Fluid identification system and production and use thereof

Abstract

A fluid identification system comprising a plurality of particles, each particle encapsulating therein at least one tracer material having an identifiable DNA, the at least one tracer material being encapsulated by an encapsulation material, wherein the particles are adapted to retain the at least one tracer material in an encapsulated form after exposure of the particles to a temperature of at least 75° C. and/or a pressure of at least 1000 psi (6.9×10 6 N/m 2 ).

What is claimed is: 
     
         1 . A method of producing a fluid identification system, the method comprising the steps of:
 a. providing at least one tracer material having an identifiable DNA;   b. complexing the at least one tracer material with at least one first polymer in a first solvent; and   c. encapsulating the at least one tracer material complex in an encapsulation material comprising at least one second polymer to form a plurality of particles, each particle comprising encapsulation material surrounding the at least one tracer material complex.   
     
     
         2 . The method according to  claim 1  wherein the encapsulation step (c) is carried out in the liquid phase and the particles are formed as an emulsion in the liquid phase, wherein the emulsion comprises an aqueous phase in an oil phase. 
     
     
         3 . The method according to  claim 2  wherein the encapsulation step (c) is carried out by polymerising a polymerisable material in the liquid phase to form the plurality of particles which include polymerised material comprised in the at least one second polymer, each particle comprising the polymerised material encapsulating therein the at least one tracer material complexed with the at least one first polymer. 
     
     
         4 . The method according to  claim 3  wherein the polymerisable material includes monomers having water-soluble and oil-soluble groups. 
     
     
         5 . The method according to  claim 3  wherein in step (c) the encapsulation is achieved by formation of polymer-coated droplets by interfacial polymerisation in an emulsion. 
     
     
         6 . The method according to  claim 5  wherein in step (c) the polymerisation occurs at a liquid-liquid interface to encapsulate the at least one tracer material complexed with the at least one first polymer. 
     
     
         7 . The method according to  claim 1  wherein in step (c) the at least one tracer material complex is present in an emulsion of aqueous-phase droplets dispersed in an oil phase, the oil phase comprising a polymer or at least one monomer to form the encapsulation material by polymerisation. 
     
     
         8 . The method according to  claim 7  wherein in step (c) the oil phase comprises at least one monomer to form the encapsulation material by free radical polymerisation. 
     
     
         9 . The method according to  claim 7  wherein the oil phase includes a second solvent for the at least one monomer, the encapsulation material being substantially insoluble in the second solvent. 
     
     
         10 . The method according to  claim 7  wherein at least one of the oil phase and the aqueous phase includes a polymerisation initiator for polymerising the at least one monomer. 
     
     
         11 . The method according to  claim 7  wherein in step (c) the oil phase comprises at least one polymer to form the polymerised material surrounding the complex by cross-linking. 
     
     
         12 . The method according to  claim 11  wherein in step (c) the oil phase comprises at least one polymer to form the polymerised material surrounding the complex by precipitation from solution in the liquid phase. 
     
     
         13 . The method according to  claim 7  wherein in step (c) at least one surfactant is present in at least one of the aqueous-phase droplets and the oil phase. 
     
     
         14 . The method according to  claim 13  wherein in the at least one surfactant comprises at least one non-ionic amphiphilic molecule selected from a polyethylene oxide—polypropylene oxide copolymer, a polyethylene oxide—hydroxyalkyl ester triblock copolymer, a sorbitan alkanoate, a sorbitan ester, a polyalkene anhydride, an alkoanol, an alkanoic acid, a sorbitan ester, an alkylpolyether, an alkyl alkylene oxide block copolymer, an alkyl-alkylene diol, or a mixture of any two or more thereof 
     
     
         15 . The method according to  claim 14  wherein the surfactant, the oil phase and the aqueous phase are present in a weight ratio of 5-30 wt % surfactant: 40-80 wt % oil phase: 2-55 wt % aqueous phase. 
     
