Characterization of orientation of perfluorostearic acid Langmuir–Blodgett multilayers by infrared spectroscopic methods

Structure of Phase-Separated Langmuir−Blodgett Films of Hydrogenated and Perfluorinated Carboxylic Acids Investigated by IR Spectroscopy, AFM, and FFM

“…The ν(CF) + r(CF 2 ) + δ(CF 2 ) region of the TIR spectra of the LB films of PA and those of the mixtures of AA and PA are shown in Figure B. Two absorption bands are evident at 1153 and 1207 cm -1 due to ν s (CF 2 ) + δ(CF 2 ) and ν(CF 2 ) + ν(CF 3 ), respectively . A shoulder is seen at ca.…”

“…IR spectroscopy has been used to investigate the structures of LB films. In particular, molecular packing, molecular orientation, and ionized state of functional groups have been clarified using IR spectroscopy. − Figure shows the TIR spectra of AA and PA in KBr pellet. The spectrum of AA is almost the same as that in the literature; the ν(CH) region in 3000−2800 cm -1 , ν(CO) at ca.…”

“…The spectrum of PA is also essentially the same as that in the literature; ν(CO) at ca. 1770−1760 cm -1 with splitting and ν(CF) + r(CF 2 ) + δ(CF 2 ) region in 1300−1100 cm -1 3 Transmission IR spectra of AA (solid line) and PA (broken line) in KBr pellets. …”

“…1240 cm -1 due to ν(CF 2 ) + r(CF 2 ). There are different assignments to the above three bands. − It is clear that the positions of these bands are the same irrespective of the mixing ratio, indicating that molecular packing does not change with mixing.

4 Transmission IR spectra in the range 3000−2800 cm -1 (A) and 1300−1100 cm -1 (B) of the LB films: solid line, AA; dotted line, AA/PA = 3/1; dashed line, AA/PA = 1/1; dashed−dotted line, AA/PA = 1/3; dashed−dotted−dotted line, PA.

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Infrared spectroscopic study of the molecular orientation in LB-multilayers of an amphiphilic oxadiazole

“…Information about molecular orientation in LB-layers has been obtained by evaluation of both infrared transmission spectra using transparent samples and reflection spectra of layers on metallic or other substrates [7][8][9][10][11]. Since transmission spectroscopy at normal incidence is sensitive to transition moments within sample plane, whereas reflection spectroscopy at grazing incidence using layers on metal substrates is sensitive nearly exclusively to transition moments perpendicular to sample surface (the transversal component of the electric vector of the incident wave approximately vanishes ) [12], the combination of the results of these experiments is well suited to study molecular orientation.…”