Untitled

Synthesis of nanostructured spherical aluminum oxide powders by plasma engineering

“…[10] This powder is also being used potentially in thermal insulation as well as in inertial confinement fusion of nuclear materials. [11] Thermal plasma spraying has been used extensively within many industries for a variety of applications because of its versatility to synthesize fine metal, alloy, ceramic, polymer, and composite powders. Plasma spheroidizing is a modified form of atomization technique, where the temperature reaches more than 15,000 K in plasma flame with gas velocities reaching speeds of 1 to 3 Mach.…”

Synthesis and characterization of uniform‐sized hollow chitosan microspheres

“…9 In an earlier investigation, the HLB values of different nonionic surfactants in Span-80 exhibited an inverse relationship to the average particle size of microspheres. 10 The surfactants in the Tween series are basically the fatty acid esters of anhydrosorbitols, 9 which are made water soluble by etherifying the free hydroxyl groups with ethylene oxide, for example, polyoxyethylene sorbitan monooleate (Tween 80), polyoxyethylene sorbitan monostearate (Tween 60). When they are not etherified, they become good oil-soluble emulsifying agents and constitute the Span series surfactants, for example, sorbitan monooleate (Span-80), sorbitan monopalmitate (Span-40).…”

“…The high interfacial tension between the "water phase" and the "oil phase" is generally reduced according to necessity by the addition of an amphiphilic surface active agent or surfactant, that is, a molecule with a polar head and a nonpolar tail. 9 The surfactant molecules orient themselves according to the polarities of the involved chemical constituents. Thus, because of the high polarity of water, the polar heads of the surfactant molecules at the oil-water (o/w) interface are oriented toward the water droplets (Fig.…”

“…A high-surfactant HLB value indicates a strongly hydrophilic character, whereas a low value is an indication of a strong hydrophobic character. 9,10 Hence, a nonionic, relatively pH-independent hydrophobic surfactant, that is, sorbitan monooleate (Span-80), with an HLB value of 4.3 was selected for the present study, 11−15 in which the hydrophilic sorbitan group acts as the "polar head" and the hydrophobic oleic acid group acts as the "nonpolar tail." Table I presents the characteristics of the particles of different viscosities.…”

Preparation of Anatase Hollow TiO2 Spheres and Their Photocatalytic Activity in the Photodegradation of Chlorpyrifos

“…This is because of their immense potential, owing to the favorable characteristics of having low density, large specific area, good mechanical and thermal stability, surface permeability. [1][2][3][4][5][6] In recent times, considerable efforts have been made to fabricate hollow titania (TiO 2 ) structures due to their potential applications in photocatalysis, 7 drug delivery, catalyst support and so on. Methods such as templating, 8,9 polymer-induced, 10 sol-gel 11 and hydrothermal 12,13 have been used for the production of hollow TiO 2 spheres.…”