Abstract: A salt-tolerant polymer microsphere plugging agent and a preparation method thereof, the agent being made of white oil, fumed silica, acrylamide monomer, acrylic acid, sorbitan fatty acid ester, N,N?-methylene bisacrylamide, ammonium persulfate, sodium bisulfite, hydrophilic surfactant and water. The present general inventive concept synthesizes salt-tolerant polymer microspheres with ultra-low interfacial tension by adopting inverse phase emulsion polymerization. The prepared polymer microsphere plugging agent is a new type of polymer microspheres with ultra-low interfacial tension, such that the tension can reach 4.3×10?3 mN/m, and the salt tolerance can reach 50000 mg/L salinity, which improves the problem of low interfacial tension and poor salt tolerance in existing polymer microspheres.

Abstract: A salt-tolerant polymer microsphere plugging agent and a preparation method thereof, the agent being made of white oil, fumed silica, acrylamide monomer, acrylic acid, sorbitan fatty acid ester, N,N?-methylene bisacrylamide, ammonium persulfate, sodium bisulfite, hydrophilic surfactant and water. The present general inventive concept synthesizes salt-tolerant polymer microspheres with ultra-low interfacial tension by adopting inverse phase emulsion polymerization. The prepared polymer microsphere plugging agent is a new type of polymer microspheres with ultra-low interfacial tension, such that the tension can reach 4.3×10?3 mN/m, and the salt tolerance can reach 50000 mg/L salinity, which improves the problem of low interfacial tension and poor salt tolerance in existing polymer microspheres.

Abstract: Disclosed are nanoparticles comprising octapod iron oxide having eight trigonal bipyramidal arms and a method of preparing the same. The nanoparticles are prepared by heating a mixture of a ferric carboxylate, a carboxylic acid, a chloride salt, water, and a non-polar solvent, to a temperature above about 300° C. Also disclosed is a method of magnetic resonance imaging a tissue in a mammal, comprising use of the aforesaid nanoparticles.

Abstract: Disclosed are nanoparticles comprising octapod iron oxide having eight trigonal bipyramidal arms and a method of preparing the same. The nanoparticles are prepared by heating a mixture of a ferric carboxylate, a carboxylic acid, a chloride salt, water, and a non-polar solvent, to a temperature above about 300° C. Also disclosed is a method of magnetic resonance imaging a tissue in a mammal, comprising use of the aforesaid nanoparticles.