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Optical and mechanical properties of different sizes and ratios of CdSe quantum dots (QDs)/PMMA nanocomposite films were investigated. Nanocomposite films of CdSe QDs (size = 3.75–5.23 nm)/PMMA (0.05 wt.%) were fabricated using casting technique. The optical properties of both colloidal CdSe QDs and CdSe QDs/PMMA nanocomposite films were recorded using UV–visible spectrophotometer. Red shifts in the absorption edges of CdSe/PMMA films have been seen compared with those of colloidal CdSe QDs. The mechanical properties including storage modulus, loss modulus, tan δ, and stiffness of the nanocomposite films as a function of temperature were recorded using a dynamic mechanical analyzer. An improvement in storage modulus, loss modulus, and stiffness have been observed for different sizes and ratios of CdSe QDs/PMMA as a function of temperature compared with those of pure PMMA film. The intensity of tan δ peak for pure PMMA film is larger than those of the nanocomposite films. The temperature at which the tan δ peak occurs is commonly known as the glass transition temperature (T g ). T g of CdSe QDs/PMMA nanocomposite film shifts towards higher temperature side with respect to pure PMMA film from 91 to 110 °C as CdSe QDs size decreases from 3.75 to 5.23 nm.

In the present work, the optical properties of polyvinyl alcohol (PVA)/polyvinyl pyrrolidone (PVP) (1:1) polymeric blend have been tuned in situ using tin sulfide (SnS) semiconductor for optoelectronics. The solution casting technique was used to prepare plain PVA/PVP polymeric blend and different weight ratios percentages ( x : 0, 0.1, 0.5, 1.0, 5.0 and 10.0 wt%) of SnS filled PVA/PVP polymeric blend nanocomposite films. The prepared films were characterized using a scanning electron microscope, X-ray diffractometer, FT-IR spectroscopic technique and UV–visible–NIR spectrophotometer. The effect of SnS concentration on the optical parameters (optical energy gap, refractive index, optical conductivity, dielectric constants, dispersion energy and average oscillator strength) has been investigated. The ability to tune the optical parameters of the prepared SnS nanocomposite polymeric blend films makes them effective candidates in many applications especially optoelectronics and optical devices.

The optical properties of polyvinylpyrrolidine (PVP) polymer have been enhanced using ternary Zn 1- x Sn x S as a filler for UV-region optical applications. Solution casting technique is used to prepare different Sn molar ratios ( x : 0–0.3) in Zn 1- x Sn x S filled PVP polymeric composite films (1.0 wt.%). SEM, FT-IR and UV–visible-NIR spectrophotometry is utilized to characterize the optical properties of the plain PVP and polymeric composite films. SEM images reveal the homogeneous dispersion of the filler (Zn 1- x Sn x S) in the host PVP matrix. The FT-IR spectroscopic measurements ensure the successful interaction of ternary Zn 1- x Sn x S material and the host PVP polymer. The cut off transmittance edge is shifted from 260 nm (host PVP) to 390 nm (polymeric composite). The direct optical energy bandgap of the prepared polymeric composite films are shifted from 4.78 eV (plain PVP) to 3.45 eV for Zn 0.7 Sn 0.3 S polymeric composite film. An enhancement of the refractive index ( n ) and the optical conductivity ( σ opt. ) of the polymeric composite films is achieved as compared with those of the plain one. The single oscillator ( E 0 ) and dispersion ( E d ) energies of the polymeric composite films were determined using Wemple and DiDomenico (WDD) model. The prepared polymeric composite films are strongly recommended for UV-region optical applications.

In the current work, the electrical and mechanical properties of the reduced graphene oxide/PVA (RGO/PVA) blend have been reinforced using Fe 2 O 3 nanoparticles for flexible electronic devices. Fe 2 O 3 polymeric nanocomposites (PNCs) were prepared by the solution casting technique, while Fe 2 O 3 NPs were synthesized via the hydrothermal procedure. TEM examination reveals that the prepared Fe 2 O 3 NPs possess spherical shapes with an average size of 22 nm. FT-IR analysis of the prepared PNCs shows a clear structures’ variation in the absorption bands of the PNCs due to Fe 2 O 3 NPs embedding as compared with the plain one. The electrical properties were performed using a four-probe stage under temperature sweeping. The DC electrical conductivity (σ dc ) of PVA is enhanced with four orders in magnitude via filling. A dynamic mechanical analyzer (DMA) was used to investigate the mechanical properties. DMA measurements analysis exhibits that both the storage modulus and stiffness of the plain PVA are twice enhanced due to Fe 2 O 3 embedding as compared with those of the plain one. The glassy transition temperature (T g ) values of the prepared PNCs were determined from the loss factor (Tan δ) measurements. T g values of the PNCs are shifted to larger temperatures relative to that of the pure PVA. The obtained findings recommend Fe 2 O 3 PNCs as active candidates for new flexible electronic devices.

