Aluminum Nitrate Nonahydrate Research Articles

Enhancing solar cell productivity with MgAl2O4–ZnAl2O4 blended anti-reflection coatings

The enhancement of productivity in solar cells primarily relies on the application of anti-reflection coatings. The current research employs coating materials such as MgAl2O4, ZnAl2O4 and blended MgAl2O4–ZnAl2O4 as an anti-reflective layer on the monocrystalline Si solar cells by employing RF sputter coating method. Magnesium nitrate hexahydrate and aluminium nitrate nonahydrate were utilized for the synthesis of MgAl2O4 by the sol-gel technique. ZnAl2O4 was synthesized using zinc nitrate hexahydrate and aluminum nitrate nonahydrate by sol–gel procedure. The performance of coated photovoltaic cells was evaluated through different characterization techniques. From the optical study, the blended MgAl2O4-ZnAl2O4 coating shows the maximum absorbance of around 93 % and lowest reflectance of 9 %. The MgAl2O4–ZnAl2O4 blend achieves a maximum power conversion efficiency (PCE) of 22.12 % in a controlled light source and 19.21 % in direct sunlight. Compared to other solar cells, blended MgAl2O4–ZnAl2O4 demonstrates low resistivity (4.23 × 10−3 Ω-cm), high carrier concentration (35.81 × 1020 cm−3) and maximum hall mobility (12.96 cm2/Vs). From the surface temperature measurement, it is evident that the MgAl2O4–ZnAl2O4 blend coated solar cell exhibits lowest temperature of 38.2 °C under simulated light. The experimental results indicate that the blended MgAl2O4–ZnAl2O4 coated photovoltaic cells exhibits superior productivity than the various coated and uncoated solar cells. Therefore, it can be stated that MgAl2O4–ZnAl2O4 blends are the excellent antireflective materials for achieving desired PCE in solar photovoltaic cells.

A facile and green alternative method for preconcentration of triazole fungicides using fabrication of melamine sponge anchoring with Ni/Al-LDH adsorbent followed by HPLC analysis

In this work, a facile and green alternative method for preconcentration of triazole fungicides (TFs) using melamine sponge anchoring with nickel/aluminium layered double hydroxide (Ni/Al-LDH-MS) as adsorbent for micro-solid phase extraction (micro-SPE). LDHs was prepared by nickel (II) nitrate hexahydrate and aluminium nitrate nonahydrate. The adsorbent was simply synthesized under facile condition via anchoring of Ni/Al-LDH on the pore of melamine sponge (MS). The material was applied for extraction of triazole fungicides prior to HPLC analysis. Under the chosen conditions, the proposed method provides wide linearity between 0.09 –1.00 µg L-1 with coefficients for determination (R2) of greater than 0.99. Low detection limits of 0.03 µg L-1 for all analytes were achieved. The satisfactory recoveries of the real samples at three different concentration levels were obtained in the range of 64.5 % to 105.6 % with RSDs lower than 7.5 %. The findings highlight the importance of developing efficient adsorbents for the enrichment of trace triazoles in surface water, soymilk, honey and egg yolk matrices. Eco-friendliness was confirmed by Analytical Eco-scale and Analytical GREEnness metric (AGREE) which shown that the recommended analytical procedure is more green than previous methods.

