Field Emission Scanning Electron Microscopy-energy Dispersive X-ray Research Articles

Optimization of basic catalyst with ammoniated polyethylene glycol for the removal of naphthenic acid from petroleum crude oil by Box–Behnken design

Naphthenic acid (NA) removal from petroleum crude oil was investigated and optimized through the utilization of a formulated basic chemical and a basic catalyst. The response surface method (RSM) by Box–Behnken design (BBD) was employed for this purpose. Ammoniated polyethylene glycol (NH3-PEG) and cerium oxide supported on alumina were selected as the basic chemical and basic catalyst, respectively. Synthesizing of the catalyst was conducted through the wet impregnation method, and calcination was performed at temperatures of 400, 700, and 1000 °C. Brunauer–Emmett–Teller analysis (BET), field emission scanning electron microscopy-energy dispersive X-ray (FESEM-EDX), and X-ray diffraction analysis (XRD) were employed for characterizing the catalyst. A preliminary study revealed that the finest catalytic activity was achieved with the calcination of the Ce/Al2O3 catalyst at 1000 °C with a NH3-PEG concentration of 1000 mg/L and a percentage of NH3-PEG/oil mass ratio of 0.40. The optimization of the parameters, which comprise catalyst calcination temperature, concentration of NH3-PEG, and the percentage of NH3-PEG/oil mass ratio on the deacidification of NA, was achieved through the utilization of the response surface method (RSM) by BBD. The optimal conditions were realized at a catalyst calcination temperature of 1,050.54 °C, a NH3-PEG concentration of 853.10 mg/L, and a percentage of NH3-PEG/oil mass ratio of 0.47. With a 0.41 % margin of error, the results from RSM were deemed in good agreement with the experimental values.

Mid-IR, Far-IR, Raman micro-spectroscopy, and FESEM–EDX study of IDP L2021C5: Clues to its origin

Interplanetary Dust Particles (IDPs) are potentially of cometary origin. They may therefore provide important clues to a better understanding of the early Solar System physical and chemical conditions. A chondritic porous aggregate IDP (named L2021C5) was analyzed using mid to far FTIR (2–60 μm) micro-spectroscopy, Raman micro-spectroscopy, field-emission scanning electron microscopy (FESEM) and energy dispersive X-ray (EDX) analyses. The IDP was pressed between diamond windows to increase the quality of the spectral data by overcoming the diffraction limitation and minimizing light scattering effects from particles of a global size similar to the wavelength of the observation. This combination of techniques has enabled a mineralogical, organic and compositional description of the compressed particle. The IR spectra show that in L2021C5 amorphous silicates are more abundant than crystalline ones, and that the crystalline component is richer in olivine than in pyroxene. The composition and distribution of these inorganic components match very well the small silicate grains emission observed for comet Hale-Bopp from ISO-SWS spectra. Raman spectroscopy has allowed the detection of carbonaceous structures displaying different degrees of order, covering almost the whole range observed so far for IDPs. The combination of the three analytical techniques indicates that L2021C5 is a low-Ca, chondritic porous aggregate that experienced only mild flash heating on atmospheric entry, as indicated by the disordered carbon properties, the Fe/S atomic ratio of sulfides, the absence of Na depletion, and the small depletion of S. Based on a plausible cometary origin and on the estimated low entry velocity, we suggest that this IDP came from the Zodiacal cloud that is dominated by dust from Jupiter-Family comets.

Copper diffusion in Ti–Si–N layers formed by inductively coupled plasma implantation

Ternary Ti–Si–N refractory barrier films of 15nm thick was prepared by low frequency, high density, inductively coupled plasma implantation of N into TixSiy substrate. This leads to the formation of Ti–N and Si–N compounds in the ternary film. Diffusion of copper in the barrier layer after annealing treatment at various temperatures was investigated using time-of-flight secondary ion mass spectrometer (ToF-SIMS) depth profiling, X-ray diffractometer (XRD), field emission scanning electron microscopy (FESEM), energy dispersive X-ray (EDX) and sheet resistance measurement. The current study found that barrier failure did not occur until 650°C annealing for 30min. The failure occurs by the diffusion of copper into the Ti–Si–N film to form Cu–Ti and Cu–N compounds. FESEM surface morphology and EDX show that copper compounds were formed on the ridge areas of the Ti–Si–N film. The sheet resistance verifies the diffusion of Cu into the Ti–Si–N film; there is a sudden drop in the resistance with Cu compound formation. This finding provides a simple and effective method of monitoring Cu diffusion in TiN-based diffusion barriers.