Environmentally\nFriendly Supramolecular Nanosheet\nParticles for Surface Coating

Global environmental problems have become increasingly\nsevere in\nthe recent years. Although inorganic nanoparticles and nanosheets\n(NSs) have been developed for their high functionality and stability,\ntheir toxicity and nonbiodegradability significantly impact the environment\nowing to their accumulation within ecosystems. This paper reports\nthe fabrication of environmentally friendly supramolecular NS particles\ncomposed of cyclodextrin (CyD), a natural oligosaccharide, and highly\nbiocompatible polyethers, and their stabilization, antifouling, and\nbiodegradation properties. Supramolecules are typically unstable due\nto their noncovalent bonds; however, end-capped-pseudopolyrotaxane\nnanosheets (PPRNSs), featuring a bulky group at the axis end, is water-insoluble,\nmaintaining stability even under extreme dilution. The capped-NSs\npossess polymer brushes, which, when coated on substrates, do not\ndissolve in water and exhibit repeatable antifouling properties. The\ncrystalline CyDs in the capped-NSs are not water-soluble; however,\nbiochemical oxygen demand (BOD) tests in seawater demonstrate their\nbiodegradability. Thus, PPRNSs have the potential to be novel NS materials\nthat can address environmental challenges. This study is expected\nto pave the way for advancements in nanosheet materials science and\nsupramolecular chemistry.