A kind of preparation method of conducting polymer nano material of spherical shell structure
Technical field
The present invention relates to a kind of conducting polymer nano material, especially relate to a kind of preparation method of conducting polymer nano material of spherical shell structure of controllable size.
Background technology
Conjugated polymers is owing to the existence of the height delocalization ∏ key in its effective conjugate length possesses special light, electricity, magnetic property, and after mixing, its specific conductivity can rise to the S order of magnitude rapidly, is conductor from semiconductor variable.Since finding conductive polymers, because the not available performance of its traditional polymer of giving, thereby very big development potentiality (MacDiarmid A.G.Synthetic Met. is arranged in fields such as lightweight battery, electromagnetic shielding material, corrosion protection coating and transmitters, 1997,84 (1-3): 27-34).Oxypolymerization is the common chemical polymerization method of conjugated polymers synthetic, and than electrochemical polymerization, that oxypolymerization has is workable, be fit to produce in enormous quantities and advantage such as can the synthetic mode of appearance changeable.
Nano material is meant that microtexture is subjected to nanoscale (1~100nm) synthetic various solid super-fine materials at least on the one dimension direction.Because nano material crystal grain is minimum, specific surface area is big, atomic percent in the grain surface lack of alignment is far longer than the shared percentage ratio of crystalline material surface atom, caused nano material to have the not available many special essential propertys of conventional solid, as surface effects, small-size effect, quantum size effect, macro quanta tunnel effect and dielectric confinement effect etc.Because nano effect, material enters the sudden change that performance can take place in the nano-scale range, therefore, becomes in recent years hot subject for the research of the controlled preparation of nanomaterials of form nuclear structure.
Conductive polymers is widely studied as support of the catalyst, as: carbon black, carbon nanotube loaded noble metal platinum and the alloy thereof that polyaniline is modified is to study more DMFC anode catalyst at present, and this catalyzer has anti-excellent properties of poisoning.The nanometer conductive polymer of controllable size can improve the noble metal support dispersion state well, can reduce cost, and improves catalytic performance and anti-poisoning capability.
(Bleda-Mart í nez M.J. such as Bleda-Mart í nez, Morall ó n E., Cazorla-Amor ó s D.ELECTROCHIM.ACTA., 2007,52 (15): 4962-4968) on carbon nanotube, carry out in-situ polymerization by aniline monomer, resultant conductive polymers/carbon pipe nano-complex and carbon nanotube have compared specific inductivity and have improved 20%, and whether the distribution homogeneous of its specific inductivity and conductive polymers has direct relation.
(Yang Y., Chu Y., Yang, F.et al such as Yang Y.; Mater.Chem.and Phys.2005,92 164-171) successfully coated electrically conductive polyaniline and polypyrrole by sulfonation after to the monodisperse polystyrene microsphere finishing, and prepared hollow conductive polymer microspheres by the stripping polymer core.This method has complicated operation, because the swelling action of vitriol oil p-poly-phenyl ethene microballoon causes sulfonation to be not limited only to take place at microsphere surface.
Summary of the invention
The object of the present invention is to provide a kind of preparation method of conducting polymer nano material of spherical shell structure of controllable size.
Technical scheme of the present invention is to adopt the dispersion polymerization means, selects suitable monomers, initiator and consumption thereof, by adjusting medium polarity and stabilizing agent dosage, and under suitable temperature, the synthetic controlled μ m level monodisperse polymer micro-sphere of a series of particle diameters.With this microballoon is nuclear, and under acidic medium, oxidation coats conductive polymers, and preparation has the nucleocapsid complex microsphere of conductive capability.With the microballoon of this nucleocapsid structure with the selective solvent of nuclear polymer with karyolysis, obtain monodispersed conductive polymers with spherical shell form of nano-scale.
The present invention includes following steps:
1) in the reactor that reflux and whipping appts are housed, adds stablizer Polyvinylpyrolidone (PVP) (PVP) and lower alcohol medium, logical N
2Emptying, stirring down, reaction makes the Polyvinylpyrolidone (PVP) dissolving, disposable adding is dissolved with the vinyl monomer of initiator, react under stirring polymer dispersion liquid, with the polymer dispersion liquid centrifugation, clean the stablizer and the oligopolymer of flush away polymer microballoon surface adsorption more repeatedly with industrial spirit, till the charateristic avsorption band of infrared absorption spectrum detection, with polymer microballoon vacuum-drying less than Polyvinylpyrolidone (PVP);
2) take by weighing polymer microballoon in reactor, add deionized water and make polymer microballoon account for 10%~30% of total reaction system, behind the ultra-sonic dispersion, add oxygenant, be stirred to the oxygenant dissolving, add mineral acid then, logical N
2The conductive polymers monomer is injected in emptying behind the ice-water bath, logical N
2, keep ice-water bath 12~24h, stir down and coat polymerization, the product centrifugation, and be washed till system repeatedly with deionized water and be neutrality, vacuum-drying gets monodispersed composite conductive micro-balloons with nucleocapsid structure;
3) with monodispersed selective solvent ultra-sonic dispersion and immersion with composite conductive micro-balloons of nucleocapsid structure with polymer microballoon, with the dispersion liquid centrifugation, and with this selective solvent disperse repeatedly, immersion, centrifugal, with the flush away nuclear polymer, product is separated the dry conducting polymer nano material that gets spherical shell structure.