Kinetics of mullitization from sol-gel synthesized precursors

The aim of this study is to shed more light on the formation of mullite and the kinetics of mullitization from sol-gel synthesized precursors. Tetraethylorthosilicate (TEOS) and aluminum nitrate nonahydrate (ANN) were used, as a source of silica and alumina, respectively, for the synthesis of homogenous mullite precursor powder. The mullitization process was characterized by thermogravimetry (TG), differential thermal analysis (DTA), thermodilatometric analysis (TDA), and x-ray powder diffraction (XRD) techniques. It was found that mullite started to crystalize at temperatures of 1050, 1200, and 1241 °C as determined by XRD, DTA, and TDA, respectively‏. Mullite crystallization kinetics was thoroughly investigated under isothermal and non-isothermal conditions using DTA. The activation energy for mullite formation was calculated, for different crystallization fractions, following the Freidman, Kissinger, Boswell, and Ozawa methods. The average values were found to be 1282.92, 1324.30, 1336.93, and 1283.09 kJ/mol, respectively. The kinetic parameters and the crystallization mechanism were determined and the results were compared with those available in the literature. The Sestak Berggren SB(m,n) model was found to be the most suitable for the determination of mullite crystallization mechanism. The calculated average values of the Gibbs free energy (ΔG#), enthalpy (ΔH#), and entropy (ΔS#) for mullite formation, at different heating rates, were 433.98 kJ/mol, 1294.20 kJ/mol, and 566.23 J/mol.K, respectively.

Synthesis, characterization and electrical studies of AlN:U/IL on some properties of PVA

To study the relationship of polymer polyvinyl alcohol PVA with properties of Ionic Liquids ILs types were also represented by deep eutectic (DESs) solvents and to identify the nature in the interaction between the polymer structure and the ionic liquid IL which is described as aluminium nitrate nonahydrate was combined with urea to form a clear colourless ionic liquid in a mole ratio (1:1.2). Then behaviour is studied in detail by varying the AlN:U/IL concentration in the PVA matrix result polymer composite. The functionality properties were analysed through the displacements that occurred by ATR-FTIR spectroscopic technique, Thermal analysis of the synthesised polymer composite TGA-DTG thermal gravimetric, and differential analysis. The dielectric (ε′) constant and dielectric loss (ε″) of varying weight ratios (5–25)% weight ratios of prepared polymer composite compared to pure polymer PVA.

Ceramic Processing of Silicon Carbide Membranes with the Aid of Aluminum Nitrate Nonahydrate: Preparation, Characterization, and Performance.

The development of a low-cost and environmentally-friendly procedure for the fabrication of silicon carbide (SiC) membranes while achieving good membrane performance is an important goal, but still a big challenge. To address this challenge, herein, a colloidal coating suspension of sub-micron SiC powders was prepared in aqueous media by employing aluminum nitrate nonahydrate as a sintering additive and was used for the deposition of a novel SiC membrane layer onto a SiC tubular support by dip-coating. The sintering temperature influence on the structural morphology was studied. Adding aluminum nitrate nonahydrate reduced the sintering temperature of the as-prepared membrane compared to conventional SiC membrane synthesis. Surface morphology, pore size distribution, crystalline structure, and chemical and mechanical stability of the membrane were characterized. The membrane showed excellent corrosion resistance in acidic and basic medium for 30 days with no significant changes in membrane properties. The pure water permeance of the membrane was measured as 2252 L h−1 m−2 bar−1. Lastly, the final membrane with 0.35 µm mean pore size showed high removal of oil droplets (99.7%) in emulsified oil-in-water with outstanding permeability. Hence, the new SiC membrane is promising for several industrial applications in the field of wastewater treatment.

A facile route to prepare ODS WC[sbnd]Co cemented carbides

Oxide dispersion strengthened (ODS) WCCo cemented carbides with excellent mechanical properties were prepared by a facile three-step method. First, the mixture of ammonium paratungstate, cobalt oxalate and aluminum nitrate nonahydrate were roasted to generate precursor powder. Then, the precursor powder was reacted with insufficient carbon black to remove oxygen to aid precise carbon addition in the next step. Finally, depending on the carbon content difference between carbothermic reduction products and target product, the sample was mixed with the required carbon black to prepare WCCoAl2O3 cemented carbides directly by the method of powder sintering. Experiments showed that after the addition of uniformly distributed nano-sized Al2O3 particles, the mechanical properties included hardness and toughness of ODS cemented carbides improved. When the content of Al2O3 was 0.5%, the densification of finally prepared WC-5.5wt%Co-0.5wt%Al2O3 alloy could reach to 99.08%, and the values of fracture toughness and Vickers hardness were 11.35 ± 0.60 MPa·m1/2 and 1756 ± 20.92 HV, respectively, thus giving excellent results.

