REPLACING AQUEOUS WITH NON-AQUEOUS SOLVENT
Disclosed are methods of dispersing sulfonated polythiophenes in a non-aqueous solvent including replacing water for organic solvent without precipitation of the polythiophene. Once dispersed in a non-aqueous solvent, the sulfonated polythiophene can be mixed with a matrix polymer. The materials can be used in organic electronic devices including OLEDs and OPVs. The solvent processes can improve the viscosity properties. Sulfonated regioregular polythiophenes can be used. A benefit is improved solvent compatibility in building organic electronic devices and improved ability to formulate with matrix materials.
1 . A method comprising:
i) providing at least one sulfonated polythiophene in at least one aqueous dispersion;
ii) adding at least one non-aqueous solvent to the dispersion to provide a mixture, wherein the sulfonated polythiophene remains dispersed in the mixture; and
iii) removing water from the mixture.
2 . The method of claim 1 , wherein the sulfonated polythiophene comprises a sulfonated regioregular polythiophene.
3 . The method of claim 1 , wherein the sulfonated polythiophene comprises a sulfonated regioregular polythiophene comprising alkyleneoxy substituent, polyether substituent, or combinations thereof.
4 . The method of claim 1 , wherein the aqueous dispersion comprises about 0.1 wt. % to about 8 wt. % of the sulfonated polythiophene.
5 . The method of claim 1 , wherein the non-aqueous solvent comprises methyl-2-pyrrolidone (“NMP”), dimethyl sulfoxide (“DMSO”), dimethylformamide (“DMF”), tetrahydrofuran (“THF”), 1-methoxy-2-propanol acetate (“PMA”), chloroform, a glycol, a glycol ether, or mixtures thereof.
6 . The method of claim 1 , wherein the non-aqueous solvent comprises methyl-2-pyrrolidone (“NMP”), dimethyl sulfoxide (“DMSO”), and dimethylformamide (“DMF”).
7 . The method of claim 1 , wherein the amount of non-aqueous solvent added to the aqueous dispersion is about 80 wt. % to about 120 wt. % of the aqueous dispersion.
8 . The method of claim 1 , wherein step iii) comprises removing water under reduced pressure.
9 . The method of claim 1 , wherein step iii) comprises removing water under a pressure of no more than about 100 mm Hg.
10 . The method of claim 1 , wherein step iii) comprises heating the mixture.
11 . The method of claim 1 , wherein step iii) comprises heating the mixture to at least about 40° C.
12 . The method of claim 1 , wherein step iii) comprises heating the mixture under reduced pressure.
13 . The method of claim 1 , wherein step iii) comprises heating the mixture to at least about 40° C. under a pressure of no more than about 100 mm Hg.
14 . The method of claim 1 , wherein step iii) comprises heating the mixture to a first temperature and then heating the mixture to a second temperature that is at least about 5 C.° higher than the first temperature.
15 . The method of claim 1 , wherein water in the aqueous dispersion of step i) is reduced by at least 80% by weight.
16 . The method of claim 1 , further comprising a step iv), wherein step iv) comprises repeating steps ii) and iii) at least once.
17 . The method of claim 1 , further comprising a step iv), wherein step iv) comprises repeating steps ii) and iii) at least once, and wherein water in the aqueous dispersion from step i) is reduced by at least 90% by weight.
18 . The method of claim 1 , further comprising a step iv), wherein step iv) comprises repeating steps ii) and iii) at least once, and wherein the amount of non-aqueous solvent added to the mixture when step ii) is repeated is about 5 wt. % to about 50 wt. % of the mixture.
19 . The method of claim 1 , further comprising a step iv), wherein step iv) comprises combining the mixture from step iii) with a matrix polymer.
20 . The method of claim 1 , further comprising steps iv) and v), wherein step iv) comprises repeating steps ii) and iii) at least once, and wherein step v) comprises combining the mixture from step iv) with a matrix polymer.
21 . A method comprising:
i) providing at least one sulfonated regioregular polythiophene in an aqueous dispersion; and
ii) adding a non-aqueous solvent to the dispersion to provide a mixture, wherein the sulfonated regioregular polythiophene remains dispersed in the mixture;
iii) removing water from the mixture.
22 . The method of claim 21 , wherein the sulfonated regioregular polythiophene comprises a sulfonated polythiophene comprising alkyleneoxy or polyether substituent groups.
23 . The method of claim 21 , wherein the aqueous dispersion comprises about 0.1 wt. % to about 8 wt. % of the sulfonated regioregular polythiophene.
