synthesis of conjugated polymer nanoparticles in non-aqueous emulsions

Synthesis of Conjugated Polymer Nanoparticles

in Non-Aqueous Emulsionsa

Kevin Muller, Markus Klapper,* Klaus Mullen*

Max Planck Institute for Polymer Research, Ackermannweg 10, D-55128 Mainz, GermanyFax: (þ49)6131-379-100; E-mail: [email protected]; [email protected]

Received: January 12, 2006; Revised: February 1, 2006; Accepted: February 2, 2006; DOI: 10.1002/marc.200600027

Keywords: conducting polymers; nanoparticles; nanoreactors; non-aqueous polymerization; oil-in-oil emulsion

Introduction

The investigation of polymer nanoparticles is still a rapidly

developing area in science.[1] Nanoparticles prepared by

emulsion polymerization, a well-established procedure for

coatings, paints, and in flocculation processes,[2] are

increasingly used in applications in the area of photonics,

diagnostics and catalysis.[3] This can be attributed to their

well-defined morphology and their unique physical and

chemical properties such as size, optical properties, and

defined nature of the surface.[4] Of special interest are

conjugated polymer nanoparticles, which are assumed to

combine the processability and mechanical properties of

latex particles with the electronic properties of conjugated

polymers.[5] Thus, they have been investigated for applica-

tions in the fields of biomedicine, microelectronics, and in

information technology.[5]

Different strategies have been developed to form well-

defined conjugated polymer nanoparticles, including direct

synthesis of the nanoparticles in emulsion or dispersion

polymerization or by creating dissolved conjugated poly-

mer droplets via miniemulsion processes.[6] Unfortunately,

water is involved in all emulsion processes. The latex

preparation of water-sensitive monomers (e.g., acid chlor-

ides) or utilizing moisture sensitive reactions cannot be

achieved by these traditional methods. This drawback

requires the development of non-aqueous (oil-in-oil, o/o)

emulsions. Besides non-aqueous miniemulsion polymer-

izations, which use dispersed monomer droplets in a non-

aqueous continuous phase, only a few mixtures of

immiscible aprotic organic solvents, such as cyclohexane/

acetonitrile, are known.[7] To form stable oil-in-oil

emulsions, suitable surfactants had to be developed. It had

been shown that low-molecular-weight compounds are not

sufficient in their amphiphilicity, but by the previous

Summary: A novel non-aqueous emulsion system, consist-ing of cyclohexane as the continuous and acetonitrile as thedispersed phase, is described. Stabilization of the system canbe achieved by using polyisoprene-block-poly(methyl meth-acrylate) copolymers as emulsifiers. The suitability of thissystem for performing water-sensitive, catalytic, and oxida-tive polymerizations and polycondensations is demonstra-ted by the synthesis of poly(3,4-ethylenedioxythiophene),poly(thiophene-3-yl-acetic acid), and polyacetylene. In allcases spherical nanoparticles with diameters as small as23 nm can be obtained.

Macromol. Rapid Commun. 2006, 27, 586–593 � 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

586 DOI: 10.1002/marc.200600027 Communication

a : Supporting information for this article is available at thebottom of the article’s abstract page, which can be accessedfrom the journal’s homepage at http://www.mrc-journal.de, orfrom the author.

work of Riess et al. it was demonstrated that in the

presence of polystyrene-block-poly(methyl methacrylate)

(PS-b-PMMA) block copolymers cyclohexane/acetonitrile

emulsions canbe stabilized.[7]A limitationof these stabilizers

was that only cyclohexane could be dispersed in acetonitrile,

and not vise versa. However, polymerization reactions in

cyclohexane that contains micelles are not very attractive as

most of the polymers are not soluble in this solvent but in

acetonitrile as the continuous phase. This would result in a

solution of the polymer in the continuous phase but not in the

desired particle formation. To form an oil-in-oil emulsion

applicable for a polymerization reaction, the development of

a suitable surfactant to stabilize acetonitrile droplets in a

hydrocarbon phase is required.

The aim of this paper is to demonstrate a non-aqueous

emulsion process using polyisoprene-block-poly(methyl

methacrylate) (PI-b-PMMA) copolymers as emulsifiers.

