohydroxyapatite-lithium (HA-Li) has been prepared through modification of HA extracted from bovine bone waste with Li at various calcination temperatures (400-700oC). Characterizations of the heterogeneous catalysts were including surface acidity-basicity, functional groups, BET surface area, particle size, and surface morphology. Optimization of catalyst ratios (1-7%) with the best characterization was applied for converting Malapari seed oil (Milletia pinnata L.) to biodiesel. The characterization results showed that HA-Li catalyst calcinated at 600oChad the highest surface basicity and Lewis acid sites revealing specific functional group of O-Li at wavenumber of 1612.49 cm-1. BET surface area of HA-Li catalyst decreased with increased average particle size. SEM analysis suggested that morfology of catalysts formed stack of agglomerates. The highest yield of biodiesel obtained on a catalyst ratio of 5% was 88.16%. GC-MS analysis showed 10 peaks, and 5 of the peaks exhibiting the highest percentage area were identified as methyl oleic, methyl palmitic, methyl erusic, methyl stearic, and methyl linoleic.

Synthesis and Sintering of Aluminium Nitride Nano-particles

2007 ◽  
Vol 1040 ◽  
Author(s):  
Zhao HAN ◽  
Mei YANG ◽  
Hongmin ZHU
Keyword(s):  
Electron Microscopy ◽  
Surface Area ◽  
Aluminum Chloride ◽  
Liquid Solution ◽  
Nano Particles ◽  
Area Measurement ◽  
Bet Surface Area ◽  
Plasma Sintering ◽  
Average Grain Size ◽  
Direct Nitridation

AbstractAluminum nitride (AlN) nano-particles were synthesized from aluminum chloride by sodium reduction in liquid ammonia. A liquid solution of sodium dissolved in ammonia was employed as a reduction-nitridation agent, which enabled direct nitridation of aluminum chloride at −45°C. The synthesized particles were heat-treated at 1000°C in vacuum, and were characterized by X-ray diffraction (XRD), scan electron microscopy (SEM), transmission electron microscopy (TEM) and BET surface area measurement. The results indicated that the product were hexagonal wurtzite AlN particles, with a specific surface area of 262 m2g−1. Spark plasma sintering (SPS) process was used to consolidate the as-prepared AlN nanoparticles, and a dense AlN ceramic (>98.5%) with average grain size of 200-400nm was obtained at 1600°C without the use of sintering additives.

scholarly journals Application of Ni0.5Zn0.5Fe2O4 magnetic nanoparticles for diclofenac adsorption: isotherm, kinetic and thermodynamic investigation

2021 ◽  
Author(s):  
Zahrasadat Mohammadi ◽  
Ahmad Rahbar Kelishami ◽  
Amir Ashrafi
Keyword(s):  
Magnetic Nanoparticles ◽  
Diclofenac Sodium ◽  
Particle Diameter ◽  
Bet Surface Area ◽  
Average Particle ◽  
Order Kinetic ◽  
Initial Ph ◽  
Order Kinetic Model ◽  
Langmuir Isotherm Model ◽  
Efficient Adsorbent

Abstract Ni0.5Zn0.5Fe2O4 magnetic nanoparticles were synthesized to obtain a new efficient adsorbent for diclofenac sodium (DF) removal. FTIR, EDS, SEM, BET and VSM were applied to characterize the prepared adsorbent. These analyses revealed that adsorbent was successfully prepared with average particle diameter of about 50 nm and a BET surface area of 168.09 m2/g. The saturation magnetization value of MNPs was found to be 24.90 emu/g, thus, adsorbent was efficiently separated from the solution by a facile and rapid magnetic separation process. The effect of adsorption time, amount of adsorbent, initial pH of the solution, initial diclofenac concentration and temperature on the removal of DF were evaluated. Also, the adsorption data were best fitted to the pseudo-first-order kinetic model and Langmuir isotherm model. The thermodynamics studies suggested spontaneous and exothermic adsorption. The maximum diclofenac adsorption amount of the synthesized nanoadsorbent was 52.91 mg/g, which is higher than many recently studied adsorbents.

scholarly journals USE OF OPAL-CRYSTOBALITE-TRIDIMITE MICRO-FILLER IN DENSE AGGREGATE CONCRETE

2020 ◽  
pp. 8-17
Author(s):  
N. Lukutcova ◽  
A. Pykin ◽  
E. Chivikova
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Particle Diameter ◽  
Component Composition ◽  
Average Particle ◽  
Maximal Effect ◽  
Aggregate Concrete ◽  
Optimal Value ◽  
Cement System

Opal-cristobalite-tridimite micro-filler (OCTMF) as a component of dense aggregate concrete (DAC), obtained by grinding of sedimentary siliceous rock – abiomorphic silicite fractions of 0.315-0.63 mm was studied considered. The chemical-mineral composition and microstructure of the of OCTMF particles were determined. Comparative analysis of the relationship between particle size distribution, average particle diameter, specific surface area of OCTMF particle and grinding period in shock-abrasive and cavitation mills was carried out. The conductometric express method was applied to study the effect of the OCTMF specific surface area on hydration activity of cement system. The optimal value of OCTMF specific surface area was (880–900 m2/kg), achieved as a result of cavitation dispersion for 5–10 minutes, that provides increasing in t hydration activity of cement system by 52–54 %. The effect of the consumption of components on strength of the DAC after 28 days of hardening was determined using mathematical statistics method. That allows predicting this parameter by varying the component composition of the concrete mix. An assessment of the OCTMF efficiency was made. It was established, the maximal effect of the OCTMF is at concentration up to 5 % (by wt. of cement), that provides an increasing the design compressive strength of DAC up to 126 %.

Synthesis and Characterization of High Surface Area Nano Titanium Dioxide

2021 ◽  
Vol 11 (4) ◽  
pp. 51-75
Author(s):  
Dalya Jasim Ahmed Ahmed ◽  
Basim Ibrahim Al-abdaly ◽  
Sattar Jalil Hussein
Keyword(s):  
Titanium Dioxide ◽  
Surface Area ◽  
Crystal Size ◽  
Anatase Phase ◽  
Sol Gel ◽  
Bet Surface Area ◽  
Average Particle ◽  
Al2o3 Nanoparticles ◽  
Water Mixture ◽  
Nano Titanium Dioxide

TiO2 and TiO2-Al2O3 nanoparticles were synthesized via sol-gel method using hydrolysis of Titanium tetraisopropoxide (TTIP) with ethanol and water mixture as titania source. TiO2-Al2O3 Nano-composite was successfully synthesized using the sol-gel technique. Tetraisopropoxide and aluminium isopropoxide were used to prepare TiO2-Al2O3. All prepared samples calcination were conducted at different temperature (400 to 700) oC. The synthesized TiO2 and TiO2-Al2O3 nanocomposites were then characterized by XRD, AFM, BET surface area, SEM, XRF. XRD, the analysis showed that the presence of alumina (Al2O3) in the TiO2 has an effect on crystal size, particles size, surface area, and crystal phases; The XRD result revealed that the prepared TiO2 nanoparticles were anatase phase at 400oC, and 500oC, and transformed to rutile from 600oC to 700oC, but after addition of alumina TiO2 was of anatase phase, without any rutile at all calcination temperatures, also, the addition of alumina leads to a significant decrease in the crystal size, particles size, especially at high temperatures while the surface area of pure titanium was increased, and this corresponds to the results of the AFM and SEM. The best-obtained surface area was 355.18 m2/ gm. with 34.98 nm of average particle size at 500oC in comparison with pure nano titanium dioxide

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