Ring Shuttling Controls Macroscopic Motion in a Three‐Dimensional Printed Polyrotaxane Monolith

Abstract

Amplification of molecular motions into the macroscopic world has great potential in the development of smart materials. Demonstrated here is an approach that integrates mechanically interlocked molecules into complex three-dimensional (3D) architectures by direct-write 3D printing. The design and synthesis of polypseudorotaxane hydrogels, which are composed of α-cyclodextrins and poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (PEO-PPO-PEO) triblock copolymers, and their subsequent fabrication into polyrotaxane-based lattice cubes by 3D printing followed by post-printing polymerization are reported. By switching the motion of the α-cyclodextrin rings between random shuttling and stationary states through solvent exchange, the polyrotaxane monolith not only exhibits macroscopic shape-memory properties but is also capable of converting the chemical energy input into mechanical work by lifting objects against gravity.

A biopolymer‐based 3D printable hydrogel for toxic metal adsorption from water

“…The solution was allowed to warm to room temperature resulting in the gel state which could be used to form the various 3D printed shapes (illustrated in Fig. ) via direct‐write printing . Direct‐write printing is a cheap and versatile layer‐by‐layer fabrication method similar to fused filament fabrication .…”

Advanced Polymer Designs for Direct‐Ink‐Write 3D Printing

“…We introduced the microcrystallization of cyclodextrin (CD)‐based polypseudorotaxanes to develop DIW inks with mechanically interlocked architectures . In this design, 3D printable polypseudorotaxane inks are composed of ring component α‐CDs and axle component PEO or F127.…”

“… a) Images of a wood‐pile polyrotaxane lattice soaked in DMSO and water, respectively. Reproduced with permission from reference . Copyright 2017 John Wiley & Sons, Inc. b) pH‐Induced multi‐stage anisotropic shape morphing of a 3D printed polyrotaxane‐based hybrid.…”

“…We introduced the microcrystallization of cyclodextrin (CD)based polypseudorotaxanes to develop DIW inks with mechan- ically interlocked architectures. [89,90] In this design, 3D printable polypseudorotaxane inks are composed of ring component a-CDs and axle component PEO or F127. In an aqueous solution, a-CD rings thread onto the axle to form at ubular polypseudorotaxane ( Figure 5a)d riven by ring-ringh ydrogenbondingi nteractions ( Figure 5b), thermodynamically favored ring-axle interactions, and the releaseo fh igh-energyw ater in the CD rings.…”

“…By facilitating the 3D printability of CD-based polypseudorotaxanest hrough microcrystallization,w ed esigned as eries of 3D polyrotaxanes that amplify the CD ring shuttling motions to the macroscale and perform useful mechanical work. [89] In an aqueous environment, the CD rings are hydrogen bonded to form static microcrystalline domains in the polyrotaxane monolith. When DMSO is introduced, the hydrogen-bonding network formed between the CD rings is disrupted.…”