The suitability of this process for performing water-

sensitive, catalytic and oxidative polymerizations in the

dispersed phase is demonstrated by the fabrication of

spherical monodisperse nanoparticles such as poly(3,4-

ethylenedioxythiophene) (PEDOT), polyacetylene, and

poly(thiophene-3-yl-acetic acid).

Experimental Part

General Remarks

All solvents and reagents were used as purchased from Acros.Cyclohexane and acetonitrile were used throughout and driedover molecular sieves (4 A). Acetylene gas dissolved inacetone was supplied in a high-pressure cylinder by Linde(Wiesbaden, Germany). 3,4-Ethylenedioxythiophene waskindly provided by H.C. Starck (Leverkusen, Germany). PI-b-PMMA copolymers were prepared using a sequentialanionic polymerization technique, described elsewhere.[8]

Gel permeation chromatography (GPC) vs. polyisoprenestandards was carried out at 30 8CusingMZ-Gel SDplus 10E6,10E4, and 500 columns, an ERC RI-101 differential refrac-tometer detector, and tetrahydrofuran (THF) as eluent. Prior tochromatography, sampleswere filtered through a 0.2mmTeflonfilter (Millipore) in order to remove particles. FT-IR spectrawere obtained by a Nicolet 730 FT-IR spectrometer using aThermo Electron Endurance ATR single-reflection ATRcrystal. Scanning electron microscopy (SEM) images weretaken by a Zeiss Gemini 912 microscope. In the samplepreparation for SEM, the nanoparticles diluted in an appro-priate solvent were drop casted on silica wafers. The averageparticle diameters were measured directly from each SEMimage. The diameters of 100 particles were measured and thevalues averaged. Dynamic light scattering (DLS) measure-ments were performed on a Malvern Zetasizer 3000.

PEDOT Nanoparticles Synthesis

PI-b-PMMA copolymer (0.530 g) was magnetically stirred incyclohexane (24 g, 285 mmol) at room temperature. Anhy-drous iron(III) chloride (1.3 g, 8 mmol) was dissolved in

acetonitrile (3 g, 73 mmol) and added dropwise to the cyclo-hexane/copolymer solution. The emulsion was formed bystirring the solution under Argon for 2 h. 3,4-Ethylenedioxy-thiophene monomer (0.500 g, 3.5 mmol) was added dropwiseand polymerization proceeded while stirring under argon for8 h. The reaction product was transferred to a separating funneland a methanol/acetonitrile (80:20 vol.-%) mixture was addedin excess to remove the emulsifier and the residual iron salts.The precipitated particles were removed by centrifugation, andwashedwith THF and acetonitrile to give 450mg of a dark bluesolid that was redispersed in cyclohexane.

Preparation of Poly(thiophene-3-yl-acetic acid)Nanoparticles

Polymerization was performed as described above, however,thiophene-3-yl-acetic acid monomer (0.500 g, 3.5 mmol) wasdissolved in acetonitrile (1 g, 24 mmol) before performing thepolymerization reaction. The precipitated particles wereremoved by centrifugation and washed with acetonitrile togive 410 mg of a yellow solid.

Synthesis of Polyacetylene Nanoparticles

PI-b-PMMA-IV diblock copolymer (0.400 g) was magneti-cally stirred in cyclohexane (24 g, 285 mmol) at roomtemperature. Sodium borohydride (0.03 g, 8 mmol), dissolvedin a mixture of acetonitrile (5 g, 120 mmol) and ethanol (0.5 g,4 mmol), was added dropwise to the cyclohexane/copolymersolution. The emulsion was formed by stirring the solutionunder argon for 2 h. Acetylene gas was passed from the supplycylinder to the reaction flask and then bubbled through theformed emulsion for 15 min. Cobalt(II) nitrate hexahydrate(0.2 g, 0.7 mmol) was dissolved in acetonitrile (1 g, 24 mmol)and added dropwise to the stirred emulsion. Polymerizationproceeded while bubbling acetylene through the reaction flaskand stirring the emulsion for 25 min. The reaction product wasplaced in a separating funnel and excess acetonitrilewas addedto remove the emulsifier and the residual iron salts. Theprecipitated particleswere removed, andwashedwith THFandacetonitrile to give 650mg of a black solid that was redispersedin cyclohexane.

