Supported chromium catalysts containing a solid oxide and 0.1 to 15 wt. % chromium, in which the solid oxide or the supported chromium catalyst has a particle size span from 0.5 to 1.4, less than 3 wt. % has a particle size greater than 100 μm, and less than 10 wt. % has a particle size less than 10 μm, can be contacted with an olefin monomer in a loop slurry reactor to produce an olefin polymer. Representative ethylene-based polymers produced using the chromium catalysts have a HLMI of 4 to 70 g/10 min, a density from 0.93 to 0.96 g/cm.sup.3, from 150 to 680 ppm solid oxide (such as silica), from 1.5 to 6.8 ppm chromium, and a film gel count of less than 15 catalyst particle gels per ft.sup.2 of 25 micron thick film and/or a gel count of less than or equal to 50 catalyst particles of greater than 100 μm per five grams of the ethylene polymer.

A bimodal polymer composition comprising a lower molecular weight homopolymer and a higher molecular weight copolymer wherein the bimodal polymer composition has a density of from about 0.930 gram per cubic centimeter (g/cc) to about 0.970 g/cc, a ratio of high load melt index:melt index of from about 10 to about 150 and an Environmental Stress Crack Resistance (ESCR) of from about 25 hours to about 300 hours when measured in accordance with ASTM D1693 or ASTM D2561. A chromium-catalyzed polymer composition comprising (i) a lower molecular weight homopolymer and (ii) a higher molecular weight copolymer, wherein the bimodal polymer composition has an Environmental Stress Crack Resistance (ESCR) of from about 25 hours to about 300 hours when measured in accordance with ASTM D1693 or ASTM D2561.

A bimodal polymer composition comprising a lower molecular weight homopolymer and a higher molecular weight copolymer wherein the bimodal polymer composition has a density of from about 0.930 gram per cubic centimeter (g/cc) to about 0.970 g/cc, a ratio of high load melt index:melt index of from about 10 to about 150 and an Environmental Stress Crack Resistance (ESCR) of from about 25 hours to about 300 hours when measured in accordance with ASTM D1693 or ASTM D2561. A chromium-catalyzed polymer composition comprising (i) a lower molecular weight homopolymer and (ii) a higher molecular weight copolymer, wherein the bimodal polymer composition has an Environmental Stress Crack Resistance (ESCR) of from about 25 hours to about 300 hours when measured in accordance with ASTM D1693 or ASTM D2561.

A method comprising a) contacting a solvent, a carboxylic acid, and a peroxide-containing compound to form an acidic mixture wherein a weight ratio of solvent to carboxylic acid in the acidic mixture is from about 1:1 to about 100:1; b) contacting a titanium-containing compound and the acidic mixture to form a solubilized titanium mixture wherein an equivalent molar ratio of titanium-containing compound to carboxylic acid in the solubilized titanium mixture is from about 1:1 to about 1:4 and an equivalent molar ratio of titanium-containing compound to peroxide-containing compound in the solubilized titanium mixture is from about 1:1 to about 1:20; and c) contacting a chromium-silica support comprising from about 0.1 wt. % to about 20 wt. % water and the solubilized titanium mixture to form an addition product and drying the addition product by heating to a temperature in a range of from about 50° C. to about 150° C. and maintaining the temperature in the range of from about 50° C. to about 150° C. for a time period of from about 30 minutes to about 6 hours to form a pre-catalyst.

A method comprising a) contacting a solvent, a carboxylic acid, and a peroxide-containing compound to form an acidic mixture wherein a weight ratio of solvent to carboxylic acid in the acidic mixture is from about 1:1 to about 100:1; b) contacting a titanium-containing compound and the acidic mixture to form a solubilized titanium mixture wherein an equivalent molar ratio of titanium-containing compound to carboxylic acid in the solubilized titanium mixture is from about 1:1 to about 1:4 and an equivalent molar ratio of titanium-containing compound to peroxide-containing compound in the solubilized titanium mixture is from about 1:1 to about 1:20; and c) contacting a chromium-silica support comprising from about 0.1 wt. % to about 20 wt. % water and the solubilized titanium mixture to form an addition product and drying the addition product by heating to a temperature in a range of from about 50° C. to about 150° C. and maintaining the temperature in the range of from about 50° C. to about 150° C. for a time period of from about 30 minutes to about 6 hours to form a pre-catalyst.

