Comparison of different spreading techniques for monolayers at the air/water interface by external infrared reflection-absorption spectroscopy

A New Approach to the IR Spectroscopic Study of Molecular Orientation and Packing in Adsorbed Monolayers. Orientation and Packing of Long-Chain Primary Amines and Alcohols on Quartz

“…The unexpected absence of the splitting can be connected with the heterogeneous (domain-like) composition of the films by analogy with the interpretation of the single δ(CH 2 ) band in the IRRAS spectra of the hexadecan-1-ol LMs in the condensed state, in which orthorhombic packing dominates. 75 Figure 12 shows the ν(CH) and δ(CH) absorption bands in the IRRAS spectra of C 16 -alcohol adsorbed on a quartz surface at 1 × 10 -4 M in two independent experiments. (Additionally, in the whole spectrum (not shown), only the broad bands at 3500 and 2500 cm -1 and the band at 1630 cm -1 assigned to, respectively, the stretching and bending bands of hydroxygroups of alcohol, adsorbed water, and quarts surface perturbed by H-bonding were observed.)…”

“…At the same time, the δ(CH 2 ) bands represent broad singlets centered at 1466 cm -1 , which testifies that the packing of the alcohol molecules is hexagonal, as in the case of the hexadecan-1-ol LMs. 75 For quantitative analysis, we calculated the DR for the asymmetrical and symmetrical methylene stretching vibrations (DR asym and DR sym , respectively) and the intensity ratio, A asym / A sym , in the s-and p-polarized spectra. As seen from Table 2, in the corresponding pairs, these values are different for the adsorbed amine, being almost the same in the case of the alcohol.…”

Anisotropic aggregation and phase transition in Langmuir monolayers of methyl/ethyl esters of 2,3-dihydroxy fatty acids

“…Alexander and Schulman had reported that on compression the head group of methyl octadecanoate underwent a conformational change from the Z to the E form [23,[34][35][36]. We inferred that M-DHO underwent similar conformational change, though its head group was not the same as methyl octadecanoate.…”

Monolayer formation of short helical turn forming peptide derivatives at the air–water and air–solid interfaces

“…The conformation of the monomers of multilayer film can be dependent on the structure of solid surfaces. From the gracing incident X-ray diffraction studies, early workers have shown that monolayer transferred from mineralizing subphase would restructure depending upon the solid surface [33][34][35]. Peptide A is not undergoing gross restructure depending upon the solid surface, whereas, peptide B undergoes variations in the conformation in quartz (hydrophilic) and ZnSe (hydrophobic) surface due to restructuring depending upon nature of the slides.…”