|Budget Amount *help
¥2,200,000 (Direct Cost : ¥2,200,000)
Fiscal Year 1996 : ¥700,000 (Direct Cost : ¥700,000)
Fiscal Year 1995 : ¥1,500,000 (Direct Cost : ¥1,500,000)
The measurement system for Visible total internal reflection (TIR) spectroscopy was developed using a slab optical waveguide (SOWG). A slab optical waveguide consists of a thin quartz glass sheet (50 mum thick) as a guide-layr, a FEP film as a clad and slide glass support. The surface of the quartz glass was chemically modified with various silylation reagents such as trimethylsilane, propylsilane, octylsilane and octadecylsilane by a reflux method or self-assembling method. The measurement system is as follows : a Xe arc lamp was used as a light source. The source light was introduced into the SOWG through an optical fiber and a coupling prism (n_D=1.8785). The output light was taken out with an another coupling prism, polarized, then led into a multichannel detector using a CCD (Hamamatsu Photonics PMA-11, Japan). The signals were then sent to a personal computer, and the time-resolved polarized Visible TIR spectra (time-resolution, 0.2s) were obtained continuously. A flow cell was built on the SOWG with PTFE block, and the aqueous dye solution was manually introduced with a syringe. The introduction of the sample solution was monitored by measuring an absorption of a perpendicularly introduced laser light. This system was applied to study the adsorption behavior of some dye molecules such as methylene blue, Rhodamine B and Rhodamine 6G onto various kinds of glass surface. For example, the Visible TIR spectrum of Rhodamine B is almost the same as the absorption spectrum of the Rhodamine B aqueous solution. That is, the ratio of the monomer of the molecule to the dimer on the SOWG surface is not much different from that in the aqueous solution. Moreover, the analysis of the polarized spectra yields an average angle of 50 degree between the long axis of the Rhodamine B molecule (monomer) and the surface normal for the not-modified glass, 50 to 57 degrees for silylated glasses.