     
         16 . The method according to  claim 1  wherein the encapsulation material comprises at least one acrylate-, methacrylate- or styrene-based polymer, a methyl methacrylate polymer, a vinylpyrrolidone polymer, a polyurethane polymer, a polystyrene polymer, a polyethylene oxide polymer, a polyethylene glycol polymer, an alkylpolyether polymer, or an epoxy polymer. 
     
     
         17 . The method according to  claim 1  wherein the particle is adapted to be degradable in order selectively to release the DNA therefrom for analysis. 
     
     
         18 . The method according to  claim 17  wherein the encapsulation material comprises a linear polymer containing degradable co-monomers or a cross-linked polymer containing degradable cross-linkers. 
     
     
         19 . The method according to  claim 18  wherein the encapsulation material includes a chemical grouping adapted to be selectively broken thereby to degrade the particle to release the DNA therefrom for analysis. 
     
     
         20 . The method according to  claim 19  wherein the breakable chemical grouping is an ester, urethane, carbonate, disulphide or amine group. 
     
     
         21 . The method according to  claim 20  wherein the breakable chemical grouping is a disulphide adapted to be reduced using a dithiothreitol (DTT) reagent thereby to degrade the particle to release the DNA therefrom for analysis. 
     
     
         22 . The method according to  claim 1  wherein the DNA of the tracer material is complexed with polyethylene imine, the molar ratio of nitrogen in the polyethylene imine to phosphorous in the DNA is from 5 to 30, the encapsulation material comprises at least one acrylate polymer, methacrylate polymer or methyl methacrylate polymer, the polymer of the encapsulation material includes a breakable chemical grouping adapted to be chemically reduced using a reagent, thereby to degrade the particle to release the DNA therefrom for analysis, and the encapsulation material has been polymerised in an oil phase by atom transfer radical interfacial polymerisation in a water-in-oil emulsion. 
     
     
         23 . The method according to  claim 22  wherein the breakable chemical grouping is a disulphide group. 
     
     
         24 . The method according to  claim 1  wherein the DNA of the least one tracer material is solubilised in the first solvent, the first solvent being an aqueous solvent. 
     
     
         25 . The method according to  claim 1  wherein the DNA of the least one tracer material is at a concentration in the solvent lower than a gelation concentration for the DNA in the solvent. 
     
     
         26 . The method according to  claim 1  wherein the DNA of the least one tracer material is at a concentration in the solvent of from 0.1 to 5 μg/ml. 
     
     
         27 . The method according to  claim 1  wherein at least one tracer material complexed with at least one first polymer has a dimension of from 1 to 100 nm. 
     
     
         28 . The method according to  claim 1  wherein the at least one first polymer comprises a cationic or hydrogen bonding polymer complexed with the DNA of the least one tracer material. 
     
     
         29 . The method according to  claim 1  wherein the at least one first polymer includes a nitrogen-containing functional group complexed with the DNA, wherein the nitrogen-containing functional group is an amine group. 
     
     
         30 . The method according to  claim 29  wherein the at least one first polymer comprises at least one of polyethylene imine and poly-L-Lysine or a mixture of two or more thereof. 
     
     
         31 . The method according to  claim 1  wherein the at least one first polymer comprises nitrogen and the molar ratio of nitrogen in the at least one first polymer to phosphorous in the DNA of the least one tracer material is from 5 to 30. 
     
     
         32 . The method according to  claim 1  wherein the at least one first polymer comprises polyethylene imine and the molar ratio of nitrogen in the polyethylene imine to phosphorous in the DNA of the least one tracer material is from 5 to 30. 
     
     
         33 . The method according to  claim 1  wherein the particles are adapted to retain the at least one tracer material in an encapsulated form after exposure of the particles to a temperature of at least 75° C. and/or a pressure of at least 1000 psi (6.9×10 6  N/m 2 ). 
     
     
         34 . The method according to  claim 1  wherein the particles have an external dimension of from 50 nanometers to 500 nanometers. 
     
     
         35 . The method according to  claim 1  wherein the at least one tracer material is dispersed in a matrix of the polymerised material. 
     
     
         36 . The method according to  claim 1  wherein the at least one tracer material is contained in a cavity within a capsule of the polymerised material.