AlCl3 Concentration Research Articles

Electrodeposition of Aluminum from 1,3-Dimethyl-2-Imidazolidinone/AlCl3 baths

This study investigated the use of novel organic solvent baths for the electrodeposition of aluminum at near-ambient temperatures. It was found that Al metal can be electrodeposited from baths that were composed of 1,3-dimethyl-2-imidazolidinone (DMI) and AlCl3, with an AlCl3 concentration greater than 50 mol%. IR spectroscopy indicated that Al2Cl7− ions were present in the baths that contained >50 mol% AlCl3, where the electrodeposition of Al occurs from Al2Cl7− ion. The DMI/AlCl3 baths with AlCl3 concentrations between 59 and 64 mol% retained a single liquid phase without precipitation at 25°C, and therefore, they can be used for Al electrodeposition near room temperature. Smooth Al films could be obtained by galvanostatic electrodeposition at 40°C using a DMI/AlCl3 bath with the addition of a trace amount of 1,10-phenanthroline.

Alumina-Precursor Nanoparticles Prepared by Partial Hydrolysis of AlCl3Vapor in Tubular Flow Reactor: Effect of Hydrolysis Conditions on Particle Size Distribution

Aluminum chloride (AlCl3) was evaporated and partially hydrolyzed in water vapor at 300–700 °C in a tubular reactor, 2.4 cm in diameter and 50 cm in length, to form alumina-precursor particles that were more spherical and less agglomerated compared with the fumed alumina produced by flame hydrolysis and oxidation. This study was focused on the effects of the H2O to AlCl3 molar ratio, the reactor temperature, the AlCl3 concentration, and the contact point of AlCl3 with H2O vapors on the morphology, size, and chemical composition of the obtained particles. The primary particle size ranged from 50 to 200 nm depending upon the operating conditions. The particle size increased with increasing AlCl3 concentration but decreased with increasing reactor temperature or with increasing molar ratio of H2O to AlCl3. The particle size became smaller and the particle size distribution narrower as the contact point of AlCl3 with H2O vapors was moved from the inlet of the reactor to a point 10 cm inward toward the center ...

Assessment of Potential Abatement provided by <i>Annona Muricata</i> (Prickly Custard Apple Leave) on the Toxic Effects of Aluminium Chloride on Albino Rats

The toxic effects of aluminium Chloride (AlCl3) in albino rats (Rattusnorvegicus) have been studied. The species weighing 250 ± 20g were administered varying concentrations of the LD50 (3630mg/kg body weight), ½ LD50 (1815mg/kg body weight) and ¼ LD50 (907.5 mg/kg body weight) of aluminium Chloride solution orally as drinking water for six weeks after which it was discontinued. The specimens were grouped into three. The first group was administered the various concentrations of (AlCl3) with no abatement, while the second and third groups were administered the same concentrations of (AlCl3) as the former but were fed respectively with 20% and 50% by weight of aqueous leaf extract of Annona muricata mixed with their feeds for six weeks as abatement. Blood samples were collected for biochemical analysis. The results showed significant increase in the levels of urea, creatine, aspartate aminotransferase (AAT), alkaline phosphatase (ALP), alanine aminotransferase (ALAT), total glyceride, total bilirubin, total cholesterol and glucose levels (P<0.05). However, significant decrease in the levels of these parameters was observed with the application of A. muricata. This reveals the potency of A. muricata leaves to abate the effects of the poison in the kidney and liver of mammals .

