Impact of the Liquid Crystal Order of Poly(azomethine-sulfone)s on the Semiconducting Properties

Abstract

Organic semiconductors are an attractive class of materials with large application in various fields, from optoelectronics to biomedicine. Usually, organic semiconductors have low electrical conductivity, and different routes towards improving said conductivity are being investigated. One such method is to increase their ordering degree, which not only improves electrical conduction but promotes cell growth, adhesion, and proliferation at the polymer–tissue interface. The current paper proposes a mathematical model for understanding the influence of the ordering state on the electrical properties of the organic semiconductors. To this end, a series of aromatic poly(azomethine)s were prepared as thin films in both amorphous and ordered states, and their supramolecular and electrical properties were analyzed by polarized light microscopy and surface type cells, respectively. Furthermore, the film surface characteristics were investigated by atomic force microscopy. It was established that the manufacture of thin films from mesophase state induced an electrical conductivity improvement of one order of magnitude. A mathematical model was developed in the framework of a multifractal theory of motion in its Schrodinger representation. The model used the order degree of the thin films as a fractality measure of the physical system’s representation in the multifractal space. It proposed two types of conductivity, which manifest at different ranges of fractalization degrees. The mathematical predictions were found to be in line with the empirical data.

Comparative Study of Bis-Schiff Case Containing Conjugated Oligomers Based on Phosphate and Silane Moieties: Investigation of Photophysical and Thermal Properties

“…66 Consequently, the Schiff base monomers depicted in Figures 2A and S1A exhibited the presence of free hydroxyl protons (OH) and azomethine protons (HC�N), indicative of their exclusive existence in the phenol-form, as elucidated. 67 This deduction was further substantiated by the nonappearance of the quinoidal C�O signal (δ = 190−220 ppm) 68 in the 13 C NMR spectra of SCH-1 and SCH-2, as seen in Figure 2B and Figure S1B.…”

“…The 13 C NMR spectra of P1−P and P1−Si are displayed in Figure 4A,B, respectively. The carbon signals for the −HC� N-group in P1−P and P1−Si were determined based on the peaks seen at 170.52 ppm and 172.24 ppm, respectively.…”

“…This determination is supported by the absence of an observable peak at around 1700 cm −1 , characteristic of the C�O stretching band. A methodology can be outlined herein for distinguishing between tautomers of SCH-1 and SCH-2, relying on the identification of specific carbon types, namely, the carbonyl carbon (C�O) and phenolic carbon (�C−OH) atoms, through their respective 13 C NMR chemical shifts. In the 13 C NMR spectra of SCH-1 and SCH-2, the absence of peaks corresponding to carbonyl carbons (C�O) is noteworthy.…”

“…The pronounced allure surrounding these conjugated polymers stems from their commendable attributes encompassing thermal stability, mechanical robustness, optoelectronic qualities, photovoltaic potential, paramagnetism, electrical conductance, liquid crystalline behavior, therapeutic functionality, and their propensity to form metal complexes. − These attributes render poly(azomethine)s suitable for sensor applications and light-emitting materials. Furthermore, diversely modified iterations of poly(azomethine)s, such as poly(azomethine-ether)s, , poly(azomethine-urethane)s, poly(azomethine-sulfone)s, and poly(azomethine-carbonate)s, have been synthesized to enhance the solubility and processability of these distinctive polymer variants.…”

“…5−9 These attributes render poly(azomethine)s suitable for sensor applications and light-emitting materials. Furthermore, diversely modified iterations of poly(azomethine)s, such as poly(azomethine-ether)s, 10,11 poly(azomethine-urethane)s, 12 This article is licensed under CC-BY 4 poly(azomethine-sulfone)s, 13 and poly(azomethinecarbonate)s, 14 have been synthesized to enhance the solubility and processability of these distinctive polymer variants. Poly(azomethine)s have emerged as prominent subjects of investigation owing to their intricate optical and electronic characteristics and have been extensively reviewed in the context of optoelectronic appliances with the inclusion of polymer light-emitting diodes and polymer solar cells.…”