Results and Discussion

Non-Aqueous Emulsion System

The strategy adopted for a non-aqueous process suitable for

the preparation of nanoparticles by moisture sensitive

polymerization reactions consists of two steps: i) Setting up

an emulsion of two immiscible organic solvents by using an

appropriate block copolymer, and ii) polymerizing polymer

nanoparticles inside the dispersed organic solvent, whereby

the dispersed droplets act as ‘nanoreactors’. Anhydrous

organic solvents would allow one to perform water-sensi-

tive polymerizations inside the ‘nanoreactors’ and to

produce nanoparticles without involving water in one of

the phases.

Synthesis of Conjugated Polymer Nanoparticles in Non-Aqueous Emulsions 587

Macromol. Rapid Commun. 2006, 27, 586–593 www.mrc-journal.de � 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

Acetonitrile is a suitable solvent for conjugated polymer

synthesis, because of its high dielectric constant, and has

been selected to be emulsified in a second organic solvent.

As a result of its immiscibility with acetonitrile, cyclo-

hexane was chosen as an appropriate continuous phase. As

mentioned above, it is not possible to obtain acetonitrile in

cyclohexane emulsions by using PS-b-PMMA copolymers,

as the solubility of the polystyrene sequence in cyclohexane

is too low at ambient temperatures.[9] Therefore, PI-b-

PMMA is chosen as an emulsifier, as polyisoprene is known

for its higher solubility in cyclohexane in comparison to

polystyrene, and PMMA is known for its insolubility in

cyclohexane but its excellent solubility in acetonitrile.[9] To

establish the appropriate emulsion conditions, several block

copolymers are anionically synthesized and their applic-

ability as emulsifier investigated (Table 1).

Cyclohexane (24 g) is mixed with the copolymer (0.5 g)

and acetonitrile (3 g) and then emulsified by stirring and

ultrasonification. It appears that only copolymers having a

PI/PMMA ratio of at least 1:1 and a molecular weight of

8 000 g �mol�1 produce stable emulsions. Successful

emulsion of the two phases is proven by DLS, which shows

the formation of acetonitrile ‘nanoreactors’, which have a

typical size distribution from 20 to 70 nm (polymer IV,

Figure 1). These results are consistentwith the findings of the

previous work of Riess et al. wherein it was demonstrated

that oil-in-oil emulsions have lower interfacial tensions

compared to oil-in-water systems and, therefore, only block

copolymers of relatively highmolecular weights are suitable

to stabilize oil-in-oil emulsions.[7]

Synthesis of Conjugated Polymer Nanoparticles

Polymerization of Poly(3,4-ethylenedioxythiophene)Nanoparticles

Polymerization reactions inside the dispersed acetonitrile

‘nanoreactors’ are investigated. To obtain conjugated

polymer nanoparticles the oxidative polymerization of

3,4-ethylenedioxythiophene (EDOT) is chosen. EDOT

shows a good solubility in cyclohexane as well as in

acetonitrile and can be polymerized using iron(III) salts as

oxidants.[10] Because of the presence of its nitrile groups,

acetonitrile is suitable to complex iron(III) ions, whereas

these ions are insoluble in cyclohexane. One can safely

assume that polymerization only occurs in the dispersed

acetonitrile phase since only in these ‘‘nanoreactors’’

monomer and oxidant are both present.

The EDOT monomer is successfully polymerized using

iron(III) chloride as the oxidant, cyclohexane as the

continuous phase, and different PI-b-PMMA copolymers

as emulsifiers (Table 2). The obtained nanoparticles are

precipitated upon addition of excess methanol/acetonitrile.