Inflammation versus oxidative stress in pathophysiology of alzheimer's disease in rat model

Background: Alzheimer's disease (AD) is a highly debilitating neurodegenerative disorder characterized by cognitive dysfunction. Inflammation and oxidative stress are thought to play major roles in the pathophysiology. Which one has the principle role is unclear. Objectives: The role of brain growth factors, cytokines and oxidative biomarkers in cognitive dysfunction induced by Aluminium chloride (AlCl3) in rats with application of an anti-inflammatory (Cilostazol) and an antioxidant (N-acetyl cysteine, NAC) were investigated to clarify the predominant pathophysiological mechanism involved. Methods: Alzheimer's model group was given AlCl3 (100 mg/kg) orally for six weeks. Alzheimer's model + NAC, and Alzheimer's model + Cilostazol groups were given (NAC) and Cilostazol respectively one hour before AlCl3 for the same duration. Results: Anti-inflammatory or antioxidant interventions significantly improved memory retention, which was evaluated by Morris Water Maze, passive avoidance task, and eight-arm radial maze. This improvement was consistent with histological recovery and was mediated by reduction AlCl3 concentration in the brain hippocampus and frontal cortex, interference with the cholinergic dysfunction, as well as prevention of oxidative damage. In addition, anti-inflammatory agents can modulate superiorly the inflammatory response via reduction of the levels of inflammatory cytokines and adjustment of the levels of brain–derived neurotrophic factors and transforming growth factor B. Conclusions: These finding support the principal role of inflammation in pathophysiology of AD and suggests the potential therapeutic application of anti-inflammatory agents for this condition.

Stability and sedimentation of silver nanoparticles in the presence of monovalent, divalent and trivalent electrolyte solutions.

The present study seeks to elucidate the effect of different electrolytes on the stability of citrate-coated silver nanoparticles synthesized by the reduction of the Ag(NH3)(2)(+) complex via Tollens' method. Time-resolved dynamic light scattering technique was used to measure the aggregation behavior of the nanoparticles over a range of electrolyte (NaCl, CaCl₂, and AlCl₃) concentrations. From the aggregation kinetic data, the critical coagulation concentration values were calculated as 0.11, 1.7 × 10⁻³, and 5.06 × 10⁻⁶ M for NaCl, CaCl₂, and AlCl₃, respectively. Supernatant of the nanoparticle suspension in presence of the three electrolytes was collected and measured using inductively coupled plasma mass spectrometry to quantify the sedimentation. It was found that the silver nanoparticle aggregates settled rapidly in the slow aggregation and fast aggregation regimes. Their sedimentation followed a nanoparticle size-dependent manner.

Identification of early Al‐responsive genes in rice bean (Vigna umbellata) roots provides new clues to molecular mechanisms of Al toxicity and tolerance

Significant secretion of citrate from root apex of rice bean (Vigna umbellata) is delayed by several hours under aluminium (Al) stress. However, the molecular basis of regulation of VuMATE1, a gene encoding an Al-activated citrate transporter, remains unclear. In this study, we used suppression subtractive hybridization together with reverse northern blot analysis and qRT-PCR to identify genes with altered transcript levels in the root apex after treatment with low (5 μm) or high (25 μm) concentration of AlCl(3) for a short time (4 h). We found that in addition to VuMATE1, 393 genes showed an early response to Al. Among functionally annotated genes, those related to 'metabolism and energy', 'signal transduction and transcription' and 'transport' was predominantly up-regulated, whereas those associated with 'protein translation, processing and degradation' was predominantly down-regulated. Comparative analysis of transcriptional profiles highlighted candidate genes associated with citrate secretion and revealed several new aspects of the molecular processes underlying Al toxicity and tolerance. Based on the data, it is proposed that metabolic changes represent adaptive mechanisms to Al stress, whereas inhibition of both cell elongation and cell division underlies Al-induced root growth inhibition.

