Electroactive actuator, mechanical device including the same, and polymer electrolyte
An electroactive actuator includes a polymer electrolyte and an electrode configured to apply an electric field to the polymer electrolyte, the polymer electrolyte includes a self-assembled block copolymer including a conductive block and a non-conductive block, a compound to form a single ion conductor with the self-assembled block copolymer, and a zwitterion. A mechanical device including the electroactive actuator and a polymer electrolyte are also disclosed.
1. An electroactive actuator, comprising
a polymer electrolyte and an electrode configured to apply an electric field to the polymer electrolyte, wherein the polymer electrolyte includes a self-assembled block copolymer including a conductive block and a non-conductive block, a compound to form a single ion conductor with the self-assembled block copolymer, and a zwitterion.
2. The electroactive actuator of claim 1 , wherein the self-assembled block copolymer has a lamellar (LAM) structure, a hexagonal cylinder (HEX) structure, a gyroid (GYR) hexagonal cylinder (HEX) structure, a gyroid (GYR) structure, or a combination thereof.
3. The electroactive actuator of claim 1 , wherein the self-assembled block copolymer has a hexagonal cylinder structure.
4. The electroactive actuator of claim 1 , wherein the self-assembled block copolymer includes styrene blocks of which at least a part is sulfonated as the conductive block.
5. The electroactive actuator of claim 1 , wherein the self-assembled block copolymer includes a sulfonated styrene block as the conductive block and a degree of sulfonation is greater than or equal to about 10 mol % based on total moles of the structural units of the styrene block.
6. The electroactive actuator of claim 1 , wherein the self-assembled block copolymer includes a block including an alkylene repeating unit as the non-conductive block.
7. The electroactive actuator of claim 1 , wherein each conductive block of the self-assembled block copolymer has a weight average molecular weight of about 10 kg/mol to about 100 kg/mol.
8. The electroactive actuator of claim 1 , wherein the compound to form the single ion conductor with the self-assembled block copolymer includes a compound represented by Chemical Formula 1, a compound represented by Chemical Formula 2, or a combination thereof:
wherein, in Chemical Formula 1 and Chemical Formula 2,
R 1 and R 2 are independently hydrogen or a C1 to C30 linear or branched alkyl group.
9. The electroactive actuator of claim 1 , wherein the zwitterion includes a sulfonic acid group as an anion component.
10. The electroactive actuator of claim 1 , wherein the zwitterion is represented by Chemical Formula 3:
R 3 -L 1 -X (Chemical Formula 3)
wherein, in Chemical Formula 3,
R 3 is represented by any one of Chemical Formulae 3-1 to 3-4,
wherein, in Chemical Formulae 3-1 to 3-4,
R 4 to R 9 are independently a substituted or unsubstituted C1 to C10 alkyl group,
L 1 is a C1 to C30 alkylene group, a C2 to C30 alkenylene group including at least one double bond, or a C2 to C30 alkynylene group including at least one triple bond, and
X is SO 3 − , PO 3 − , or COO − .
11. The electroactive actuator of claim 1 , wherein the zwitterion is at least one represented by Chemical Formula 4 to Chemical Formula 6:
12. The electroactive actuator of claim 1 , wherein the compound to form the single ion conductor with the self-assembled block copolymer and the zwitterion are included in a mole ratio of about 1:3 to about 3:1 in the polymer electrolyte.
13. The electroactive actuator of claim 1 , wherein the polymer electrolyte has a dielectric constant of greater than or equal to about 10.
14. The electroactive actuator of claim 1 , wherein the polymer electrolyte has a form of a polymer thin film.
15. The electroactive actuator of claim 1 , wherein the electrode configured to apply an electric field to the polymer electrolyte is a single wall carbon nanotube (SWCNT) electrode, a multi-walled carbon nanotube (MWCNT) electrode, a PEPOT:PSS (poly(3,4-ethylenedioxythiophene) polystyrene sulfonate) conductive polymer electrode, a metal electrode, or a combination thereof.
16. A mechanical device comprising the electroactive actuator of claim 1 .
17. The mechanical device of claim 16 , wherein the mechanical device is a sensor or an artificial muscle.
18. A polymer electrolyte comprising a self-assembled block copolymer including a conductive block and a non-conductive block, a compound to form a single ion conductor with the self-assembled block copolymer, and a zwitterion, wherein a dielectric constant of the polymer electrolyte is greater than or equal to about 10.
19. The polymer electrolyte of claim 18 , wherein the self-assembled block copolymer includes styrene blocks of which at least a part is sulfonated as the conductive block and a block including an alkylene repeating unit as the non-conductive block, and has at least one structure selected from a lamellar (LAM) structure, a hexagonal cylinder (HEX) structure, a gyroid (GYR) hexagonal cylinder (HEX) structure, and a gyroid (GYR) structure.
20. The polymer electrolyte of claim 19 , wherein the compound to form the single ion conductor with the self-assembled block copolymer comprises a compound represented by Chemical Formula 1, a compound represented by Chemical Formula 2, or a combination thereof:
wherein, in Chemical Formula 1 and Chemical Formula 2,
R 1 and R 2 are independently hydrogen or a C1 to C30 linear or branched alkyl group.