Application of Photochromism to Fluid Measurements

本研究为光致变色技术在流体测量和流动显示中的应用进行了基础性实验。获得了以下结果。(1)光致变色染料的吸光度研究了5种螺吡喃类光致变色染料的吸光度随照射光波长的变化。将光致变色染料溶解在乙醇中。发现1，3，3-三甲基吲哚啉-6 ′-硝基苯并吡喃在紫外区的吸光度比其它染料大得多。因此，这种染料非常适合流体测量和流动可视化。(2)染料迹线的长度和密度为了在流体测量和流动可视化中使用光致变色，必须选择最合适的染料密度和激光功率。使用受激准分子激光束（由XeCl操作，波长= 308 nm）来形成染料迹线。将染料溶解在乙醇中。取决于染料的密度（0.04-0.00075重量%），通过CCD照相机测量染料迹线的长度和厚度。结果表明，低浓度染料的染痕长度大于高浓度染料的染痕长度。提出了用于流体测量和流动显示的最佳染料浓度条件。

In this research, fundamental experiments for application of photochromism to fluid measurements and flow visualization are carried out. Following results are obtained.(1) Absorbance of photochromic dyes; Absorbance, which depends on wave length of irradiated light, of 5 photochromic dyes of spiropyrans is investigated. The photochromic dyes are dissolved in ethanol. It is found that 1, 3, 3-trimethylindolino-6'-nitrobenzopyrylospiran has much larger absorbance in the ultra violet region than the other dyes. Therefore, this dye is very suitable for fluid measurements and flow visualization.(2) Length and density of dye trace For use of photochromism in fluid measurements and flow visualization, it is necessary that the most suitable density of dye and power of the laser are selected. The excimer laser beam (operated by XeCl, wave length = 308 nm) is used to form a dye trace. The dye is dissolved in ethanol. Length and thickness of the dye trace, depending on the density of dye (0.04-0.00075 weight %), are measured by a CCD camera. It is found that the length of the dye trace is longer for low density of dye than for high density. The optimum condition of density of dye is proposed for fluid measurements and flow visualization.