Organic-inorganic hybrid composite of polymerized nitroxide compound and inorganic particles

An organic-inorganic hybrid composite comprising inorganic particles and a polymer,

• wherein the inorganic particles are silica particles with an average particle diameter of 3 nm to 1000 nm, or magnetic particles including one or more kinds selected from the group consisting of Fe3O4, γ-Fe2O3 and FePt with an average particle diameter of 3 nm to 1 mm, and
• the polymer is represented by General Formula (II):
• in which A represents an unsubstituted or substituted C1-C12 alkoxy, with the substituent if any being a formyl group or a group represented by R1R2CH— (in which R1 and R2 are independently C1-C4 alkoxy groups or R1 and R2 together form —OCH2CH2O—, —O(CH2)3O— or —O(CH2)4O—);
• L1 is selected from the group consisting of a single bond, —(CH2)cS— and —CO(CH2)cS—, in which c is an integer from 1 to 5;
• L2 is —C1-6 alkylene—NH—(C1-6 alkylene)q— or —C1-6 alkylene—O—(C1-6 alkylene)q—, in which q is 0 or 1;
• R is selected from the group consisting of 2,2,6,6-tetramethylpiperidine-1-oxyl-4-yl, 2,2,5,5-tetramethylpyrrolidine-1-oxyl-3-yl, 2,2,5,5-tetramethylpyrroline-1-oxyl-3-yl, 2,4,4-trimethyl-1,3-oxazolidine-3-oxyl-2-yl, 2,4,4-trimethyl-1,3-thiazolidine-3-oxyl-2-yl and 2,4,4-trimethyl-imidazolidine-3-oxyl-2-yl;
• L2-R is present in at least 50% of the total number n, and when it is not present, the remaining L2-R parts may be methyl, halomethyl or hydroxymethyl groups;
• m is an integer from 20 to 5,000;
• and
• n is independently an integer from 3 to 1,000.