Showing papers on "Aluminium hydroxide published in 2011"

Influence of the calcium sulphate source on the hydration mechanism of Portland cement–calcium sulphoaluminate clinker–calcium sulphate binders

Abstract: Two different binders composed of Portland cement, calcium sulphoaluminate clinker and calcium sulphate were studied from early hydration to 28 days, one containing gypsum and one containing anhydrite at equimolar CaSO4 amount. Sodium gluconate was used as retarder to obtain a sufficient fluidity to cast the samples. Solids were analyzed by X-ray diffraction, scanning electron microscopy and thermogravimetric analysis and quantified by Rietveld refinement, while pore solutions were measured by ion chromatography. Thermodynamic modelling was used to model the hydration process of the ternary binders. This combined study allowed a precise understanding of the hydration process over time and the determination of the composition of the crystalline and of the X-ray amorphous hydrates present in the binders, which cannot be determined by conventional methods. Results show that the hydration mechanisms are similar in presence of gypsum or anhydrite, the difference being in the kinetics of reactions due to the slower dissolution of anhydrite compared to gypsum in the presence of sodium gluconate. The hydration starts with the formation of ettringite and of some X-ray amorphous hydrates. In the anhydrite-bearing system, the ettringite-forming reaction is stronger delayed by the addition of the retarder compared to the gypsum-bearing system. This stronger delay results in the formation of a significant amount of X-ray amorphous hydrates. The hydrates amorphous fraction is composed of different phases and its chemical composition is changing over time. During early hydration, it is mainly composed of aluminium hydroxide and stratlingite, while in the anhydrite-bearing system it can additionally contain some monosulphoaluminate. At later ages, the aluminium hydroxide content decreases and additional monosulphoaluminate and a C-S-H type phase are formed.

Biocompatible inorganic nanoparticles for [18F]-fluoride binding with applications in PET imaging.

Abstract: A wide selection of insoluble nanoparticulate metal salts was screened for avid binding of [18F]-fluoride. Hydroxyapatite and aluminium hydroxide nanoparticles showed particularly avid and stable binding of [18F]-fluoride in various biological media. The in vivo behaviour of the [18F]-labelled hydroxyapatite and aluminium hydroxide particles was determined by PET-CT imaging in mice. [18F]-labelled hydroxyapatite was stable in circulation and when trapped in various tissues (lung embolisation, subcutaneous and intramuscular), but accumulation in liver via reticuloendothelial clearance was followed by gradual degradation and release of [18F]-fluoride (over a period of 4 h) which accumulated in bone. [18F]-labelled aluminium hydroxide was also cleared to liver and spleen but degraded slightly even without liver uptake (subcutanenous and intramuscular). Both materials have properties that are an attractive basis for the design of molecular targeted PET imaging agents labelled with 18F.

Alkali-free liquid accelerating agent and preparation method thereof

Abstract: The invention belongs to the technical field of tunnel construction, and relates to an alkali-free liquid accelerating agent for tunnel wet jet concrete and a preparation method thereof. The alkali-free liquid accelerating agent is characterized in that aluminium sulphate is adopted to serve as a main accelerating component; aluminium is added to an aluminium sulphate solution to be polymerized in a form of aluminium fluoride; aluminium ions are introduced to the greatest extent so as to reduce other ion introduction; and the accelerating effect is ensured. The alkali-free liquid acceleratingagent comprises the following components in percentage by mass: 30-55% of aluminium sulphate, 5-15% of aluminium hydroxide, 10-30% of hydrofluoric acid, 0.5-5% of water glass, 0-0.2% of stabilizing agent, and the balance of water. For jetting concrete, the alkali-free liquid accelerating agent disclosed by the invention has the positive effects that: ordinary cement can be initially solidified within 2 min in lower doping quantity and finally solidified within 4 min; the 1d strength of cement plaster can achieve above 15 MPa; the 28d compressive strength ratio is more than 100%; and the alkali-free liquid accelerating agent has good adaptability to different types of cements.

Adsorption of paracetamol and chloroquine phosphate by some antacids.