The energy bandgap of ternary alloyed lead cobalt sulfide quantum dots has been engineered for visible light optoelectronic applications. Ternary Pb 0.8 Co 0.2 S QDs were synthesized in situ onto TiO 2 electrodes using a sub-sequential chemical bath deposition method up to 7 times. The surface morphology of the prepared alloyed Pb 0.8 Co 0.2 S QDs photoanodes was characterized using a transmission electron microscope. The X-ray diffraction technique was used to study the structural properties of the prepared alloyed photoanodes. The optical properties were characterized using a UV–visible–NIR spectrophotometer in the visible region range. The absorption of the prepared photoanodes increases as the no. of deposition times rises up to 7. Besides, the energy bandgap of the alloyed photoanodes is red-shifted from 3.15 eV (393 nm) to 1.68 eV (738 nm). These bandgap red shifts are mainly attributed to the quantum confinement effect. Based on optical properties measurements, the prepared ternary alloyed QDs could be utilized effectively in visible light optoelectronic applications.

Novel cyano-benzylidene xanthene derivatives were synthesized using one-pot and condensation reactions. A diprotic Brønsted acid (i.e., oxalic acid) was used as an effective catalyst for the promotion of the synthesis process of the new starting xanthene–aldehyde compound. Different xanthene concentrations (ca. 0.1–2.0 mM) were applied as corrosion inhibitors to control the alkaline uniform corrosion of aluminum. Measurements were conducted in 1.0 M NaOH solution using Tafel extrapolation and linear polarization resistance (LPR) methods. The investigated xanthenes acted as mixed-type inhibitors that primarily affect the anodic process. Their inhibition efficiency values were enhanced with inhibitor concentration, and varied according to their chemical structures. At a concentration of 2.0 mM, the best-performing studied xanthene derivative recorded maximum inhibition efficiency values of 98.9% (calculated via the Tafel extrapolation method) and 98.4% (estimated via the LPR method). Scanning electron microscopy (SEM) was used to examine the morphology of the corroded and inhibited aluminum surfaces, revealing strong inhibitory action of each studied compound. High-resolution X-ray photoelectron spectroscopy (XPS) profiles validated the inhibitor compounds’ adsorption on the Al surface. Density functional theory (DFT) and Monte Carlo simulations were applied to investigate the distinction of the anticorrosive behavior among the studied xanthenes toward the Al (111) surface. The non-planarity of xanthenes and the presence of the nitrile group were the key players in the adsorption process. A match between the experimental and theoretical findings was evidenced.

(Tl2O3)30-(Li2O)10-(B2O3)(60−y)-(Sm2O3)y glass system with various Sm2O3 additives (y = 0, 0.2, 0.4, 0.6) was studied in detail. The vibrational modes of the (Tl2O3)30-(Li2O)10-(B2O3)(60−y) network were active at three composition-related IR spectral peaks that differed from those mixed with Samarium (III) oxide at high wavenumber ranges. These glass samples show that their permeability increased with the Samarium (III) oxide content increase. Additionally, the electronic transition between localized states was observed in the samples. The MAC, HVL, and Zeff values for radiation shielding parameters were calculated in the energy range of 0.015–15 MeV using the FLUKA algorithm. In addition, EBF, EABF, and ΣR values were also determined for the prepared glasses. These values indicated that the parameters for shielding (MAC, HVL, Zeff, EBF, EABF, and ΣR) are dependent upon the Samarium (III) oxide content. Furthermore, the addition of Samarium (III) oxide to the examined glass samples greatly reinforced their shielding capacity against gamma photon. The findings of the current study were compared to analyses of the XCOM software, some concretes, and lead. In the experiment, it was found that the SMG0.6 glass sample was the strongest shield.

