Additive manufacturing processes featuring consolidation of thermoplastic particulates may form printed objects in a range of shapes. Inorganic nanoparticles disposed upon the outer surface of the thermoplastic particulates may improve flow performance of the thermoplastic particulates during additive manufacturing, but may be undesirable to incorporate in some printed objects. Polymer nanoparticles may be substituted for inorganic nanoparticles in some instances to address this difficulty and provide other advantages. Particulate compositions suitable for additive manufacturing may comprise: a plurality of thermoplastic particulates comprising a thermoplastic polymer and a plurality of polymer nanoparticles disposed upon an outer surface of the thermoplastic particulates, the polymer nanoparticles comprising a crosslinked fluorinated polymer.

Covalently linked linear polyethylenimine (PEI) clusters are provided that change conformation depending upon changes in counterion concentrations. The structures may be used for the storage, delivery, and/or transport of substances.

Covalently linked linear polyethylenimine (PEI) clusters are provided that change conformation depending upon changes in counterion concentrations. The structures may be used for the storage, delivery, and/or transport of substances.

A method of extracting underground resources including a step of mixing hydrolysable particles and a proppant to an aqueous dispersion fluid, and introducing the fluid with pressure into an ore chute formed under the ground, wherein as the hydrolysable particles, use is made of spherical particles that include a hydrolysable resin of a weight average molecular weight (Mw) of not less than 5,000 and, specifically, not less than 10,000, and that have an average particle size (D.sub.50) in a range of 300 to 1,000 μm, and a circularity of a short diameter/long diameter ratio of not less than 0.8. The spherical particles have a hyrolysable capability, a circularity and a particle size adapted to the hydraulic fracturing.

A method of extracting underground resources including a step of mixing hydrolysable particles and a proppant to an aqueous dispersion fluid, and introducing the fluid with pressure into an ore chute formed under the ground, wherein as the hydrolysable particles, use is made of spherical particles that include a hydrolysable resin of a weight average molecular weight (Mw) of not less than 5,000 and, specifically, not less than 10,000, and that have an average particle size (D.sub.50) in a range of 300 to 1,000 μm, and a circularity of a short diameter/long diameter ratio of not less than 0.8. The spherical particles have a hyrolysable capability, a circularity and a particle size adapted to the hydraulic fracturing.

A water dispersion of gel particles, in which the gel particles having a polymerizable group, having a three-dimensional crosslinked structure including at least one bond selected from a urethane bond and a urea bond, and including at least a photopolymerization initiator and a resin are dispersed in water, a method of producing the water dispersion, and an image forming method using the water dispersion.

Compounded copolyamide powders, processes for preparation of compounded copolyamide powders, articles made therefrom and uses.

Modified plastic surfaces with perfluoropolymers are provided, whereby plastic surfaces that are intended for use under tribological conditions have substantially improved assembly properties and/or sliding friction properties and exhibit a very low degree of wear. Accordingly, modified plastic surfaces with perfluoropolymers are provided in which, after a reactive conversion under mechanical stress at room temperature, at least the reactive —NH groups and/or —OH groups present at the surface of plastics are present in a chemically covalently coupled manner with the perfluoropolymer carboxylic acid halide present at least in the surface-proximate region of modified perfluoropolymer (micro)powders and/or with the grafted (meth)acrylic acid halide present via perfluoropolymer (peroxy) radicals of the perfluoropolymer (micro)powders and/or (meth)acrylic acid that has been modified into (meth)acrylic acid halide before the reactive conversion.

Modified plastic surfaces with perfluoropolymers are provided, whereby plastic surfaces that are intended for use under tribological conditions have substantially improved assembly properties and/or sliding friction properties and exhibit a very low degree of wear. Accordingly, modified plastic surfaces with perfluoropolymers are provided in which, after a reactive conversion under mechanical stress at room temperature, at least the reactive —NH groups and/or —OH groups present at the surface of plastics are present in a chemically covalently coupled manner with the perfluoropolymer carboxylic acid halide present at least in the surface-proximate region of modified perfluoropolymer (micro)powders and/or with the grafted (meth)acrylic acid halide present via perfluoropolymer (peroxy) radicals of the perfluoropolymer (micro)powders and/or (meth)acrylic acid that has been modified into (meth)acrylic acid halide before the reactive conversion.

Embodiments of a spray-drying process for producing low aspect ratio particles of poly[(methyl methacrylate)-co-(methacrylic acid)] (PMMAMA) are disclosed. In some examples, at least 95% of PMMAMA-containing particles made by the process have an aspect ratio <10. The particles may further include an active ingredient and/or an excipient.