Hydrothermal synthesis and characterization of nano-particles γ-Al2O3

The study of hydrothermal treatment on the phase formation and the crystallites of gamma-alumina (γ-Al2O3) was performed. Different reaction time and temperature of hydrothermal treatment were investigated. The preparation of γ-Al2O3 includes precipitation of aluminum nitrate nonahydrate by ammonia, aging, washing, transferred the gel into the hydrothermal reactor, drying, and calcination at 600 °C. The precipitation was stopped at pH equals 7.5. The reaction times of hydrothermal treatment were 1 – 2 hours, and the temperatures were 140 – 200 °C. X-Ray Diffraction analysis was used to investigate the phase formation and the particle size. The results show all the samples represented pure nano γ-Al2O3. The examination of hydrothermal treatment of y-Al2O3 reveals as the reaction time longer, the crystallite grows bigger, as well as the higher temperature applied. The smallest γ-Al2O3 obtained based on the Scherrer equation is 4 nm and the biggest is 6.5 nm. Interestingly, the peaks of the γ-Al2O3 prepared by hydrothermal treatment at the longest time and the highest temperature have shifted into a higher diffraction angle. In the case of this sample, the peaks shifted into a higher diffraction angle. That is means there is a change in the lattice structure of γ-Al2O3 probably was affected by the lattice of hydroxyl content.

Tailoring thermal development of gamma alumina sorbents material using combustion synthesis: the effect of amino acids (G, A, N) and equivalence ratio

Using a combustion synthesis, the range of achievable textures is broader than using conventional synthesis methods and can be controlled more successfully. As a tool allowing the achievement and control of desired textures, here we bring about wet chemistry synthesis using aluminium nitrate nonahydrate (ANN) precursor systematically combined with different fuels (amino acids). The amino acids; glycine (G), alanine (A) and asparagine (N) have been specifically selected in order to show the role of gradual increase in their: (1) molar mass, (2) enthalpy of combustion, (3) amine groups content and (4) ratio to ANN. Detailed (micro) structural and thermal characterisations confirm that the nanocrystalline character and thermomechanical stability were not diminished in the course of this synthesis. The conditions leading to development of different morphologies from gels to powders were found to be heavily under the influence of fuel/oxygen ratio, i.e. of the smouldering versus flaming mechanism of the combustion. Higher content of nitrates (predominately from amino-rich amino acids) strongly promoted auto-combustion behaviour. As-derived alumina precursors have been thermally treated at various temperatures (quenched and soaked), to monitor γ- and α-alumina crystallisation, with respect to the development of morphology. Different texture types have been observed, such as porous wormhole, porous and porous expanded flakes. Higher fuel levels promote specific surface increase. This combustion synthesis allows facile tailoring of nanocrystalline γ-alumina with different morphological features, whereas samples having optimal parameters were suitable for catalyst support application on behalf of rapid sorption performance.

On the Structural, Optical and Electrical Characterization of Zinc Oxide and Aluminium doped Zinc Oxide for Optoelectronic Applications

