The Er3+ doped Al2O3 powders were prepared by the sol-gel method using the aluminium isopropoxide [Al(OC3H7)3]-derived Al2O3 sols with addition of the erbium nitrate [Er(NO3)3.5H2O]. The different phase structure, inc...The Er3+ doped Al2O3 powders were prepared by the sol-gel method using the aluminium isopropoxide [Al(OC3H7)3]-derived Al2O3 sols with addition of the erbium nitrate [Er(NO3)3.5H2O]. The different phase structure, including three crystalline types of (Al,Er)2O3 phases, γ, θ, α, and two Er-Al-O phases, ErAlO3 and Al10Er6O24, was obtained with the 1 mol% Er3+ doped Al2O3 powders at the different sintering temperatures of 600―1200℃. The green and red up-conversion emissions centered at about 523, 545 and 660 nm, corresponding respectively to the 2H11/2, 4S3/2→4I15/2 and 4F9/2→4I15/2 transitions of Er3+, were detected by a 978 nm semiconductor laser diodes excitation. The phase structure and OH content had evident influence on the up-conversion emissions intensity. The maximum intensities of both the green and red emissions were obtained respectively for the Er3+ doped Al2O3 powders sintered at 1200 ℃, which was composed mainly of α-(Al,Er)2O3, less of ErAlO3 and Al10Er6O24 phases, and with the least OH content. The two-photon absorption up-conversion process was involved in the green and red up-conversion emissions of the Er3+ doped Al2O3 powders.展开更多
We reported a nano-Ag/liquid crystalline elastomer（LCE） nanocomposite by incorporating silver nanopar- ticles into a monodomain polysiloxane-based LCE matrix via a novel experimental protocol. The photo-thermo- mech...We reported a nano-Ag/liquid crystalline elastomer（LCE） nanocomposite by incorporating silver nanopar- ticles into a monodomain polysiloxane-based LCE matrix via a novel experimental protocol. The photo-thermo- mechanical actuation of the LCE matrix was realized via the surface plasmon resonance of silver nanoparticles while converting light into heat. The photoresponsive properties of nano-Ag/LCE nanocomposites were investigated with varying ilhunination intensities and silver nanoparticle doping concentrations（0.04% to 0.2%, mass fraction）. The nano-Ag/LCE nanocomposites show sensitive deformation under irradiation due to their excellent photothermal con- version efficiency, and this photostimulated muscle-like actuation is fully reversible via the on-off behavior of light. Incorporating silver nanoparticles into the LCE matrix also improves the mechanical properties and enhances the load-actuation capability of the material.展开更多
文摘The Er3+ doped Al2O3 powders were prepared by the sol-gel method using the aluminium isopropoxide [Al(OC3H7)3]-derived Al2O3 sols with addition of the erbium nitrate [Er(NO3)3.5H2O]. The different phase structure, including three crystalline types of (Al,Er)2O3 phases, γ, θ, α, and two Er-Al-O phases, ErAlO3 and Al10Er6O24, was obtained with the 1 mol% Er3+ doped Al2O3 powders at the different sintering temperatures of 600―1200℃. The green and red up-conversion emissions centered at about 523, 545 and 660 nm, corresponding respectively to the 2H11/2, 4S3/2→4I15/2 and 4F9/2→4I15/2 transitions of Er3+, were detected by a 978 nm semiconductor laser diodes excitation. The phase structure and OH content had evident influence on the up-conversion emissions intensity. The maximum intensities of both the green and red emissions were obtained respectively for the Er3+ doped Al2O3 powders sintered at 1200 ℃, which was composed mainly of α-(Al,Er)2O3, less of ErAlO3 and Al10Er6O24 phases, and with the least OH content. The two-photon absorption up-conversion process was involved in the green and red up-conversion emissions of the Er3+ doped Al2O3 powders.
基金Supported by the National Natural Science Foundation of China（No.61275117）.
文摘We reported a nano-Ag/liquid crystalline elastomer（LCE） nanocomposite by incorporating silver nanopar- ticles into a monodomain polysiloxane-based LCE matrix via a novel experimental protocol. The photo-thermo- mechanical actuation of the LCE matrix was realized via the surface plasmon resonance of silver nanoparticles while converting light into heat. The photoresponsive properties of nano-Ag/LCE nanocomposites were investigated with varying ilhunination intensities and silver nanoparticle doping concentrations（0.04% to 0.2%, mass fraction）. The nano-Ag/LCE nanocomposites show sensitive deformation under irradiation due to their excellent photothermal con- version efficiency, and this photostimulated muscle-like actuation is fully reversible via the on-off behavior of light. Incorporating silver nanoparticles into the LCE matrix also improves the mechanical properties and enhances the load-actuation capability of the material.
