Synthesis and Photoinduced Anisotropy of Polymers Containing Nunchaku-Like Unit with an Azobenzene and a Mesogen

Influence of heating temperature on the optical response properties and surface relief patterns of TiO2/GeO2/ormosils composite films containing azobenzene

With the progress of modern integrated optical technology, organic-inorganic composite materials have been widely used in integrated optoelectronic devices. Because of satisfying optical response properties among azobenzene, it will be an ideal choice to introduce the material into organic-inorganic composite materials. TiO₂/GeO₂/ormosils composite films containing azobenzene were prepared by combining the solgel technique with the spin-coating process. The optical transmission modes and loss of as-prepared samples at different transmission wavelengths were researched by a prism coupler. The result shows that the composite film is multi-mode transmission at the transmission wavelength of 633 nm and single-mode transmission at 1538 nm. The transmission loss is sufficient for applications in optical elements. The response properties and Fourier transform infrared spectroscopy of as-prepared samples at different heating temperatures were also studied. The composite films obtained at 50°C have the best optical response properties. Furthermore, the banding energy and chemical composition among the films were measured through x-ray photoelectron spectroscopy. Finally, the surface topography of as-prepared samples was observed by atomic force microscopy. The surface of the composite film appears with patterns of relief under the appropriate temperature. The above results show that the as-prepared TiO₂/GeO₂/ormosils composite films containing azobenzene will be a kind of ideal material in the field of integrated optics applications.

Absorption and Isomerization of Azobenzene Guest Molecules in Polymeric Nanoporous Crystalline Phases

PPO co-crystalline (CC) films including azobenzene guest molecules have been prepared and characterized by WAXD, FTIR and UV-Visible measurements. Isomerization reactions of azobenzene (photo-induced trans to cis and spontaneous cis to trans) included in α and β nanoporous-crystalline (NC) phases leading to CC phases, or simply absorbed in amorphous phase have been studied on thick and thin films. Spectroscopic analysis shows that photo-isomerization of azobenzene occurs without expulsion of azobenzene guest molecules from crystalline phases. Sorption studies of α and β NC films immersed into photo-isomerized azobenzene solution reveal a higher selectivity of the β NC phase toward cis azobenzene isomer than the α NC phase, inducing us to propose the β NC phase as particularly suitable for absorbing spherically bulky guest molecules.

Titanium content influence on the optical response characteristics of TiO2/ormosils composite films doped with azobenzene

TiO₂-based organic-inorganic composite films doped with azobenzene and photosensitive groups were prepared by combining a low-temperature solgel technique and a spin-coating method. The influence of TiO₂ content on the optical and structural properties of the composite films including the film thickness, the refractive index, the transmission loss, the thermal gravity analysis, and Fourier transform infrared spectroscopy spectra was studied. Photoisomerization and optical switching characteristics of the composite film were investigated under the irradiation of 365 nm ultraviolet light and 450 nm visible light. Results indicate that several micrometer thick films can be easily obtained at room temperature and there is a proportional relationship between the refractive index value and the TiO₂ content. In addition, the composite films have a low optical propagation loss of about 0.1 dB/cm. The composite films with 0.2 M TiO₂ content have an obvious photoisomerization and good optical switching properties. Finally, the hexagonal microlens array was fabricated in the composite films by using an ultraviolet nanoimprint technology. All these results above indicate that the as-prepared TiO₂-based organic-inorganic composite film has potential applications in optical switching devices and photonic elements.

N-Alkylated Iminosugar Based Ligands: Synthesis and Inhibition of Human Lysosomal β-Glucocerebrosidase

The scope of a series of N-alkylated iminosugar based inhibitors in the d-gluco as well as d-xylo configuration towards their interaction with human lysosomal β-glucocerebrosidase has been evaluated. A versatile synthetic toolbox has been developed for the synthesis of N-alkylated iminosugar scaffolds conjugated to a variety of terminal groups via a benzoic acid ester linker. The terminal groups such as nitrile, azide, alkyne, nonafluoro-tert-butyl and amino substituents enable follow-up chemistry as well as visualisation experiments. All compounds showed promising inhibitory properties as well as selectivities for β-glucosidases, some exhibiting activities in the low nanomolar range for β-glucocerebrosidase.

Facile Synthesis of Self-Assembled NiFe Layered Double Hydroxide-Based Azobenzene Composite Films with Photoisomerization and Chemical Gas Sensor Performances

Two kinds of layered double hydroxide (LDH) Langmuir composite films containing azobenzene (Azo) groups were successfully prepared by Langmuir-Blodgett (LB) technology. Then, an X-ray diffractometer (XRD), a transmission electron microscope (TEM), and an atomic force microscope (AFM) were used to investigate the structures of NiFe-LDH and the uniform morphologies of the composite LB films. The photoisomerization and acid-base gas sensor performances of the obtained thin film samples were tested by infrared visible (FTIR) spectroscropy and ultraviolet visible (UV-vis) spectroscropy. It is proved that the Azo dye molecules in the composite film are relatively stable to photoisomerization. In addition, the prepared composite films have high sensing sensitivity and good recyclability for acid-base response gases. The present research proposes a new clue for designing thin film materials for chemical gas response with good stability and sensitivity.