Self-cleaning antireflected surfaces based on treated PEO/SiO2 nanocomposite films

In this study, the polyethylene oxide (PEO)/SiO₂ nanoparticles (NPs) nanocomposite films with various SiO₂ NPs concentrations were prepared using an in situ formation of NPs in the polymer matrix for self-cleaning antireflected surface applications. The effect of SiO₂ NPs in PEO/SiO₂ NPs nanocomposite films on the structural, morphological, chemical, thermal, optical, and electrical properties of PEO/SiO₂ NPs nanocomposite films was performed. According to the x-ray diffraction and the differential scanning calorimetry analysis, the crystallinity degree of the nanocomposite films decreases by increasing the SiO₂ NPs concentrations. The bandgap energy of PEO/SiO₂ NPs nanocomposite films decreases from 3.95 to 3.55 eV as the SiO₂ NPs concentration increases up to 10 wt.%. The average electrical conductivity of the PEO/SiO₂ NPs nanocomposite films increases from 5.1 × 10⁻⁷ to 2.0 × 10⁻⁶ S/cm as the SiO₂ NPs concentration increases up to 10 wt.%. The refractive index decreases to 1.64 at 550 nm for the PEO/SiO₂ NPs nanocomposite films with 10 wt.% of SiO₂ NPs, and the water contact angle decreases to around 0° after thermal treatment, which confirms that the PEO/SiO₂ NPs nanocomposite films can be used as self-cleaning antireflected surfaces.     

Synthesis,optoelectronic and thermal characterization of PMMA-MWCNTs nanocomposite thin films incorporated by ZrO2 NPs

PMMA polymer doped by multi-walled carbon nanotubes (MWCNTs) has attracted much attention as promising materials for photovoltaic and optoelectronic applications. The undoped poly(methyl methacrylate) (PMMA) and PMMA/MWCNTs nanocomposite films doped with varying concentrations of Zirconium dioxide nanoparticles (ZrO₂ NPs) are synthesized using the casting method. It is found that the transmittance (\(T\%\)) decreases significantly as wt%?=?5% of MWCNTs is injected into PMMA matrix. In addition, increasing the concentration of ZrO₂ NPs into PMMA- MWCNTs nanocomposite thin films results in a further reduction of the transmittance and a further increase of the reflectance (\(R\%\)). The optical band gap energy (E_g) of PMMA-MWCNTs/ZrO₂ NPs decreases from 4.063 \(eV\) to 3.845 \(eV\) upon injection of 5% of MWCNTs and gradually increasing the ZrO₂ concentration in PMMA matrix. Furthermore, other essential optical parameters are estimated using different classical models such as Drude, Spitzer-Fan, Sellmeier, and Wemple–DiDomenico (WDD). Interestingly, thermal stability of PMMA-MWCNTs nanocomposite films is enhanced dramatically upon increasing the content of ZrO₂ NPs. The synthesized nanocomposite thin films could be potential candidates for fabrication realistic scaled optoelectronic devices.

     

Effect of hydrogen-related shallow donor on the physical and chemical properties of Ag-doped ZnO nanostructures

Journal of Materials Science: Materials in Electronics - Silver-doped zinc oxide nanostructures (Ag/ZnO NSs) with Ag content of 0 wt%, 5 wt%, 10 wt%, and 20 wt% were synthesized using a...     

Studies of composite films of polyethylene oxide doped with potassium hexachloroplatinate

The permittivity and conductivity relaxation processes of polyethylene oxide (PEO) composite along with potassium hexachloroplatinate (K₂PtCl₆) electrolytes additive forming PEO/K₂PtCl₆ complex composite have been investigated. The complex composite has been used as a model for dry-polymer electrolytes (PEs) due to the fact that, the anion is large enough for mimicking the immobilized anion in real dry-polymer electrolytes. Stand-free composite films with 0%, 1%, 3%, and 5% concentrations of K₂PtCl₆ have been studied using broadband dielectric spectroscopy in the temperatures range from 150 K until 345 K. The microstructural dynamics revealed the α-, β-, and σ-relaxations and their salient spectral characteristics at various concentrations of K₂PtCl₆ in PEO. The experimental ε” master curves were fitted to HN function for one and/or two relaxation peaks with and without the electrical conductivity contribution in order to investigate the relaxation time (τ), dielectric strengths (Δε), modulus formalism (M”) and the electrical conductivitie (σ). The translational and reorientational degrees of freedom of PEO/K₂PtCl₆ complex composites are responsible for the relaxation behavior which is predicted to be correlated to the relaxation behavior of the polymer electrolyte below and above the glass transition temperature (T_g). The relaxation time (τ) deduced from β-relaxation follows Arrhenius-like behavior while that deduced from α-relaxation process follows Vogel–Tamman–Fulcher (VTF) behavior.     

