Monodispersed and transparent hybrid silica wires were synthesized by the sol–gel method using the chemical surfactant trimethoxyoctylsilane (C 8 TMOS or C 11 H 26 O 3 Si) and, for the first time, by green surfactants ( Nelumbo nucifera /lotus leaf extract). The purpose was to introduce a less toxic, cost-effective, and one-step easy approach to get superhydrophobic silica films. Each of the surfactants was used at two different concentrations to investigate hydrophobicity of the films. Assembly of silica wires was obtained by dip-coating and vacuum filtration methods on glass and cellulose acetate filter paper as substrates, respectively. The water contact angle (CA) up to 154° was measured for hybrid silica films on filter paper, which revealed their superhydrophobicity as compared to hydrophobic behavior of those films coated on a glass substrate with CA up to 135°. Chemical, optical, and structural properties of prepared films were characterized by Fourier transform infrared spectroscopy, UV–vis spectroscopy, scanning electron microscopy, thermogravimetry, and differential scanning calorimetry. The hybrid silica wires prepared displayed good transparency, low surface energy, and superhydrophobicity. These silica assemblies can create outstanding and multifunctional structures with superhydrophobic coatings for waterproof electronic devices, military uniforms, self-cleaning surfaces, etc.

The highly luminescent CdSe/CdS/ZnS core–multi-shell quantum dots (QDs) were prepared without a protective atmosphere through the precursor injection method (phosphine free) in paraffin liquid and oleic acid. Polymers (PEG, PVA, PVP, and PAA) were coated to CdSe/CdS/ZnS core–multi-shell quantum dots to increase stability. However, core–multi-shell structured QDs reveal enhanced emission in the range 355–410 nm by suppressing the defect sensitive cores and nonradioactive recombination in PL spectra. The cubic zinc blended quantum dots with crystallite size in the range 22–44 nm, as confirmed by XRD, were obtained. The resultant absorption spectra of all the samples showed that the samples were absorbent in the UV region over the 302–380 nm range. In the FT-IR spectrum 712, 731, and 400–700 cm–1 band values were assigned to CdSe, CdS, and ZnS band stretching, respectively. Images of CdSe, CdSe/CdS, and CdSe/CdS/ZnS quantum dots obtained from the SEM were spherical whereas QDs capped with different polymers (PEG, PVA, PVP, and PAA) showed nanofibers that were linear and homogeneous size ranged between 12 and 38 nm. These as prepared QDs were placed under visible light for 48 h. After absorbing UV light, the range of UV–vis intensity was enhanced until 389–464 nm and emission intensity enhanced until 492–509 nm, which was confirmed by UV and PL spectra. CdSe/CdS/ZnS QDs with organic ligands revealed antibacterial activity over a broad range against Klebsiella Pneumoniae and Pseudomonas aeruginosa.

Alkyl silica membranes and wires were synthesized by a sol−gel method, which has the capacity to control the size of the particles or membranes by controlling the reactions. Trimethoxyoctylsilane (C 8 TMOS) was used as a chemical surfactant; poly(vinylpyrrolidone) (PVP) as an emulsifier, dissolved in butanol for emulsion; and tetraethylorthosilicate (TEOS) as a precursor and a source of silica. An assembly of silica wires was fabricated on glass and cotton substrates by the dipcoating technique. Porous membranes and silica wires were observed using scanning electron microscopy (SEM) images. The contact angles of all of the samples were in the range of 140−154°as measured by ImageJ software, which confirmed the hydrophobic nature of the samples. The contact angle was increased by increasing the amount of the surfactant. Phase changes of silica wires and membranes were investigated by thermogravimetric analysis. Chemical bonds of the sample were studied using Fourier transform infrared (FTIR) spectroscopy. The band gap of silica nanowires was measured to be 3.8−3.4 eV using the UV−visible spectrum and decreased as compared to that of bulk silica. These silica-based porous membranes with enhanced transport properties can be used in filtration and separation techniques. This fabricated hybrid silica membrane showed ∼96% salt rejection within a permeation flux of 3.04 L/m 2 h.