Abstract: The adsorption of paracetamol and chloroquine phosphate onto some antacids with adsorptive properties, has been studied. Dissolution of the drugs from commercial tablets was significantly retarded in the presence of the antacids. The adsorption and retardation of dissolution of both drugs by the adsorbent antacids studied followed the rank order magnesium trisilicate greater than magnesium oxide greater than aluminium hydroxide greater than edible clay. The concomitant administration of the drugs and antacid formulations containing any of these should be discouraged.

Use of Aluminium Hydroxide Sludge as Adsorbents for the Removal of Reactive Dyes: Equilibrium, Thermodynamic, and Kinetic Studies

Abstract: This study investigated the removal of RR-2 and RB-4 dyes from aqueous solutions by adsorption using poppy bagasse, sugar beet bagasse, aluminium hydroxide sludge, phosphogypsum, ferrochromium plant waste, and orange peel. Aluminium hydroxide sludge had the highest adsorption capacity for both dyes. The equilibrium time was 2 days. The effects on adsorption of pH, adsorbent concentration, and stirring rate were investigated. The highest removal percentage was 80.75% and 99.74% for RR-2 and RB-4, respectively. Adsorption of RR-2 was expressed better with a Freundlich adsorption equation, while adsorption of RB-4 was expressed better with a Langmuir adsorption equation. Adsorption of RR-2 agreed with the pseudo-first-order rate equation and adsorption of RB-4 followed the pseudo-second-order rate equation. Moreover, both removal processes are endothermic. Various thermodynamic parameters, such as ?G°, ?HG°, and ?SG°, were calculated.

The comparative protective effects of degraded carrageenin and aluminium hydroxide on experimentally produced peptic ulceration

Abstract: ACUTE peptic ulceration of the duodenum can be produced experimentally in guinea pigs within 24 hours of the administration of a large dose of histamine in beeswax-oil provided a covering dose of an antihistamine is given to protect the animals from acute shock. Degraded carrageenin, a sulphated polysaccharide (Ebimar) has been shown to react with mucus lining the gastric mucosa and in low concentrations to interfere with peptic digestion. It provides complete protection against duodenal ulceration produced by the above method1**. In the present experiments we have compared its effects on ulcerogenesis with those of aluminium hydroxide. Methods. Male guinea pigs (300400 g.) were prepared for experiment by depriving them of food from 5 p.m. on the day before the experiment. The next day at 4.30 p.m. the animals were injected intraperitoneally with promethazine 7.5 mg., followed within half an hour by an intra-muscular injection of histamine acid phosphate 30 mg./kg. in a 10 per cent (w/v) beeswax: arachis oil vehicle. The suspension was made by triturating 1.5 g. histamine acid phosphate (200 mesh) with the vehicle and adjusting the volume to 50 ml. The animals were studied in groups of five, and the drugs were administered in 2 ml. doses intra-oesophageally at 3 hour intervals from 6 hours before to 21 hours after the histamine injection. Ebimar was given in aqueous solutions containing 20, 10,5, 1, or 0-2 per cent w/v. Aluminium hydroxide was administered as liquid gel containing the equivalent of 4, 2, or 1 per cent A1,0, w/w. The control group were given 2 ml. of water at the same intervals. The animals were killed 24 hours after the histamine injection. The stomach and duodenum were removed, fixed in formol saline, and the degree of damage was assessed numerically according to the scheme, Table I. Results. The degree of damage in the stomach and duodenum in each group of five animals is recorded in Table I. The maximum score if all five animals were severely damaged would be 15 for the stomach, 15 for the duodenum, giving a total score of 30. It is seen in the control group which received water only that the maximum score was reached in the duodenum. Considerable protection from ulceration in the duodenum was apparent in the groups treated with

Chemical reactivity of aluminium-based pharmaceutical compounds used as phosphate-binders.

