Spectroscopic characterizations of the mixed Langmuir–Blodgett (LB) films of 2,2′-biquinoline molecules: Evidence of dimer formation

Abstract

Abstract:3 This communication reports the π -A isotherms and spectroscopic characterizations of mixed Langmuir and Langmuir-Blodgett (LB) films of nonamphiphilic 2, 2 -biquinoline (BQ) molecules, mixed with polymethyl methacrylate (PMMA) and stearic acid (SA). The

Role of microenvironment in the mixed Langmuir–Blodgett films

“…The close similarity of the absorption spectra of the mixed LB films at higher mole fractions to that of the microcrystal spectrum may be due to the formation of low-dimensional microcrystalline aggregates in the mixed LB films. It may be mentioned in this context that there are certain rigid nearly planar platelike molecules, namely pyrene [19], or rodlike molecules, anthracene [20] or biquinoline [14], that form aggregates in the mixed LB films. These molecules are sandwiched among the matrix molecules (SA/PMMA) to form aggregates in the LB films and partial or total binary demixing occurs in the mixed LB films.…”

Photophysical characterizations of 2-(4-biphenylyl)-5 phenyl-1,3,4-oxadiazole in restricted geometry

“…Non-amphiphilic molecules are not ideally suited for thin film deposition by this technique. However, some recent works [10][11][12][13][14][15][16][17] showed that highly organized LB films of these materials can be formed, when a long-chain fatty acid or some inert polymer matrix was used as the supporting medium. Since these non-amphiphilic molecules are easily available and have wide varieties having different interesting physical properties, hence a lot of investigations on LB films using these molecules are necessary.…”

J-aggregates of thiacyanine dye organized in LB films: Effect of irradiation of light

“…Allowing 15 min to evaporate the solvents, the barrier was compressed at a rate of 10 mm / min to record the surface pressure -area (π-A) per molecule isotherm. The surface pressure (π) versus average area available for one molecule (A) was measured by a Wilhelmy plate arrangement, as described elsewhere [31][32]. Stability tests for the Langmuir films were done by checking the variation of area per molecule keeping the surface pressure constant during 1 h. The films were found to be stable.…”