Short-chain fluorosurfactants with iodide additives for forming silver nanowire-based transparent conductive films

1. A purified surfactant formulation comprising

(1) a short-chain fluorosurfactant represented by Formula (I):

(2) an impurity represented by Formula (II) at an amount of less than about 3% by weight of the short-chain fluorosurfactant,

 and

(3) an iodide additive providing iodide at an amount of about 0.5-2.5% of the short-chain fluorosurfactant, wherein:

m is 0, 1, 2, 3, 4 or 5;

n is 1, 2, 3, or 4;

X is —O—; —S—; or a direct bond;

Y is hydrogen, —OH or fluoro;

Z is —CH 3 , —CH 2 F, —CHF 2 or —CF 3 ;

M + is Li + , Na + , K + , H + or NH 4 + ; and

R 1 , R 2 , R 3 , R 4 and R 5 , at each occurrence, are the same or different and independently fluoro or hydrogen.

2. The purified surfactant formulation of claim 1 , wherein the short-chain fluorosurfactant of Formula (I) has no more than 6 fluoro-bearing carbons.

3. The purified surfactant formulation of claim 1 , wherein X is a direct bond.

4. The purified surfactant formulation of claim 1 , wherein Y is —OH.

5. The purified surfactant formulation of claim 1 , wherein Z is —CF 3 .

6. The purified surfactant formulation of claim 1 , wherein m is 6 and n is 2.

7. The purified surfactant formulation of claim 1 , wherein the impurity represented by Formula (II) is less than about 0.4% of the short-chain fluorosurfactant.

8. The purified surfactant formulation of claim 1 , wherein the iodide in the purified surfactant formulation is about 0.6-2.4% by weight of the short-chain fluorosurfactant.

9. A two-part kit for coating silver nanowires, comprising:

(1) a first container including a nanowire formulation including:

a) a plurality of silver nanowires;

b) a viscosity modifier;

c) an optional dispersant; and

d) a liquid carrier including water;

(2) a second container including a purified surfactant formulation of any one of claims 1 - 8 , wherein:

the nanowire formulation comprises silver ions at an amount of 0.005-0.02% per 1% of the silver nanowires by weight; and

the purified surfactant formulation comprises iodide ions at an amount of about equimolar of the silver ions of the nanowire formulation.

10. The two-part kit of claim 9 , wherein a ratio of iodide ions and the silver ions is about 0.98:1-1.3:1.

11. The purified surfactant formulation of claim 2 , wherein X is a direct bond.

12. The purified surfactant formulation of claim 2 , wherein Y is —OH.

13. The purified surfactant formulation of claim 2 , wherein Z is —CF3.

14. The purified surfactant formulation of claim 2 , wherein m is 6 and n is 2.

15. The purified surfactant formulation of claim 2 , wherein the impurity represented by Formula (II) is less than about 0.4% of the short-chain fluorosurfactant.

16. The purified surfactant formulation of claim 2 , wherein the iodide in the purified surfactant formulation is about 0.6-2.4% by weight of the short-chain fluorosurfactant.

17. The purified surfactant formulation of claim 3 , wherein Y is —OH.

18. The purified surfactant formulation of claim 3 , wherein Z is —CF 3 .

19. The purified surfactant formulation of claim 1 , wherein m is 6 and n is 2.

20. The purified surfactant formulation of claim 1 , wherein:

the short-chain fluorosurfactant of Formula (I) has no more than 6 fluoro-bearing carbons;

X is a direct bond;

Y is —OH;

Z is —CF 3 ;

m is 6 and n is 2;

the impurity represented by Formula (II) is less than about 0.4% of the short-chain fluorosurfactant; and

the iodide in the purified surfactant formulation is about 0.6-2.4% by weight of the short-chain fluorosurfactant.