Analysis of Interfacial Water at a Hydrophilic Silicon Surface by in-Situ FTIR/Internal Reflection Spectroscopy

Langmuir ◽  
1996 ◽  
Vol 12 (17) ◽  
pp. 4176-4184 ◽  
Author(s):  
M. R. Yalamanchili ◽  
A. A. Atia ◽  
J. D. Miller
Keyword(s):  
Silicon Surface ◽  
Internal Reflection ◽  
Interfacial Water ◽  
In Situ Ftir ◽  
Reflection Spectroscopy ◽  
Internal Reflection Spectroscopy

In Situ Measurements of Water Content for Sub-Surface Planetary Applications Using Near-Infrared Internal Reflection Spectroscopy (IRS) with a Multimode Optical Fiber

2018 ◽  
Vol 74 (2) ◽  
pp. 160-167
Author(s):  
Osazonamen J. Igbinosun ◽  
Adam P. Bruckner ◽  
Stephen E. Wood
Keyword(s):  
Optical Fiber ◽  
Water Content ◽  
Near Infrared ◽  
Optical Fiber Sensor ◽  
Internal Reflection ◽  
Reflection Spectroscopy ◽  
Dispersion Effects ◽  
Spectral Shifting ◽  
Internal Reflection Spectroscopy

Results and analysis of internal reflection spectral absorbance experiments are reported for near-infrared (NIR) spectra obtained using an optical fiber sensor system. We present a preliminary study to diagnose the efficacy of our fiber optic system to observe and distinguish various phases of water, i.e., ice, liquid, and adsorbed. This study was motivated by the need for a technique capable of obtaining soil water content measurements in real time and in situ, at low humidity conditions for simulation studies of planetary bodies such as Mars. Spectral signatures were observed for the solid, liquid, and adsorbed phases of water. For all phases, peak absorbance at λ ≈1.45 and 1.94 μm was observed despite slight peak shifting due to dispersion effects. Dispersion effects commonly obscure spectra obtained with internal reflection spectroscopy for particular spectral regions. Here we report a spectral region with minimal distortions. Internal reflection spectra were compared directly to transmission spectra with only slight variations. Spectral matching was performed to determine sample penetration depths for unknown incidence angles. In general, relative absorbance and spectral shifting can distinguish spectra of the various phases of water.

scholarly journals Chemical Changes of Flattened Enamel Surfaces with in Vitro Weak Acid Demineralization

1971 ◽  
Vol 50 (6) ◽  
pp. 1589-1593 ◽  
Author(s):  
David J. Krutchkoff ◽  
Nathaniel H. Rowe
Keyword(s):  
Surface Chemistry ◽  
Weak Acid ◽  
Internal Reflection ◽  
Reflection Spectroscopy ◽  
Chemical Changes ◽  
Internal Reflection Spectroscopy

Infrared internal reflection spectroscopy (IRS) was used to study changes in surface chemistry of enamel after in vitro weak acid demineralization. Hypotheses that relate previous histomorphologic observations to current IRS findings are discussed.

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