Polarized Infrared Attenuated Total Reflection for the in Situ Determination of the Orientation of Surfactant Adsorbed at the Solid/Solution Interface

1998 ◽  
Vol 102 (26) ◽  
pp. 5107-5114 ◽  
Author(s):  
David J. Neivandt ◽  
Michelle L. Gee ◽  
Michael L. Hair ◽  
Carl P. Tripp
Keyword(s):  
Solid Solution ◽  
Total Reflection ◽  
Attenuated Total Reflection ◽  
Solution Interface

In situ nanoscale visualization of solvent effects on molecular crystal surfaces

CrystEngComm ◽  
2021 ◽  
Author(s):  
Mikkel Herzberg ◽  
Anders Støttrup Larsen ◽  
Tue Hassenkam ◽  
Anders Østergaard Madsen ◽  
Jukka Rantanen
Keyword(s):  
Solid Solution ◽  
Solvent Effects ◽  
Molecular Crystal ◽  
Rational Design ◽  
Molecular Level ◽  
Molecular Crystals ◽  
Crystal Surfaces ◽  
Solution Interface ◽  
Atomic Force

Solvents can dramatically affect molecular crystals. Obtaining favorable properties for these crystals requires rational design based on molecular level understanding of the solid-solution interface. Here we show how atomic force...

scholarly journals Toward Chalcogenide Platform Infrared Sensor Dedicated to the In Situ Detection of Aromatic Hydrocarbons in Natural Waters via an Attenuated Total Reflection Spectroscopy Study

Sensors ◽  
2021 ◽  
Vol 21 (7) ◽  
pp. 2449
Author(s):  
Marion Baillieul ◽  
Emeline Baudet ◽  
Karine Michel ◽  
Jonathan Moreau ◽  
Petr Němec ◽  
...  
Keyword(s):  
Natural Water ◽  
Natural Waters ◽  
Total Reflection ◽  
Attenuated Total Reflection ◽  
Infrared Sensor ◽  
Reflection Spectroscopy ◽  
Infrared Spectral ◽  
Micro Sensor ◽  
In Situ Detection

The objective of this study is to demonstrate the successful functionalization of the surface of a chalcogenide infrared waveguide with the ultimate goal of developing an infrared micro-sensor device. First, a polyisobutylene coating was selected by testing its physico-chemical compatibility with a Ge-Sb-Se selenide surface. To simulate the chalcogenide platform infrared sensor, the detection of benzene, toluene, and ortho-, meta- and para-xylenes was efficaciously performed using a polyisobutylene layer spin-coated on 1 and 2.5 µm co-sputtered selenide films of Ge28Sb12Se60 composition deposited on a zinc selenide prism used for attenuated total reflection spectroscopy. The thickness of the polymer coating was optimized by attenuated total reflection spectroscopy to achieve the highest possible attenuation of water absorption while maintaining the diffusion rate of the pollutant through the polymer film compatible with the targeted in situ analysis. Then, natural water, i.e., groundwater, wastewater, and seawater, was sampled for detection measurement by means of attenuated total reflection spectroscopy. This study is a valuable contribution concerning the functionalization by a hydrophobic polymer compatible with a chalcogenide optical sensor designed to operate in the mid-infrared spectral range to detect in situ organic molecules in natural water.

scholarly journals The Anomalous Influence of Polyelectrolyte Concentration on the Deposition and Nanostructure of Poly(ethyleneimine)/Poly(acrylic acid) Multilayers

Molecules ◽  
2019 ◽  
Vol 24 (11) ◽  
pp. 2141 ◽  
Author(s):  
Martin Müller
Keyword(s):  
Acrylic Acid ◽  
Attenuated Total Reflection ◽  
Silicon Substrates ◽  
Acid Base ◽  
Exponential Relationship ◽  
Individual Adsorption ◽  
The Individual ◽  
Poly Acrylic Acid

The deposition and nanostructure of polyelectrolyte (PEL) multilayers (PEMs) of branched poly(ethyleneimine)/poly(acrylic acid) (PEI/PAA) onto silicon substrates was studied in terms of the dependence of pH and the PEL concentration (cPEL) in the individual adsorption steps z. Both a commercial automatic dipping device and a homebuilt automatic stream coating device (flow cell) were used. Gravimetry, SFM, transmission (TRANS) and in situ attenuated total reflection (ATR) FTIR spectroscopy were used for the quantitative determination of the adsorbed amount, thickness, chemical composition and morphology of deposited PEMs, respectively. Firstly, the combination of pH = 10 for PEI and pH = 4 for PAA, where both PEL were predominantly in the neutral state, resulted in an extraordinarily high PEM deposition, while pH combinations, where one PEL component was charged, resulted in a significantly lower PEM deposition. This was attributed to both PEL conformation effects and acid/base interactions between basic PEI and acidic PAA. Secondly, for that pH combination an exponential relationship between PEM thickness and adsorption step z was found. Thirdly, based on the results of three independent methods, the course of the deposited amount of a PEM-10 (z = 10) versus cPEL in the range 0.001 to 0.015 M at pH = 10/4 was non-monotonous showing a pronounced maximum at cPEL = 0.005 M. Analogously, for cPEL = 0.005 M a maximum of roughness and structure size was found. Fourthly, related to that finding, in situ ATR-FTIR measurements gave evidence for the release of outermost located PEI upon PAA immersion (even step) and of outermost PAA upon PEI immersion (odd step) under formation of PEL complexes in solution. These studies help us to prepare PEL-based films with a defined thickness and morphology for interaction with biofluids in the biomedical and food fields.

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