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.     

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...     

TOF-SIMS and principal component analysis characterization of the multilayer surface grafting of small molecules: antibacterial furanones

Furanone compounds (fimbrolides) have attracted interest as antibacterial compounds for use in human health care, for instance, as an antibacterial coating for medical devices to combat device-centered infections. To ensure effectiveness for extended periods of time, they must be immobilized covalently onto a device surface; in this study, this was done via azide/nitrene chemistry and photochemical coupling. However, the detection and quantification of surface-immobilized small molecules such as furanones presents a considerable analytical challenge, yet is necessary for optimization of coatings and reliable interpretation of biological responses. We have utilized the surface sensitivity and chemical specificity of time-of-flight secondary ion mass spectrometry (TOF-SIMS) to characterize each step of the grafting sequence. On account of the complexity of the data, principal component analysis (PCA) was used to interpret and compare spectra. The results demonstrate the utility of TOF-SIMS with PCA for the detection of the surface-grafted small molecules azidoaniline and a brominated furanone; imaging of the bromine ion peaks also enabled assessment of grafting uniformity. Thus, successful multilayer coating and furanone grafting was observed, and substantial and uniform coverage of furanone molecules on the surface. Even multiple grafting steps involving, in the present case, two low molecular weight compounds can readily be disentangled by PCA. The utility of TOF-SIMS analysis with PCA is particularly well illustrated in the present case by the grafting of the furanone molecules, which did not yield a singular unique peak in the positive ion mass spectra, whereas the collective spectral changes elucidated by PCA provided unambiguous verification of successful grafting of this low molecular weight compound.     

Fabrication and characterization of biorenewable plasma polymer films using sandalwood oil precursor

Sandalwood oil is a natural, biorenewable oil which has many beneficial properties such as being anticarcinogenic and cytotoxic to some viruses, while being safe for human consumption. Therefore, thin films derived from sandalwood oil are of interest in the biomedical field. Here, thin films using sandalwood oil as the precursor are deposited via plasma polymerization with the aim of minimizing degradation of the precursor structure. The chemical properties of the plasma phase were measured by optical emission spectroscopy and the degradation pathways of the precursor molecules were elucidated via mass spectrometry. Combined with surface analysis of the thin films, partial structural retention of precursor molecules is demonstrated.     

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...     

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...