No abstract

SiO2 nanoparticles of a quantum size (15 nm or less) were prepared via sol–gel method using tetraethylorthosilicate as a precursor. SiO2 nanoparticles were characterized by X‐ray diffraction (XRD) and field‐emission scanning electron microscopy (FESEM) analyses. Polyethersulfone/silica (PES/SiO2) crystal structure nanocomposite was prepared by in situ polymerization using silica nanoparticles as reinforcement filler. The polymerization reaction was done at 160°C in paraffin bath in the presence of diphenolic monomers. XRD and FESEM analyses were used to study the morphology of the synthesized nanocomposite. The purity and thermal property of the PES/SiO2 nanocomposite were studied by energy dispersion of X‐ray analysis and differential scanning calorimetry, respectively. The effect of silica particles on the hydrophilicity of PES/SiO2 nanocomposite was also investigated. It was showed that the PES/SiO2 nanocomposite had a higher swelling degree when compared with the pure PES. The synthesized PES/SiO2 powder was used to remove Cu(II) ions from its aqueous solution. The effect of experimental conditions such as pH, shaking time, and sorbent mass on adsorption capacity of PES/SiO2 nanocomposite were investigated. It was found that incorporation of a low amount of silica (2 wt%) into the polymer matrix caused the increase of the Cu(II) ions adsorption capacity of PES. POLYM. COMPOS., 2012. © 2012 Society of Plastics Engineers

The present work studies the thermal and physical properties of aviation turbine kerosene (ATK)–boron nanofuels, including stability time, viscosity, thermal behavior, and energy content. Also, this study tries to explore the effects of the size and concentration of boron particles, surfactant type, and temperature on the stability and viscosity of nanofuel. Nanofuel samples were prepared and characterized at 0.5–4 wt % of particle loading and 0.1–2 wt % of surfactant loading ranges, for micro- and nanosized boron particles. Various surfactants, such as oleic acid, propylene glycol (PG), sorbitan oleate, Tween 85, and cetyltrimethylammonium bromide (CTAB), were used to stabilize the nanofluids. The results showed that sorbitan oleate was the best surfactant and the best weight ratio of boron particles/sorbitan oleate was about 2. With the increase of the nanoparticle concentrations from 2 to 4 wt % at 5 °C, the nanofuel viscosity was increased 24%, and with the increase of the temperature from 5 to 40 °C at a constant particle concentration (4 wt %), a 67% decrease was obtained in viscosity. Also, the effect of the particle concentration on the energy content and thermal behavior of nanofuel was determined, and it was noticed that 3 wt % boron nanoparticles could decrease the boiling point and increase the energy content of ATK fuel, significantly.

Nanofluid fuels, a new class of nanotechnology-based fluids, are liquid fuels with a stable suspension of nanometre-sized particles. The preparation of fuel mixtures and achieving to a stable and long-term suspension is the key step in nanofluid synthesis. The idea of this work is to suspend nano-and micron-sized boron particles in kerosene, exploring the differences between the complete sedimentation times of particles in fuel at various weight fractions of surfactants and investigating the viscosity of nanofluid at low weight concentration of nanoparticles. Various surfactants including oleic acid, propylene glycol, sorbitan oleate, Tween 85 and CTAB were used to prepare stable kerosene/boron slurries. Suspensions were prepared with varying surfactant loadings of 0.1-2.0% by weight, in steps, for the same particle loading of 0.5 wt%. The results showed that sorbitan oleate was the best surfactant and the optimum weight ratio of boron particle to sorbitan oleate for enhanced stability of nanofluid was determined to be 2. The complete sedimentation time of nanoparticles at the most stable nanofluid was ∼57 h. At low temperature and high weight fraction of particles, nanofluids showed similar 67% enhancement in viscosity properties.