PREPARATION OF UNIQUE COLORED GLASSES LIKE A BLUEBROWN DICHROIC GLASS BY COLLOIDAL GOLD AND THE OPTICAL

在52.5SiO_2-13.3Al_2O_3-17.4B_2O_3-10.2CaO-2.0MgO-4.6Li_2O(摩尔分数)玻璃体系中，加入0.022%(质量分数)的金，可制得透射色为深蓝色、表面色为棕色的胶体金二色性玻璃。蓝棕色二向色性玻璃含有半径约50-60 nm的金八面体晶体。与Mie理论计算的光谱相比，二向色性玻璃在可见光的蓝光区有较低的消光，在红光区有较强的散射。计算得到的真吸收光谱随着颗粒尺寸的增大没有峰出现，当颗粒半径大于45边时。因此，蓝棕色二色性起源于金颗粒的分散，金颗粒呈八面体形状并聚集成簇状。在55.0SiO_2-7.0Al_2O_3-17.5B_2O_3-10.5CaCO_3-2.0MgO-0.7BaCO_3-0.5NaBF_4-4.2Na_2CO_3-2.6K_2CO_3(摩尔%)的组成中，加入0.002%的金和0.2%的锡，可制得在可见光区域发射红光的白色乳白色玻璃。在该玻璃中，可见光区550 nm以下的波长被强烈散射，红光通过。

Blue-brown dichroic glass by colloidal gold which displays deep blue transmitted color and brown surface color was prepared in the glass system of 52.5 Si0_2-13.3 A1_20_3-17.4 B_20_3-10.2 CaO-2.0 MgO-4.6 Li_2O (mol%) adding 0.022 wt% of gold without reducing agents. The blue-brown dichroic glass contained octahedral crystals of gold size of about 50-60 nm in radius. The dichroic glass exhibited a lower extinction in blue light region and a stronger scattering in red light region of visible light, than those in the calculated spectra by Mie theory. The calculated true absorption spectra had no peak as the size of particles became larger beyond 45 rim in radius. It was concluded, therefore, that the blue-brown dichroism was originating from scattering itself by gold particles, shaped in octahedron and aggregated into cluster. A white opaline glass which transmits the red light in visible light region could be prepared from the composition of 55.0 SiO_2-7.0 A1_20_3-17.5 B_20_3-10.5 CaCO_3-2.0 MgO-0.7 BaCO_3-0.5 NaBF_4-4.2 Na_2CO_3-2.6 K_2C0_3 (mol%) adding 0.002 wt% of gold and 0.2 wt% of Sn. In this glass, the wavelength below 550 nm in visible light region was strongly scattered out and red light was passing through.