ABSTRACT
The construction of flexible actuators with ultra-fast actuation and robust mechanical properties is crucial for soft robotics and smart devices, but still remains a challenge. Inspired by the unique mechanism of pinecones dispersing seeds in nature, a hygroscopic actuator with interlayer network-bonding connected gradient structure is fabricated. Unlike most conventional bilayer actuator designs, the strategy leverages biobased polyphenols to construct strong interfacial H-bonding networks between 1D cellulose nanofibers and 2D graphene oxide, endowing the materials with high tensile strength (172 MPa) and excellent toughness (6.64 MJ m-3). Furthermore, the significant difference in hydrophilicity between GO and rGO, along with the dense interlayer H-bonding, enables ultra-fast water exchange during water absorption and desorption processes. The resulted actuator exhibits ultra-fast driving speed (154° s-1), excellent pressure-resistant and cyclic stability. Taking advantages of these benefits, the actuator can be fabricated into smart devices (such as smart grippers, humidity control switches) with significant potential for practical applications. The presented approach to constructing interlayer H-bonding in gradient structures is instructive for achieving high performance and functionalization of biomass nanomaterials and the complex of 1D/2D nanomaterials.
ABSTRACT
The asymmetric unit of the title compound, [Rb(C(6)H(3)N(2)O(5))(H(2)O)](n), comprises a rubidium cation, a 2,4-dinitro-phenoxide anion and a water mol-ecule. The Rb(+) cation is 11-coordinated by O atoms from 2,4-dinitro-phenolate anions and water mol-ecules. The metal centre is firstly coordinated by two µ(3)-H(2)O to form a one-dimensional ladder-shaped unit, [Rb(2)(µ(3)-H(2)O)(2)], which is further linked by 2,4-dinitro-phenolate to give the three-dimensional framework of the title compound. The crystal structure involves O-Hâ¯O hydrogen bonds.