Zinc Oxide (ZnO) and Aluminium doped Zinc Oxide (AZO) thin films are deposited on the glass slides by sol-gel spin coating technique. Zinc acetate dehydrate, 2 methoxyethanol, and diethanolamine are respectively used as a precursor, solvent, and stabilizer. Aluminium nitrate nonahydrate was used as the dopant source to obtain the atomic percentage of the dopant of 2%, 4%, 6% and 8%. The structural, optical, and electrical properties of the films were investigated using X-ray Diffraction (XRD), UV-visible spectrophotometry, and a Four-point probe technique respectively. The results from structural analyses show that the films are polycrystalline with a hexagonal wurtzite structure and a preferential orientation alongside the \(c\)-axis. The value obtained for the unit cell \(a=3.020\) A and \(c= 5.108\) A are in line with the reported literature. The transmittance of the films was observed within the visible region of the spectrum and the optical bandgap of the un-doped ZnO was established to be around 4.11 eV. However, the optical bandgap of the AZO films (4 and 6 at %) marginally decreases with doping concentration, which may be ascribed to the shrinkage of band effect due to the increase in carrier concentration. The lowest resistivity of \(3.53\times {10}^{-3}\,\Omega\) cm was observed for the doping concentration of 2% of Al. From the results, it was established that as the doping concentration increases, the thicknesses of the thin films were increased. Likewise, the increase in doping leads to a better uniformly distributed absorption spectra of the deposited AZO thin films.

The effects of pre-heating and sintering temperature on the sol-gel synthesis of mullite nanoparticles

The aim of this study was to synthesize the mullite nanoparticles by sol-gel method using tetraethylorthosilicate (TEOS) and aluminum nitrate nonahydrate (ANN) as the precursors. The effects of the pre-heating process and sintering temperature on the structure of the synthesized powders were characterized by thermal analysis, x-ray diffraction (XRD) and scanning electron microscopy (SEM) images. Thermal analysis and XRD results showed that the crystallization temperature of the mullite phase was significantly decreased owing to application of pre-heating. The pre-heating process led to disappearances of the Al-Si spinel phase in the XRD pattern of the samples. Moreover, the SEM images of the samples demonstrated that by applying pre-heating, the growth type of mullite phase was changed from isotropic growth to the anisotropic one.

Effects of aluminum doping on the structural and optical properties of ZnO nanorods grown on highly conductive films

ZnO nanorods were grown on ∼ 50-nm-thick transparent conductive oxide thin films by hydrothermal synthesis. The resistivity of the ZnO films was lowered to 4 × 10−4 Ω cm upon Ga doping. Zinc nitrate hexahydrate, mixed with hexamethylenetetramine, was dissolved in deionized water to prepare a synthesis solution. Aluminum nitrate nonahydrate was added to the synthesis solution to dope the Al into ZnO nanorods. X-ray diffraction analysis and field-emission scanning electron microscopy were conducted to study the crystal structure and morphology of the nanorods, respectively. Al doping enhanced the preferential orientation to (002) of a wurtzite structure and increased the compressive strain. The trace of Al in the ZnO nanorods was detected by energy dispersive X-ray spectroscopy. The optical properties were investigated by measuring the transmittance, Raman shift, and photoluminescence. Al doping led to a blue shift or red shift in the energy band gap. The results of the Raman shift confirmed the compressive stress in the ZnO nanorods. Sharp ultraviolet (UV) and broad visible photoluminescence peaks were obtained irrespective of Al concentration in the ZnO nanorods. The intensity of the UV peak doubled by Al doping.

Effect of solution molarity on optical properties of Al doped ZnO thin films

Undoped and Al-doped ZnO thin films have been prepared by the sol gel method. Zinc acetate dihydrate, ethanol and monoethanolamine were used as precursor, solvent and stabilizer, respectively. In the case of molarity study for Al-doped ZnO, aluminum nitrate nonahydrate was added to the precursor solution from 0 at. % to 6 at. % at molarity of 0.1 M, 0.2 M and 0.3 M. The optical properties were characterized using UV-Vis where the band gap of undoped ZnO increases as the annealing temperature increase and the band gap decrease as the molarity increment. Meanwhile the band gap increase upon increment of Al dopant under molarity of 0.1 M and 0.2 M due to Burstein-moss effects. Meanwhile at 0.3 M, the bandgap increase until 4 at. % of Al and suddenly decrease abruptly at 6 at. % of Al. The effect of molarity and dopant percentage on the thin film gives a different value of energy band gap.

