Water‐Induced Transitions from Ellipsoidal Micelles to Chain‐Like Nanostructures Self‐Assembled by the Coil‐Rod‐Coil Block Copolymer Based on Hydrogen‐Bonding Urea Groups

Abstract

Herein, a novel coil‐rod‐coil triblock copolymer with the coil blocks composed of poly(ethylene glycol) methyl ether and the rigid midterm block alternatively connected with isophorone diisocyanate and isophorone diamine is developed. The triblock copolymer can self‐assemble into ellipsoidal micelles in 1‐methyl‐2‐pyrrolidinone. After the addition of a second coil‐selective solvent (water) to the micellar solutions, these ellipsoidal micelles can further transform into chain‐like nanostructures. The self‐assembly behavior is highly influenced by the additional order of the solvents, which is considerably due to the impacts of the hydrogen‐bonding urea groups and rigid motifs. The transition of the ellipsoidal micelles to chain‐like nanostructures is governed by the water molar fractions. The sizes of the chain‐like nanostructures increase first and then decrease with the growth of the water molar fractions in the mixed solutions.

Fabrication of Multilayered Two-Dimensional Micelles and Fibers by Controlled Self-Assembly of Rod-Coil Block Copolymers

“…Solution self-assembly of block copolymers is a low-cost and effective method to fabricate the defined nanomaterials. By means of adjusting the chemical constituents and the environmental conditions, the block copolymer can self-assemble into various nanostructures, such as spherical micelles [ 1 , 2 , 3 ], one-dimensional (1D) micelles [ 4 , 5 , 6 , 7 , 8 ], two-dimensional (2D) micelles [ 9 , 10 , 11 ], hierarchical nanostructures [ 12 , 13 , 14 , 15 ], etc. Recently, fabrication of nanomaterials with hierarchical structures by self-assembly of the block copolymer attracts great interest.…”

Reduction of Line Edge Roughness of Polystyrene-block-Poly(methyl methacrylate) Copolymer Nanopatterns By Introducing Hydrogen Bonding at the Junction Point of Two Block Chains

“…In this study, we introduced urea (U) and N-(4-aminomethyl-benzyl)-4-hydroxymethyl-benzamide (BA) moieties at the junction between PS and PMMA chains. The combination of hydrogen bonding sites (U) and rigid rod groups (BA) in block copolymers facilitates molecular alignment, in comparison to only U group. − The lateral stacking of U-BA groups results in the larger effective χ value. Thus, the interfacial width between PS and PMMA nanodomains would be reduced by increase of effective χ value, resulting in improved LER, as schematically shown in Figure .…”