Inspired by the hierarchical structure and excellent mechanical performance of nacre, LDH nanosheets with an appropriate aspect ratio to withstand significant loads and at the same time allow for rupture under the pull-out mode were synthesized as artificial building blocks for the fabrication of nacre-like films. Multilayered PVA/LDH films with a high tensile strength and ductility were prepared for the first time by bottom-up layer-by-layer assembly of pretreated LDH nanosheets and spin-coating of PVA. The weight fraction of inorganic LDH platelets in the hybrid PVA/LDH films (wp) was controlled by changing the concentration of PVA solution applied in the spin-coating process. The resulting films revealed that the PVA/LDH hybrid films were piled close together to form a well-defined stratified structure resembling the brick-and-mortar structure of natural nacre. In the hybrid films, the content of inorganic LDH platelets was comparable to the value in nacre, up to 96.9 wt %. It could be clearly seen that the mechanical performance of the as-prepared PVA/LDH films was greatly improved by increasing the rigid building-block LDHs. The tensile strength of the 2 wt % PVA/LDH hybrid film reached a value of 169.36 MPa, thus exceeding the strength of natural nacre and reaching 4 times that of a pure PVA film. Meanwhile, its elastic modulus was comparable to that of lamellar bone.

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Renewable nacre-like heparin (HEP)/layered double hydroxide (LDH) ultrathin films were first fabricated via a bottom-up layer by layer (LBL) deposition technique, which simultaneously showed largely enhanced mechanical properties and good blood compatibility. The results of UV-vis, FTIR, XRD and SEM analysis indicate that the HEP/LDH ultrathin films stacked densely together to form a well-defined brick-and-mortar structure. A strong electrostatic and hydrogen bond network at the organic-inorganic interface allowed the modulus of the film reach ca. 23 GPa, which was remarkably enhanced compared to previously reported polymer-LDH hybrid films. Due to the interlamellar heparin, the (HEP/LDH) n film may prove to be beneficial for new medical applications or as a replacement for conventional petroleum based plastics. Experimental MaterialsThe following analytical grade reagents were purchased from Sinopharm Chemical Reagent Co. Ltd and used as received: heparin (HEP, M w ¼ 6-20 kD), Ni(NO 3

The combination of two or more seemingly distinct properties into a unique composite is an exciting direction for the fabrication of novel multifunctional materials. A vacuum-filtration method was used to fabricate strong and multifunctional heparin/layered double hydroxide (HEP/LDH) films mimicking nacre. The experimental results confirm that the prepared films show a layered nano/microscale-hierarchical structure, in which the LDHs are aligned, with a very high loading amount of LDHs closely comparable to that in the natural nacre, up to 87.5 wt %. Both the modulus (E r ≈ 23.4 GPa) and hardness (H ≈ 0.27 GPa) of the HEP/LDH films are remarkably high. Furthermore, the hybrid films show a combination of outstanding properties of UV-blocking and fire-resistance properties. Therefore, this work provides a way of fabricating multifunctional organic− inorganic hybrid films, which have potential applications in the areas of optical applications, transportation, and construction.

A novel Co 3 O 4 /flocculent graphene (FG) hybrid on commercial Ni foam (NF) has been prepared. The unique flocculent graphene structure is prepared by combining a rapid filtering approach through Ni foam and a template method, in which the thermally expanded graphite is used as precursor and polystyrene (PS) microspheres are used as templates. The PS spheres play an important role in preventing the re-stacking of graphene nanosheets and the formation of flocculent graphene on NF. The PS spheres were first introduced as a guest material and were subsequently removed by calcination. The resulting freestanding FG/NF provides a three-dimensional and high conductivity scaffold for the hydrothermal growth of Co 3 O 4 nanoclusters. The obtained Co 3 O 4 /FG/NF hybrid could be directly used as a binderfree supercapacitor electrode. Moreover, the Co 3 O 4 nanoclusters on FG/NF scaffold exhibit improved specific capacitance of 1615 F g À1 compared to that of the bare NF. The 3D active material layer of Co 3 O 4 /FG/NF hybrid, high conductivity of 3D FG/NF scaffold and functional features of the Co 3 O 4 nanocluster morphology synergistically result in an improved electrochemical performance.