Differential effects of aluminum on in vitro primary root growth, nutrient content and phospholipase C activity in coffee seedlings (Coffea arabica)

Coffea arabica is a woody species that grows in acid soils, where aluminum is available and may affect growth and productivity. To determine the effect of aluminum on primary root growth of C. arabica cv. Typica, seedlings were exposed over 30days to different concentrations of AlCl3 (0, 100, 300 and 500μM) in vitro. The aluminum effect on primary root growth was dose-dependent: low aluminum concentrations (100 and 300μM) stimulated primary root growth (6.98±0.15 and 6.45±0.17cm, respectively) compared to the control (0μM; 5.24±0.17cm), while high concentrations (500μM) induced damage to the root tips and inhibition of primary root growth (2.96±0.28cm). Aluminum (100μM) also increased the K and Ca contents around 33% and 35% in the coffee roots. It is possible that aluminum toxicity resides in its association with cell nuclei in the meristematic region of the root. Additionally, after 30days of treatment with aluminum, two different effects could be observed on phospholipase C (PLC) activity. In shoots, aluminum concentrations ≥300μM inhibited more than 50% of PLC activity. In contrast, in roots a contrasting behavior was determined: low (100μM) and toxic concentrations (500μM) increased the activity of PLC (100%). These results suggest the possible involvement of the phosphoinositide signal transduction pathway, with the phospholipase C enzyme participating in the beneficial and toxic effects of aluminum in plants.

Catalytic Conversion of Empty Fruit Bunch of Palm Oil for Producing Lactic Acid

Catalytic conversion of lignocellulosic biomass such as Empty Fruit Bunch (EFB) of Palm Oil into valuable chemicals such as lactic acid (LA) is an alternative route to currently fermentation route and it is a sustainable process for substituting petro-based chemical with biomass-based chemical. Conversion of lignocellulosic biomass (EFB) was conducted in a 100-ml batch reactor in aqueous solution using homogeneous AlCl3 catalyst at mild temperature in the range of 140-240°C, under hydrothermal condition. Some chemicals are identified in the product especialy LA and levulinic acid which are valuable chemicals produced by hydrolysis of lignocellulosic biomass and yield of LA compared with cellulosic biomass for comparison of feedstock. The sugar units in the lignocellulosic biomass (EFB) was around 48.75%, dominated by glucose (28%), xylose (16.5%), and followed with lower composistion of other sugar units such as galactose (1%), arabinose (2.5%) and mannose (0.75%). The yield of EFB conversion to lactic acid was found in the range 6-8.9% at temperature 140-240°C while for cellulosic material 19%, with reaction time 3hours and range of fixed AlCl3 concentration 50-100mM. Experimental results show that higher operating temperature and higher concentration of catalyst will produce higher percentage of LA. However, pretreatment of lignocelluloses with NaOH produced lower yield of LA 3.18 to 5.69% and probably the pretreatment leading to degradation of sugar units in the biomass.

The Effects of Electrolytes on the Properties of Coal Pitch-water Slurry

The coal pitch-water slurry was prepared using coal pitch powder of Alfred particle size distribution, dispersant, and electrolytes solution with different concentrations. The effects of electrolytes on the zeta potential of coal pitch surface, slurry ability of coal pitch, rheological behavior, and stability of coal pitch-water slurry were studied in this article. The results show that the zeta potential of coal pitch surface decreases and then increases with increasing the concentration of NaCl and CaCl2, while that increases and then decreases with increasing the concentration of AlCl3. The changing trend of the apparent viscosity of coal pitch-water slurry is reverse with that of the zeta potential. The rheological behavior of coal pitch-water slurry is improved with the addition of NaCl, CaCl2, and AlCl3. The stability of coal pitch-water slurry is improved distinctly with the addition of NaCl and CaCl2 and not changed much with the addition of AlCl3.

Impact of AlCl3 on the Self-Assembly of the Anionic Surfactant Sodium Polyethylene Glycol Monoalkyl Ether Sulfate in Aqueous Solution

Small-angle neutron scattering has been used to study the self-assembly of the anionic surfactant sodium polyethylene glycol monoalkyl ether sulfate in aqueous solution and in the presence of Al(3+) multivalent counterions in the form of AlCl3. The addition of the Al(3+) ions promotes significant micellar growth of the initially globular micelles into highly elongated structures until ultimately lamellar structures form. Increasing the size of the polyethylene oxide, EO, group progressively suppresses micellar growth before lamellar formation. Reducing the alkyl chain length has a similar effect on the structural evolution. Both trends are associated with increased solubility with increasing EO group size and decreasing alkyl chain length. Both the size of the EO group and the length of the alkyl chain affect sodium diethylene glycol monododecyl ether sulfate/Al(3+) complex formation and drive lamellar formation to progressively higher AlCl3 concentrations.