Air particulate matter with a diameter of 2.5 µm (PM2.5) were assembled for a whole year from the historical Jeddah district. Additional PM2.5 aerosols were collected during the autumn and winter seasons from another newly constructed district in Jeddah city (Alnaeem). The annual concentration of the total mass of the PM2.5 aerosols from the historical Jeddah site was found to be 43 ± 6 µg/m3. In addition, the average of the total mass concentration at the Alnaeem site was 61 ± 14 µg/m3. These values were greater than the annual mass concentration of the air quality standards of the European Commission (25 µg/m3) and the World Health Organization (10 µg/m3). The elemental analysis of the collected fine atmospheric aerosols was achieved by energy dispersive X-ray fluorescence (EDXRF) with three secondary targets (CaF2, Ge, and Mo). Quantitative elemental analyses of twenty-two (22) elements were achieved starting from the low atomic number element (Na) up to the high atomic number element (Pb). Although the historical Jeddah site is not well organized, the elemental concentrations and total mass concentrations were lower than those of the other site. The statistical analyses including enrichment factors, correlation analysis, and the principal component analysis revealed more information about the source identification of the PM2.5 aerosols collected from both locations. It was recognized that the elements Al, Si, K, Ca, Ti, Mn, Fe, Rb, and Sr originated from a natural source. On the other hand, the elements Ta, Br, Pb, Sc, Ni, Cu, Zn, and S originated from anthropogenic sources. Finally, the elements Na, Cl, and Br came mainly from the sea spray source.

The optical properties of ternary alloyed Cd 1−x Pb x S (x: 0, 0.33, 0.5, 0.67 and 1) quantum dots (QDs) photoanodes are studied using photoacoustic (PA) technique. Ternary alloyed Cd 1−x Pb x S QDs were adsorbed onto TiO 2 electrodes using successive ionic layer adsorption and reaction technique. The structural properties of the prepared QDs photoanodes have been investigated. X-ray diffraction measurements confirm the formation the cubic crystalline structures of the ternary alloyed Cd 1−x Pb x S QDs photoanodes. The elemental analysis of the ternary alloyed Cd 1−x Pb x S QDs were studies using an energy dispersive X-ray spectrometer. The optical properties of the ternary alloyed Cd 1−x Pb x S QDs photoanodes have been studied with PA technique, UV–visible spectrophotometer and photoluminescence spectrofluorometer. The energy band gap of the prepared ternary QDs alloys decreases from 2.74 to 1.87 eV as x value increases from 0 to 1.0. This red shift in the energy band gap is due to alloying and Pb incorporation. The modified Vegard’s model is used to calculate the bulk values of the energy band gap of alloyed Cd 1−x Pb x S. Also, the bowing parameter of the ternary alloyed Cd 1−x Pb x S QDs is determined and equal 0.49 eV. The size of the prepared alloyed QDs are calculated for both CdS QDs (x = 0) and PbS QDs (x = 1) using the effective approximation (EMA) model and found 2.06 and 2.09 nm respectively.

Polyvinyl alcohol (PVA) is considered as one of the most attractive polymers due to its unique physical and chemical characteristics. This work aims to enhance the optical and electrical performance of PVA/MWCNTs blend via doping with Cu/ZnS nanoparticles (NPs) for flexible eco-friendly applications. The optical and electrical performance of MWCNTs/PVA blend has been enhanced via doping with Cu/ZnS nanoparticles (NPs) for flexible optoelectronics. Undoped and Cu/ZnS doped MWCNTs/PVA polymeric nanocomposites (PNCs) films were equipped by casting method. The structure and optical characteristics were explored using Fourier transform infrared (FT-IR) and UV–visible–NIR spectrophotometery. The electrical properties as a function of temperature were studied using a four-probe stage and a Keithley sourcemeter. FT-IR measurements reveal clear variations in the structure of the PNCs due to Cu/ZnS doping. The impact of Cu/ZnS content on the major optical constants of MWCNTs/PVA has been investigated. The direct/indirect optical bandgap ( E g dir . / E g indir ) decreases from 5.40 and 4.92 eV (undoped MWCNTs/PVA) to 4.77 eV and 4.24 eV (5 wt% PNCs). Wemple-DiDomenico (WDD) and Sellmeier oscillator models were used to investigate the dispersion constants. The influence of Cu/ZnS content on electrical conductivity ( σ dc ) and activation energy has been explored. Great enhancement of the optical and electrical constants of MWCNTs/PVA is achieved via doping with Cu/ZnS NPs. The obtained results nominate Cu/ZnS PNCs for applications in flexible optoelectronics. Graphical abstract