Abstract
In-situ measurement techniques are reviewed on the heterogeneous reactions including a crystal growth from solution, an electrochemical reaction on electrode and a boiling phenomenon at a heated surface. These reactions are traditionally utilized in the industrial separation technology and extractive metallurgy. The frontier of electrochemical reaction engineering has also been exploited in microelectronics and energy science fields based on the measurements. Some techniques can be applicable to the drop shaft facility. The characteristics inherent to the in-situ measurement techniques are described not only on the design of a quasi-two dimensional cell, but also on the optical deflection effect in a steep refractive index gradient. Some researches performed in a drop shaft are described. Boiling phenomena were observed with two-wavelength Mach-Zehnder interferometer. Malangoni convection caused by the non-uniformity concentration distribution appeared
at the later stage of boiling of non-azeotropic mixture. The wettability of electrolyte introduced the different behavior of gas evolving electrodes, when the water electrolysis was conducted. Anodic dissolution phenomena were also observed with a common path interferometer. The numerical simulation results agreed with the observed transient behavior of interference fringe pattern. The careful and persevering preparations may provide the possibilities of new phenomena inside the drop shaft capsule, if in-situ measurement techniques are reasonably designed.
