Microphase separation of block copolymer bottlebrushes
Provided herein are microphase-separated materials including a plurality of block copolymers tethered together at their A-B junction points. The tethered-together block copolymers, referred to as a block copolymer bottlebrush, provide microphase-separated materials having smaller domain spacing than previously achievable using block copolymer systems.
1. A composition comprising:
a material comprising a block copolymer bottlebrush, wherein the block copolymer bottlebrush comprises a backbone and a plurality of A n B m block copolymers, with n≧1 and m≧1, wherein each of the plurality of A n B m block copolymers comprises at least one block of an A polymer joined at an A-B junction to at least one block of a B polymer and is covalently linked to the backbone at the A-B junction, and wherein the material is microphase-separated into periodic domains of the A polymer and the B polymer.
2. The composition of claim 1 , wherein the domain size is smaller than the minimum domain size of an AB diblock copolymer material that is microphase separated into periodic domains of the A polymer and the B polymer, the AB diblock copolymer material comprising a plurality of AB diblock copolymers, each of which comprises one block of the A polymer and one block of the B polymer, that are not linked to a backbone.
3. The composition of claim 2 , wherein the domain size is at least 25% smaller than the minimum domain size of the AB diblock copolymer material.
4. The composition of claim 1 , wherein the material is in a thin film.
5. The composition of claim 1 , wherein material is a bulk-phase material.
6. The composition of claim 1 , further comprising a substrate underlying the material, wherein the periodic domains are oriented perpendicular to the substrate.
7. The composition of claim 1 , wherein the A n B m block copolymers are symmetric AB diblock copolymers.
8. The composition of claim 1 , wherein the A n B m block copolymers are asymmetric AB diblock copolymers.
9. The composition of claim 1 , wherein the A n B m block copolymers are A 2 B block copolymers.
10. The composition of claim 1 , wherein the A n B m block copolymers are A 2 B 2 block copolymers.
11. A composition comprising:
a microphase-separated block copolymer material comprising a plurality of AB diblock copolymers, each of which comprises one block of an A polymer and one block of a B polymer, characterized by the segmental interaction parameter χ AB , wherein the AB diblock copolymers in the microphase-separated block copolymer material have an average degree of polymerization N n such that χ AB N n is less than 7.5, and wherein the microphase-separated block copolymer material is microphase-separated into periodic domains of the A polymer and the B polymer.
12. The composition of claim 11 , wherein the AB diblock copolymers in the microphase-separated material have an average degree of polymerization N n such that χ AB N n is less than 5.
13. The composition of claim 11 , wherein the AB diblock copolymers in the microphase-separated material have an average degree of polymerization N n such that χ AB N n is less than 4.
14. A composition comprising:
a microphase-separated block copolymer material comprising a plurality of AB diblock copolymers, each of which comprises one block of an A polymer and one block of a B polymer, characterized by the segmental interaction parameter χ AB and wherein the AB diblock copolymers in the microphase-separated material are microphase-separated into periodic lamellae having a lamellar spacing of less than 3.8×1.096a AB χ −1/2 .
15. The composition of claim 14 , wherein the periodic lamellae in the microphase-separated material have a lamellar spacing of less than 3×1.096a AB χ −1/2 .