A method of preparing a catalyst comprising a) contacting a non-aqueous solvent, a carboxylic acid, and a chromium-containing compound to form an acidic mixture; b) contacting a titanium-containing compound with the acidic mixture to form a titanium treatment solution; c) contacting a pre-formed silica-support comprising from about 0.1 wt. % to about 20 wt. % water with the titanium treatment solution to form a pre-catalyst; and d) thermally treating the pre-catalyst to form the catalyst. A method of preparing a catalyst comprising a) contacting a non-aqueous solvent and a carboxylic acid to form an acidic mixture; b) contacting a titanium-containing compound with the acidic mixture to form a titanium treatment solution; c) contacting a pre-formed chrominated silica-support comprising from about 0.1 wt. % to about 20 wt. % water with the titanium treatment solution to form a pre-catalyst; and d) thermally treating the pre-catalyst to form the catalyst.

A method of preparing a catalyst comprising a) contacting a non-aqueous solvent, a carboxylic acid, and a chromium-containing compound to form an acidic mixture; b) contacting a titanium-containing compound with the acidic mixture to form a titanium treatment solution; c) contacting a pre-formed silica-support comprising from about 0.1 wt. % to about 20 wt. % water with the titanium treatment solution to form a pre-catalyst; and d) thermally treating the pre-catalyst to form the catalyst. A method of preparing a catalyst comprising a) contacting a non-aqueous solvent and a carboxylic acid to form an acidic mixture; b) contacting a titanium-containing compound with the acidic mixture to form a titanium treatment solution; c) contacting a pre-formed chrominated silica-support comprising from about 0.1 wt. % to about 20 wt. % water with the titanium treatment solution to form a pre-catalyst; and d) thermally treating the pre-catalyst to form the catalyst.

A method of preparing a catalyst comprising a) contacting a non-aqueous solvent, a carboxylic acid, and a chromium-containing compound to form an acidic mixture; b) contacting a titanium-containing compound with the acidic mixture to form a titanium treatment solution; c) contacting a pre-formed silica-support comprising from about 0.1 wt. % to about 20 wt. % water with the titanium treatment solution to form a pre-catalyst; and d) thermally treating the pre-catalyst to form the catalyst. A method of preparing a catalyst comprising a) contacting a non-aqueous solvent and a carboxylic acid to form an acidic mixture; b) contacting a titanium-containing compound with the acidic mixture to form a titanium treatment solution; c) contacting a pre-formed chrominated silica-support comprising from about 0.1 wt. % to about 20 wt. % water with the titanium treatment solution to form a pre-catalyst; and d) thermally treating the pre-catalyst to form the catalyst.

A hydrogel comprising water, and a plurality of titanium-silica nanoparticle agglomerates, wherein each titanium-silica nanoparticle agglomerate is an agglomeration of titanium-silica nanoparticles, the agglomerates having an average titanium loading designated x with a coefficient of variation for the average titanium loading of less than about 1.0, wherein a silica content of the hydrogel is of from about 10 wt. % to about 35 wt. % based on a total weight of the hydrogel.

A hydrogel comprising water, and a plurality of titanium-silica nanoparticle agglomerates, wherein each titanium-silica nanoparticle agglomerate is an agglomeration of titanium-silica nanoparticles, the agglomerates having an average titanium loading designated x with a coefficient of variation for the average titanium loading of less than about 1.0, wherein a silica content of the hydrogel is of from about 10 wt. % to about 35 wt. % based on a total weight of the hydrogel.