Abstract: Several aluminium-containing substances, including antacids used as phosphate-binders in treating renal failure, have been analysed in-vitro under different pH conditions for the release of Al3+ ions and for binding of phosphate. Control experiments on different forms of pure aluminium hydroxide validated the methods. At pH 2 it was the most amorphous forms which released Al3+ most rapidly. These aluminium ions, available for absorption by the patient, were released from all antacids tested, but no firm phosphate-binding was detected while the pH remained at 2. Phosphate was bound at pH 8, by adsorption onto the surface of aluminium hydroxide. No significant amounts of free Al3+ exist in solution at pH 8, since at that pH aluminium hydroxide is precipitated. The most amorphous forms of this solid were the most efficient phosphate-binders. Alumino-silicate salts require prior exposure to acid to produce free Al3+ before they can act as phosphate-binders, whereas amorphous aluminium hydroxide acts as an efficient phosphate-binder without prior exposure to acid. Chemical principles are employed to show why aluminium release and phosphate-binding are separate and independent processes. Methods are proposed for maximizing the activity of phosphate- binders in-vivo, while minimising aluminium release.

Modified nano aluminium hydroxide water expansion type overcoating fire retardant paint and preparation method thereof

Abstract: The invention discloses a modified nano aluminium hydroxide water expansion type overcoating fire retardant paint and a preparation method thereof. The paint is prepared from the following raw materials in percentage by weight: 22%-28% of organic silicon modified styrene-acrylate emulsion, 13%-17% of mixture of anatase type titanium dioxide and modified nano aluminium hydroxide powder, 16%-19% ofammonium polyphosphate, 8%-13% of tripolycyanamide, 5%-9% of pentaerythritol, 3%-7% of auxiliary and 21%-27% of water; and the modified nano aluminium hydroxide is prepared from the raw materials in parts by weight: 60-85 parts of nano aluminium hydroxide powder, 0.8-2.5 parts of sodium hexametaphosphate powder and 18-24 parts of water. The paint is a water system having obvious inflaming retarding effect, high fireproof performance, good brushing resistance, weather resistance and smearing hardness and low fuming amount, and has the beneficial effects of simple production process, good dispersing effect, low cost, stable quality and long service life, and is energy-saving and environment-friendly.

Low-alkaline liquid accelerating agent and preparation method thereof

Abstract: The invention belongs to the technical field of tunnel construction, and relates to a low-alkaline liquid accelerating agent and a preparation method thereof. For the low-alkaline liquid accelerating agent, aluminium sulfate solution is neutralized with sodium aluminate solution to produce aluminium hydroxide collosol, and then aluminium sulfate and aluminium hydroxide collosol conduct polymerization reaction in an original solution system to produce polymerized aluminium sulfate, so that the accelerating agent solution has higher aluminium ion content and liquid stability; the low-alkaline liquid accelerating agent is prepared by aluminium sulfate, sodium aluminate and stabilizing agent; and the mass percentage of the components are as follows: 40 to 60 percent of aluminium sulfate, 6 to12 percent of sodium aluminate, 0 to 0.2 percent of stabilizing agent, and the balance of water. The invention has the following positive effects to sprayed concrete: initial set of common cement can be realized in five minutes and final set of the common cement can be realized in eight minutes under lower doping amount; the 1d strength of cement mortar can reach more than 12MPa, and the 28d compression strength ratio of the cement mortar is more than 100 percent; and the invention has good adaptability to cement of different varieties.

Method for improving specific surface area of diatomite

Abstract: The present invention relates to material field, which is a method for improving specific surface area of diatomite. Specific surface area of natural diatomite is about 20 m[2]/g, which restricting its performance exertion. Increase of specific surface area by scrub purification and pickling reaming is not obvious; technics of zeolite synthesis is complex and the whole reaction process is hard tocontrol. The invention uses sodium hydroxide and aluminium hydroxide of same weight to synthesize sodium aluminate sol at a temperature of 90-110 DEG, and adding water to prepare sodium aluminate solution of 4 mol/L; mixing sodium hydroxide, diatomite and water and dissolving at a temperature of 90-100 DEG for 1-2 hours; and adding the sodium aluminate solution into the mixture while stirring at atemperature of 30-50 DEG; and adding at least one of ethanediol and ethane diamine and continue stirring until forming uniform gel, crystallization in the reactor at a temperature of 100 DEG for 5-15hours, pumping filtration washing and drying. Specific surface area of the diatomite obtained by the method is more than 116 m[2]/g and reaching 297 m[2]/g for highest.

