Schematic drawing of the IR beam path used in the design of a PM-IRRAS cell for solid-liquid interface investigation. The fraction of light being reflected or transmitted is indicated by the product of the relevant reflectance or transmittance ; is the prism angle and is the incident angle at the metal surface.
Prism angle dependent surface absorption factor for water, toluene (tol), and cyclohexane (chx). The inset shows the overall transmittance as a function of the prism angle.
(Left) Entire view of the PM-IRRAS cell in the open mode. (Right) Cross section of the cell in the closed mode. (1) IR light path; (2) prism; (3) RE (sample); (4) Micrometer; (5) Calibration knob for the control of liquid layer thickness; (6) Fluid-inlets; (7) Fluid-outlet; (8) Peltier elements; (9) In- and outlets for external temperature regulation; (10) Entrance for the thermocouple at the Peltier element; (11) Entrance for the thermocouple at the RE.
Spectra recorded after CO adsorption on a 100 nm Pt thin film. (Left) Sum reflectivity , difference reflectivity , and the raw PM-IRRA surface spectrum obtained by the quotient of the difference and the sum reflectivity ; the spectra are scaled and offset for clarity. (Right) Corresponding normalized surface spectra. Experimental parameters: CO saturated cyclohexane, flow rate 0.3 ml/min, liquid film thickness, 100 nm Pt thin film on 10 nm Ta thin film, and 298 K.
In-phase PM-IRRA liquid-phase spectrum of salicylic acid in cyclohexane and in-phase PM-IRRA surface spectrum of salicylic acid interacting with in cyclohexane. Parameters: salicylic acid in -saturated cyclohexane, liquid film thickness: ; liquid flow: 0.3 ml/min over a 10 nm thin film deposited on Al; temperature: 288 K; the spectrum is averaged over five modulation periods at a modulation frequency: 2.3 mHz.
(a) Liquid and (b) surface time-resolved PM-IRRAS signal at . Parameters: salicylic acid in -saturated cyclohexane over a 10 nm thin film, liquid film thickness: ; liquid flow: 0.3 ml/min; temperature: 288 K; the signal is averaged over 12 modulation periods at a modulation frequency: 9.37 mHz.
Temperature profile during two temperature modulation experiments with the temperature ranges set at (a) 289–301 K and (b) 289–314 K . The gray and black lines represent the temperatures measured at the Peltier element and the sample, respectively. Parameters: salicylic acid in -saturated cyclohexane over a 10 nm thin film, liquid film thickness: ; seven modulation periods at a modulation frequency of 2.35 mHz.
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