Supramolecular polymer networks with high compressibility and fast self-recovery

Highly compressible supramolecular polymer networks are highly desirable but seldom reported. In a recent work published in Nature Materials by Scherman et al., glass-like high-performance successfully developed means of slow-dissociative non-covalent cross-linkers. The resulting demonstrate superior compressive strength up to 100 MPa and rapid room-temperature self-recovery (<120 s). Supramolecular (SPNs), fascinating class soft materials, three-dimensional structures composed transiently cross-linked linear macromolecules connected bonds.1Xia D. Wang P. Ji X. Khashab N.M. Sessler J.L. Huang F. Functional polymeric networks: the marriage covalent polymers macrocycle-based host-guest interactions.Chem. Rev. 2020; 120: 6070-6123Crossref PubMed Scopus (319) Google Scholar Unlike bond networks, SPNs integrate features chemical physical multifunctionality chemosynthetic flexibility cross-linking endows resultant with remarkable reversibility2Qin B. Zhang S. Sun Tang Yin Z. Cao Chen Q. Xu J.-F. Tough multi-recyclable polyureas via incorporating noncovalent bonds into main-chains.Adv. Mater. 32: e2000096Crossref (127) stimuli responsiveness.3Gao Han Y. Li Tong H. Photoresponsive hydrogen assisted molecular tweezer/guest complexation.ACS Macro Lett. 2017; 6: 541-545Crossref (33) Furthermore, can be customized meet specific requirements.4Löwenberg C. Balk M. Wischke Behl Lendlein A. Shape-memory hydrogels: evolution structural principles enable shape switching hydrophilic networks.Acc. Chem. Res. 50: 723-732Crossref (206) Indeed, have been applied many fields, including fabrication self-healing materials,5Wang Wu McDowell M.T. Cui Bao Self-healing chemistry enables stable operation silicon microparticle anodes for high-energy lithium-ion batteries.Nat. 2013; 5: 1042-1048Crossref (938) memory retention materials,6Zhao R. Zhao T. Jiang Liu Shi Yang E.-Q. Thermoplastic high strain multishape polymer: side-chain polynorbornene columnar liquid crystalline phase.Adv. 29: 1605908Crossref (54) drug-delivery devices.7Zhang Bellinger A.M. Glettig D.L. Barman Lee Y.-A.L. Zhu J. Cleveland Montgomery V.A. Gu L. Nash L.D. al.A pH-responsive gel as an enteric elastomer use gastric devices.Nat. 2015; 14: 1065-1071Crossref (239) However, construction rapidly recoverable is challenging. A significant breakthrough field was recently reported Materials. coworkers excellent introducing cross-linkers dissociation rate constant kd < 1 s?1.8Huang O’Neill S.J.K. G. Whitaker D.J. McCune J.A. O.A. networks.Nat. 2022; 21: 103-109Crossref (69) Notably, no fracture observed even when were compressed at 93% strain, these possessed fast capacity on short timescales <120 s. their work, cross-link design prepared based CB[8]-mediated ternary complexation (Figure 1A), dynamic could regulated manipulating structure second guest (RBVI). Specifically, obtained photopolymerization cross-linker 5FBVI-CB[8]-RBVI, viscoelasticity evaluated using oscillatory rheology. constructed NVI or BVI containing CB[8] showed higher than those without 1B). Meanwhile, 20°C, time-temperature superposition (TTS) time-kinetics experiments indicated that (diMeBVI, ClBVI, BVI, CNBVI) exhibited performance similar lower 40–80°C (Figures 1C 1D). This implies effectively modifying instead raising temperature 1). compressibility also investigated representative testing equipment 1E). It found increased gradually decrease kd, SPN slowest dissociative 5FBVI-CB[8]-NVI highest MPa. Moreover, 2.5 mol% achieved maximum 1.04 GPa total monomer concentration (CM) 6.0 M 1F). Clearly, far better numerous elastomers, gels, bovine cartilage. To reversible 5FBVI-CB[8]-NVI-cross-linked SPN, cuboid specimen length, width, thickness 70, 50, 6 mm, respectively, produced car-compression experiment 1G). car weighing 1200 kg placed top min, repeatedly compacted 16 times. No irreversible deformation because complete SPN. al. series performances developing cross-links, which find potential applications fields robotics, artificial muscles, tissue engineering, wearable bioelectronics. study financially supported National Natural Science Foundation China (22061018), Distinguished Young Scholars Jiangxi Province (20212ACB213003), Academic Technical Leader Plan Provincial Main Disciplines (20212BCJ23004). authors declare competing interests.