Aluminum Nitrate Salts Research Articles

Thermal Characterization of [C2Im][NO3] and Multivalent Nitrate Salts Mixtures

Due to their intrinsic properties, the current applicability of ionic liquids is enormous. In particular, their use in electrochemistry is beyond question. Numerous studies on these compounds and their mixtures, especially with lithium salts, focus on their use as electrolytes for batteries and other energy storage devices. This includes thermal energy storage devices, where 4th generation ionic liquids and their derivatives show a huge potential. Nevertheless, considering the uneven availability of the raw materials, such as lithium, research has extended to mixtures of these compounds with other salts of different metals that are more abundant and widely distributed, such as magnesium or aluminum. This work presents a comprehensive thermal characterization, using differential scanning calorimetry and thermogravimetry, of the protic ionic liquid ethylimidazolium nitrate and its mixture with magnesium and aluminum nitrate salts at different concentrations. Additionally, a comparison between these results and previous studies of mixtures of this ionic liquid with lithium nitrate, as well as mixtures of the protic ionic liquid EAN with the same metal salts, was also performed. The results indicated that the salt addition tends to broaden and reduce crystallization and melting peaks, while the glass transition becomes more visible and shifts to higher temperatures with increasing salt concentration. This is due to the disorder generated by the rearrangement of ions in the polar domains, which erodes the hydrogen bond network of the protic ionic liquid. Nevertheless, the thermal stability of the blended samples does not change significantly compared to the bulk ionic liquid.

The Effect of Peptizing Agent Concentration on Processing and Properties of Alumina Based Catalyst Support

Gamma alumina (γ-Al2O3) has drawn attention as a support material for heterogeneous catalysts extensively used in the oil and gas industry due to its superior properties. Boehmite (AlOOH) is an industrially accepted and well-known precursor to produce gamma alumina-based support. The process additions such as nitric acid (HNO3) are commonly used in shaping process of alumina to control textural, mechanical and structural properties of final catalyst support. In this work, gamma alumina precursor boehmite was peptized by nitric acid at molar ratio of HNO3/AlOOH ranging from 0 to 0.054. With addition of nitric acid, extrusion paste showed higher plasticity up to 0.017 mole of HNO3/AlOOH. The addition of more than this point led to an inhomogenity of extrusion paste caused by hard and brittle structure caused by the formation of aluminum nitrate salts. Also, higher mechanical strength was observed for samples peptized with lower nitric acid concentration because of effective deagglomeration by peptization. The pore size of catalyst support pellets increased up to an acid/ boehmite molar ratio of 0.017 by peptizing of boehmite. However, beyond this point pore size decreased due to dissolution of boehmite.

Solid Polymer Electrolyte (SPE) from Corn Starch and Aluminum Nitrate Salt Composites for Aluminum - ​​Ion Battery

The increasing of need for portable electrical energy makes the demand for rechargeable batteries high. Aluminum-ion battery with Solid Polymer Electrolyte (SPE) produced from the natural polymer corn starch with salt additive has the potential to be developed. The flexibility and resilience of SPE are enhanced by glycerol (C3H8O3). Throughing gelatinization of the linear monomer chains to become amorphous, the space for the ions in it is more free so that the ionic conductivity is high. By means of solution casting, heating temperature of 50°C for 9 hours found SPE with a strong structure. With the same concentration CS-Al has a higher conductivity with σ = 4.93 x 10-5 S/cm than CS-Na whose value is σ = 2,92 x 10-5 S/cm. This is due to the SPE CS-Al show more amorphous structure which allow more flexible ionic segmental motion. This is in accordance with XRD resulting which shows that the addition of aluminum nitrate salt is more amorphous than sodium acetate; the shift in peak pattern is also greater due to cation intercalation Al3+ with corn starch. FTIR is the result found that nitrate fixed by corn starch, indicated a change in the hydroxyl group of corn starch amylopectin. SEM photo of result also showed aluminum nitrate salt ion more easily in overcoming than sodium acetate. The indicate of SPE was more homogeneous because corn starch was already intercalated. They are combined to Al3+ and NO3- ions. With this value it can be an appropriate reference for developing SPE on Aluminum-ion batteries with aluminum nitrate salts have higher performance and environment friendly Keywords: Aluminum-ion battery, Solid Polymer Electrolyte, corn starch, ionic conductivity, and Amorphous

