A three-step synthetic strategy is established for the preparation of functionalized bottlebrush copolymers. In this scheme, the highly efficient nature of thiol-epoxy coupling chemistry is employed for the attachment of thiol terminated poly(ethylene glycol) (PEG) polymers (0.18, 0.8, and 2 kDa) to the poly(glycidyl methacrylate) (PGMA) backbone (25 and 46 kDa). This coupling reaction resulted in the formation of water-soluble bottlebrush copolymers (50–426 kDa) with grafting densities ranging from 88 to 97%. The coupling process also produced reactive hydroxyl groups in the vicinity of the polymer backbone. These hydroxyl groups could be functionalized with pyrene (a fluorescent probe) or biotin (a biological ligand) molecules through an esterification reaction. Therefore, fluorescent/biorelevant bivalent bottlebrushes could be obtained in three linear synthetic steps starting from a commercially available monomer. The prepared polymers displayed structure dependent thermal and optical properties, and single bottlebrushes could be visualized with the help of atomic force microscopy (AFM).

By introducing neutral star copolymers consisting of poly(styrene-r-methyl methacrylate) (PS-r-PMMA) arms, a perpendicular orientation of PS-b-PMMA microdomains in thin films could be achieved without any surface treatment. The star copolymers were synthesized by arm-first method in which short chain arms are cross-linked by employing a multifunctional coupling reagent via atom transfer radical polymerization. To find the optimal neutral composition for the perpendicular orientation, we varied the composition of MMA in PS-r-PMMA arms from 40 mol % to 80 mol %. It was found that the star copolymer having an overall PS and PMMA composition of 59:41 exhibits the well-ordered perpendicular orientation of lamellar structures after thermal annealing. Furthermore, we also prepared the deuterated star copolymers to trace them within PS-b-PMMA films along vertical direction by neutron reflectivity. In this case, it was observed that star copolymers were mainly located at the top surface and bottom interface of the films, thereby effectively neutralizing the surface/interfacial energy differences.

Self-assembly of a binary mixture of poly(styrene)336-block-poly(4-vinyl pyridine)25 (PS336-b-P4VP25) and poly(ethylene glycol)113-block-poly(4-hydroxy styrene)25 (PEG113-b-P4HS25) is shown to give rise to a cylindrical morphology in thin films through pyridine/phenol-based hetero-complementary hydrogen bonding interactions between the P4VP and P4HS copolymer segments. Removal of the cylindrical phase (PEG-b-P4HS) allowed access to porous materials having a pore surface decorated with P4VP polymer blocks. These segments could be transformed into cationic polyelectrolytes through quaternization of the pyridine nitrogen atom. The resulting positively charged nanopore surface could recognize negatively charged gold nanoparticles through electrostatic interactions. This work, therefore, outlines the utility of the supramolecular AB/CD type of block copolymer towards preparation of ordered porous thin films carrying a chemically defined channel surface with a large number of reactive sites.

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