The Formation of Surface Multilayers at the Air–Water Interface from Sodium Diethylene Glycol Monoalkyl Ether Sulfate/AlCl3 Solutions: The Role of the Alkyl Chain Length

The influence of the alkyl chain length on surface multilayer formation at the air-water interface for the anionic surfactant sodium diethylene glycol monoalkyl ether sulfate, SAE2S, in the presence of Al(3+) multivalent counterions, in the form of AlCl3, is described. In the absence of electrolyte, the saturated monolayer adsorption is determined by the headgroup geometry and is independent of the alkyl chain length. In the presence of Al(3+) counterions, surface multilayer formation occurs, due to the strong SAE2S/Al(3+) binding and complexation. The neutron reflection data show that the alkyl chain length of the surfactant has a significant impact upon the evolution of the surface multilayer structure with surfactant and AlCl3 concentration. Increasing the alkyl chain length from decyl to tetradecyl results in the surface multilayer formation occurring at lower surfactant and AlCl3 concentrations. At the short alkyl chain lengths, decyl and dodecyl, the regions of multilayer formation with a small number of bilayers are increasingly extended with decreasing alkyl chain length. For the alkyl chain lengths of tetradecyl and hexadecyl, the surface behavior is further affected by decreases in the surfactant solubility in the presence of AlCl3, and this ultimately dominates the surface behavior at the longer alkyl chain lengths.

Preparation of PVA hydrogel beads and adsorption mechanism for advanced phosphate removal

Poly(vinyl alcohol) (PVA) hydrogel beads with aluminum ion on its cross-linking structure were prepared by chemical cross-linking in the mixed aqueous solution of saturated boric acid and AlCl3. It was found that with increasing AlCl3 concentration and cross-linking time, the permeability of PVA hydrogel decreased, and the phosphate adsorption capacity of the hydrogel presented the trend of first increasing and then decreasing. For the hydrogel after phosphate adsorption, a new peak at 1044cm−1 attributed to the bending vibration of phosphate appeared in FTIR analysis, the surface became smooth, and the characteristic signal of phosphate also appeared in EDAX analysis, indicating that phosphate was adsorbed onto PVA hydrogel by a relatively strong bonding. Aluminum can be found in the hydrogel both before and after adsorption, indicating that aluminum ion has been grafted onto the PVA hydrogel beads. To study the mechanism of adsorption process, we examined the Lagergren pseudo-first-order kinetic model, and pseudo-second-order kinetic model, and the intra-particular diffusion model, and found pseudo-second-order kinetic model exhibited the best correlation with our experimental data. Furthermore, our adsorption equilibrium data could be better described by the Langmuir adsorption isotherm model, indicating the phosphate adsorbed on the PVA hydrogel beads was the homogeneous nature of the monolayer adsorption. The maximum phosphate adsorption capacity of the PVA hydrogel reached 11.5mg-P/g at proper pH value and initial concentration of the phosphate solution. A relatively good reusability of the PVA hydrogel beads for phosphate removal can be achieved.

Kinetics of leaching fluoride from mixed rare earth concentrate with hydrochloric acid and aluminum chloride

A mixed rare earth concentrate from Baotou was adopted to investigate the complex leaching kinetics of fluoride with a HCl–AlCl3 solution. In addition, we explored the effects of HCl concentration, AlCl3 concentration, temperature, reaction time, liquid–solid ratio and stirring speed on leaching kinetics of fluoride. The results showed that an extraction of about 99% was achieved under the leaching conditions: 4M HCl, 1.5M AlCl3, 85°C, 20ml/g liquid–solid ratio, 300rpm stirring speed and 90min. SEM and XRD analysis indicated that no new reaction solid product was formed on the surface of leaching residue particle. The apparent activation energy was 40.4kJ/mol and the reaction orders with respect to hydrochloric acid concentrations, aluminum chloride concentrations and liquid–solid ratio were determined to be 1.66, 1.54 and 1.48, respectively. A semi-empirical rate equation was obtained to describe the process. The kinetic data fitted a new variant of the shrinking core model, in which both the interfacial transfer and diffusion through the product layer affected the reaction rate.

