Sulfur Nanoparticles Synthesis and Characterization from H2S Gas, Using Novel Biodegradable Iron Chelates in W/O Microemulsion

Sulfur nanoparticles were synthesized from hazardous H2S gas using novel biodegradable iron chelates in w/o microemulsion system. Fe3+–malic acid chelate (0.05 M aqueous solution) was studied in w/o microemulsion containing cyclohexane, Triton X-100 andn-hexanol as oil phase, surfactant, co-surfactant, respectively, for catalytic oxidation of H2S gas at ambient conditions of temperature, pressure, and neutral pH. The structural features of sulfur nanoparticles have been characterized by X-ray diffraction (XRD), transmission electron microscope (TEM), energy dispersive spectroscopy (EDS), diffused reflectance infra-red Fourier transform technique, and BET surface area measurements. XRD analysis indicates the presence of α-sulfur. TEM analysis shows that the morphology of sulfur nanoparticles synthesized in w/o microemulsion system is nearly uniform in size (average particle size 10 nm) and narrow particle size distribution (in range of 5–15 nm) as compared to that in aqueous surfactant systems. The EDS analysis indicated high purity of sulfur (>99%). Moreover, sulfur nanoparticles synthesized in w/o microemulsion system exhibit higher antimicrobial activity (against bacteria, yeast, and fungi) than that of colloidal sulfur

Nanoreactors for nanostructured materials

Organized systems such as micelles, reverse micelles, vesicles, polyelectrolyte capsules, liquid crystals, etc., formed through a self-assembling process represent nanoreactors that can be used for preparing nanostructured materials. Besides a fascinating academic subject, these nanoreactors provide a unique way to develop a special type of advanced material for a wide variety of applications in electronics, photonics, biomedical and other areas. The article examines the formation, functioning, properties and special attributes of these nanoreactors with a view towards their engineering analysis, design and possible integration in manufacturing technology

Synthesis and characterization of lithium aluminate nanoparticles

In this work, we report the synthesis of lithium aluminate nanoparticles using simple coprecipitation method in various aqueous surfactant solutions and microemulsion systems. The particles have also been synthesized by coprecipitation without surfactants and sol-gel methods for comparison purpose. Nanocrystalline powders of lithium aluminate with spherical shape were obtained upon calcination. The resultant powders were characterized by XRD, SEM, TGA and BET techniques. As per the results from X-ray diffraction (XRD), the powder prepared by coprecipitation in the presence of Tween 80 and sol-gel showed purer γ -phase when it was calcined at 950 ° C. Scanning electron microscopy (SEM) results show that the type of surfactant used has a distinct effect on the size of the lithium aluminate particles. The sample prepared by microemulsion technique shows smaller average particle size of 30 nm and high surface area (70 m2/g)

Reverse microemulsion mediated sol-gel synthesis of lithium silicate nanoparticles under ambient conditions: scope for CO<SUB>2</SUB> sequestration

We report on the synthesis of nanocrystalline lithium silicate by coupling of sol-gel method in reverse microemulsion. The sample calcined at 800 &#176; C gives pure phase lithium metasilicate nanocrystallites. X-ray diffraction and transmission electron microscopy confirmed the formation of nanocrystalline lithium silicate particles with a narrow size distribution. The nanoparticle prepared in the microemulsion shows enhanced CO2 sorption capacity and shorter retention times at higher temperature (&#8764;131ml/g at STP at 610 &#176; C) which are better than the best known results

Green synthesis of silver nanoparticles using sunlight

Silver nanoparticles (AgNPs) are currently among the most widely used man-made nanomaterials, present in a huge range of consumer products. Here we report a simple ‘green’ method of AgNP synthesis of using an anionic surfactant without use of any additional reducing agents. It was observed that synthesis of AgNPs at room temperature (25–35 °C) using sodium dodecyl sulphate (SDS) and sunlight. The nanoparticles have been characterised using high-resolution transmission electron spectroscopy (HRTEM), UV–vis spectrophotometry, X-ray photoelectron spectroscopy (XPS) and Fourier Transform Infrared Spectroscopy (FTIR) and are found to have an average diameter of 30 nm. The nanoparticles are water soluble and the nature of the process is amenable to scaling up