FT-IR spectroscopy of the particles show the characteristic

ring vibration of the thiophene ring at 1 470 cm�1 and of

PEDOT at 1 355 cm�1, which can be attributed to the

quinoidal C–C and C C structure. Further vibrations at

1 186, 1 139, and 1 080 cm�1 are assigned to the C–O–C

bond stretching, whereby the C–S bond vibrations in the

thiophene ring is found at 990, 840, and 695 cm�1.[11] As

both blocks of the PI-b-PMMA copolymer are completely

soluble in THF, it is possible to obtain pure PEDOT

nanoparticles upon washing the precipitate with THF. FT-

IR spectra of the pure nanoparticles display no carbonyl

bands, which would indicate the presence of residual PI-b-

PMMA copolymer. One could, therefore, conclude that the

emulsifier has been removed from the nanoparticle surface.

The commonly observed drawback of dispersion polymeri-

zation to obtain conducting polymer nanoparticles is the

difficult removal of the polymeric stabilizer from the

particle surface after polymerization. The residual copoly-

mer shell, however, keeps the obtained nanoparticles apart

and the charge carrier percolation pathways between the

particles are interrupted.[12]

The obtained nanoparticles have a sphericalmorphology.

For all the prepared samples, the number average diameters

are found to be smaller than 30 nm (Figure 2, Table 2).

This is calculated directly from the SEM images based on

100 particles.

By comparing the diameter of the obtained PEDOT

nanoparticles with those of the dispersed acetonitrile

Table 1. Investigated PI-b-PMMA copolymers.

Copolymer Mn PIa) Mn PMMAa) PI/PMMA Mn total

a) Dispersity Mean dropletsizeb)

g �mol�1 g �mol�1 ratio g �mol�1 nm

PI-b-PMMA I 7 500 27 500 0.3/1 35 000 1.4 Phase separationPI-b-PMMA II 3 000 4 000 0.8/1 7 000 1.3 Phase separationPI-b-PMMA III 15 500 15 500 1/1 31 000 1.1 58PI-b-PMMA IV 5 500 2 500 2/1 8 000 1.2 37PI-b-PMMAV 15 500 7 000 2/1 22 500 1.2 42PI-b-PMMAVI 23 000 7 000 3/1 30 000 1.3 32

a) By GPC vs polyisoprene standard in THF.b) By DLS.

588 K. Muller, M. Klapper, K. Mullen


droplets as measured by DLS it becomes apparent that the

obtained particles are always much smaller than the dis-

persed acetonitrile droplets. This can easily be explained by

the fact that in the case of the stabilized droplets, the

diameter is determined by the amount of acetonitrile

inside the micelle and by the surrounding block copolymer,

while the formed PEDOT nanoparticles are only deter-

mined by the amount of conjugated polymer without the

solvent and the stabilizer. As the obtained PEDOT nano-

particles show a spherical shape and as the used oxidant is

not soluble in the cyclohexane phase, one can assume that

the polymerization takes place only inside the dispersed

acetonitrile droplets (‘nanoreactors’), which indicates a

miniemulsion mechanism (Figure 3). However, as the

monomer diffuses into the nanoreactors during polymer-

ization, the process could also be described as an emulsion

polymerization. Therefore, the mechanism cannot be

unambiguously assigned to either an emulsion or a

miniemulsion process.

The polymerization of PEDOT nanoparticles success-

fully shows that polymerizations of polymer nanoparticles

can be performed in a non-aqueous emulsion system.

Because of this result, the applicability of the present

emulsion system to other moisture sensitive polymer-

izations is investigated.

Polymerization of FunctionalizedPoly(thiophene) Nanoparticles

In previous studies it has been shown that functionalized

polypyrrole lattices can be used asmarker particles invisual

agglutination immunodiagnostic assays for the pregnancy

hormone hCG, the hepatitis B surface antigen, and the HIV

antibody.[13] However, functionalization of the latex

involves multistep procedures and several transfers

between aqueous and non-aqueous solvents, which make

the production of functionalized conjugated nanoparticles

difficult.[14] This raises the question whether the poly-

merization of thiophene-3yl-acetic acid (TAA) can be

achieved by the described non-aqueous emulsion system,

especially as TAA can only be polymerized in the absence

of water.[15]

The use of anhydrous iron(III) chloride as oxidant allows

the successful TAA polymerization inside the acetonitrile-

filled micelles dispersed in cyclohexane. The presence of

Figure 1. DLS measurement of 3 g of acetonitrile dispersed in 24 g of cyclohexane, using0.5 g of PI-b-PMMA-IV copolymer as emulsifier. Emulsification was achieved by stirring(20 min) and ultrasonification (3 min).