Adjuvant effect of aluminium monostearate paraffin gels on antitoxin response

Abstract: Clostridium welchii Type D toxoid has been dispersed in aluminium monostearate-hydrocarbon gels. When these are injected subcutaneously in laboratory animals the antitoxin response is influenced by the method of preparation of the gels. The level and duration of the antitoxin titre in the blood is related directly to the viscosity of the vaccine preparations. Six months after injection, the residual antitoxin titre produced by the most successful treatments was still as good as the peak titre obtained from simple aluminium hydroxide adsorbed vaccine.

Production of alumina

Abstract: Aluminium minerals are abundant in the earth’s crust with equatorial lateritic bauxites the dominant Al bearing resource used as the raw material for alumina production. The Bayer process, essentially unchanged for more than 100 years, accounts for much of this production. The process involves ore digestion in a hot caustic soda solution, the clarification of a sodium aluminate solution and the precipitation of aluminium hydroxide, subsequently calcined to produce alumina. Refinery operation and particularly the processes of gibbsite precipitation and calcination have a profound effect on the properties of the product alumina, and its use in the production of aluminium metal in the Hall-Heroult process. Although around 95% of alumina production is used in primary metal production, there are also increasing specialist markets for alumina in applications as diverse as catalysis, in microelectronics and as an absorbent.

The production and properties of gel precipitated aluminium hydroxide spheres containing imipramine

Abstract: The production of aluminium hydroxide spheres containing imipramine by gel precipitation of liquid feed solutions has been described. Washing and heating procedures applied to the precipitated spheres markedly affected the rate of drug release from the spheres into 0.1M hydrochloric acid. Increasing the imipramine content of the spheres also altered the drug release rate. The effects described have been explained with reference to model theories of the precipitation and ageing of aluminium hydroxide gels in the presence and absence of 'foreign' anions.

Method for preparing silicone oil surface modified aluminium hydroxide flame retardant

Abstract: The invention discloses a method for preparing a silicone oil surface modified aluminium hydroxide flame retardant, which is characterized by taking silicone oil as a surface modifier, uniformly wrapping the surface of aluminium hydroxide powder with the silicone oil through physical adsorption under action of stirring and then adding a catalyst to impel the functional groups on the molecules of the modified silicon oil to react with the hydroxyl groups on the surface of aluminium hydroxide powder so that the silicone oil is tightly wrapped on the surface of aluminium hydroxide powder throughchemical bonding, thus obtaining the modified aluminium hydroxide powder. The modified aluminium hydroxide prepared by the method has good thermal stability and high decomposition temperature, can improve the mechanical property and flame retardant property of the composite materials and has simple process.

Bauxite-based nanometer composite oxide ceramic bond A1203-MgO-C unfired product and preparation method thereof

Abstract: The invention relates to an A1203-MgO-C unfired product with carbon wrapped by nano Al2O3-MgO film and a preparation method thereof. The product uses natural high alumina bauxite (AlOOH) and sintered periclase (MgO) as initial raw material and employs method of sol-gel technology, which comprises following steps, putting superfine high alumina bauxite, carbon dust, water and additive into high speed impact mixer, carrying out coating process so as to let the materials have strong impact and mix with each other to form high density composite sol suspension liquid of carbon and aluminium hydroxide, therefore Al(OH)3 is mightily adsorbed on the surface of carbon, then realizing workmanship of coating powdered carbon by aluminium hydroxide. During the wet-milled process of mixture, the magnesium oxide powder and the mixture water in the matrix powder have hydration reaction to produce magnesium hydroxide sol, and the magnesium hydroxide sol and the aluminium hydroxide sol have situ synthesis reaction to produce nanostructured matrix of carbon-aluminium spinel to prepare A1203-MgO-C unfired product of the invention.

