A flexible metal-organic framework (MOF)-based one-dimensional photonic crystal (1DPC) was fabricated by a spin-coating method. The flexible MOF, NH 2 -MIL-88B (MIL ¼ Materials from Institute Lavoisier), was selected and implanted as the intrinsic functional layer of 1DPCs because of its selective breathing behavior upon exposure to various guests. TiO 2 nanoparticles were used as another component to ensure a high refractive index contrast. The optical properties of the 1DPCs were tailored by varying the number of bilayers, incident angles, and physical thickness of the individual slabs. The fabricated 1DPCs showed a selective response toward various organic vapors as a result of the selective breathing behavior of the NH 2 -MIL-88B layer. Selective quantitative measurements of the ethanol concentrationwere achieved when the 1DPC was exposed to the vapors of an ethanol and water mixture. The fabricated 1DPCs exhibited high long-term, thermal, and mechanical stability, which are beneficial for practical applications. 84574241 † Electronic supplementary information (ESI) available: Characterization of NH 2 -MIL-88B and TiO 2 nanoparticles, optical responses of 1DPC upon various organic vapors, photographs of 1DPC aer high thermal, long term and ultrasonic treatments. See

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Optical properties, which determine the application of optical devices in different fields, are the most significant properties of optical thin films. In recent years, Metal-organic framework (MOF)-based optical thin films have attracted increasing attention because of their novel optical properties and important potential applications in optical and photoelectric devices, especially optical thin films with tunable optical properties. This study reports the first example of tuning the optical properties of a MOF-based optical thin film via post-modification. The MOF-based optical thin film was composed of NH2-MIL-53(Al) nanorods (NRs) (MIL: Materials from Institute Lavoisier), and was constructed via a spin-coating method. Three aldehydes with different lengths of carbon chains were chosen to modify the MOF optical thin film to tune their optical properties. After post-modification, the structural color of the NH2-MIL-53(Al) thin film showed an obvious change from purple to bluish violet and cyan. The reflection spectrum and the reflectivity also altered in different degrees. The effective refractive index (neff) of MOFs thin film can also be tuned from 1.292 to 1.424 at a wavelength of 750 nm. The success of tuning of the optical properties of MOFs thin films through post-modification will make MOFs optical thin films meet different needs of optical properties in various optical and optoelectronic devices.

Graphene oxide (GO) was served as mechanical strengthening to prepare GO/Polyvinyl Alcohol(PVA) composite film. This was accomplished in order to explore the influence of contents of GO on the tensile strength and failure strain of GO/PVA composite film. The results showed that as the GO content increased, the tensile strength of the composite film became greater rapidly at first, and then decreased gradually. When the GO content was 20%, the film had its maximum tensile strength (59.6 MPa). This is over 500% of the tensile strength of pure PVA film. The failure strain of GO/PVA composite film decreased rapidly as the GO content increased. The enhancement mechanism of the composite can be explained by the existence of multi-hydrogen bonds between the hydroxyl (-OH) groups of PVA and oxygen-containing functional groups of GO.