24 . The method of claim 21 , wherein the non-aqueous solvent comprises methyl-2-pyrrolidone (“NMP”), dimethyl sulfoxide (“DMSO”), dimethylformamide (“DMF”), tetrahydrofuran (“THF”), 1-methoxy-2-propanol acetate (“PMA”), chloroform, a glycol, glycol ether, or mixtures thereof.
25 . The method of claim 21 , wherein the amount of non-aqueous solvent added to the aqueous dispersion is about 80 wt. % to about 120 wt. % of the aqueous dispersion.
26 . The method of claim 21 , wherein step iii) comprises removing water under reduced pressure.
27 . The method of claim 21 , wherein step iii) comprises heating the mixture.
28 . The method of claim 21 , wherein water in the aqueous dispersion of step i) is reduced by at least 80% by weight.
29 . The method of claim 21 , further comprising a step iv), wherein step iv) comprises repeating steps ii) and iii) at least once.
30 . The method of claim 21 , further comprising a step iv), wherein step iv) comprises combining the mixture from step iii) with a matrix polymer.
31 . A method comprising:
i) providing at least one sulfonated polythiophene in an aqueous dispersion;
ii) adding a non-aqueous solvent to the dispersion to provide a mixture, wherein the sulfonated polythiophene remains dispersed in the mixture; and
iii) exposing the mixture to vacuum, wherein the relative water content of the mixture increases with exposure to vacuum.
32 . The method of claim 31 , wherein the sulfonated polythiophene is not associated with a doping polymer.
33 . The method of claim 31 , wherein the aqueous dispersion does not comprise PEDOT or PEDOT:PSS.
34 . The method of claim 31 , wherein the method increases the viscosity of the dispersion of polythiophene.
35 . The method of claim 31 , wherein a matrix material is blended into the sulfonated polythiophene.
36 . The method of claim 31 , wherein a matrix polymer is blended into the sulfonated polythiophene which is soluble in the non-aqueous solvent.
37 . The method of claim 31 , wherein the water content increasing results from azeotropic removal of water.
38 . The method of claim 31 , wherein the non-aqueous solvent is a polar, aprotic solvent.
39 . The method of claim 31 , wherein the method is used to formulate an ink for a hole injection layer, hole collection, or hole transport layer.
40 . The method of claim 31 , wherein the sulfonated polythiophene is mixed with a hole transport material.
41 . A composition prepared by the method comprising:
i) providing at least one sulfonated polythiophene in an aqueous dispersion;
ii) adding a non-aqueous solvent to the dispersion to provide a mixture, wherein the sulfonated polythiophene remains dispersed in the mixture;
iii) removing water from the mixture to provide a non-aqueous dispersion of the sulfonated polythiophene; and
iv) combining the non-aqueous dispersion with a matrix polymer to form the composition.
42 . The method of claim 41 , wherein the sulfonated polythiophene comprises a sulfonated poly(3-(alkoxy)thiophene).
43 . The method of claim 41 , wherein the sulfonated polythiophene comprises a sulfonated poly(3-(methoxyethoxyethoxy)thiophene).
44 . The method of claim 41 , wherein the aqueous dispersion comprises about 0.1 wt. % to about 8 wt. % of the sulfonated polythiophene.
45 . The method of claim 41 , wherein the non-aqueous solvent comprises methyl-2-pyrrolidone (“NMP”), dimethyl sulfoxide (“DMSO”), dimethylformamide (“DMF”), tetrahydrofuran (“THF”), 1-methoxy-2-propanol acetate (“PMA”), chloroform, or mixtures thereof.
46 . The method of claim 41 , wherein the non-aqueous solvent comprises methyl-2-pyrrolidone (“NMP”), dimethyl sulfoxide (“DMSO”), and dimethylformamide (“DMF”).
47 . The method of claim 41 , wherein the amount of non-aqueous solvent added to the aqueous dispersion is about 80 wt. % to about 120 wt. % of the aqueous dispersion.
48 . A composition prepared by the method comprising:
i) providing at least one sulfonated regioregular polythiophene in an aqueous dispersion;
ii) adding a non-aqueous solvent to the dispersion to provide a mixture, wherein the sulfonated regioregular polythiophene remains dispersed in the mixture;
iii) removing water from the mixture to provide a non-aqueous dispersion of the sulfonated regioregular polythiophene; and
iv) combining the non-aqueous dispersion with a matrix polymer to form the composition.
49 . A composition prepared by the method of claim 1 , 21 , or 31 .