Characterization of Al-doped ZnO nanorods grown by chemical bath deposition method

Introduction: In recent years a metal oxide semiconductors have been paid attention due to their excellent chemical and physical properties.ZnO (Zinc oxide) is considered as one of the most attractive semiconductor materials for implementation in photo-detectors, gas sensors, photonic crystals, light emitting diodes, photodiodes, and solar cells, due to its novel electrical and optoelectronic properties. There are different uses of metal oxide semiconductors such us, UV photodetectors which are useful in space research’s, missile warning systems, high flame detectors, air quality spotting, gas sensors, and precisely calculated radiation for the treatment of UV-irradiated skin. ZnO is a metal oxide semiconductors and it is used as a transparent conducting oxide thin film because it has the best higher thermal stability, best resistance against the damage of hydrogen plasma processing and relatively cheaper if one compares it with ITO. Materials and Methods: On glass substrates, Al-doped ZnO (AZO) nanorods have been grown by a low -cost chemical bath deposition (CBD) method at low temperature. The seed layer of ZnO was coated on glass substrates. The effect of the Al-doping on the aligned, surface morphology, density, distribution, orientation and structure of ZnO nanorods are investigated. The Al-doping ratios are 0%, 0.2%, 0.8% and 2%. The Aluminum Nitrate Nonahydrate (Al (NO3)3.9H2O) was added to the growth solution, which is used as a source of the aluminum dopant element. The morphology and structure of the Al-doped ZnO nanorods are characterized by field emission scanning electron microscopy (FESEM) and high-resolution X-ray diffractometer (XRD). using the radio RF (Radio frequency) magnetron technique. Results and Discussion: The results show that the Al-doping have remarkable effects on the topography parameters such as diameter, distribution, alignment, density and nanostructure shape of the ZnO nanorods. These topography parameters have proportionally effective with increases of the Al-doping ratio. Also, X-ray diffraction results show that the Al-doping ratio has a good playing role on the nanostructure orientation of the ZnO nanorods. Conclusions: The Aluminum Nitride Nanohydrate considered as a good Aluminu source for doping ZnONR. It is clear from FESEM results that the Al-doping of ZnONR has a remarkable effect on the surface topography of nanorods for all aluminum doping ratios. From XRD patterns, it concludes that as the Al-doping ratio increases, the reorientation of the nanostructure of ZnO increases towards [100] direction. The results obtained also have shown that the average diameter of a nanorod is increased with increasing the ratio of Al-doping.

Al- & Al-Ca-doped ZnO Thin Films by Sol-Gel Method for Solar Cell Application

Zinc oxide (ZnO) thin films, due to their excellent photovoltaic properties, are gaining much attention to be used as n-type semiconductor material for modern day solar cell. The change in photoelectric properties of zinc oxide with doping is an area of much consideration. In this work, 1.17%Al, 1.17%Al-2%Ca and 1.17%Al-4%Ca doped ZnO thin films were produced on glass substrate by Sol-Gel spin coating technique. Zinc acetate dihydrate, triethanolamine and isopropanol were used for making precursor solution. For Al doped ZnO, aluminum nitrate nona hydrate was added to the precursor solution as source of Al. Aluminum nitrate nona hydrate and calcium chloride dihydrate were utilized as source of Al and Ca respectively for Al-Ca doped ZnO. The films were deposited from precursor solutions at 1300 rpm for 20 seconds. After deposition, annealing was done at 520°C for one hour. Properties of deposited films were characterized by X-ray Diffractometer (XRD), Scanning Electron Microscopy (SEM) and UV-Vis spectroscopy. From XRD spectra the theoretical grain size was measured which increased from 0.31 nm to 0.33 nm because of doping. From SEM micrograph the uniformity and homogeneity of thin film was observed. The band gap of deposited thin films was measured from absorbance spectra. The band gap decreased from 3.27 eV to 3.17 eV because of doping 4% Ca in addition to 1.17% Al. From transmittance spectra, it was found that all films were transparent with average percentage of transmittance of more than 86%.

