Physicomechanical studies on the langmuir‐blodgett films of polythiophene containing mesogenic side chains

Abstract

Liquid crystalline materials display unique properties, which can be exploited in various optoelectronic device applications. The Langmuir-Blodgett (LB) film characteristics of polythiophene model compounds containing phenyl rings linked with azomethine, ester, and alkoxy functional groups poly-4-{[(E)-thiophen-3ylmethylidene]amino}phenyl 4-alkyloxybenzoate (PTAPAB series) and poly-4-alkyloxy phenyl 4-{[(E)-thiophen-3-ylmethylidene]amino}benzoate (PAPTAB Series) were explored in this study. The AM1 optimized geometries of the aforementioned compounds showed that the films have different type of orientation in space because of the change in the linking functional group. The LB film characteristics were studied by applying the concepts of the failure mechanism in tensile failure. The compression-expansion hysteresis cycle of the LB films at predetermined area per repeat unit was used to study the viscous, elastic, and plastic nature of the films. The results showed that in PAPTAB series compounds, the LB films were more flexible and took less surface energy than its PTAPAB series homologues, which formed into LB films of rigid nature. The LB films of PAPTAB series compounds were of more viscoplastic in nature. The studies suggested that PAPTAB series structures exhibited good thin film forming nature than its PTAPAB series homologues.

Minimizing Defects in Polymer-Based Langmuir–Blodgett Monolayers and Bilayers via Gluing

“…Langmuir–Blodgett films continue to be of broad interest because of their potential as ultrathin electronic and optical materials and as ultrathin coatings and membranes. − Polymeric analogues (i.e., p -LB films) are of special interest in this regard because of their greater robustness. − Here, we show how gluing (i.e., noncovalent cross-linking of LB assemblies through ionic and hydrophobic association with a water-soluble polymer) can minimize the formation of defects within p -LB monolayers and bilayers to give higher quality thin films. , …”

Studies on the Langmuir–Blodgett films of polythiophene containing a mesogenic side chain

“…22 The inuence of linking group on the surface isotherm and packing is reported. 23 In the present study, Langmuir lms of poly4-{(E)-[4-alkoxy phenyl imino]methyl}phenyl thiophene-3-carboxylate (Fig. 1) have been studied.…”