Block Copolymer Self-Assembly and Nanostructure Formation

Block copolymers are macromolecules comprised of covalently linked segments of distinct chemical character. When the incompatibility between blocks, as quantified by the Flory–Huggins interaction parameter (χ), exceeds a threshold, the material undergoes microphase separation to form periodic domains on the 5–100 nm scale. The resulting morphologies—lamellae, cylinders, spheres and gyroid networks—are dictated by the relative volume fractions of each block and the overall degree of polymerisation. Control over orientation, feature size and long-range order is achieved through thermal or solvent annealing, chemical prepatterning, surface energy modification and field‐directed techniques. Recent advances have extended the native block copolymer phase library by combining templating with photothermal processing, by sequentially layering or sequentially infiltrating inorganic precursors into polymer domains, and by finely tuning block chemistry to raise χ and suppress interfacial mixing. These developments have enabled reliable sub-10 nm feature sizes, two- and three-dimensional nanomeshes with arbitrary symmetries, and hybrid organic–inorganic architectures with potential applications in next-generation lithography, nanoelectronics, photovoltaics and catalysis.

Research from Nature Portfolio

Recent studies have demonstrated that chemical modification of a polystyrene‐block‐poly(glycidyl methacrylate‐random‐poly(methyl methacrylate)) copolymer can yield Flory–Huggins parameters three to five times higher than conventional systems, enabling perpendicular lamellae with domain spacings down to 12.3 nm and half-pitch sizes as small as 7.6 nm via directed self-assembly. Complementary work has introduced neutral surface layers by filtered plasma treatment, which universally promote perpendicular orientation across diverse block chemistries and molecular weights, opening routes to stacked three-dimensional nanostructures without reliance on bespoke surface chemistry. Foundational efforts have further shown that photothermal annealing combined with sequential inorganic conversion can produce two-dimensional block copolymer nanomeshes with any desired Bravais lattice symmetry, moving beyond the limited morphology set dictated by energy minimisation in unassisted self-assembly.

Block Copolymer Self-Assembly and Nanostructure Formation publication trend

The graph below shows the total number of articles in block copolymer self-assembly and nanostructure formation across all publications each year (not limited to Nature Index journals).

Technical terms

Block copolymer: A macromolecule consisting of two or more chemically distinct polymer segments linked in sequence, which can microphase separate into nanoscale domains.

Flory–Huggins interaction parameter (χ): A dimensionless measure of the enthalpic incompatibility between polymer blocks that drives microphase separation.

Microphase separation: The self-organization process by which incompatible polymer blocks demix into periodic nanometre-scale domains while remaining covalently linked.

Directed self-assembly (DSA): Techniques that use chemical, topographical or field-based templates to control the orientation, registration and long-range order of block copolymer microdomains.

Sequential infiltration synthesis (SIS): A vapour-phase method for growing inorganic materials selectively within block copolymer domains to form hybrid organic–inorganic nanostructures.

References

1. Chemically tailored block copolymers for highly reliable sub-10-nm patterns by directed self-assembly. Nature Communications (2024).
2. Universal perpendicular orientation of block copolymer microdomains using a filtered plasma. Nature Communications (2019).
3. Arbitrary lattice symmetries via block copolymer nanomeshes. Nature Communications (2015).
4. Understanding and Controlling Polymer–Organometallic Precursor Interactions in Sequential Infiltration Synthesis. Chemistry of Materials (2020).
5. Automated Defect and Correlation Length Analysis of Block Copolymer Thin Film Nanopatterns. PLOS ONE (2015).
6. Aligned silicon nanofins via the directed self-assembly of PS- b -P4VP block copolymer and metal oxide enhanced pattern transfer. Nanoscale (2015).