A type of highly exfoliated, dispersed, and oriented organic montmorillonite filled polyimide (DABPI/OMMT) nanocomposites has been prepared successfully via in situ polymerization. Compared with the pristine DABPI, the DABPI/OMMT nanocomposites exhibit much better barrier and thermal performance. The water vapor permeability and oxygen permeability of DABPI/OMMT (5 wt%) are low to 0.31 g mil m−2 day−1 and 0.72 cm3 mil m−2 day−1, respectively. Meanwhile, its 5% weight‐loss temperature and coefficient of thermal expansion are 568°C and −1.1 ppm K−1, respectively. The results of transmission electron microscopy, 1D and 2D wide angle X‐ray diffractograms, as well as positron annihilation lifetime spectroscopy reveal that the excellent barrier and thermal performance of DABPI/OMMT (5 wt%) are mainly because of the high orientation of OMMT, increased crystallinity and low free volume of DABPI matrix. These are resulted from the “dual‐plane” structure effect, which is the synergistic orientation effect between the rigid planar molecular chains of DABPI and nanoplatelets of OMMT. POLYM. COMPOS., 39:E1725–E1732, 2018. © 2017 Society of Plastics Engineers

Yb-doped titanium dioxide nanoparticles were synthesized using collagen as the template, and characterized by means of X-ray diffraction (XRD), transmission electron microscopy (TEM), UV-Vis spectrophotometry, and Fourier transform infrared (FT-IR) spectra. The effect of doping concentration and calcination temperature on structure of TiO2was discussed. The results showed the Yb-TiO2nanoparticles have high crystallinity with the size of 18-28 nm. Ytterbium doping could inhibit the phase transformation from anatase to rutile of TiO2, reduce the crystallite size, improve thermal stability, and improve the light absorption. This study indicates that collagen could be used as an ideal biological template to prepare metal oxide nanoparticles with high crystallinity.

Anatase Ce/TiO2 materials were synthesized by using collagen as a template, cerium nitrate as cerium source, and titanium sulfate as titanium source. The structure of Ce/TiO2 was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), thermogravimetric and differential thermal analysis (TG–DTA) and DR UV-Vis. The effects of pH, doping amount and calcination temperature on Ce/TiO2 were investigated. The incorporation of Cerium could effectively inhibit the phase transformation from anatase to rutile of TiO2, reduce the crystallite size, improve thermal stability, enhance the light absorption, and enhance photocatalytic activity. The degradation rate of methyl orange was improved by burning temperature increasing. collagen could be used as an ideal bio-template to prepare metal oxide nanoparticles with high crystallinity.