Preparation of mullite from alumina/aluminum nitrate and kaolin clay through spark plasma sintering process

In the present study, the in-situ synthesized mullite has been prepared successfully by mixing kaolinite with alumina and aluminum nitrate nonahydrate (ANN) powders through high energy milling followed by spark plasma sintering (SPS). Using a high-energy ball-mill, the stoichiometric compositions of the starting powders, considering their final transformation to Al2O3 and SiO2, have been mixed. The SPS process has been performed at 1400 and 1375 °C for the specimens containing Al2O3 and ANN, respectively. XRD patterns of the milled powders after 30 h showed the formation of quartz from kaolinite for both starting batches. The displacement-temperature-time (DTT) curves and the corresponded vacuum changes indicated the dehydration and phase transformation of ANN and kaolinite at different stages of the sintering process. The XRD patterns of the sintered samples revealed the formation of mullite alongside un-reacted Al2O3 and crystobalite for the batches containing Al2O3 and ANN, respectively. The results of the physical and mechanical properties tests showed higher amounts of bending strength (397 ± 18 MPa), Vickers hardness (16.32 ± 0.21 GPa) and fracture toughness (3.81 ± 0.24 MPa m−1/2) alongside a lower porosity (0.070 ± 0.02%) for the prepared sample containing Al2O3, than those of the sample containing ANN.

Development of Room-Temperature Ferromagnetism in Nanocomposite CdO Codoped with Al and Gd: Treatment in Hydrogen Atmosphere

Cadmium oxide codoped with Al and Gd ion powders was synthesised by thermal codecomposition of a mixture of complexes of cadmium acetate dihydrate, gadolinium acetate hydrate, and aluminum nitrate nonahydrate. The mass ratio of Al/Cd was fixed while the mass ratio of Gd/Cd varied systematically. The purpose of the present study is to synthesise and study the transparent conducting oxide (TCO) CdO powder having room-temperature ferromagnetic (RT-FM) properties. To realize that purpose, the synthesised Al/Gd-codoped CdO powder was annealed under hydrogen gas with certain conditions. The X-ray diffraction (XRD) method confirmed the formation of a single nanocrystalline structure; thus, both Al/Gd ions were incorporated into CdO lattice forming solid solutions. Magnetic measurements revealed that some of the doped CdO powders gained paramagnetic (PM) properties where the susceptibility increases with increasing dopant Gd content; the measured effective magnetic moment of dopant Gd3+ was around 8 μB. Furthermore, the magnetic energy of the created RT-FM of the codoped CdO samples by hydrogenation was found to be dependent on the Gd% doping level. For hydrogenated CdO powder doped with 3% Gd, the coercivity (Hc) was 195.9 Oe, the remanence (Mr) was 0.77 memu/g, the saturation magnetisation (Ms) was 5.05 memu/g, and the energy product (Um) was 150.6 merg/g. Thus, the possibility of production of TCO CdO with RT-FM, where magnetic characteristics can be tailored by doping and post treatment under H2 gas, was proven. Thus, a new potential candidate to be used as a dilute magnetic semiconductor (DMS) was successfully synthesised.

Structural Properties and Magnetic Interactions in Al3+ and Co2+ Co-Incorporated CdO: Efficient Act of Hydrogenation on Ferromagnetic Order