A solid polymer electrolyte for aluminum ion conduction

We report on the synthesis and characterization of a solid polymer electrolyte for aluminum ion conduction. The solid polymer electrolyte is produced via the copolymerization of a low molecular weight polytetrahydrofuran and a cycloaliphatic epoxy. The crosslinked copolymer is swollen in THF solutions of different concentrations of aluminum nitrate as the aluminum ion source. The conductivity as a function of concentration is measured via AC impedance spectroscopy over a temperature range of 20–110 °C. We attain conductivities that increase with salt loading, reaching a value of 2.86 × 10−5 S·cm−1. Thermogravimetric analysis shows the electrolytes are stable up to 150 °C. Raman spectroscopy reveals complete dissociation of the aluminum nitrate salt in the electrolyte over the concentration range explored. This study establishes a polymer system and synthetic route towards solid polymer electrolytes for aluminum ion conduction, for the development of all solid-state aluminum ion batteries.

Design challenges in electrodepositing metal-anionic clay nanocomposites: Synthesis, characterization, and corrosion resistance of nickel-LDH nanocomposite coatings

A method was developed to electrochemically synthesize metal-anionic clay nanocomposite coatings. The coatings consist of Zn-Al layered double hydroxide (LDH) nanoplatelets incorporated into a nickel matrix (Ni-LDH), and were evaluated for their corrosion resistance versus pure nickel coatings on steel substrates. The LDH nanoplatelets incorporated into the nickel coatings were synthesized from zinc and aluminum nitrate salts using a refluxing coprecipitation method. These nitrate platelets were intercalated with sodium dodecylsulfate, increasing the gallery spacing from 9.06 Å to 37.6 Å, followed by refluxing in butanol to delaminate the LDH crystal sheets, giving a 1.5 g/L loading of LDH in the continuous phase. The average platelet size was found to be 631 ± 43 nm. Aliquots of the delaminated LDH colloid were added to a modified nickel bath for electrodeposition. Challenges for electrodepositing these metal anionic clay nanocomposites from an aqueous bath are reviewed and discussed. EDS analysis confirms the presence of the nanoplatelets in the metal coating. The resulting nanocomposite films have a preferred (220) orientation and crystallite sizes ranging from 25 to 60 nm as measured by XRD. Corrosion resistance of the coatings was also improved over the pure nickel coatings and measured in 3.5% NaCl with potentiodynamic polarization and electrochemical impedance spectroscopy. Suggestions for future design and improved properties are discussed for these types of nanocomposite coatings.

Transformation kinetics of θ- to α-phase of alumina powders prepared from different alumina salts by chemical processing

The aim of this study was to produce nanosized alumina powders from two different aluminum salts (AlCl3 and AlNO3.9H2O) by precipitation method and to investigate transformation kinetics of α-Al2O3 crystallization obtained from quantitative DTA curves via Kissinger–Akahira–Sunose (KAS) method. Precipitates are dried at 80 °C for 24 h and then calcinated at 1200 and 1300 °C for 1 h. Dried powders have bayerite [Al(OH)3] and calcinated powders have theta- (θ) and alpha (α)-alumina phases which confirmed by XRD analysis, and the crystallite size of powders determined by Scherrer equation is about 30 nm for dried powders and ranged from approximately 15–35 nm for calcinated powders. Scanning electron microscopy studies revealed that the morphology and size of powders precipitated from two different salts are similar to each other, and powders contain mainly sub-micrometer-sized particles and close to spherical form. Activation energy values determined by KAS equation range from 717 to 411 kJ mol−1 for powders produced from aluminum nitrate salt and from 844 to 476 kJ mol−1 for powders produced from aluminum chloride salt depending on the transformation rate.

