Preparation of polymer particles

Abstract

A process for the preparation of polymer magnetic particles, which comprises: (a) providing a water phase containing magnetic components homogeneously dispersed therein; (b) wherein the water phase is contacted with or further contains a polymerisable metal-containing or organic monomer which is soluble in the water phase; and (c) polymerizing the monomer in the presence of the magnetic in which the magnetic components are substantially uniformly distributed; wherein at least a part of the polymerizing step (c) is carried out in a water-in-oil emulsion in which the water phase containing the magnetic components homogeneously dispersed therein is present as a discontinuous phase in a continuous oil phase.

1 . A polymer magnetic particle, prepared by a process comprising:
 (a) providing a water phase containing magnetic components homogeneously dispersed therein;   (b) wherein the water phase is contacted with or further contains a polymerisable monomer comprising a metal oxide or hydroxide, or a metal alkoxide precursor compound which is converted to said monomer by hydrolysis, which is soluble in the water phase; and   
     wherein if the metal in the metal alkoxide is silicon the metal alkoxide is tetraalkoxysilane;
 (c) polymerizing the monomer in the presence of the magnetic components so as to form polymer magnetic particles in which the magnetic components are substantially uniformly distributed; 
 wherein at least a part of the polymerizing step (c) is carried out in a water-in-oil emulsion in which the water phase containing the magnetic components homogeneously dispersed therein is present as a discontinuous phase in a continuous oil phase, and 
 wherein said process results in the magnetic particles being substantially uniformly distributed throughout the entire polymer matrix of said polymer particle. 
 
   
   
       2 . A polymer magnetic particle, prepared by a process comprising:
 (a) providing a water phase containing magnetic components homogeneously dispersed therein, wherein the water phase is provided in a water-in-oil emulsion in which said water phase is present as a discontinuous phase in a continuous oil phase;   (b) contacting the emulsion with a polymerisable monomer comprising a metal oxide or hydroxide, or a metal alkoxide precursor compound which is converted to said monomer by hydrolysis, which is soluble in the water phase; and wherein if the metal in the metal alkoxide is silicon the metal alkoxide is tetraalkoxysilane; and   (c) polymerizing the monomer in the presence of the magnetic components so as to form polymer magnetic particles in which the magnetic components are substantially uniformly distributed;   wherein at least a part of the polymerizing step (c) is carried out in the water-in-oil emulsion, and   wherein said process results in the magnetic particles being substantially uniformly distributed throughout the entire polymer matrix of said polymer particle.   
   
   
       3 . The polymer magnetic particle according to  claims 1  or  2 , wherein the monomer is contacted with the water phase by mixing the emulsion with an oil-soluble metal-containing or organic precursor compound under conditions to convert the precursor compound into the monomer. 
   
   
       4 . The polymer magnetic particle according to  claims 1  or  2 , wherein the water phase has a pH in the range 1 to 5 or 8 to 14. 
   
   
       5 . The polymer magnetic particle according to  claim 3 , wherein the alkoxide is a methoxide. 
   
   
       6 . The polymer magnetic particle according to  claims 1  or  2 , wherein the metal oxide or hydroxide is a silicon oxide or hydroxide. 
   
   
       7 . The polymer magnetic particle according to  claims 1  or  2 , wherein the largest dimension of the magnetic components is in the range 1 to 15 nm. 
   
   
       8 . The polymer magnetic particle according to  claims 1  or  2 , wherein the magnetic components comprise a magnetic metal oxide. 
   
   
       9 . The polymer magnetic particle according to  claim 8 , wherein the magnetic metal oxide is an iron oxide or an iron oxide in which all or a part of the ferrous iron thereof is substituted by a divalent transition metal selected from cadmium, chromium, cobalt, copper, magnesium, manganese, nickel, vanadium, and zinc. 
   
   
       10 . The polymer magnetic particle according to  claim 9 , wherein the magnetic metal oxide is an iron oxide. 
   
   
       11 . The polymer magnetic particle according to  claim 8 , wherein the magnetic metal oxide is provided as a magnetic fluid. 
   
   
       12 . The polymer magnetic particle according to  claim 11 , wherein the magnetic fluid comprises a ferro fluid. 
   
   
       13 . The polymer magnetic particle according to  claims 1  or  2 , wherein the water phase of the emulsion comprises water droplets. 
   
   
       14 . The polymer magnetic particle according to  claim 13 , wherein the size of the water droplets is controlled by the mixing conditions used to form the emulsion. 
   
   
       15 . The polymer magnetic particle according to  claim 14 , wherein the size of the water droplets is in the range 0.1 to 100 μm. 
   
