Preliminary studies carried out with cysteine 2% solution showed that pH adjusted to isoelectrical pH (i.e., 4.9) led to enhance stability during autoclaving and ensured no significant degradation during at least 14 days if stored at 2-8 degrees C protected from light. Optimized formulations combined either cysteine(2%)/Poloxamer407(16.5%) or cysteine(2%)/Poloxamer407(20%)/Poloxamer188(5%) and were characterized by an adequate temperature of gelification (TG) (25.9 degrees C and 26.9 degrees C, respectively), an important gel strength (5.1daN and 5.3daN, respectively) and a drastic increase in the apparent viscosity between 24 degrees C and 32 degrees C (multiplication factor of 78 and 77-fold, respectively). Cysteine addition produced only slight but significant decrease in temperature of gelification and increase in gel strength.
In this study, TEG-reinforced polytetrafluoroethylene (PTFE) nanocomposites were prepared.The structural properties of the PTFE/TEG composites were then investigated using X-ray diffraction (XRD) and infrared spectroscopy (FT-IR). Subsequently, the thermal stability, thermal resistance of the composites were studied through differential scanning calorimetry (DSC) and thermo-gravimetric analysis (TGA). The XRD results allowed to report a high degree of dispersion of the TEG inside of the PTFE matrix. Moreover, milling at high temperature was found to enhance the dispersion of the TEG inside of the polymer matrix. Furthermore, the results revealed an increase of the glass-transition temperature when using an increased concentration of TEG. This result confirms that the degradation of the TEG/PTFE nanocomposite occurs at a higher temperature with a greater TEG loading. These finds give an indication of the potential of TEG to improve the thermal properties and durability of PTFE, for instance with application in the field of aeronautics.
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HighlightsWe synthetize Mg-La powders by means of an electrodeposition process.We characterize Mg-La powders using EDS, SEM, XRD and FTIR techniques.
EDS analyses indicate the presence of three elements (Mg, La and O).The two phases, Mg(OH) 2 and La(OH) 3 are identified in specimens.Concentration and voltage effects are investigated using a design of experiments.
AbstractIn this paper, magnesium-lanthanum powders were synthesized by an electrodeposition technique using an aqueous solution, based on magnesium chloride hexahydrate and showed the existence of two distinct phases in the obtained deposits which are magnesium hydroxide (Mg(OH) 2 ) and lanthanum hydroxide (La(OH) 3 ). FTIR analyses confirm the presence of the two phases identified in XRD diffractograms and they can be exhibited by clear peaks. In the studied ranges of voltage and La weight percentage, their peak transmittances have non-monotonic behaviors. A design of experiments was used to determine the influence of these two processing parameters and their interaction on the products formation. The parameters effects were ranked as follow: the first was the voltage then the interaction between the two parameters and finally the La content.
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