3D Hollow Xerogels with Ordered Cellulose Nanocrystals for Tailored Mechanical Properties

Advanced materials with aligned cellulose nanocrystals (CNCs) have attracted much attention due to their remarkable mechanical and optical properties, but most of them still focus on 1D or 2D architectures. Herein, complex 3D architectures as pseudo catenoid hollow xerogels with aligned CNCs are prepared from dynamic hydrogels by mechanical stretching and air-drying process. Aligned CNCs endow the pseudo catenoids with distinct birefringence in addition to reinforcement. The mechanical properties of pseudo catenoid architecture are revealed for the first time to be controlled at two stages on diverse length scales. Both the aligned CNCs on the nanoscale and the geometry of the xerogels affect the mechanical properties. The inwardly curved surface of the pseudo catenoid xerogel makes the structure conducive to energy dissipation. These both stages of controls on the mechanical properties can be adjusted by changing the morphology of the initial hydrogels and the mechanical stretching ratios. These results will provide a new perspective for the design and manufacture advanced materials with tailored mechanical properties and functions.