Significant Liver Toxicity in Albino Rats Upon Oral Aluminium Administration: A Serious Public Health Implication

Abstract: Aluminium is widely used in medicines, as food additives, as water purification agent, as in the making of household cookware and storage utensils. Aluminium absorption depends on the chemical form of aluminium taken up. Aluminium hydroxide and chlorides are absorbed more efficiently than its phosphorus and fluorine compounds. As aluminium is stored mainly in the liver,1 the present work is conducted to study the morphological and morphometric changes in the liver produced by aluminium chloride(AICI3). 20 inbred adult albino rats weighing 150–200gm each were administered 37.5mg per day of aluminium chloride orally for 21 days with maintenance of 20 similar controls. A small piece of liver tissue was processed for paraffin sections. 7μ thick sections were stained with hematoxylin and eosin stain and observed under light microscope. The changes were observed at tissue and cellular level along with general architectural derangement, degenerative changes and nuclear variations such as karryorrhexis, pyknosis. These findings are highly conclusive of toxic hepatitis.

Preparation method of expanding type halogen-free organic fireproof blocking material

Abstract: The invention relates to a preparation method of an expanding type halogen-free organic fireproof blocking material. The preparation method comprises the following steps of: selecting raw materials of aluminium hydroxide, ceramic powder, expanding type graphite, iron oxide red, dioctyl phthalate, zinc borate, alumina silicate fibre, acrylic resin, dibutyl phthalate, polyamide resin 650, gaseous phase white carbon black and ammonium polyphosphate in a certain ratio; mixing and stirring the polyamide resin 650, the dioctyl phthalate, the gaseous phase white carbon black, the ammonium polyphosphate and the dibutyl phthalate to obtain bonded resin; placing the aluminium hydroxide, the ceramic powder, the expanding type graphite and the iron oxide red into a stirring machine to stir; adding the bonded resin and the acrylic resin into a premixed filler to mix and stir into a viscous soft ball-like substance; and placing the viscous soft ball-like substance in the above procedure into an extruder to perform extrusion molding. By the preparation method, the defect that irritant gases and smoke generated by the conventional organic fireproof blocking material under the action of a fire disaster penetrate holes to diffuse and spread all around is overcome; and the problems of damage to a human body and corrosion to equipment caused by toxic halogen acid hydrogen are solved.

The routine determination of the antacid efficiency of aluminium hydroxide gels.

Abstract: Summary 1 In vitro methods for assessing the therapeutic value of antacids have been discussed in relation to the routine evaluation of aluminium hydroxide gels. 2 Experiments based on these tests and the conclusions drawn from the discussion have been carried out with a view to establishing a suitable routine test. 3 A form of test has been given in detail and limits have been suggested.

Effect of Oral Aluminium Hydroxide on Iron Absorption from Iron(III)-hydroxide Polymaltose Complex in Patients with Iron Deficiency Anemia

Abstract: The study was carried out as an open-label, laboratory-blind, single-dose, randomized, two-period crossover, isotope efficacy study. Twenty-two patients with iron-deficiency anemia were enrolled in the study. The study consisted of two treatment phases of 15 days each, including blood sample measurements for Fe-59 activity. The 2 treatments were given orally. Treatment A was Fe-59 labeled iron(III) -hydroxide polymaltose complex (IPC, Maltofer © ), equivalent to 100 mg elemental iron given orally, and Treatment B consisted of Treatment A combined with 600 mg aluminium hydroxide (CAS 21645-51-2) (10 ml). No differences between the two treatment groups with regard to the erythrocyte uptake were found, and thus IPC can be used with aluminium hydroxide, if necessary.

Aqueous fire-retardant composition for a mat made from mineral fibres, and resulting mats

Abstract: The invention relates to an aqueous fire-retardant composition for a mat made from mineral fibres, such as glass or rock, said composition comprising: at least one thermoplastic or thermosetting resin, magnesium hydroxide Mg(OH) 2 and aluminium hydroxide oxide (AlOOH) as flame retardants, and optionally carbon black. The invention also relates to mats treated with the aforementioned fire-retardant composition.