Table 2. Characteristics of EDOT polymerizations in non-aqueous acetonitrile/cyclohexane emulsion, polymerizationsperformed in 24 g of cyclohexane and 3 g of acetonitrile.

Sample Emulsifier EDOT Fe(Cl)3 Meanparticle

diameterb)

Type %a) mmol mol-%per EDOT

nm

I PI-b-PMMA IV 1.5 3.4 197 30 (�13)II PI-b-PMMAV 2.2 3.7 186 23 (�6)III PI-b-PMMAV 1.9 3.7 186 23 (�7)IV PI-b-PMMAVI 1.9 3.7 230 24 (�5)

a) Wt.-% of cyclohexane.b) Determined by SEM.



Figure 2. SEM images of the PEDOT nanoparticles; a) and b) sample II, c) sample III.

Figure 3. Preparation of PEDOT nanoparticles in a non-aqueous emulsion.



the carboxylic acid group is demonstrated by FT-IR

spectroscopy, which reveals the characteristic COOH

vibration at 1 729 cm�1. The shape of the obtained particles

is characterized by SEM. A spherical geometry is observed

with an average diameter of 28 nm (�5 nm). Compared to

the traditional synthetic method that includes post func-

tionalization of the particle surface, the polymerization can

now be performed in one-step without transferring the

particles between solvents of different polarity. This

promises a facile procedure for developing novel immuno-

diagnostic assays.

Polymerization of Polyacetylene Nanoparticles

The metallic conductivity of doped polyacetylene has

generated much attention in this simplest of all conjugated

polymers.[16] However, because of its insolubility and

inherent instability in both the pristine and doped state under

ambient conditions, a successful application of this polymer

is still lacking.[16] Producing polyacetylene latex nanopar-

ticles would offer not only novel processing pathways, but

would also allow the utilization of these particles as pigment

materials and anti-static additives in various inert polymer

matrices. The matrix would protect the nanoparticles

from atmospheric oxidation while retaining most of the

desired electrical properties. To the best of our knowledge,

only two approaches for obtaining polyacetylene nanopar-

ticles have been performed.[17] In both cases, it is only

possible to obtain polyacetylene nanoparticles that have

diameters over 100 nm and possess a corona of sterically

demanding stabilizers around the particles. Unfortunately,

because of the protection by the residual emulsifier shell,

doping of conjugated polymer nanoparticles is difficult to

achieve.[18]

The approach to obtain polyacetylene nanoparticles here

is to polymerize acetylene in the above described non-

aqueous emulsion system using a Luttinger catalyst

system.[19] The Luttinger catalyst system is chosen since

polyacetylene prepared by this method exhibits a higher

stability towards oxygen than polyacetylene prepared by the

original Shirakawamethod.[20] Thereby, the cobalt(II) nitrate

and sodium borohydride based Luttinger catalyst system is

enclosed in the dispersed acetonitrile droplets. Polymer-

ization is achieved at room temperature upon a flow of

acetylene gas through the stirred emulsion. FT-IR spectro-

scopy of the polyacetylene particles shows the trans-C–H

out-of-plane deformation band at 1 012 cm�1 and the cis-C–

H out-of-plane deformation band at 749 cm�1, which

indicates that cis/trans polyacetylene is obtained. This result

is consistent with the cis-openingmechanism as proposed by

Ikeda and co-workers,[20] and is typical for polyacetylene

polymerized at ambient temperature.

IR spectroscopy demonstrates that the emulsifier shell no

longer encloses the polyacetylene nanoparticles. After

washing, the very intense carbonyl band from the PMMA

sequence of the PI-b-PMMA emulsifier is not observed in

the IR spectra (sensitivity of the method <1%, Supporting

Information, Figure 2).

A typical SEM image of the particles obtained using the

non-aqueous emulsion procedure is presented in Figure 4.

Figure 4. SEM image of polyacetylene nanoparticles, using PI-b-PMMA IVas emulsifier.