Effect of thermal treatment on the synthesis of NiAl 2 O 4 spinel oxide using chitosan as precursor

Abstract Nickel aluminate oxide (NiAl2O4) was prepared using chitosan as polymeric precursor and ammonia solution as a precipitating agent. In addition, nickel nitrate and aluminum nitrate salts were used as sources of Ni and Al, under stoichiometric amounts (molar ratio Ni:Al = 1:2). NiAl2O4 particles were prepared at different calcination temperatures and their properties were investigated. The synthesized materials were characterized by X-ray diffraction, infrared spectroscopy, atomic force microscopy, thermogravimetric analysis and nitrogen adsorption-desorption isotherms. The results showed that the thermal treatment process strongly influence on the formation of a single-phase structure of NiAl2O4 spinel. Nickel aluminate spinel with a porous structure and high surface area was obtained at temperatures above 700 ºC.

High temperature CO2 adsorption by mesoporous silica supported magnesium aluminum mixed oxide

Magnesium aluminum mixed oxide (Mg–Al–O) was deposited in various weight percentages into SBA-15 mesoporous silica through excess solution impregnation of magnesium and aluminum nitrate salts and subsequent high temperature calcination. In all the syntheses the Mg:Al mole ratio was fixed at 2. High temperature CO2 uptake capacity of these composites were measured in the temperature range 300–400°C and were compared with the capacity of the unsupported mixed oxide phase with same Mg:Al mole ratio of 2. An improvement in the specific equilibrium capacity as well as uptake kinetics for CO2 was observed in the composite adsorbent after an optimum loading of the mixed oxide. The result could be explained on the basis of better accessibility of the active sites for CO2 adsorption following dispersion of the mixed oxide on to the high surface area SBA-15 support. The CO2 adsorption capacity is higher than recent reports of Mg–Al–O supported on graphene oxide and CNT where there is additional complication of support degradation during thermal decomposition of Mg/Al salt precursors to corresponding metal oxides during adsorbent preparation.

DSC and TGA Measurements of Room Temperature Ionic Liquids (RTILs) Containing Ammonium Alum or Aluminum Nitrate with Amide Compounds

Characterization of some room temperature ionic liquids (RTILs) as thermal storage media and heat transfer fluids in thermal applications were investigated. Five ionic liquids prepared from ammonium alum NH4Al(SO4)2.12H2O as inorganic salt with urea NH2CONH2 or acetamide CH3CONH2 as organic compounds, and aluminum nitrate salt Al(NO3)3.9H2O either with urea or acetamide compounds in two mole ratios were investigated using Thermo-Gravimetric Analysis (TGA), Differential Scanning Calorimetry (DSC), X-ray diffraction (XRD), Fourier Transform Infrared (FTIR) spectroscopy and conductivity measurements. Thermo-physical properties such as enthalpy, heat capacity and thermal energy storage capacity were determined. It was found that ammonium alum: urea (USIL) in the mole ratio (1:5) and aluminum nitrate: acetamide (AN2IL) in the mole ratio (1:22) ionic liquids to be characterized with high density, wide liquid temperature range, high chemical stability, high heat capacity and high thermal energy storage capacity. Based on experimental results, it is concluded that ionic liquids could be considered as a candidate for liquid thermal storage media and heat transfer fluids.

Low temperature synthesis of ultrafine non vermicular α-alumina from aerosol decomposition of aluminum nitrates salts

Abstract In this paper, spherical, smooth and unagglomerated ultrafine amorphous powder particles were prepared by ultrasonic spray pyrolysis (USP) of easy-handling aqueous aluminum nitrate salts increasing the precursor solute concentration to 0.5 mol L −1 and reducing the pyrolysis temperature to 700 °C. The transformation of the USP alumina powders into α-Al 2 O 3 was studied using combination of X-ray diffraction, electron microscopy, infrared spectroscopy, BET surface area, thermogravimetry and differential thermal analysis. A downward shift of the onset temperature of α-phase transformation to 900 °C has been detected using a larger precursor solution concentration and performing a milling before calcination due to an increase in the surface density of defects, in surface area and in anisotropic particle shape. Additional post-milling of the low calcined powders allowed the preparation of agglomerate-free pure ultrafine α-Al 2 O 3 powder particles (∼100 nm, 28 m 2 g −1 ), free of vermicular microstructures.

