We report the synthesis of hybrid thin films based on polymethyl methacrylate) (PMMA) and polystyrene (PS) doped with 1%, 3%, 5%, and 7% of cerium dioxide nanoparticles (CeO₂ NPs). The As-prepared thin films of (PMMA-PS) incorporated with CeO₂ NPs are deposited on a glass substrate. The transmittance T% (λ) and reflectance R% (λ) of PMMA-PS/CeO₂ NPs thin films are measured at room temperature in the spectral range (250–700) nm. High transmittance of 87% is observed in the low-energy regions. However, transmittance decreases sharply to a vanishing value in the high-energy region. In addition, as the CeO₂ NPs concentration is increased, a red shift of the absorption edge is clearly observed suggesting a considerable decrease in the band gap energy of PMMA-PS/CeO₂ NPs thin film. The optical constants (n and k) and related key optical and optoelectronic parameters of PMMA-PS/Ce NPs thin films are reported and interpreted. Furthermore, Tauc and Urbach models are employed to elucidate optical behavior and calculate the band gaps of the as-synthesized nanocomposite thin films. The optical band gap energy of PMMA-PS thin film is found to be 4.03 eV. Optical band gap engineering is found to be possible upon introducing CeO₂ NPs into PMMA-PS polymeric thin films as demonstrated clearly by the continuous decrease of optical band gap upon increasing CeO₂ content. Fourier-transform infrared spectroscopy (FTIR) analysis is conducted to identify the major vibrational modes of the nanocomposite. The peak at 541.42 cm⁻¹ is assigned to Ce–O and indicates the incorporation of CeO₂ NPs into the copolymers matrices. There were drastic changes to the width and intensity of the vibrational bands of PMMA-PS upon addition of CeO₂ NPs. To examine the chemical and thermal stability, thermogravimetric (TGA) thermograms are measured. We found that (PMMA-PVA)/CeO₂ NPs nanocomposite thin films are thermally stable below 110 °C. Therefore, they could be key candidate materials for a wide range of scaled multifunctional smart optical and optoelectronic devices.

We fabricated ferroelectric films of the organic molecular diisopropylammonium chloride (DIPAC) using the dip-coating technique and characterized their properties using various methods. Fourier-transform infrared, scanning electron microscopy, and X-ray diffraction analysis revealed the structural features of the films. We also performed ab-initio calculations to investigate the electronic and polar properties of the DIPAC crystal, which were found to be consistent with the experimental results. In particular, the optical band gap of the DIPAC crystal was estimated to be around 4.5 eV from the band structure total density-of-states obtained by HSE06 hybrid functional methods, in good agreement with the value derived from the Tauc plot analysis (4.05 ± 0.16 eV). The films displayed an island-like morphology on the surface and showed increasing electrical conductivity with temperature, with a calculated thermal activation energy of 2.24 ± 0.03 eV. Our findings suggest that DIPAC films could be a promising alternative to lead-based perovskites for various applications such as piezoelectric devices, optoelectronics, sensors, data storage, and microelectromechanical systems.

We report the effect of an iodine filler on photoisomerization kinetics of photo-switchable PEO-BDK-MR thin films. The kinetics of photoisomerization and time progression of PEO-BDK-MR/I₂ nanocomposite thin films are investigated using UV-Vis, FTIR spectroscopies, and modified mathematical models developed using new analytical methods. Incorporating iodine filler into the PEO-BDK-MR polymeric matrix enhances the isomerization energy barrier and considerably increases the processing time. Our outcomes propose that enhanced photoisomerized and time processed (PEO-BDK-MR)/I₂ thin films could be potential candidates for a variety of applications involving molecular solar thermal energy storage media.

Background: Gestational diabetes mellitus (GDM) is a transient elevation of blood glucose during pregnancy. It is typically not associated with diabetic retinopathy. However, certain investigators revealed retinal microvascular injury. In this study, we aimed to assess the ophthalmic findings, optical coherence tomography (OCT) parameters, and retinal vascular thickness and macular density through fundus autofluorescence (FAF). Methods: Prospectively, women diagnosed with GDM were enrolled in this study. All the participants underwent comprehensive ophthalmic examination. Furthermore, macular OCT with analysis of the central subfield thickness (CST) and total thickness was carried out. Moreover, FAF was performed, and the macular density and retinal vascular thickness were extracted using ImageJ software. Results: Thirty-four women were enrolled. The mean maternal age was 32.7 years. No participant had diabetic retinopathy, nine eyes had early cataract, and two eyes had keratoconus. Higher levels for the 1 h oral glucose tolerance test (OGTT) were associated with a drop in the CST and total thickness. Moreover, women who underwent CS had higher levels of total thickness. Higher levels for the fasting OGTT were associated with a thinner inferior temporal retinal artery. Pregnant women with miscarriages had lower macular density on FAF, as represented by lower values of integrated density and mean gray values. Higher levels for the fasting OGTT were associated with higher values of integrated density. Conclusions: Although GDM is typically not associated with diabetic retinopathy, microscopic changes involving the microvascular environment and the macula may occur. Regular ophthalmic screening for women with GDM may be advised. Larger studies with more investigations may reveal further findings.