Liquids for tunable optical devices
The present invention relates to an optical tuneable device comprising a volume and a polydimethylsiloxane (PDMS) membrane, wherein the membrane delimits the volume at least partially and the volume is filled with a silicone-based polymer of formula 1, with R 1 being an alkyl moiety, —(CH 2 )-phenyl, phenyl, CF 3 or alkyl-CN moiety, R 2 to R 8 being —H, an alkyl, (CH 2 )-phenyl or phenyl moiety. The polymer may optionally be substituted by —F. Furthermore, the present invention relates to the use of said polymer in an optical tuneable device.
1. An optical tuneable device comprising a volume and a membrane, wherein the membrane delimits the volume at least partially and the volume is filled with a liquid comprising at least one compound of formula 1,
wherein
each R 1 is independently from any other R 1 selected from C x -alkyl-A, particularly
each R 1 is selected from C x -alkyl-A, with
A being selected from —H, —CN, phenyl, —(CH 2 )-phenyl and —CF 3 , and
x being an integer between 3 and 20,
each R 2 is independently from any other R 2 selected from C y -alkyl, C y -alkyl-B, phenyl, —(CH 2 )-phenyl, in particular from any other R 2 selected from —H, C y -alkyl, phenyl, —(CH 2 )-phenyl, with
B being selected from —CN, phenyl, —(CH 2 )-phenyl and —CF 3 , in particular —CF 3 and —CN
y being an integer between 1 and 17
R 3 , R 4 , R 5 , R 6 , R 7 and R 8 are independently selected from —H, C 1-4 -alkyl, phenyl, and —(CH 2 )-phenyl,
n is an integer between 1 and 50,
the sum of x and y is ≤21,
and wherein
the membrane is a polydimethylsiloxane (PDMS) membrane or a substituted PDMS, in particular an unsubstituted PDMS.
2. The optical tuneable device according to claim 1 , wherein the refractive index for the compound of formula 1 is between 1.33 and 1.6.
3. The optical tuneable device according to claim 1 , wherein the viscosity of the compound of formula 1 is ≤100000 cSt.
4. The optical tuneable device according to claim 1 , wherein in case of A being —CN, x is an integer between 3 and 13.
5. The optical tuneable device according to claim 1 , wherein in case of n≥2, A is —CN in at least 50% of all R 1 .
6. The optical tuneable device according to claim 1 , wherein A is —CN for all R 1 .
7. The optical tuneable device according to claim 1 , wherein A is —H for all R 1 .
8. The optical tuneable device according to claim 1 , wherein in case of A being —H, x is an integer between 6 and 20.
9. The optical tuneable device according to claim 1 , wherein the C x -alkyl of the moiety C x -alkyl-A is linear.
10. The optical tuneable device according to claim 1 , wherein n is an integer between 1 and 10.
11. The optical tuneable device according to claim 1 , wherein n is an integer between 11 and 29.
12. The optical tuneable device according to claim 1 , wherein n is an integer between 30 and 50.
13. The optical tuneable device according to claim 1 , wherein the membrane is transparent and stable at a temperature between −40° C. and +200° C.
14. Use of a compound of formula 1 as described in claim 1 in an optical tuneable device.
15. The optical tuneable device according to claim 1 , wherein y being an integer between 1 and 6.
16. The optical tuneable device according to claim 1 , wherein R 3 , R 4 , R 5 , R 6 , R 7 and R 8 are methyl.
17. The optical tuneable device according to claim 1 , wherein R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 and R 8 are optionally substituted by one or more substituents —F.