The particles show a nearly spherical geometry and a

narrow particle size distribution. The number-average

diameter of the particles is found to be 43 nm (�10 nm).

Experiments are currently underway to examine the

doping behavior of the polyacetylene particles. It is

expected that because of the absence of an emulsifier shell,

the doping reactions can be performed successfully.

Conclusion

A novel oil-in-oil emulsion system, stabilized by a PI-b-

PMMA block copolymer, is presented and the versatile

fabrication of polymer nanoparticles is described. One of the

particularly important advantages of the developed emulsion

procedure is the use of non-aqueous solvents, which facilitate

moisture sensitive catalytic or oxidative polymerizations. In

addition, the remarkable suitability of the stabilized aceto-

nitrile ‘nanoreactors’ for the preparation of spherical PEDOT,

poly(thiophene-3-yl-acetic acid), and polyacetylene nano-

particles, havingaveragediameters as lowas 23 nm, is shown.

In the case of THF-insoluble polymers, it is further

demonstrated that the emulsifier could be removed from the

particle surface by washing with THF. This leads to

nanoparticles of conjugated polymers without an emulsifier

shell, which is necessary for obtaining an undisturbed charge

carrier percolation pathway between the nanoparticles.

Conjugated polymer nanoparticles prepared according to

this route are expected to find many applications, such as

antistatic pigments, materials for radio frequency identi-

fication technologies, and in building up novel immuno-

diagnostic devices.

The emulsion processes described here are anticipated to

be adaptable for polymerizing a broad variety of monomers

to form polymer nanoparticles in the absence of water.

Examples currently under investigation are the catalytic

polymerization of olefins, the transition-metal catalyzed

polymerization of halogen-substituted aromatic com-

pounds, and the polycondensation reaction of diacid

chlorides with diols and diamines. While particles of the

materials obtained by these processes are already accessible

in the size range of mm to mm by suspension processes, this

newmethod offers the opportunity to obtain them one order

of magnitude smaller. Another aspect is the formation of

core-shell structures. Up to now core–shell structures are

typically formed in emulsion by the sequential addition of

monomers that can only be polymerized by free radical

polymerization. This new system should also offer the

opportunity to incorporate polycondensates as a rigid core

thus making new spherical multi-layer structures acces-

sible.

Acknowledgements: 3,4-Ethylenedioxythiophene was kindlyprovided by H. C. Starck (Leverkusen, Germany).

[1] F. Caruso, R. A. Caruso, H. Mohwald, Science 1998, 282,1111.

[2] [2a] D. I. Lee,Prog.Org. Coat. 2002, 45, 341; [2b] Z. G. Yan,Y. L. Deng, Chem. Eng. J. 2000, 80, 31.

[3] [3a] M. Koch, M. Stork, M. Klapper, K. Mullen,Macromolecules 2000, 33, 7713; [3b] M. Koch, A.Falcou, N. Nenov, M. Klapper, K. Mullen,Macromol. RapidCommun. 2001, 22, 1455; [3c] T. A. Taton, C. A. Mirkin,R. L. Letsinger, Science 2000, 289, 1757; [3d] E.Hutter, J. H.Fendler, Adv. Mater. 2004, 16, 1686.

[4] [4a] A. P. Alivisatos, Science 1996, 271, 933; [4b] Z. Tang,N. A. Kotov, Adv. Mater. 2005, 17, 951; [4c] V. I. Klimov, A.A. Mikhailovsky, S. Xu, A. Malko, J. A. Hollingsworth, C.A. Leatherdale, H.-J. Eisler, M. G. Bawendi, Science 2000,290, 314.

[5] [5a] X. Gao, Y. Cui, R. M. Levenson, L. W. K.Chung, S. Nie, Nat. Biotechnol. 2004, 22, 969; [5b] M.Bruchez, M. Moronne, P. Gin, S. Weiss, A. P. Alivisatos,Science 1998, 281, 2013; [5c] A. Morrin, F. Wilbeer,O. Ngamna, A. J. Killard, S. E. Moulton, M. R. Smyth,G. G. Wallace, Electrochem. Commun. 2005, 7, 317; [5d] B.Miksa, S. Slomkowski, Colloid Polym. Sci. 1995, 273,47; [5e] S. P. Armes, ‘‘Conducting Latex Particles’’in Handbook of Conducting Polymers, 2nd edition,T. A. Skotheim, Ed., Marcel Dekker, New York 1998,p. 423 ff.

