Amplified friction via a cooperative entanglement domains and steric hindrance for damping hydrogels.

Abstract

Damping hydrogels play a crucial role in dissipating vibrational and impact energy, thereby ensuring material durability. However, the increasingly diverse and complex application scenarios impose different requirements on damping hydrogels, and it remains a challenge to develop hydrogels that exhibit excellent multidimensional damping performance along with robust mechanical properties. Here, we propose a friction-amplification strategy based on synergistic entanglement domains and steric hindrance, which simultaneously increases the frictional resistance to chain sliding, expands the frictional interfaces, and enhances chains interactions. In this design, the entanglement domains act as amplifiers that significantly elevate the energy barriers for chain sliding imposed by steric hindrance. This approach differs from conventional methods that rely solely on increasing the density of binary entanglement points, which offer limited energy dissipation performance. This strategy achieves an order-of-magnitude enhancement in damping capacity (610-fold increase) of hydrogels while maintaining high damping efficiency (96.3%) and considerable loss factor. We further demonstrate that it substantially improves the mechanical properties of hydrogels, exhibits broad universality, and shows promise for impact protection and vibration suppression.