Aluminium hydroxide

About: Aluminium hydroxide is a research topic. Over the lifetime, 2043 publications have been published within this topic receiving 22032 citations. The topic is also known as: Al(OH)3 & Amphojel.

Effect of mechanochemical treatment on the synthesis of calcium dialuminate

Abstract: Calcium dialuminate (CaAl4O7) powders were synthesised from mechanochemically treated mixtures of aluminium hydroxide + calcium hydroxide and aluminium hydroxide + calcium carbonate. On grinding, both mixtures produce X-ray amorphous precursor phases which show 27Al MAS NMR resonances characteristic of Al in octahedral and tetrahedral sites, and a site identified by a resonance at 37–39 ppm (possibly pentahedral Al). Although grinding does not completely destroy the carbonate XRD reflections in the carbonate mixture, both precursors show a high degree of homogeneity and behave similarly on heating, forming monophase CaAl4O7 at <1050 °C. By contrast, the same unground compositions form mixtures of α-alumina and various calcium aluminates (but not CaAl4O7) on heating as high as 1250 °C. Calcium dialuminate synthesised from the carbonate-containing mechanochemical precursor had a smaller particle size which may be advantageous for subsequent fabrication and sintering.

Halogen-free non-phosphorus flame-retarded cable sheath material

Abstract: Material of sheath includes polyolefine as resin of basal body, A type flame retardant and B type flame retardant. A type flame retardant is hydrated metal oxide or modified hydrated metal oxide, and B type flame retardant is hydrated metal oxide modified anion surface active agent. The hydrated metal oxide is magnesium hydroxide or aluminium hydroxide. Components of the material in weight portion are as following: resin of basal body 100, copolymer of ethane- vinyl acetate 50-100, low density polyethylene 0-25, copolymer of ethane and octane 0-20; fire retardant 140-170; lubricant 0-2; antioxidant 1-5. The material of sheath possesses excellent flame retardant property and mechanical property, and produces products of cable in various colors by combining with each color batch.

Aluminium hydroxide impregnated macroreticular aromatic polymeric resin as a sustainable option for defluoridation

Abstract: The purpose of the present study was to explore the potential application of aluminium hydroxide impregnated macroporous polymeric resin as a sustainable option for fluoride removal from aqueous solution. Electrostatic interaction between fluoride and the cationic metal hydroxide as well as hydrogen bonding (metal-OH⋯F) could be inferred through Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) techniques. This macroreticular adsorbent gave a high adsorption capacity (92.39 and 36.61 mg g −1 at pH 3.0 and 7.0) by fitting the experimental data with the nonlinear Langmuir isotherm model. The pseudo-second-order adsorption process could be described using surface and intraparticle diffusion. Thermodynamics of adsorption accounted for the spontaneity and exothermic interaction with a corresponding decrease in entropy. The Al(OH) 3 impregnated polymeric resin adsorbent was tested with 5 mg L −1 fluoride and its efficacy was demonstrated in a laboratory scale column study. The resin exhibits good potential towards practical applications for the remediation of fluoride.

Aluminium, tau and Alzheimer's disease.

Abstract: I would like to bring to the attention of your readers fundamental flaws in both the methodology and philosophy of a paper recently published in JAD [13]. The most significant problems concern the former and they seriously undermine both the interpretation of the results and the conclusions drawn by the authors. For example, Fig. 1 purports to demonstrate the effects of AlCl3 on tau aggregation in vitro. What these experiments actually demonstrate is that AlCl3 inhibited the heparin-induced aggregation of tau. When one considers the extraordinarily high concentrations of AlCl3 used in these experiments (0.2–20.0 mM) compared to those of tau (10 μM) and heparin (10 μM) and the well known ability for aluminium hydroxide to adsorb and precipitate the highly polyanionic heparin [3,16,17], (it is not a coincidence that aluminium is a major contaminant of parenteral heparin solutions [2,9]) it should have come as no surprise to find that super-saturated solutions of AlCl3 precipitated heparin and inhibited its induction of the assembly of tau filaments in vitro. However, to test the influence of aluminium upon heparininduced aggregation of tau the authors needed to ensure that heparin was present to a significant excess, at least ten times the concentration of AlCl3. There can be no good reason for designing experiments in which the ratio of total aluminium to tau was at its minimum 20 and at its maximum 2000! There can be no physiological significance to such experiments and I urge the authors to repeat these experiments in the presence of a significant excess of heparin (or another inducer of tau polymerisation which will not bind aluminium) and using stoichiometric ratio’s of aluminium to tau of no more than 10. Only then will the authors actually address the hypothesis that they set out to test. Unfortunately this was not the only significant oversight in the chosen methods. The remainder of the experiments use aluminium which the authors describe as aluminium maltolate. However, their method of preparing Almaltolate will not result in Al-maltolate and nor do they provide any evidence that what they have in their stock solutions is Al-maltolate. The decision to prepare their maltol solution in phosphate-buffered saline (PBS) ensured that they introduced a minimum of 5 mM inorganic phosphate into the Al-maltolate stocks and this would have ensured that a significant proportion of the total aluminium would have been precipitated at pH 7.4 as mixed hydroxyphosphates. In addition if the dilutions of this stock solution, used in particular for the experiments reported in Fig. 2, were made with PBS (which includes 10 mM inorganic phosphate), as it appeared they were, then this would have ensured that approximately all of the aluminium would be precipitated as aluminium hydroxyphosphates in these treatments. Thus the N2a cells were not exposed to the designated concentrations of Al-maltolate but to unspecified concentrations of aluminium hydroxyphosphates in the presence of maltol. These problems will also influence the intraperitoneal injections of aluminium reported in Table 1 and Fig. 3 where one is also left wondering how you can produce a 50 mM Al-maltolate stock from an original stock which was only 25 mM? One final word of caution concerning experiments with aluminium and tau is that aluminium catalyses both phosphorylation [12] and phosphoincorporation [1] of proteins, including tau, and considering the role played by phosphorylation in the aggregation of tau one