Robust Self-Healing Omniphobic Coatings Enabled by Dynamic Networks of Polyhedral Oligomeric Silsesquioxane

Omniphobic NP-GLIDE (no-problem-to-glide) coatings allow virtually any everyday liquid─water, oils, sauces, biological fluids─to roll off effortlessly, making them powerful candidates for self-cleaning and protective surface technologies. Yet, as with all coatings, surface wear and microdamage remain unavoidable during use, creating a pressing need for materials that can reliably repair themselves. To address this challenge, we introduce a new class of inorganic-organic self-healing NP-GLIDE coatings based on polyhedral oligomeric silsesquioxane (POSS) cages bearing thiol (SH) and tert-butylamino (tA) groups, with only ∼1% of the thiol groups grafted with 2.0 kDa antismudge poly(dimethylsiloxane) chains. Cross-linking these multifunctional POSS precursors with either a flexible hexamethylene diisocyanate trimer (HDIT) or a rigid isophorone diisocyanate (IPDI) generates networks containing dynamic thiourethane (from SH) and hindered urea (from tA) linkages. Systematic comparisons reveal that IPDI-cross-linked coatings achieve markedly higher nanoindentation hardness and more robust antismudge performance than their HDIT analogues. Furthermore, tuning the tA/SH ratio provides a molecular handle to balance mechanical strength and autonomous repair: higher tA content accelerates both surface and bulk healing at the expense of hardness. Strikingly, the IPDI-cross-linked materials combine hardness values between those of poly(ethylene terephthalate) and polystyrene with rapid self-healing, establishing a versatile design platform for durable, high-performance NP-GLIDE coatings.