Optical and structural properties of (PANI-CSA-PMMA)/NiNPs nanocomposites thin films for organic optical filters

Synthesized nanocomposite of protonated polyaniline with camphorsulfonic acid (PANI-CSA) hosted in poly(methyl methacrylate) (PMMA) and incorporated with nickel nanoparticles (NiNPs) were coated as thin films on activated fused silica substrates using oxygen-plasma and spin coating techniques. Weight percent ratios of 0, 10, 20, 30, 60, and 90% of NiNPs with respect to PANI-CSA thin films have been studied in order to investigate the optical, structural, and morphological properties of (PANI-CSA-PMMA)/NiNPs by employing UV–Vis spectrometer, XRD, scanning electron microscopy (SEM), contact angle (CA) goniometry, impedance analyzer, and thermogravimetric analysis. Deduced refractive indices (n) from UV–Vis data were in the range from 1.5 up to 2.2. SEM micrographs show the typical crystalline structure of PANI was vanishing gradually with increasing the NiNPs content. Optical properties such as refractive index (n), extinction coefficient (k), absorption coefficient (α) as well as the band-gap energies (E_g) were mathematically deduced throughout the experimental transmittance and absorbance UV–Vis spectra. Calculated refractive indices (n) were in the range from 1.5 up to 2.2. Optical band-gap energies decrease in a monoexponential decay for samples up to 60% NiNPs/PANI-CSA, samples with 90% concentration had substantial drop in its value due to the NiNPs percolations. The incorporation with NiNPs leads to the development of a new morphological states (sheet-like heterostructure) which start to be obvious at 30%, at this concentration the CA was maxima (54°), at this concentration and the crystallite size are maximum and the CA was maximum (highest hydrophobicity). © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48643.     

Structural,chemical, morphological and optical properties of thin films based on potassium bis(2-methyllactato) borate hemihydrate doped by iodine

Journal of Materials Science: Materials in Electronics - Complex composite films of potassium bis(2-methyllactato) borate hemihydrate (KMB) doped with iodine (I2) were dip-synthesized on glass...     

Constant and Intermittent Drying Characteristics of Olive Cake

The drying kinetics of olive cake, the solid by-product of the olive oil extraction process, has been experimentally investigated in a small-scale tray dryer using both constant and intermittent (on/off) heating schemes. The parameters investigated include inlet air temperature and intermittency of heat input. The drying kinetics was interpreted through two mathematical models, the Page equation and the Lewis equation. The Page equation was most appropriate in describing the drying behavior of olive cake. A diffusion model was used to describe the moisture transfer and the effective diffusion coefficient at each temperature was determined. The dependence of the effective diffusion coefficient on drying temperature can be adequately explained based on an Arrhenius-type relation. The effective diffusion coefficient varied between 7.6 × 10^?8 and 2.5 × 10^?7 m²/min with an activation energy of 38.55 kJ/mol. Comparison of time evolution of material moisture content due to intermittent and constant drying is also made.     

Optical and electrical analysis of polyethylene oxide/disodium hexachloroplatinate complex composite films

The present study reports the synthesis of composite films comprising PEO/Na₂PtCl₆ complex and their deposition onto fused silica substrates via the dip-coating method. Chemical, crystallographic, and thermal characterizations are carried out to confirm the incorporation of Na₂PtCl₆ and PEO matrix into the films. The transmittance of the PEO film is initially high and decreases subsquently with an increase in Na₂PtCl₆ content. The optical band-gap energy of the composite films decreases exponentially from 4.62 to 3.79 eV with the increase in Na₂PtCl₆ content. Furthermore, in the normal dispersion region, the refractive index of the PEO film decreases from 2.00 to 1.670 as the wavelength increases from 400 to 700 nm. The refractive index values increase with an increase in the concentration of Na₂PtCl₆ in the PEO film up to 8 wt.%. The incorporation of Na₂PtCl₆ into the PEO matrix increases the electrical conductivity because of the combined enhancement of the PEO conductivity and increase i Na₂PtCl₆. These findings suggest that PEO/Na₂PtCl₆ complex composite films have potential applications in UV-shielding and optoelectronic devices.     

Optical and structural properties of aluminium nitride thin-films synthesized by DC-magnetron sputtering technique at different sputtering pressures

Microsystem Technologies - Aluminium nitride thin-films (AlN) were fabricated by a DC-magnetron sputtering technique at different background pressures while maintaining the same deposition...     

Constant and Intermittent Drying Characteristics of Olive Cake

The drying kinetics of olive cake, the solid by-product of the olive oil extraction process, has been experimentally investigated in a small-scale tray dryer using both constant and intermittent (on/off) heating schemes. The parameters investigated include inlet air temperature and intermittency of heat input. The drying kinetics was interpreted through two mathematical models, the Page equation and the Lewis equation. The Page equation was most appropriate in describing the drying behavior of olive cake. A diffusion model was used to describe the moisture transfer and the effective diffusion coefficient at each temperature was determined. The dependence of the effective diffusion coefficient on drying temperature can be adequately explained based on an Arrhenius-type relation. The effective diffusion coefficient varied between 7.6 × 10^-8 and 2.5 × 10^-7 m²/min with an activation energy of 38.55 kJ/mol. Comparison of time evolution of material moisture content due to intermittent and constant drying is also made.