Removal of a Reactive Dye by Adsorption Utilizing Waste Aluminium Hydroxide Sludge as an Adsorbent

Abstract: Removal of a reactive dye (Reactive blue 4) by adsorption utilizing waste aluminium hydroxide sludge as an adsorbent was investigated. The removal of the dye was optimized using response surface methodology (RSM). In the RSM experiments; initial dye concentration, adsorbent concentration and contact time were critical parameters. RSM experiments were performed at the range of initial dye concentration 31.82-368.18 mg/L, adsorbent concentration 3.18-36.82 g/L, contact time 15.8256.18 h. Optimum initial dye concentration, adsorbent concentration and contact time were obtained as 108.83 mg/L, 29.36 g/L and 33.57 h respectively. At these conditions, maximum removal of the dye was obtained as 95%. The experiments were performed at the optimum conditions to verify these results and the same results were obtained. Keywords—Adsorption, Reactive blue 4, Response surface methodology (RSM), Waste aluminium hydroxide sludge

Effect of aluminium hydroxide on “raft-forming” antacids

Abstract: There are a number o f antacid preparations used i n the t rea tment o f gastro-oesophageal ref lux which contain both alginate and sodium bicarbonate. The alginate entraps the carbon dioxide produced from the reaction o f the bicarbonate and gastric acid. Consequently this forms a viscous gel layer which f loats on the gastric contents (May e t al, 1984). i n t o the oesophagus in preference t o the acid gastric contents (Malmud e t a1,1979). An additional mechanism o f act ion might result f rom reduction of ref lux events due t o the mechanical properties o f the barrier. Apparatus has been developed t o measure the strength of alginic acid ra f ts and t o investigate the e f fec t of adding aluminium hydroxide t o the ra f t . This was also used t o compare a number of alginate-containing antacid preparations. A beam balance was modified t o pul l a horizontal probe upwards through the r a f t a t a constant rate. The probe consisted of a 25mm tinned copper wire (0.6mm diameter) suspended from one arm of the balance. The force was applied t o the opposite arm by addition of a chain weight controlled by a stepping motor. The position of the beam was monitored by a linearly graded optical f i l ter and the output f rom the photodetector recorded by computer. required t o pul l the probe through the same distance in water. Progressively increasing the percent age o f aluminium hydroxide added t o "Gaviscon"(Reckitt & Colman Pharmaceuticals, Hull) caused a corresponding decrease in the strength of the ra f t (Figure 1). This suggested tha t formulations containing aluminium hydroxide plus alginate might form weaker ra f t s than those containing alginate alone. To examine this hypothesis various alginate-based antacid preparations have been tested using the apparatus described above. Due t o experimental restrictions, half the recommended doses were used for a l l the formulations. The results are shown in Table 1. The neutral layer i s reported t o be refluxed

Method for preparing submicron aluminium oxide by two-stage roasting method

Abstract: The invention provides a method for preparing submicron aluminium oxide by a two-stage roasting method, relating to a method for preparing important structural and functional material submicron aluminium oxide used in the fields of electricity, medical treatment, information and the like. The method is characterized in that fluidization primary roasting is carried out on industrial aluminium hydroxide taken as a raw material at the temperature of 400-900 DEG C under the protection of nitrogen, thus obtaining activated aluminium oxide; then organic pickling is carried out, filtering and drying are carried out, and additive is added, so that particle dispersion is uniform, aluminium oxide crystal grains are inhibited from growing at high temperature, and the crystal grains purified; and the crystal grains are evenly mixed, and secondary roasting is carried out at the temperature of 1100-1400 DEG C, thus obtaining the submicron aluminium oxide powder. The submicron aluminium oxide powder prepared by the method has uniform particles, the average grain size is less than or equal to 0.9mu m, the purity is high, and the dispersibility is good. The preparation method is simple, and is low in cost and good in repeatability, thus being easy to realize industrialization.