Nano-powder samples of cadmium oxide doped with Al-Co ions were synthesized by the sol–gel technique using a mixture of complexes of cadmium acetate dihydrate, gadolinium acetate hydrate, and aluminum nitrate nonahydrate. The mass ratios of Al/Cd and Co/Cd in the investigated samples (CdO:Al, CdO:CO, and CdO:Al;Co) were 0.5% and 1%, respectively. X-ray diffraction studies confirmed the formation of a single-phase crystalline structure. Thus, both Al and Co ions were successfully incorporated into the CdO lattice. The present work aims to investigate the possible creation of room-temperature (RT) ferromagnetic properties in host CdO for the field of dilute magnetic semiconductorz (DMS). Annealing in H2 atmosphere under certain conditions was extensively utilized to enhance the Heisenberg interactions between the spins of the incorporated dopant ions which boosted the created FM behavior. Optical measurements revealed the redshift of the bandgap by doping and hydrogenation. RT magnetic measurements disclosed various magnetic properties [diamagnetic, paramagnetic (PM), and FM) at RT depending on the dopant type]. However, the hydrogenation converted all the investigated samples to FM. It was established that the hydrogenation could enhance the saturation magnetisation of CdO:Al:Co nano-powder by ∼ 400 times. Therefore, the system of Al/Co-doped CdO nano-powders, owning these amazingly tunable magnetic properties, can be considered as a potential candidate for many applications such as DMS in addition to its transparent conducting oxide properties.

Synthesis and Characterization of Allophane-Like as Chromium (Cr) Ion Adsorbent

The synthesis and characterization of allophane-like as chrom (Cr) ion adsorbent has been studied. The objectives of this study is to determine the characteristics of allophane-like and determine ratio of Al/Si, chromium solution pH, and contact time to get the best decreasing metal ion chrom (Cr) adsorption condition. The study was conducted with the ratio of Al/Si ratios 0.5; 0.75; 1.0; 1.25 and 1.5 from Tetraetyl Orthosilicate (TEOS) solution and Aluminium Nitrate Nonahydrate [Al(NO3)3.9H2O] in pH 3-4. The result of synthetic was characterized on functional groups and cristallinity. Experiment of adsorption ability using variation of Cr solution pH 3-7, contact time 30, 60, 90 and 120 minutes with batch method. The results by FTIR shows that functional groups-OH, the asymmetry groups O-Si-O or O-Al-O, relatively weak absorption which stronger then the presence of OH and bending vibration Si-O or Al-O on allophane-like. The best conditions of chromium metal adsorption with adsorbent allophane-like was obtained at pH 5, contact time 90 minutes, and the ratio Al/Si 1.5. Types of adsorption in this study follows Freundlich and Langmuir isotherm.

An alternate method to synthesize zeolites for biological applications

Zeolites find use in various applications in biological/medical field where the majority of them were prepared using Cetrimonium Bromide (CTAB), Carboxymethylcellulose (CMC) and fly ash as binders. In this work, two new zeolites were prepared by using polyethylene glycol (PEG) as binder starting from aluminium nitrate nonahydrate (ANN) and tetraethylortho silicate (TEOS) through sol-gel technique. The resultant zeolites were compared with the one synthesized using CTAB as binder. Zeolites prepared using PEG was found to be polycrystalline with an average grain size of 0.5-1nm by X-ray analysis. The new zeolites were characterized using SEM, XRD, EDAX and FTIR analysis. The zeolites prepared were comparable with those used in biological applications.

Synthesis of nanocrystalline alumina (Al2O3) particles from an aqueous precursor by flame-assisted spray pyrolysis

Nanocrystalline alumina particles were successfully synthesized in an indigenously built flame-assisted spray pyrolysis (FASP) setup. Aluminium nitrate nonahydrate was dissolved in deionized water in the desired amount to get a precursor solute concentration of 0.01 mol L-1. The solution was then atomized by using a jet nebulizer. The droplets were then pyrolyzed in an oxy-LPG (liquifiedpetroleum gas) flame producing nanocrystalline alumina particles which were confirmed by x-ray diffraction (XRD) and transmission electron microscopy (TEM) analysis. Particle morphology was studied using scanning electron microscopy (SEM). The synthesized powders were predominantly metastable transition aluminas exhibiting spherical morphology and were unagglomerated. The synthesized powders were then calcined at 1473 K for 2 hour to transform into the stable α-Al2O3 (corundum) phase.