title: Bioinspired design and assembly of layered double hydroxide/poly(vinyl alcohol) film with high mechanical performance.
abstract: 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.
authors.affiliation: The College of Materials Science and Engineering, Beijing University of Technology , Beijing 100124, P. R. China.
authors.forename: Yingqi
authors.initials: Y
authors.lastname: Shu
authors.forename: Penggang
authors.initials: P
authors.lastname: Yin
authors.forename: Benliang
authors.initials: B
authors.lastname: Liang
authors.forename: Hao
authors.initials: H
authors.lastname: Wang
authors.forename: Lin
authors.initials: L
authors.lastname: Guo
mesh_terms: D032701:Biomimetics / Q000379:methods*; D006878:Hydroxides / Q000737:chemistry*; D055595:Mechanical Phenomena; D008855:Microscopy, Electron, Scanning; D060734:Nacre / Q000737:chemistry*; D011143:Polyvinyl Chloride / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D013314:Stress, Mechanical; D013818:Thermogravimetry; D014961:X-Ray Diffraction
chemical_list: D006878:Hydroxides; D060734:Nacre; D011143:Polyvinyl Chloride; C031356:hydroxide ion
keywords: bioinspired design; interfacial adhesion; layered double hydroxide; mechanical properties; poly(vinyl alcohol)