Synthetic functionalized additives may comprise a layered magnesium silicate. The layered magnesium silicate may comprise a first functionalized silicate layer comprising a first tetrahedral silicate layer covalently bonded to at least two different functional groups, an octahedral brucite layer, and a second functionalized silicate layer comprising a second tetrahedral silicate layer covalently bonded to at least two different functional groups. A drilling fluid may comprise the synthetic functionalized additive.

The present disclosure relates to a method for producing lanthanide doped layered double hydroxides (Ln-doped LDHs). The method includes the steps of preparing a carbonate free alkaline solution; preparing a solution of metal salts comprising a salt of a lanthanide; co-precipitating the alkaline solution and the solution of metal salts to form a mixture and Ln-doped LDH precipitate wherein the pH of the mixture is maintained at a constant value; aging the precipitate; and separating the precipitate from the solution. The alkaline solution is an aqueous ammonia solution. The present disclosure is also related to lanthanide-doped layered double hydroxides (La-doped LDHs) obtainable by such a method, as well as to the use of the lanthanide-doped layered double hydroxides obtainable by such a method.

A lithium-manganese composite oxide represented by formula (1): Li.sub.1+x[(Fe.sub.yNi.sub.1y).sub.zMn.sub.1z].sub.1xO.sub.2 (1) wherein x, y, and z satisfy the following: 0<x, 0y<1.0, and 0<z0.6, and wherein the content ratio of Li to the total content of Fe, Ni, and Mn (Li/(Fe+Ni+Mn)) is 1.55 or less on a molar ratio basis, the lithium-manganese composite oxide containing a crystalline phase having a layered rock-salt structure. This composite oxide is a novel material made from less resource-constrained and cheaper elements, and exhibits a high specific capacity, excellent charge-and-discharge cycle characteristics, and a high discharge capacity at a high current density (excellent rate characteristics), when used in the positive electrode material for lithium-ion secondary batteries.

The present invention provides a layered double hydroxide with improved conductivity, a layered double hydroxide and a composite material containing the layered double hydroxide. The layered double hydroxide is represented by the general formula: [Mg.sup.2+.sub.(1-y)M1.sup.+.sub.y].sub.1-x[Al.sup.3+.sub.(1-z)M2.sup.+.sub.z].sub.x(OH).sub.2A.sup.n.sub.x/n.mH.sub.2O, wherein 0.1x0.4, 0y0.95, and 0z0.95, provided that both y and z are not 0 at the same time; =1 or 2; =2 or 3; A.sup.n is an n-valent anion, provided that n is an integer of 1 or greater; m0; M1.sup.+ is a cation of at least one substituent element selected from monovalent elements, transition metal elements, and other elements with an ionic radius greater than that of Mg.sup.2+; and M2.sup.+ is a cation of at least one element selected from divalent elements, transition metals, and other elements with an ionic radius greater than that of Al.sup.3+.

A catalyst for methane synthesis is made up from layered double hydroxides represented by the following general formula (1).

[M.sup.2+.sub.1-xM.sup.3+.sub.x(OH).sub.2].sup.x+[A.sup.n?.sub.x/n.Math.yH.sub.2O](1)

In formula (1), M.sup.2+ is Ni.sup.2+ and M.sup.3+ is Al.sup.3+ or Cr.sup.3+. Further, A.sup.n? is CO.sub.3.sup.2?. Furthermore, the term x lies within a range of 0.19 to 0.34 (0.19?x?0.34), and y is 0 or a positive integer.

The present invention aims to provide techniques for preparing complexes of a hydrotalcite and a fiber. The complexes of a hydrotalcite and a fiber can be synthesized efficiently by synthesizing the hydrotalcite in an aqueous system in the presence of the fiber.

Surface-modified layered double hydroxides (LDHs) are disclosed, as well as processes by which they are made, and uses of the LDHs in composite materials. The surface-modified LDHs of the invention are more organophilic than their unmodified analogues, which allows the LDHs to be incorporated in a wide variety of materials, wherein the interesting functionality of LDHs may be exploited.

The invention relates to a method for exchanging interlayer anions of a layered double hydroxide (LDH) with other anions whose affinity for the LDH is lower than the one of the starting interlayer anions, which comprises the successive steps of: (1) exchanging the starting interlayer anions of a layered double hydroxide with polyoxometalate anions in order to obtain a layered double hydroxide with polyoxometalate anions as interlayer anions, and (2) exchanging the polyoxometalate anions of the layered double hydroxide obtained in step (1) with other anions whose affinity for the LDH is lower than the one of the starting interlayer anions in order to obtain a layered double hydroxide with other anions as interlayer anions.

The invention has for its object to use an evaporation-spray drying process thereby providing layered silicate powder granules, each one containing a flat particle having an opening or recess in its surface center. Each of the layered silicate powder granule contains a flat particle including a layered silicate formed by evaporation-spray drying and a rheology modifier for modifying the crystal edge face of the layered silicate and having an opening or recess in its surface center.

A nanostructured material having a coral reef morphology of nanoflake walls is described. The nanostructured material comprises a Fe(II)/Fe(III) layered double hydroxide intercalated with an azo dye, and a synthesis method is discussed. The nanostructured material may be used to remove a contaminant from a solution by adsorption. The nanostructured material may be cleaned and reused with high adsorption efficiency.