The creation of structural composites with combined strength, toughness, low density, and biocompatibility remains a long-standing challenge. On the other hand, bivalve marine shells -Clinocardium exhibit strength, stiffness and toughness that surpass even that of the nacre which is the most widely mimicked model for structural composites. The superior mechanical properties of Clinocardium shells originate from their cross-lamella design, comprising CaCO3 mineral platelets arranged in an 'interlocked' herringbone fashion. Reproduction of such hierarchical designs could offer multifunctionality, potentially combing strength and toughness at low densities and capability for seamless integration with biological systems. Here, we demonstrate manufacturing of the cross-lamella design by biomineralizing aragonite films with saw-tooth patterns and assembling them in a chitosan/fibroin matrix to generate a composite with interlocked mineral layers. The resultant composite -with a similar constitution to the biological counterpart, nearly doubles the strength of previous nacre-mimetic composites while improving the tensile toughness and simultaneously exhibiting stiffness and biocompatibility.

The ORCID identification number(s) for the author(s) of this article can be found under https://doi.org/10.1002/mame.201900856.Electrospun electret filter material is widely studied because of its excellent removal effect on particulate matter from air streams. Here, a kind of high efficiency and low pressure drop nanofiber (NF) membrane with both electret effect and magnetic effect is developed, and compounded it with glass fiber mesh and polyester (polyethylene terephthalate) mesh to prepare a sandwich structure of NF anti-haze window screen. Under the synergistic effect of magnetic particles, when the density is 2.06 g m −2 , the filtration efficiency of NF anti-haze window screen can reach 99.95% for the fine particles below 0.3 µm, while the filtration pressure drop is only 58.5 Pa, with good light transmittance and excellent breaking strength (6.32 MPa). Therefore, polyvinylidene fluoride/Fe 3 O 4 composite NF membrane has a potential application prospect in the field of air filtration.The authors declare no conflict of interest.

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Degradation of diamond strength resulting from thermal damage in vacuum brazing process constrains the application of Ni-based brazed diamond tools. To reduce the thermal damage to brazed diamonds, the effectiveness of coating diamond with tungsten was investigated by scanning electron microscopy, Raman spectroscopy and friability test. Tungsten coating was deposited on diamond surfaces by vacuum diffusion method. The experimental results show that tungsten coating, as a buffering layer, plays a stress-relaxing role and brings about fewer cracks in the Ni-based matrix near diamond grains. Graphitization of W-coated diamond after brazing is much slighter than that of uncoated diamond and Ti-coated diamond, according to the morphology and Raman spectra. The isolation of diamond from nickel catalyst by tungsten coating inhibits the graphitization of diamond, which can further explain the increase in the toughness index of brazed diamonds.