Highly Harsh-Environment-Stable and Sustainable Multifunctional Silk Textiles Enabled by Programmable Underwater Robust yet Stimulus-Reversible Cation-π Adhesion.

Durable multifunctional textiles with advanced protective performance are increasingly crucial for maintaining stability in complex and harsh environments. However, the prevalent use of disposable synthetic surface treatments poses an intractable challenge to the circular economy focused on sustainability. In this study, we introduce an innovative biomimetic sustainable silk textile that is stable in harsh environments and offers high flame retardancy, antibacterial, and anti-mildew properties through a simple yet effective surface treatment strategy. This treatment leverages a specially designed aromatic polyorganosiloxane with quaternary ammonium structures, capable of programmable, robust, and stimulus-responsive reversible cation-π adhesion. The resulting strong water-insensitive cohesive energy from biomimetic cation-π interactions between aromatic and cationic moieties ensures that the multifunctional textiles exhibit excellent long-term durability, even under challenging conditions such as underwater, in saltwater, and in acidic or alkaline solutions. Moreover, the reversible reconstruction of cation-π adhesion allows for on-demand surface treatment recycling, achieving a 100% recycling rate. This study offers a new approach to creating smart and multifunctional textiles that combine sustainability with robust performance in harsh environments.