The Formation of Surface Multilayers at the Air–Water Interface from Sodium Polyethylene Glycol Monoalkyl Ether Sulfate/AlCl3 Solutions: The Role of the Size of the Polyethylene Oxide Group

Neutron reflectivity, NR, and surface tension, ST, have been used to study the surface adsorption properties at the air-water interface of the anionic surfactant sodium polyethylene glycol monododecyl ether sulfate (sodium lauryl ether sulfate, SLES) in the presence of Al(3+) multivalent counterions, by the addition of AlCl3. In the absence of AlCl3 and at low AlCl3 concentrations monolayer adsorption is observed. With increasing AlCl3 concentration, surface multilayer formation is observed, driven by SLES/Al(3+) complex formation. The onset of multilayer formation occurs initially as a single bilayer or a multilayer structure with a limited number of bilayers, N, ≤3, and ultimately at higher AlCl3 concentrations N is large, >20. The evolution in the surface structure is determined by the surfactant and AlCl3 concentrations, and the size of the polyethylene oxide group in the different SLES surfactants studied. From the NR data, approximate surface phase diagrams are constructed, and the evolution of the surface structure with surfactant and electrolyte concentration is shown to be dependent on the size of the polyethylene oxide group. As the polyethylene oxide group increases in size the multilayer formation requires increasingly higher surfactant and AlCl3 concentrations to promote the formation. This is attributed to the increased steric hindrance of the polyethylene oxide group disrupting SLES/Al(3+) complex formation.

Electrochemical preparation of Mg-Li-Al-Er alloys by co-reduction in molten chloride

The electrochemical behavior of Mg, Li, Al and Er were investigated by electrochemical techniques in LiCl-KCl-MgCl2-AlCl3-ErCl3 melts at 823 K. The cyclic voltammetry and chronopotentiometry indicated that the co-reduction of Mg, Li, Al and Er occurs at current densities more negative than −0.89 A·cm−2. Er(III) under-potential deposited on pre-reduced Al electrode formed Al-RE alloys. X-ray diffraction (XRD) results indicated that Mg17Al12, Al2Er, Al2Er3 and Al4Li9 phases were prepared by galvanostatic electrolysis. ICP analyses of samples showed that lithium and aluminum contents of Mg-Li-Al-Er alloys could be controlled by concentration of AlCl3 and cathodic current density.

Band gap energy and optical transitions in polyenes formed by thermal decomposition of polyvinyl alcohol

The band gap of the ensemble of oligoene clusters formed by thermocatalytic decomposition of polyvinyl alcohol is parametrized using optical absorption spectra. A band gap energy of E gm =1.53 ± 0.02 eV at the end of an infinite polyene chain is found by extrapolating the energies of π → π* transitions in clusters with a number of double bonds varying from 4 to 12. This value is close to the band gap of trans-polyacetylene and the lower bound for the Tauc energy E gT =1.50 eV, which characterizes the minimum interband transition energy. E gT is essentially independent of the concentration of oligoene clusters, which is determined by the concentration of the AlCl3 thermal decomposition catalyst. The Urbach energy determined from the long wavelength edge of the spectrum falls from 2.21 to 0.66 eV as the AlCl3 concentration is raised from 11.1 to 41.7 mmol per mol of polyvinyl alcohol structural units.