[6] [6a] T. Kietzke, D. Neher, K. Landfester, R. Montenegro,R. Gunter, U. Scherf, Nat. Mater. 2003, 2, 408; [6b] X.Wang, J. Zhuang, Q. Peng, Y. Li, Nature 2005, 437, 121;[6c] J. Jang, J. H. Oh, G. Stucky,Angew. Chem. Int. Ed. 2002,41, 4016; [6d] O. Quadrat, J. Stejskal, C. Klason, J. Kubat,D. H. McQueen, J. Phys. Condens. Matter. 1995, 7,3287.

[7] [7a] K. Landfester, M. Willert, M. Antonietti, Macromole-cules 2000, 33, 2370; [7b] G. Riess, C. Labbe, Macromol.Rapid Commun. 2004, 25, 401; [7c] G. Riess, Prog. Polym.Sci. 2003, 28, 1107; [7d] J. Periard, A. Banderet, G. Riess,Polym. Lett. 1970, 8, 115.

[8] [8a] O. Tcherkasskaya, J. G. Spiro, S. Ni, M. A. Winnik,J. Phys. Chem. 1996, 100, 7114; [8b] S. Ni, P. Zhang,Y. Wang, M. A. Winnik, Macromolecules 1994, 27,5742.

[9] D. R. Bloch, ‘‘Solvents and Non Solvents for Polymers’’, inPolymerHandbook, 4th edition, J. Brandrup, E.H. Immergut,E. A. Grulke, Eds., J. Wiley & Sons, New York 1999, p. VII/497 ff.

[10] [10a] S. Kirchmeyer, K. Reuter, J. Mater. Chem. 2005, 15,2077; [10b]M.Lefebvre, Z.Qi,D.Rana, P.G. Pickup,Chem.Mater. 1999, 11, 262.

[11] [11a] K. I. Seo, I. J. Chung, Polymer 2000, 41, 4491;[11b] C. Kvarnstrom, H. Neugebauer, S. Blomquist, H. J.Ahonen, J. Kankare, A. Ivaska, Electrochim. Acta 1999, 44,2739.

[12] S. P. Armes, Curr. Opin. Colloid Interface Sci. 1996, 2,214.

[13] [13a] US 5 252 459 (1993), invs.: P. J. Tarcha, M.Wong, J. J.Donovan; [13b] M. R. Pope, S. P. Armes, P. J. Tarcha,Bioconjugate Chem. 1996, 7, 436.

[14] G. P. McCarthy, S. P. Armes, S. J. Greaves, J. F. Watts,Langmuir 1997, 13, 3686.

[15] K. H. Hsieh, K. S. Ho, Y. Z. Wang, S. D. Ko, S. C. Fu, Synth.Met. 2001, 123, 217.

[16] [16a] H. Shirakawa,Angew. Chem. 2001, 113, 2643; [16b] T.Ito, H. Shirakawa, S. Ikeda, J. Polym. Sci., Polym. Chem. Ed.1974, 12, 11.



[17] [17a] J. Edwards, R. Fisher, B. Vincent, Makromol. Chem.,Rapid Commun. 1983, 4, 393; [17b] J. O. Krause, U. Anders,R. Weberskirch, O. Nuyken, M. R. Buchmeiser, Angew.Chem. 2003, 115, 6147.

[18] S. P. Armes, B. Vincent, Synth. Met. 1988, 25, 171.

[19] [19a] L. B. Luttinger, J. Org. Chem. 1962, 27, 1591; [19b] V.Enkelmann, G. Lieser, W. Muller, G. Wegner, Angew.Makromol. Chem. 1981, 94, 105; [19c] J. Frohner, L.Wuckel, Acta Polym. 1987, 6, 334.

[20] T. Ito, H. Shirakawa, S. Ikeda, Polym. J. 1971, 2, 231.



synthesis of conjugated polymer nanoparticles in non-aqueous emulsions

Documents