The present invention relates to the petroleum drilling fluid field, and discloses a modified silicon dioxide nano-particle comprising a modifying polymer chain composed of structural units provided by one or more of monomers represented by the following formula (1) and one or more of monomers represented by the following formula (2). The present invention provides a method for preparing modified silicon dioxide nano-particles and a drilling fluid suitable for shale gas wells containing the modified silicon dioxide nano-particles as a plugging agent. When the modified silicon dioxide nano-particles provided in the present invention are used as a plugging agent in a drilling fluid, they will not agglomerate into large-size particles, and can achieve a good plugging effect. ##STR00001##

This disclosure relates to polymer coatings with desirable anti-fouling properties. In certain embodiments, polymers are coated on particles which allow for conjugation with targeting moieties. In certain embodiments, the particles are nanoparticles with targeting moieties that bind with tumor associated antigens.

A silica-containing resin composition, characterized by containing a resin and silica particles in an amount of 5 to 300 parts by mass, with respect to 100 parts by mass of the resin, wherein the silica particles satisfy the following requirements (a) to (c): (a) the silica particles have a specific surface area, as determined through a nitrogen absorption method, of 20 to 500 m.sup.2/g; (b) the silica particles have a percent moisture absorption of 5.0 mass % or less at a relative humidity of 50%; and (c) the silica particles contain substantially no metallic impurity or halogen.

Treated, mesoporous aggregates comprising a plurality of coated particles that comprise an inorganic oxide core having a surface area of about 50 to about 500 square meters per gram and a shell or coating consisting of an array of fluoroalkyl molecular chains covalently bonded to the core at a density of at least one chain per square nanometer. The aggregates are formed by the chemical attachment of fluoroalkyl-alkylsilanes after exposure to an alkylamine and followed by an extraction to remove any unbound organic material. The dense packing of molecular chains in the fluoroalkyl shell combined with a mesoporous structure imparts a very low surface energy, a very high specific surface area, and surface texture over a wide range of length scales. Such features are highly desirable for the creation of, for example, superhydrophobic and superoleophobic surfaces, separation media, and release films.

An intumescent polymer is provided for molding fire-retardant structures. Expandable graphite is mixed in a polymer matrix to form the intumescent polymer. The expandable graphite is treated with silane to improve the strength of the polymer. Other ingredients may also be included within the polymer, including an acid source, blowing agent, char forming agent, an inorganic filler and a cross-linking agent.

A method comprises: dispersing a nanoparticle sol, ammonia water and a waterborne hydrophobic treatment agent in deionized water to prepare a modified nanoparticle suspension, and obtaining a superhydrophobic modified nanoparticle powder by means of a spray drying process; and adding a porous ceramic micro-powder and a waterborne silane coupling agent into deionized water, then adding the superhydrophobic modified nanoparticle powder, performing constant stirring to prepare a superhydrophobic particle impregnating porous particle suspension, and obtaining the impregnated porous powder with superhydrophobic particles by means of a filter drying process or the spray drying process.

Provided is an inorganic oxide dispersion (sol) in which inorganic oxide particles are dispersed in silicone oil.

Silica particles includes a nitrogen-containing compound. The ratio of the integral C of a signal observed at a chemical shift of −50 ppm or more and −75 ppm or less in a .sup.29Si solid-state nuclei magnetic resonance (NMR) spectrum of the silica particles, the .sup.29Si solid-state NMR spectrum being obtained by cross polarization/magic angle spinning (CP/MAS), to the integral D of a signal observed at a chemical shift of −90 ppm or more and −120 ppm or less in the .sup.29Si solid-state NMR spectrum, that is, C/D, is 0.10 or more and 0.75 or less. The amount X of the nitrogen-containing compound extracted from the silica particles with a mixed solution of ammonia and methanol is 0.1% by mass or more. The amount X of the nitrogen-containing compound extracted and the amount Y of the nitrogen-containing compound extracted from the silica particles with water satisfy Y/X<0.3.

Provided is a hydrophilic precipitated silica which is well suited to use in silicone rubber formulations (RTV-1, RTV-2, HTV and LSR), particularly well suited to use in HTV silicone rubber formulations. It has a BET surface area of 185˜260 m.sup.2/g, a CTAB surface area of 100˜160 m.sup.2/g, a BET/CTAB ratio of 1.2˜2.6, and a conductivity of <250 μS/cm. Also provided are a process for producing the precipitated silica and the use of the precipitated silica for thickening and reinforcing silicone rubber formulations.

The present invention provides a method that enables production of a surface-treated colored inorganic particle with which the desired color tone can be consistently reproduced as intended with no variation occurring in the color tone of the compositions produced with the particle, within each production and over multiple production runs. The invention relates to a method for producing a surface-treated colored inorganic particle, comprising spray drying a mixture of a dispersion [I] and a solution [II], wherein the dispersion [I] is a dispersion of inorganic particles having an average particle diameter of 0.005 to 5 μm dispersed in a solvent with a pigment, and the solution [II] is a solution of a surface treatment agent hydrolyzed in the presence of a hydrolysis aid.