Mixed rare earth concentrate leaching with HCl–AlCl3 solution

A method of Baotou mixed rare earth concentrate leaching was investigated. According to the principle of complex leaching, the quadratic orthogonal regression experiment was used to investigate effect of six factors. An optimal condition of low energy and environment friendly was determined as follows: HCl acidity is 4 mol·L−1, AlCl3 concentration is 2 mol·L−1, reaction temperature is 85 °C, reaction time is 90 min, liquid to solid ratio is 35 ml·g−1, and stirring speed is 100 r·min−1. According to this condition, the leaching ratio of mixed rare earth concentrate is 76.5 %. The analyses of X-ray diffraction shows that bastnasite disappears, and the main peaks of filter residue is monazite and cheralite after leaching of HCl–AlCl3 solution. The result indicates that REFCO3 of the mixed rare earth concentrate can be dissolved, but REPO4 remains in the leaching residue. This method provides a way to separate and extract rare earth.

Initial Research on the Effect of Inorganic Salt on Rate of Penetration (ROP) in Drilling Fluids

The authors attempt to investigate the interaction between inorganic components of drilling fluids and sandstones as well as the influence on the rate of penetration (ROP) imposed by inorganic components. With the analysis of Zeta potential of cuttings solution, the mechanism of the experiment is initially achieved. The results show that the ROP will be enhanced by 33.7% when AlCl3 concentration is up to 0.01 mol/L, and therefore AlCl3 and Al2(SO4)3 possess a tendency to enhance ROP. In addition, Al3+ enables Zeta potential of the solution containing cuttings shifted from negative value to zero, and finally to positive value by means of analyzing Zeta potential, which contributes to the significant improvement of ROP when Zeta potential is greater than −10 mV. Higher surface free energy created by the close-to-zero Zeta potential is conducive to crushing rocks, which in turn increases the ROP and meanwhile reduces drilling costs.

Electrochemical behaviour and codeposition of Al-Li-Er alloys in LiCl-KCl-AlCl3-Er2O3 melts

The electrochemical behaviour of Al, Li, and Er were investigated by electrochemical techniques, such as cyclic voltammograms, chronopotentiometric, chronoamperograms, and open circuit chronopotentiogram on molybdenum electrodes. The results showed that the underpotential deposition of erbium on pre-deposited Al electrodes formed two Al-Er intermetallic compounds. The codeposition of Al, Li, Er occurred and formed Al-Li-Er alloys in LiCl-KCl-AlCl3-Er2O3 melts at 773 K. Different phases such as Al2Er, Al2Er3 and βLi phase of Al-Li-Er alloys were prepared by galvanostatic electrolysis and characterized by X-ray diffraction (XRD). Scanning electron microscopy (SEM) indicated that Er element mainly distributed at the grain boundary. ICP analyses showed that lithium and erbium contents of Al-Li-Er alloys could be controlled by AlCl3 and Er2O3 concentration and electrochemical parameters.

Extraction of thorium from LiCl–KCl molten salts by forming Al–Th alloys: a new pyrochemical method for the reprocessing of thorium-based spent fuels

The co-reduction process of Th(IV) and Al(III) ions in the LiCl-KCl-AlCl3-ThO2 molten salts with different concentrations of AlCl3 was investigated at 800 K on the tungsten electrode. Cyclic voltammetry, square wave voltammetry and open-circuit chronopotentiometry techniques were used to study electrochemical behaviors of Al(III), Th(IV) and Al-Th alloy formation processes. The results showed that five kinds of Al-Th intermetallic compounds could be formed in the AlCl3 poor system, whereas only one kind of Al-Th compound formed in the AlCl3 rich system. Al-Th alloys were obtained by potentiostatic electrolysis on aluminum electrodes and by galvanostatic electrolysis on a tungsten electrode. All the Al-Th alloys were characterized by scanning electron microscopy ( SEM) with energy dispersive spectrometry (EDS), X-ray diffraction (XRD) and inductively coupled plasma atomic emission spectrometry (ICP-AES). The XRD results showed that the Al-Th compound prepared in the AlCl3 rich system was