In this work, sepiolite hybrid pigments were prepared with four kinds of cationic dyes with different structures and functional groups, Basic orange 2 (BO2), Mytheme blue (MB), Basic red 18 (BR18) and Basic red 2 (BR2), by the vacuum method. The obtained samples were respectively named as BO2/Sep, MB/Sep, BR18/Sep and BR2/Sep. The sepiolite hybrid pigments were characterized and tested by XRD, FT-IR, Microporous physical/chemical adsorption analyzer, thermal analyzer, et al. The effects of cationic dyes structure and functional groups types on the positions and loading capacity of cationic dyes in sepiolite hybrid pigments were investigated. The results indicated that positions and loading capacity of cationic dyes in sepiolite hybrid pigments are not only related to the size of the cationic dyes but also related to the functional groups and electrical properties of the cationic dyes. The smaller the size of the cationic dyes, the greater the positive charge, and the stronger the functional groups interact with the sepiolite, the greater the amount that enters the sepiolite channel and is adsorbed. The loading capacity of cationic dyes in hybrid pigments dropped as the order MB/Sep, BO2/Sep, BR18/Sep, BR2/Sep. In addition, the position and interaction of cationic dye in sepiolite determine the stability of hybrid pigments. The resistance of hybrid pigments to the acid decreased as the order MB/Sep, BR18/Sep, BO2/Sep, BR2/Sep. In the base medium, the order is MB/Sep, BO2/Sep, BR18/Sep, BR2/Sep. The weatherability of the hybrid pigments was also better than pure cationic dyes.

In this work, graphene oxide@Fe3O4 (GO@Fe3O4) two-dimensional magnetically oriented nanocomposites were prepared through the co-precipitation approach using graphene oxide as the carrier and FeCl3·6H2O and FeSO4·7H2O as iron sources. The samples were characterized and tested by X-ray diffraction, a transmission electron microscope, Fourier-transform infrared spectroscopy, a vibrating-specimen magnetometer, a polarized optical microscope, an optical microscope, etc. The effects of material ratios and reaction conditions on the coating effects of Fe3O4 on the GO surface were investigated. The stable GO@Fe3O4 sol system was studied and constructed, and the optical properties of the GO@Fe3O4 sol were revealed. The results demonstrated the GO@Fe3O4 two-dimensional nanocomposites uniformly coated with Fe3O4 nanoparticles were successfully prepared. The GO@Fe3O4 two-dimensional nanocomposites exhibited superparamagnetic properties at room temperature, whose coercive force was 0. The stable GO@Fe3O4 sol system could be obtained by maintaining 1 < pH < 1.5. The GO@Fe3O4 sol showed magneto-orientation properties, liquid crystalline properties, and photonic crystal properties under the influence of the external magnetic field. The strength and direction of the magnetic field and the solid content of the GO@ Fe3O4 sol could regulate the aforementioned properties. The results suggest that GO@Fe3O4 two-dimensional magnetically oriented nanocomposites have potential applications in photonic switches, gas barriers, and display devices.

No abstract

No abstract