Patterning nano-scale patterns on a film comprising unzipping copolymers
The invention concerns a method for patterning a surface of a material. A substrate having a polymer film thereon is provided. The polymer is a selectively reactive polymer (e.g., thermodynamically unstable): it is able to unzip upon suitable stimulation. A probe is used to create patterns on the film. During the patterning, the film is locally stimulated for unzipping polymer chains. Hence, a basic idea is to provide a stimulus to the polymeric material, which in turn spontaneously decomposes e.g., into volatile constituents. For example, the film is thermally stimulated in order to break a single bond in a polymer chain, which is sufficient to trigger the decomposition of the entire polymer chain.
1. An imaging medium comprising a single layer of a polymer film, the single layer of film comprising:
polymer chains which can be unzipped upon stimulation; and
nano-scale dimensioned patterns in the film, wherein the polymer chains comprise copolymers derived from two or more monomers, one of the monomers being a dialdehyde compound, and wherein the nano-scale dimensioned patterns are obtained according to a method comprising stimulating the film with a nano-scale dimensioned probe for selectively triggering an unzipping reaction of the polymer chains of the film to provide the nano-scale dimensioned patterns, wherein the polymer chains are configured to produce volatiles upon the stimulation to define the nano-scale dimensioned patterns.
2. The medium of claim 1 , wherein said one of the monomers is a phthalaldehyde compound.
3. The medium of claim 1 , wherein polymer chains comprise copolymers of phthalaldehyde compounds and benzaldehyde compounds.
4. The medium of claim 3 , wherein at least some of the benzaldehyde compounds in the polymer chains of the polymer film provided are functionalized benzaldehyde compounds.
5. The medium of claim 1 , wherein at least some of the polymer chains comprise block copolymers of two or more homopolymer units, one of the homopolymer units deriving from the dialdehyde compound.
6. The medium of claim 5 , wherein said at least some of the polymer chains of the polymer film provided are ordered by way of another one of the homopolymer units substantially more stable than said one of the homopolymer units upon stimulation.
7. The medium of claim 6 , wherein the polymer chains have an average orientation with a non-zero component perpendicular to a plane of the polymer film.
8. The medium of claim 7 , wherein the polymer chains are further ordered such that said at least some of the polymer chains that comprise block copolymers form a structured pattern in the plane of the polymer film.
9. The medium of claim 7 , wherein the polymer chains in the polymer film provided are further ordered such that said at least some of the polymer chains that comprise block copolymers form a two-dimensional lattice in the plane of the polymer film.
10. The medium of claim 5 , wherein said one of the homopolymer units derives from a phthalaldehyde compound, whereas another one of the homopolymer units derives from a compound comprising a functional group capable of initiating a ring-closing polymerization of phthalaldehyde.