Reversible multifunctional mural protective material with high durability, anti-aging, breathability, and harsh-environment resistance

Abstract

Murals, as irreplaceable cultural heritage, are undergoing accelerated degradation from environmental stressors (thermo-hygrometric fluctuations and salt crystallization), exacerbated by anthropogenic climate change and pollution intensification. There is sustained advocacy by international heritage conservation bodies (ICOMOS/ICCROM) for sustainable mural preservation strategies. Prevailing materials, however, demonstrate enduring durability deficits and interfacial irreversibility, accelerating structural deterioration under environmental stress. To address these challenges, we developed a fluorosilane-modified polyacrylic resin protective material (P(HMT-Si-F)) via multicomponent molecular engineering. P(HMT-Si-F) integrates fluorinated hydrophobes, acrylic hydrophiles, and flexible siloxanes with dynamic non-covalent networks (hydrogen bonds, π-π stacking, and F···F interactions). The engineered P(HMT-Si-F) achieves 100 % reversible recovery, coupled with broad thermal adhesion stability (shear strength range 0.06 MPa, −20 °C–100 °C). Remarkably, the material demonstrates an order-of-magnitude reduction in pigment loss (70.8 % freeze-thaw; 127.3 % salt crystallization) under accelerated aging, outperforming conventional systems through environmental stressor decoupling. The hydrophilic-hydrophobic architecture achieves exceptional moisture resistance (5.8 % uptake) while preserving 91.3 % of the original mural pore structure, thereby resolving the long-standing protection-breathability trade-off. This molecular engineering strategy synergistically enhances moisture barrier efficacy, vapor permeability, and interfacial adhesion through multicomponent coordination, establishing a unified conservation framework for heritage stabilization in hygrothermal/salt-rich environments.