Mechanical properties of an interpenetrating network poly(vinyl alcohol)/alginate hydrogel with hierarchical fibrous structures.

Bioinspired hierarchical fibrous structures were constructed in an interpenetrating poly(vinyl alcohol, PVA)/alginate hydrogel network to improve its mechanical properties. The interpenetrating hydrogel network with hierarchical fibrous structures was prepared by combining the confined drying method and freeze-thaw method. First, Ca cross-linked alginate formed a nano-micro hierarchical fibrous structure the confined drying method.

ZrB-Based "Brick-and-Mortar" Composites Achieving the Synergy of Superior Damage Tolerance and Ablation Resistance.

The intrinsic brittleness and poor damage tolerance of ultrahigh-temperature ceramics are the key obstacles to their engineering applications as nonablative thermal protection materials. Biomimetic layered or "brick-and-mortar" hybrid composites composed of alternative strong/weak interfaces exhibit excellent strength and high toughness; however, the commonly used interfacial materials are weak and have poor thermal stability and ablation resistance, which strictly limit their use in high-temperature and oxidative environments. In this work, ZrB-based "brick-and-mortar" hybrid ceramics were constructed with a hierarchical biomimetic design to improve the fracture resistance and damage tolerance.

Ordered Silica Nanoparticles Grown on a Three-Dimensional Carbon Fiber Architecture Substrate with Siliconborocarbonitride Ceramic as a Thermal Barrier Coating.

Hierarchical structure consisting of ordered silica nanoparticles grown onto carbon fiber (CF) has been fabricated to improve the interfacial properties between the CFs and polymer matrix. To improve the reactivity of CFs, their surface was modified using poly(1,4-phenylene diisocyanate) (PPDI) via in situ polymerization, which also resulted in the distribution of numerous isocyanate groups on the surface of CFs. Silica nanoparticles were modified on the interface of CF-PPDI by chemical grafting method.