In step 1), vinyl monomer is that ((at least a in the ester of C1~C8), concentration accounts for 10%~30% of total reaction system quality for C1~C4) ester, vinylformic acid and lower alcohol thereof for vinylbenzene, vinyl toluene, methacrylic acid and lower alcohol thereof.Initiator is organo-peroxide class, azo class etc., preferred dibenzoyl peroxide, and consumption is 0.1%~5% of a vinyl monomer quality.Stablizer is Polyvinylpyrolidone (PVP) (PVP), and consumption is 1%~15% of a vinyl monomer quality.Lower alcohol as dispersion medium is (alcohol of C1~C5) and composition thereof, preferred alcohol.The temperature of described reaction is 60 ℃~90 ℃, and preferred 75 ℃~85 ℃, the time of reaction is 6~12h, preferred 9h.
In step 2) in, the conductive polymers monomer is aniline, ring substituted aniline or pyrroles etc.,, the monomeric consumption of conductive polymers is 10%~40% of a polymer microballoon quality.Oxygenant is Potassium Persulphate or ammonium persulphate etc., and the consumption of oxygenant is 50%~250% of a conductive polymers monomer molar number.Mineral acid is hydrochloric acid or sulfuric acid etc., and the consumption of mineral acid is that to make the acid concentration of reaction system be 0.01mol/L~2.00mol/L.The temperature of reaction system is 0 ℃~25 ℃, and the reaction times is 12~24h.
In step 3), described selective solvent is decided because of the described micro polymer ball material of step 1: for the polystyrene nucleoid, selective solvent can be a kind of in aromatic hydrocarbons, halohydrocarbon, pyridine, butylacetate, butanone, pimelinketone, dioxane, naphthane, the dithiocarbonic anhydride etc.; For (methyl) esters of acrylic acid, selective solvent can be a kind of in aromatic hydrocarbons, ethyl acetate, halohydrocarbon, acetone, the tetrahydrofuran (THF) etc.
The endosphere size diameter of the conducting polymer nano material of spherical shell structure of the present invention can be regulated the control of dispersion polymerization implementation condition by changing, shell thickness can be regulated by the implementation condition that changes the oxypolymerization coating, thereby the preparation method of the conducting polymer nano material of a kind of spherical shell structure of the present invention is the controlled preparation method of nano material of a kind of nano-scale.
Description of drawings
Fig. 1 is the nucleocapsid structure microballoon of the embodiment of the invention and the pattern contrast Electronic Speculum figure of spherical shell structure.(a) for having the pattern Electronic Speculum figure of nuclear (polystyrene) shell (polyaniline) structure microballoon; (b) be polyaniline spherical shell Electronic Speculum figure.
Embodiment
Embodiment 1: add amount of monomer 10% stablizer PVP in the three-necked bottle that reflux condensing tube and mechanical stirrer are housed, medium is an ethanol, logical N
2Emptying is warming up to temperature of reaction and makes the PVP dissolving under stirring, 80 ℃ of property addings next time are dissolved with the St of 1%BPO, continue logical N
22h, stirring down, isothermal reaction 9h gets polymer dispersion liquid.With emulsion with low speed centrifuge 2500 change under centrifugation 20min, lower floor's industrial spirit ultra-sonic dispersion is centrifugal again, clean the stablizer and the oligopolymer that swim with the flush away surface repeatedly five times.Microballoon is being lower than 60 ℃ of dryings down.The polyalcohol microspherulite diameter 1.5 μ m that obtain, polydispersity index 1.049.
Take by weighing 1g polystyrene mono-dispersion microballoon in three-necked bottle, add deionized water 20ml, after ultrasonic 30min disperses, add 0.57gAPS, magnetic agitation makes it dissolving.The HCl that adds 5ml 1mol/L then, logical N
2Emptying behind the ice-water bath 30min, is injected aniline 0.182ml with microsyringe, logical N
2, keeping more than the ice-water bath 5h, reaction 12h coats polymerization under the magnetic agitation.Product low speed centrifuge centrifugation, and use the deionized water redispersion, centrifugal again, be washed till neutrality repeatedly.
The microballoon 0.2g of the nucleocapsid structure that weighing is above-mentioned with the butylacetate ultra-sonic dispersion and soaked 3, separates the dispersion liquid quiescent setting, and disperses repeatedly, soaks, separates with butylacetate, with the flush away polystyrene; Product is separated dry.
Embodiment 2: with embodiment 1, stabilizing agent dosage is 4.5%, the polyalcohol microspherulite diameter 2.491 μ m that obtain, polydispersity index 1.036.Used selective solvent is a tetrahydrofuran (THF).
Embodiment 3: with embodiment 1, stabilizing agent dosage is 3%, the polyalcohol microspherulite diameter 2.026 μ m that obtain, polydispersity index 1.061.Oxygenant is 0.675gKPS, and the aniline consumption is 0.220mL, and used selective solvent is a tetrahydrofuran (THF).
Embodiment 4: with embodiment 1, stabilizing agent dosage is 4%, and medium is a propyl carbinol, the polyalcohol microspherulite diameter 3.426 μ m that obtain, polydispersity index 1.047.Oxygenant is 0.54gKPS, and monomer is 0.138mL.Selective solvent is a tetrahydrofuran (THF).