Variable-temperature diffuse reflectance infrared Fourier transform spectroscopy (VT-DRIFTS) is proving to be a powerful tool for rapid and qualitative investigations of certain surface reactions. Murthy and Leyden have shown that room-temperature (RT) DRIFTS is useful for the determination of the concentration of a silane on the surface of silica gel. However, when VT-DRIFTS was attempted for quantitative purposes, two problems became obvious. First, the thermal expansion of the sample post at higher temperature resulted in changes in band intensities. To eliminate this experimental artifact, we modified the DRIFTS accessory (DRA-2CN) from Harrick Scientific Corp. to include a one-dimensional translation stage. This permitted precise location of the sample at the optimum height, thus minimizing effects due to thermal expansion. The second problem was the need for precise control of the temperature for every VT-DRIFTS scan so that results from different scans could be compared. A survey of commercially available temperature controllers revealed that they were expensive and did not have adequate flexibility. We decided to build a temperature controller around an Apple II+ microcomputer. This note describes the hardware and software details of such a controller.

PDF Article

Cited By

You do not have subscription access to this journal. Cited by links are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
Login to access OSA Member Subscription