Photothermally Directed Assembly of Block Copolymers

Abstract

Block copolymers self‐assemble into nanoscale morphologies, spontaneously ordering under thermal annealing conditions owing to the chemical incompatibility between the blocks. While the morphologies that form can be rationalized based on equilibrium arguments, the structures seen experimentally are strongly influenced by kinetic effects including process history. Recently, a variety of photothermal processing techniques have been used to control block copolymer ordering. Photothermal methods provide access to extreme conditions, including high temperatures, large heating rates, and sharp thermal gradients. This can correspondingly be used to greatly accelerate block copolymer ordering kinetics, to pattern material order, or to probe fundamental aspects of self‐assembly by exploring process histories.

Bottom‐Up Assembly of Micro/Nanostructures

“…Novak et al focus their review on thermal and photo‐thermal approaches that provide access to extreme processing conditions, such as very high temperatures, large heating rates and very sharp thermal gradients. [ 14 ] As a consequence, photo‐thermal methods often achieve vastly improved order using much shorter annealing times compared to conventional annealing in oven or on hot plate, broadening the versatility of block copolymer materials. In particular, photo‐thermal zone annealing, which involves the movement of a hot zone through the polymeric film, provides an efficient method to promote high order and facile macroscopic alignment in the block copolymer template.…”

Hyperbolic Metamaterials via Hierarchical Block Copolymer Nanostructures

“…Lots of efforts have been made in order to address the nanofeatures ordering by homopolymer blending [ 27–29 ] and implementing the BCP self‐registration into prepatterned substrates, e.g., directed self‐assembly (DSA) or self‐registered self‐assembly (SRSA). [ 30–35 ]…”

Vertical Cylinder-to-Lamella Transition in Thin Block Copolymer Films Induced by In-Plane Electric Field

“…Directed self-assembly of block copolymers is a comprehensive concept that encompasses a variety of techniques implemented to obtain large defect-free high aspect ratio patterns [13,14] in a technologically reasonable time [15]. The ways to effectively tailor an emerging nanodomain structure exploit the selectivity of copolymer blocks toward film surfaces (exposure to solvent vapors [16][17][18][19] and chemo-or grapho-epitaxy [20,21]), organic or inorganic dopants [22][23][24][25], and long-range shear, thermal, light, electric, or magnetic external fields [26][27][28][29][30][31][32].…”