Here, we report on the fabrication of flame retardant hydrophobic cotton fabrics based on the coating with two-dimensional hexagonal boron nitride (2D hBN) nanosheets. A simple one-step solution dipping process was used to coat the fabrics by taking advantage of the strong bonding between diethylenetriamine and hBN on the cotton surface. Exposure to direct flame confirmed the improvement of the flame retardant properties of the coated cotton fabrics. In turn, removal of the flame source revealed self-extinguishing properties. Molecular dynamics simulations indicate that hBN hinders combustion by reducing the rate at which oxygen molecules reach the cotton surface. This time-saving and one-step approach for the fabrication of flame-retardant cotton fabrics offers significant advantages over other, less efficient production methods.

Structural materials that feature hierarchical architectures (e.g., fractals) display remarkable mechanical properties. Menger sponge is one of the fractal geometries defined in Mathematics and made up of a unit cube with three orthogonal cavities. The precise fractal dimensions are fabricated using 3D printing. Experiments and simulations are conducted on the structure under uniaxial compression. The effect of increasing the levels of orthogonal cavities of the Menger sponge structure as well as the changing shape of the cavity are studied. The results show an interesting correlation between mechanical properties and the effective density of the structure. Multiple levels of hierarchy are analyzed in terms of different cavity shapes. These comparisons suggest that hierarchical structures are used to obtain better performance with a lower effective density of the resulting structures. Damage initiation for the different cavity shapes shows how each of the cavity shapes behaves under compressive loading. Herein, it is discerned how hierarchical architecture is used to access the unique properties of structures, providing insight into the role of design in regulating the mechanical properties of such mechanical structures. The result of acoustic investigation shows that it is a better absorber as compared with commercial sponge in the low‐frequency regime.

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To enhance the overall energy efficiency of the individual parts used in automobile and aerospace industries, study of the specific strength of the components becomes crucial. As a result, in the last couple of decades, large efforts have been made to develop porous architecture with light weight and high specific strength. Herein, an easily scalable and controlled processing of a stochastic bicontinuous atomic scale structure inspired complex porous architecture using 3D printing is demonstrated. The complex topology of the architecture provides enhanced mechanical properties (specific strength, modulus, specific energy absorption etc.). These properties can be easily tuned with the help of changing density and surface area. Based on experimental observations, an analytical model is proposed to correlate these properties with density. These individual architectures can be stacked on top of each other with different combinations to build hierarchical structures, which allows engineering of the directional dependency of the mechanical response.

Objectives The present work aimed to investigate the deformation behavior of complex ant mound architectures under compression. Methods We have used the cement casting method to extract four different ant nest morphologies. These casted cement structures were digitalized using a 3D micro-computer tomography (CT) scan. The digitized structures were simulated under different loading conditions using Finite Element Methods (FEM). In order to supplement the numerical understanding, the digital architectures were 3D printed and experimentally tested under uniaxial loading conditions. Results Ants produce a variety of complex architectures for adapting to the surrounding environment and ants’ needs. Ant mound consists of at least one pillar with a broad base tapered towards its tip. Anthill architectures have unique topological features. Mechanical strength of ant mould can be 600 times enhanced by tuning topology. Thickness and angle of pillars have huge effect on load-bearing property Conclusion The branched structures can endure larger stress and deform in the process under a volumetric pressure application, making them sacrificial units for extreme disasters like floods and earthquakes. The 3D printing experiments and Finite Element Methods simulations are needed to tackle the complex ant mound architectures and appear in good agreement, suggesting a robust design and thus the possibility of constructing anthill-inspired civil buildings with a tree-trunk-like geometry.