Application process for drying aluminium hydroxide fines

Abstract: The invention provides a process for applying dry aluminum hydroxide fine materials, comprising the following steps: an aluminum hydroxide finished product is obtained from sodium aluminate seminal fluid through crystal seed decomposition, separation and washing; the aluminum hydroxide finished product is dried and then screened so as to form a coarse material part and a fine material part; the coarse material part is used as raw material to be sent into an aluminum fluoride production system; and the fine material part which is dried and screened is used as a crystal seed for a crystal seed decomposition procedure of the sodium aluminate seminal fluid. As the process directly uses the fine material part after screening the aluminum hydroxide for the crystal seed decomposition procedure of the sodium aluminate seminal fluid, the fine material part of which the price per ton is about 300 yuan lower than the aluminum hydroxide finished product can be directly transformed into the normalaluminum hydroxide finished product, thereby greatly reducing the cost of the aluminum hydroxide finished product and reducing the cost of ton products of the aluminum hydroxide and aluminum fluoridejoint production by 12 to 40 yuan as well. The process realizes the reutilization of resources, accords with sustainable development strategy, and has higher economic benefit and social benefit.

Some factors affecting the release of imipramine from gel-precipitated aluminium hydroxide spheres.

Abstract: Changing the pH of the dissolution medium has been found to affect the release of imipramine from gel-precipitated aluminium hydroxide spheres. Release from unwashed, unheated spheres into solutions of pH 1.2 was controlled by dissolution of the gel matrix, whereas that into solutions of pH 3 and pH 5 appeared to be under diffusion control. The liberation of drug from unwashed, heated spheres into the media of higher pH exhibited more complex kinetics. Washed spheres failed to release significant amounts of imipramine into the solutions of pH 3 and 5. Changing the ionic strength of the media had little effect on drug release. These phenomena have been explained with reference to model theories of the precipitation and ageing of aluminum hydroxide gels and their pH-solubility profiles.

Electrochemical method of producing aluminium hydroxide

Abstract: FIELD: chemistry. ^ SUBSTANCE: invention relates to production of aluminium hydroxide from aluminium metal, which can be used as a modifying additive for polymer materials for producing active aluminium oxide for making extra strong and fire resistant ceramic articles, composite materials and antipyrenes. The electrochemical method of producing aluminium oxide involves anodic dissolution aluminium metal in a chlorine-containing electrolyte solution, followed by washing and thermal treatment. Anodic dissolution is carried out in a coaxial electrolysis cell with the surface area of the anode at least twice greater than that of the cathode and the precipitate is then held in the electrolyte solution. Concentration of chloride in the electrolyte solution is equal to 0.05-0.8 mol/l and anode current density is equal to 50-300 A/m2. ^ EFFECT: invention enables to control the phase ratio of boehmite and bayerite and obtain aluminium hydroxide nanoparticles with size in the range of 10-200 nm. ^ 1 dwg, 2 tbl, 4 ex, 1 dwg

Application of Attapulgite Clay Mineral Modified by Flame Retarder in Green Building Materials

Abstract: In this thesis, the composite of aluminum hydroxide on the surface of natural one-dimensional nano minerals and the nanocrystallization of inorganic flame retarder (aluminium hydroxide) are achieved by hydrothermal method. The obtained nano-composite flame retarder is applied in the preparation of straw based panel to improve its flame retardant performance. After ultrasonic dispersion and complex purification with the addition of EDTA, the crude attapulgite clay minerals is put in acid solution of PH 2 or 3, where the surface of the complex is modified with the addition of cetyl trimethyl ammonium bromide (CTAB).Then add into it aluminum hydroxide of different amounts, to start the hydrothermal composite reaction and get aluminum hydroxide/ nano-attapulgite composite flame retarder. After the characterization by SEM the best hydrothermal reaction conditions for preparing aluminum hydroxide/attapulgite are obtained. The prepared nano composite flame retarder, the PF adhesive and straw shavings are mixed in different proportions and made into straw based panel by hot pressing. Then the study on the flame retardant performance and the mechanical properties of the straw based panel is carried out.