چكيده به لاتين
Accumulation of hazardous industrial wastes not only has environmental issues, but also can cause depletion of valuable elements. Reusing wastes for fabricating advanced/new materials can be important from environmental and economical aspects for human and industrial communications. Because of unique structure, aerogels have potentional applications in different industrial fields such as aquastic and thermal insulating. However, their industrial applications are limited due to their processing costs and safety. Thie study aims to use secondary aluminum dross (SAD) as aluminum source for synthesizing monolithic alumina aerogel through a novel synthesis route at ambient pressure. The introduced synthesis process mediates the costs and improve the safety. The synthesis process includes extraction of aluminum from the SAD in the form of sodium aluminate, gelation by employing different gelating agents, solvent exchange step using acetonitrile as a proper organic solvent, drying at ambient pressure, and finally calcination at 600˚C. The above-mentioned solvent not only has appropriate properties for aerogel synthesis at ambient pressure, but also is inexpensive and safe. The synthesized alumina aerogels were characterized utilizing various analyses including X-ray diffractometry (XRD), X-ray fluorescence (XRF) spectroscopy, field emission scanning electron microscopy (FESEM), high-resolution transmission electron microdscopy (HRTEM), Nitrogen sorpotometry, thermogravimetry (TGA), differential thermal analysis (DTA), and differential scanning calorimetry (DSC) analysis. The characterization results reveald that the synthesized aerogels were as eta phase with a high purity of more than 95%. Also, the synthesized aerogels exhibited high specific surface area, and high total pore volume. All samples exhibited a similar thermal phase change confirmed by thermal analyses.