Biological Evaluation of a Novel Tissue Engineering Scaffold of Layered Double Hydroxides (LDHs)

Bone Tissue Engineering (BTE) composed of three main parts: scaffold, cells and signaling factors. Several materials and composites are suggested as a scaffold for BTE. Biocompatibility is one of the most important property of a BTE scaffold. In this work synthesis of a novel nanocomposite including layered double hydroxides (LDH) and gelatin is carried out and its biological properties were studied. The co-precipitation (pH=11) method was used to prepare the LDH powder, using calcium nitrate, Magesium nitrate and aluminum nitrate salts as starting materials. The resulted precipitates were dried. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) analyses were used to characterize the synthesized powders. The results demonstrated the presence of nanocrystals of Ca-LDH and Mg-LDH as Hexagonal and Layered Morphology. The obtained powders were composed to gelatin via solvent casting method then freez dried. The scaffold was prepared via membrane lamination method from the resulted layers that linked together with gelatin as binder. In order to investigate the scaffold cytotoxicity MTT assay was done with a osteosarcoma cell line. No toxic response was observed in specimens. As a major result, it was demonstrated that the specimen showed a significant cellular response. Then osteosarcoma cells were cultured for 7-day and 14-day extract of powders. The composites osteoconductivity was investigate with cells alkaline phosphatase extraction. The results demonstrated that the Ca-LDH/gelatin composite scaffold has a good potential for bone tissue engineering applications and Mg-LDH specimen has a better osteconductivity.

A Simple Mechanochemical Route to Layered Double Hydroxides: Synthesis of Hydrotalcite‐Like Mg‐Al‐NO3‐LDH by Manual Grinding in a Mortar

AbstractHydrotalcite‐like Mg‐Al‐NO3‐layered double hydroxide (LDH) was successfully prepared in a mortar by manually grinding the hydrated magnesium and aluminum nitrate salts with sodium hydroxide. Various techniques, including XRD, MAS NMR, FTIR, SEM; thermogravimetric and differential thermal analyses (TGA,DTA), surface area and zeta potential measurements were used to establish a correlation between the LDH samples prepared in the mortar and by co‐precipitation. The LDH prepared in the mortar showed all the characteristics of a layered structure but with a lower crystallinity. This product was tested for its anion exhange property with tetraborate anions and 52 % of the theoretical exchange capacity was reached. The mortar route does not require heating/refluxing treatment, CO2‐free atmosphere and solvent as in the conventional preparation methods and allows obtaining LDHs in a short reaction time.

Temperature-programmed reduction and acidic properties of molybdenum supported on MgO–Al2O3 and their correlation with catalytic activity

A series of catalyst with Mo loading from 2 to 14 wt.% on MgO–Al2O3 mixed oxide support was prepared by incipient wetness impregnation method. Pure MgO and Al2O3 were prepared by using Mg(NO3)2·6H2O and Al(NO3)3·9H2O salt solutions and urea as hydrolyzing agent. MgO–Al2O3 (1:1) mixed oxide was prepared by co-precipitation of appropriate quantities of magnesium nitrate and aluminum nitrate salts. BET surface area, pore volume, pore size distribution, TPR, acidity and acid strength distributions of catalysts and supports were measured. MgO–Al2O3 (1:1) mixed oxide showed a biomodal pore size distribution. LTOC and TPR results show that an optimum 8% Mo on MgO–Al2O3 is sufficient to form MoO3 monolayer. TPR technique can also be used as a vital tool to determine the monolayer coverage. HDS activity has been correlated with LTOC. Introduction of basic MgO in the lattice of Al2O3 moderates the strong acidity in MgO–Al2O3. Impregnation of acidic MoO3 species further enhances the acidity favorable for HYC.