Synthesis and self-assembly of new fluorescent cholesteryloxy-substituted fluorinated terphenyls with gel formation and mesogenic phases

Preparation and Application of Polymer-Dispersed Liquid Crystal Film with Step-Driven Display Capability

The realization of multifunctional advanced displays with better electro-optical properties is especially crucial at present. However, conventional integral full drive-based transparent display is increasingly failing to meet the demands of the day. Herein, partitioned polymerization as a novel preparation method was introduced innovatively into polymer-dispersed liquid crystals (PDLC) for realizing a step-driven display in agreement with fluorescent dye to solve the above drawback. At first, the utilization of fluorescent dye to endow the PDLC film with fluorescent properties resulted in a reduction in the saturation voltage of the PDLC from 39.7 V to 25.5 V and an increase in the contrast ratio from 58.4 to 96.6. Meanwhile, the experimental observations and theoretical considerations have elucidated that variation in microscopic pore size can significantly influence the electro-optical behavior of PDLC. Then, the step-driven PDLC film was fabricated through the exposure of different regions of the LC cell to different UV-light intensities, resulting in stepwise voltage-transmittance (V-T) responses of the PDLC film for the corresponding regions. Consequently, under appropriate driving voltages, the PDLC can realize three different states of total scattering, semi-transparent and total transparent, respectively. In addition, the PDLC film also embodied an outstanding anti-aging property and UV-shielding performance, which makes it fascinating for multifunctional advanced display applications.

Effect of Electrospinning Network Instead of Polymer Network on the Properties of PDLCs

In this study, polymer-dispersed liquid crystal (PDLC) membranes were prepared by combining prepolymer, liquid crystal, and nanofiber mesh membranes under UV irradiation. EM, POM, and electro-optic curves were then used to examine the modified polymer network structure and the electro-optical properties of these samples. As a result, the PDLCs with a specific amount of reticular nanofiber films had considerably improved electro-optical characteristics and antiaging capabilities. The advancement of PDLC incorporated with reticulated nanofiber films, which exhibited a faster response time and superior electro-optical properties, would greatly enhance the technological application prospects of PDLC-based smart windows, displays, power storage, and flexible gadgets.

Synthesis, molecular docking, and antioxidant activity of new fluorescent tetrafluoroterphenyl analogues

Nucleophilic aromatic substitution (S_N Ar) chemistry has been applied to develop many functionalized pentafluorobenzene derivatives. Those compounds are highly specific at the para position of the fluorinated ring. Therefore, they are typical adducts for the preparation of antioxidant molecular systems. In this context, we report the use of S_N Ar chemistry as a suitable and simple approach for the synthesis of fluorescent antioxidant perfluorinated materials bearing ether bonds in various para-substituted alkoxy chains and with high purity and excellent yields. The fluoroterphenyl core was prepared via alkylation, Cu(I)-assisted decarboxylation, and cross-coupling using the potassium salt of fluorobenzoate, followed by the reaction with different alcohols. The structures of the synthesized fluoroterphenyl adducts were investigated using FT-IR, ¹ H NMR, ¹³ C NMR, and ¹⁹ F NMR spectroscopy. The emission spectra and absorption spectra showed solvatochromism. The newly prepared tetrafluoroterphenyl analogues were investigated by antioxidant examination using the 2,2-diphenyl-1-picrylhydrazyl assay. Results were compared with ascorbic acid and butylated hydroxytoluene as references, and revealed that the tetrafluoroterphenyl analogues containing a decyl chain had the highest activity, with an IC₅₀ value of 22.36 ± 0.19 g/ml. The produced tetrafluoroterphenyl analogues were used in molecular docking strategies with a Protein Data Bank protein ID 5IKQ. The antioxidant investigations and docking results were convergent.

Synthesis and Self-assembly of Novel Nanofeather-like Fluorescent Alkyloxy-Containing Diphenyl Ether Organogelators

In this study, novel fluorescent low molecular-weight organogelators are derived from diphenyl ethers and substituted with para-alkoxy groups of different aliphatic chain lengths. The present research promotes the preparation of innovative nanofeather-like assemblies from the synthesized diphenyl ether-derived organogelators. The gelation performance of the prepared alkoxy-substituted diphenyl ethers was reported. The synthesis procedure was achieved by using a base-catalyzed reaction of hydroxyl-substituted diphenyl with various alcohols of different aliphatic chain lengths. The chemical structures of the synthesized diphenyl ether derivatives were studied by ¹H/¹³C NMR and infrared spectroscopy. Fluorescence and UV-vis absorption spectral analyses showed solvatochromism. The diphenyl ether derivatives with longer alkoxy terminal substituents showed enhanced thermoreversible gelation activity as compared to the diphenyl ether derivatives with shorter alkoxy terminal substituents. The morphological properties of the self-assembled diphenyl ethers were studied by transmission electron microscopy and scanning electron microscopy, which showed supramolecular architectures of highly ordered nanofeathers, enforced by van der Waals interactions and π-stacks. Depending on the length of the aliphatic tail, different morphologies were detected, including nanofeathers, nanofibers, and nanosheets. The antimicrobial and cytotoxic properties of the prepared diphenyl ether-derived organogelators were examined to confirm their possible use in various fields like drug delivery systems.