Particles

Abstract

A coated magnetic particle comprising an optionally porous magnetic polymer particle of a matrix polymer, said polymer particle having on a surface and/or in the pores thereof superparamagnetic crystals, said coated particle having a coat formed of a coating polymer, wherein said coated magnetic particle is essentially non-autofluorescent.

1 - 31 . (canceled) 
     
     
         32 . A composition comprising a non-autofluorescent coated magnetic polymer particle comprising:
 a porous matrix polymer particle comprising superparamagnetic crystals on the surface and in the pores thereof, wherein majority of the superparamagnetic crystals are within pores of the porous matrix polymer particle, and wherein the porous matrix polymer particle is essentially free of conjugated delocalised electron systems other than those found in benzene rings; and   a coat of a coating polymer wherein the coating polymer is formed by the polymerization of coating monomers wherein the coating monomers are essentially free of conjugated delocalised electron systems other than those found in benzene rings, wherein the coated magnetic polymer particle is essentially non-autofluorescent,   wherein the coated magnetic polymer particle has a coefficient of variation (CV) of less than 10%, and   wherein the coated magnetic polymer particle has a level of autofluorescence corresponding to a difference in the Mean Grey Value (ΔMGV) at an excitation wavelength of 450±25 nm for an exposure time of 500 ms or 600 ms of less than 600.   
     
     
         33 . The non-autofluorescent coated magnetic polymer particle of  claim 32 , further surface functionalized with a functional group essentially free of conjugated delocalised electron systems other than those found in benzene rings. 
     
     
         34 . The non-autofluorescent coated magnetic polymer particle of  claim 33 , wherein the functional group is selected from a sulphonic acid, a carboxylic acid, an amine, or an epoxy group. 
     
     
         35 . The non-autofluorescent coated magnetic polymer particle of  claim 33 , wherein the functional group is not a nitro group. 
     
     
         36 . The non-autofluorescent coated magnetic polymer particle of  claim 32 , wherein the porous matrix polymer particle is selected from an acrylic polymer, a vinylic polymer, or a styrenic polymer. 
     
     
         37 . The non-autofluorescent coated magnetic polymer particle of  claim 36 , wherein the porous matrix polymer is an acrylic polymer. 
     
     
         38 . The non-autofluorescent coated magnetic polymer particle of  claim 37 , wherein monomers of the porous matrix polymer are selected from methyl methacrylate, methacrylic acid, hydroxyethyl methacrylate, glycidyl methacrylate, butylmethacrylate, acrylic acid, ethyleneglycol dimethacrylate, trimethylolpropane trimethacrylate, trimethylol triacrylate, pentaerythritol tetraacrylate and other acrylic or methacrylic monomers. 
     
     
         39 . The non-autofluorescent coated magnetic polymer particle of  claim 36 , wherein the porous matrix polymer is preferably not waterswellable. 
     
     
         40 . The non-autofluorescent coated magnetic polymer particle of  claim 32 , wherein the superparamagnetic crystals are magnetic iron oxides or mixed metal oxides. 
     
     
         41 . The non-autofluorescent coated magnetic polymer particle of  claim 40 , wherein the superparamagnetic crystals are magnetic iron oxides. 
     
     
         42 . The non-autofluorescent coated magnetic polymer particle of  claim 41 , wherein the magnetic iron oxide is magnetite or maghemite. 
     
     
         43 . The non-autofluorescent coated magnetic polymer particle of  claim 40 , wherein the superparamagnetic crystals are mixed metal oxides. 
     
     
         44 . The non-autofluorescent coated magnetic polymer particle of  claim 40 , wherein quantity of crystalline magnetic material present in the superparamagnetic crystal is from about more than 1% up to more than or equal to 5% by weight of the iron or other metal weight upon the overall dry weight of the epoxy coated matrix polymer particles. 
     
     
         45 . The composition of  claim 32 , wherein the non-autofluorescent coated magnetic polymer particles have diameters in the ranges of 0.3 μm to 100 μm. 
     
     
         46 . The composition of  claim 32 , wherein the non-autofluorescent coated magnetic polymer particles have diameters in the ranges of 0.5 μm to 50 μm. 
     
     
         47 . The composition of  claim 32 , wherein the non-autofluorescent coated magnetic polymer particles have diameters in the ranges of 0.8 μm to 10 μm. 
     
     
         48 . The composition of  claim 32 , wherein the non-autofluorescent coated magnetic polymer particles have diameters in the ranges of 2 μm to 10 μm. 
     
     
         49 . The composition of  claim 32 , wherein the non-autofluorescent coated magnetic polymer particles have diameters in the ranges of 5 μm and 8 μm. 
     
     
         50 . A non-autofluorescent uncoated magnetic polymer particle comprising:
 porous matrix polymer particles substantially free from conjugated delocalized electron systems other than benzene rings; and   superparamagnetic polymer particles in the pores of the porous matrix polymer particles.   
     
     
         51 . The non-autofluorescent uncoated magnetic polymer particle of  claim 50 , further surface functionalized with a functional group essentially free of conjugated delocalised electron systems other than those found in benzene rings. 
     
     
         52 . The non-autofluorescent uncoated magnetic polymer particle of  claim 51 , wherein the functional group is selected from a sulphonic acid, a carboxylic acid, an amine, or an epoxy group. 
     
     
         53 . The non-autofluorescent uncoated magnetic polymer particle of  claim 51 , wherein the functional group is not a nitro group. 
     
     
         54 . The non-autofluorescent uncoated magnetic polymer particle of  claim 50 , having a Mean Grey Value (ΔMGV) value of less than 300. 
     
     
         55 . The non-autofluorescent uncoated magnetic polymer particle of  claim 50 , having a Mean Grey Value (ΔMGV) value of less than 200. 
     
     
         56 . The non-autofluorescent uncoated magnetic polymer particle of  claim 50 , having a Mean Grey Value (ΔMGV) value of less than 100.