Search

Zinc oxide (ZnO)‐based composites are among the semiconductor photocatalytic materials that exhibit promising research opportunities in the fields of optical, biomedical, and environmental materials because of their excellent physical stability, biocompatibility, low cost, and ease of fabrication. This article discusses the fabrication and use of ZnO‐based composites with excellent catalytic activity. Here, the various combinations of sol‐gel ZnO coatings were prepared using the spin coating technique, and characterized by 3D laser profilometry, UV–visible spectroscopy, scanning electron microscopy (SEM). To determine the main functional groups, present in the prepared polymeric film, an FTIR investigation was conducted. The inclusion of Aloe vera with PF‐127 in the ZnO lattice is confirmed by the structural study of the X‐ray diffraction (XRD) pattern of Z‐PS, ZAL‐PS, and ZALPF‐PS, which showed a hexagonal wurtzite crystal structure and increasing in the peak position. The variation in strcuture and bandgap play major role in the enhancement of photocatalytic and antibacterial activity with ZALPF‐PS as compared to ZAL‐PS and Z‐PS. In contrast, water contact angle analysis reveals that the polymeric coating changes the surface roughness while simultaneously increasing the surface nonwettability. The prepared samples are also shown to be more resistant to Escherichia coli and Pseudomonas aeruginosa than standard antibiotics. This occurred because photocatalytic activity and superhydrophobic contact work together as a synergistic antibacterial mechanism. Furthermore, the nonwettable cotton substrate was also prepared, and their roughness behavior examined, which exhibited superhydrophobic performance against water, milk, coke, and coffee, which can be useful for medical purposes. [ABSTRACT FROM AUTHOR]

Anti‐reflection coatings have potential usage in photovoltaic solar cells, sensors, and display devices to reduce reflectance, glare and enhance light transmission. ARC was developed to increase more efficiency of solar cell cover glasses, by depositing SnO2/TEOS/MTMS coating using the sol–gel spin coating technique. The coating showed a maximum transmittance of 92.70% at 399 nm wavelength with an average refractive index of 1.42. The transmittance of the antireflective film was increased by 2.29% than the bare glass substrate. The surface morphology of the coatings was investigated using FESEM analysis. The mechanical stability of the coating was evaluated using ASTM standard D 3363–05 pencil scratch test, and it demonstrated good performance against 3H hardness pencil. The efficiency of solar cells has been increased by 1.56% after depositing with single layer SnO2/TEOS/MTMS film. Moreover, the coating maintains the solar cell's performance even during dust exposure, because of its self‐cleaning ability with water contact angle of 94°. Thus, the Anti‐reflection coating can be applied to enhance the efficiency of photovoltaic system. [ABSTRACT FROM AUTHOR]

Antireflective (AR) coatings are widely used in the various applications of optical devices, flat panel displays, automotive windshields, and solar cell cover glasses. Usually, coatings with high transmittance and self-cleaning capability enhance solar cell efficiency. In this work, SnO2 thin film with TEOS, ITES, and MTES by spin coating was deposited on glass substrates and analyzed. The prepared films was characterized by Fourier Transform Infrared Spectroscopy, UV-visible spectroscopy, FESEM, and Water contact angle measurements (WCA). The prepared SnO2/TEOS/ITES and SnO2/TEOS/MTES films showed good optical transmittance of 92.46% and 92.56% with WCA of 9° and 92° respectively. The transmittance of the antireflective films was increased by 2% than the bare glass substrate. Also, the antifogging behavior of SnO2/TEOS/ITES film was examined. Furthermore, the self-cleaning ability of the coatings helps to maintain the efficiency of the solar cell even during dust exposure. Thus, the antireflection coating can be applied to enhance the efficiency of the photovoltaic system. [ABSTRACT FROM AUTHOR]

Hydrophobic self‐cleaning surfaces exhibit low surface energy. The low surface interaction allows the water droplets to roll off easily. In this work, transparent hydrophobic coating was fabricated using precursors Polydimethylsiloxane (PDMS), Isobutyltriethoxysilane (iTES), and Pluronic F127 (PF‐127), as pore generator. PDMS/PF‐127 and iTES/PF‐127 composite films were fabricated by acid catalyzed sol gel technique. UV‐visible spectroscopy analysis revealed enhancement of optical transparency by 3% for PDMS/PF‐127 than iTES/PF‐127 composite surface. Transparency of PDMS/PF‐127 was maintained throughout visible region proving film stability. Porous nature was confirmed by Field Emission Scanning Electron Microscopy analysis. Water contact angle of 107° for PDMS/PF‐127 and 103° for iTES/PF‐127 was obtained. 3D laser profilometery analysis revealed PDMS/PF‐127 coated surface was rougher than iTES/PF‐127 composite film. Sand particles sprinkled on coated surface buckled upon contact with water, exhibiting self‐cleaning ability. [ABSTRACT FROM AUTHOR]

A positive change in crystal can be induced by dye. Pure and Acid Red 1 dye (AR) doped triglycine acetate (TGAc) single crystals are synthesized by solution approach to enrich the characteristics of pure TGAc crystals. The crystalline nature of the grown crystals is investigated using powder X-ray diffraction. The Scherrer method has been used to calculate the crystallite size of both developed crystals and is compared to the Williamson and Hall method. Fourier transform infrared spectroscopy confirms the existence of several functional groups as well as dye inclusion in the produced crystals. Four distinct absorption bands are found in UV-vis-NIR absorption spectra at the location where AR dye is inserted into the TGAc matrix. Different optical constants, such as optical bandgap (Eg), extinction coefficient (k), refractive index (n) and optical conductivity (σ) are measured for both samples based on transmittance measurements. The thermal stability and decomposition temperature of 0.05 mol% AR dye doped TGAc are found to be higher. The doped crystals' improved optical characteristics and thermal stability prove their applicability for optoelectronic applications. [ABSTRACT FROM AUTHOR]

The water and liquid repelling materials due to their low surface energy and specific nanometer and micrometer scale roughness have particular interest due to the great variety of potential applications ranging from self-cleaning surfaces to microfluidic devices. Natural plant-based polymer hydrophobic coatings have several engineering and biomedical applications. In this study, natural plants such as Aloe vera and Acalypha indica were used for preparation of polystyrene hydrophobic film by the dip-coating method. The effects of Aloe vera and Acalypha indica extract on the morphological, structural, optical and antibacterial properties of as-prepared polystyrene thin films were studied. FTIR spectra were carried out to ascertain the presence of functional groups in the prepared polymeric film. Contact angle measurement showed that the PS/ Aloe vera has higher anti-wetting property (CA = 112°) compared to PS/ Acalypha indica (CA = 104°), which could be confirmed by the surface morphology analysis. Furthermore, the effective antibacterial activity against Klebsiella pneumoniae and Staphylococcus aureus was compared by agar-well diffusion method. The observed result reports, PS with Aloe vera film exhibit higher hydrophobic with antibacterial activity compared to PS with Acalypha indica film. In addition, the PS/ Aloe vera coated cotton maintained their repellent properties against various liquids for 10 h, while PS/ Acalypha indica coated cotton exhibit anti-wetting property for 4 h. These findings open up new avenues for the preparation of hydrophobic film for various biomedical applications. [ABSTRACT FROM AUTHOR]