摘要:
This patent describes economical and environment-friendly processes for the synthesis of Al-containing non-Mg anionic clays. It involves hydrothermally reacting a slurry comprising a divalent metals source with a trivalent metals source to directly obtain Al-containing non-Mg anionic clay, at least one of the metal sources being an oxide, hydroxide or a carbonate. There is no necessity to wash or filter the product. It can be spray dried directly to form microspheres or can be extruded to form shaped bodies. The product can be combined with other ingredients in the manufacture of catalysts, absorbents, pharmaceuticals, cosmetics, detergents, and other commodity products that contain anionic clays.
摘要:
A nanocomposite structure comprising a nanostructured filler or carrier intimately mixed with a matrix, and methods of making such a structure. The nanostructured filler has a domain size sufficiently small to alter an electrical, magnetic, optical, electrochemical, chemical, thermal, biomedical, or tribological property of either filler or composite by at least 20%.
摘要:
Nanostructured materials and processes for the preparation of these nanostructured materials in high phase purities using cavitation is disclosed. The method preferably comprises mixing a metal containing solution with a precipitating agent and passing the mixture into a cavitation chamber. The chamber consists of a first element to produce cavitation bubbles, and a second element that creates a pressure zone sufficient to collapse the bubbles. The process is useful for the preparation of catalysts and materials for piezoelectrics and superconductors.
摘要:
An antimicrobial agent containing at least one of an oxide solid solution of the formula (1), �(M.sub.1.sup.2+).sub.y (M.sub.2.sup.2+).sub.1-y !.sub.1-x M.sup.3+.sub.x-a O (1) wherein M.sub.1.sup.2+ is Zn.sup.2+ and/or Cu.sup.2+, M.sub.2.sup.2+ is Mg.sup.2+ and/or Ca.sup.2+, M.sup.3+ is at least one trivalent metal selected from Al.sup.3+, Fe.sup.3+, Co.sup.3+, Cr.sup.3+, In.sup.3+ and Bi.sup.3+, x is a number in the range of 0.01.ltoreq.x
摘要:
There is provided a method for making a polyvalent inorganic anion-intercalated hydrotalcite-like material by first reacting a magnesium-containing powder and a transition alumina powder in a carboxylic acid-free, aqueous suspension to form a meixnerite intermediate. This intermediate is then contacted with a polyvalent inorganic anion, in its acid, acid salt or ammonium salt form, to make a hydrotalcite-like material. The latter is then separated from the suspension. Representative materials include a borate- metatungstate- and paramolybdate-intercalated hydrotalcite-like material.
摘要:
There is provided an improved method for making synthetic hydrotalcite by first reacting powdered magnesium oxide with a high surface area, transition alumina in a solution or suspension to form a meixnerite-like intermediate. This intermediate is then contacted with an anion source such as an acid, and most preferably carbon dioxide, to form the layered double hydroxide which is separated from the suspension by filtering, centrifugation, vacuum dehydration or other known means. On a preferred basis, the transition alumina combined with activated magnesia consists essentially of an rehydratable alumina powder having a surface area of 100 m.sup.2 /g or greater. To make related double hydroxide compounds, still other reactants such as bromides, chlorides, boric acids, or salts thereof, may be substituted for the carbon dioxide gas fed into this suspension.
摘要:
A catalytic process for the conversion of hydrocarbons is described. Catalyst in this improved process is made by thermally activating a hydrotalcite-type clay of formula:M.sup.2+.sub.2x M.sup.3+.sub.2 (OH).sub.4x+4 A.sup.n-.sub.2/n.ZH.sub.2 Owhere M.sup.2+ is one or more metal ion selected from the group consisting of Mg.sup.2+, Zn.sup.2+ Cu.sup.2+, Ni.sup.2+, Co.sup.2+, Mn.sup.2+ and Fe.sup.2+ and M.sup.3+ is one or more metal ion selected from the group consisting of Al.sup.3+, Fe.sup.3+, Co.sup.3+, Mn.sup.3+ and Cr.sup.3+, x runs between 1.5 and 5, A is one or more anions selected from the group consisting of B(OH).sub.4.sup.-, [B.sub.3 O.sub.3 (OH).sub.4 ].sup.-, V.sub.2 O.sub.7.sup.4-, V.sub.4 O.sub.12.sup.4-, and V.sub.3 O.sub.9.sup.3-, n is 1, 3 or 4, and Z runs between 0 and about 4. These hydrotalcite-type clays have an X-ray diffraction d(001) value greater than about 7.7 Angstroms.
摘要:
An improved process for preparing crystalline mixed metal oxides, such as barium titanate, in which an organometallic compound is reacted simultaneously and continuously with a solution of a divalent alkaline earth metal ion in an alkaline high turbulence energy environment, the reaction product is crystallized, and the crystals are isolated.
摘要:
In a method for producing PLZT powder, the A-site components are co-precipitated simultaneously and mixed with the B-site components which are also co-precipitated simultaneously. As a result, the powder obtained by calcination of the precipitates has less fluctuation in the chemical composition compared with the prior art.