   
       16 . Polymer magnetic particles obtained by the process according to  claims 1  or  2 , in which the magnetic component thereof is substantially uniformly distributed. 
   
   
       17 . Polymer magnetic particles according to  claim 16 , which are substantially spherical and have a diameter in the range 0.1 to 100 μm. 
   
   
       18 . Polymer magnetic particles according to  claim 17 , wherein the diameter is in the range of 0.5 to 50 μm. 
   
   
       19 . Polymer magnetic particles according to  claim 17 , wherein the diameter is in the range of 1 to 10 μm. 
   
   
       20 . A method for separating a target substance from a sample comprising contacting the target with polymer magnetic particles according to  claim 16 . 
   
   
       21 . A polymer magnetic particle prepared by a process comprising:
 (a) providing a water phase containing magnetic components homogeneously dispersed therein;   (b) wherein the water phase is contacted with or further contains a polymerisable monomer comprising a metal oxide or hydroxide, or a metal alkoxide precursor compound which is converted to said monomer by hydrolysis, which is soluble in the water phase; and   
     wherein if the metal in the metal alkoxide is silicon the metal alkoxide is tetraalkoxysilane;
 (c) polymerizing the monomer in the presence of the magnetic components so as to form polymer magnetic particles in which the magnetic components are substantially uniformly distributed; 
 wherein at least a part of the polymerizing step (c) is carried out in a water-in-oil emulsion in which the water phase containing the magnetic components homogeneously dispersed therein is present as a discontinuous phase in a continuous oil phase, and wherein the magnetic components comprise a ferro fluid, and 
 wherein said process results in the magnetic particles being substantially uniformly distributed throughout the entire polymer matrix of said polymer particle. 
 
   
   
       22 . A polymer magnetic particle prepared by a process comprising:
 (a) providing a water phase containing magnetic components homogeneously dispersed therein;   (b) wherein the water phase is contacted with or further contains a polymerisable monomer comprising a metal oxide or hydroxide which is soluble in the water phase; and   (c) polymerizing the monomer in the presence of the magnetic components so as to form polymer magnetic particles in which the magnetic components are substantially uniformly distributed; and   wherein at least a part of the polymerizing step (c) is carried out in a water-in-oil emulsion in which the water phase containing the magnetic components homogeneously dispersed therein is present as a discontinuous phase in a continuous oil phase; and   wherein the largest dimension of the magnetic components is in the range 1 to 15 nm and the water phase of the emulsion comprises water droplets having a size in the range of 0.1 to 100 μm; and   wherein said process results in the magnetic particles being substantially uniformly distributed throughout the entire polymer matrix of said polymer particle.   
   
   
       23 . A polymer magnetic particle prepared by a process comprising:
 (a) providing a water phase containing magnetic components homogeneously dispersed therein, wherein the water phase is provided in a water-in-oil emulsion in which said water phase is present as a discontinuous phase in a continuous oil phase;   (b) contacting the emulsion with a polymerisable monomer comprising a metal oxide or hydroxide, which is soluble in the water phase; and   (c) polymerizing the monomer in the presence of the magnetic components so as to form polymer magnetic particles in which the magnetic components are substantially uniformly distributed; and   wherein at least a part of the polymerizing step (c) is carried out in the water-in-oil emulsion; and   wherein the largest dimension of the magnetic components is in the range 1 to 15 nm and the water phase of the emulsion comprises water droplets having a size in the range of 0.1 to 100 μm; and   wherein said process results in the magnetic particles being substantially uniformly distributed throughout the entire polymer matrix of said polymer particle.   
   
   
       24 . A polymer magnetic particle prepared by a process comprising:
 (a) providing a water phase containing magnetic components homogeneously dispersed therein;   (b) wherein the water phase is contacted with or further contains a polymerisable monomer comprising a metal oxide or hydroxide which is soluble in the water phase; and   (c) polymerizing the monomer in the presence of the magnetic components so as to form polymer magnetic particles in which the magnetic components are substantially uniformly distributed; and   wherein at least a part of the polymerizing step (c) is carried out in a water-in-oil emulsion in which the water phase containing the magnetic components homogeneously dispersed therein is present as a discontinuous phase in a continuous oil phase, and wherein the magnetic components comprise a ferro fluid; and   wherein the largest dimension of the magnetic components is in the range 1 to 15 nm and the water phase of the emulsion comprises water droplets having a size in the range of 0.1 to 100 μm; and   wherein said process results in the magnetic particles being substantially uniformly distributed throughout the entire polymer matrix of said polymer particle.