Fracture Behavior of Polyrotaxane-Toughened Poly(Methyl Methacrylate).

The fracture behavior of polyrotaxane (PR)-modified poly(methyl methacrylate) (PMMA) was investigated. PR is a supramolecule with rings threaded onto a linear backbone chain, which is capped by bulky end groups to prevent the rings from de-threading. The ring structure is α-cyclodextrin (CD), and it can be functionalized to enhance its affinity with the hosting polymer matrix.

Polymer Brush Formation Assisted by the Hierarchical Self-Assembly of Topological Supramolecules.

The development of methods for the polymer brush layer formation on material surfaces to improve the surface properties has been researched for decades. Here, we report a novel approach for the formation of a polymer brush layer on materials and the alteration of the surface properties using a pseudo-polyrotaxane nanosheet (PPRNS). In the PPRNS, β-cyclodextrin (CD) selectively covered the central poly(propylene oxide) segment of the carboxyl-terminated poly(ethylene oxide)--poly(propylene oxide)--poly(ethylene oxide) (COOH-EOPOEO) triblock copolymer to form columnar crystals.

Molecular Recognition of Fluorescent Probe Molecules with a Pseudopolyrotaxane Nanosheet.

Pseudopolyrotaxane nanosheets (PPRNS) are ultrathin two-dimensional (2D) materials fabricated via supramolecular self-assembly of β-cyclodextrin (β-CD) and poly(ethylene oxide)--poly(propylene oxide)--poly(ethylene oxide) triblock copolymers. In this study, the molecular loading of various fluorescent probe molecules onto PPRNS was systematically investigated. H NMR study for R6G absorption to PPRNS indicated that the small hydrophobic groups, such as the methyl group, of R6G were absorbed by PPRNS.

Precise control of cyclodextrin-based pseudo-polyrotaxane lamellar structure axis polymer composition.

Self-assembly of cyclodextrin (CD) with guest polymers has attracted much attention owing to its biocompatibility and accessibility. In this study, we investigate the composition effect of poly(ethylene oxide)m-b-poly(propylene oxide)n-b-poly(ethylene oxide)m (EOmPOnEOm) triblock copolymers on lamellar or plate structures formed by complexation with β-CD. EO5PO29EO5, EO14PO29EO14, and EO75PO29EO75 show periodic lamellar morphology consisting of single-crystalline pseudo-polyrotaxane (PPR) nanosheets with a thickness equal to the central PO length.

Autonomously isolated pseudo-polyrotaxane nanosheets fabricated via hierarchically ordered supramolecular self-assembly.

We succeeded in obtaining autonomously isolated nanosheets consisting of pseudo-polyrotaxane (PPR) fabricated via hierarchically ordered supramolecular self-assembly of β-cyclodextrin and a poloxamer by introducing charged groups to the axis ends of the poloxamer. The isolated PPR nanosheets exhibited a tunable structural coloration and were aligned using a strong magnetic field.

Drastic Change of Mechanical Properties of Polyrotaxane Bulk: ABA-BAB Sequence Change Depending on Ring Position.

Polyrotaxane (PR), consisting of many ring molecules and an axis polymer, is a typical supramolecular structure with unique topological characteristics. In this study, we demonstrated the drastic change of the macroscopic mechanical properties depending on the ring position of PR in bulk. Poly(ethylene oxide)--poly(propylene oxide)--poly(ethylene oxide) (PEO-PPO-PEO) triblock copolymer was employed as an axis polymer to control the position of β-cyclodextrin (β-CD).