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Currently, there has been a growing interest of zeolite materials for industrial and scientific purpose. Synthetic zeolites are more often used than natural ones due to its higher purity and more uniform particle sizes. Numerous investigations are conducted in searching of inexpensive raw materials suitable for zeolite synthesis. Moreover, the temperature, pressure, times and SiO2/Al2O3 ratio are the most important parameters which play key roles in the synthesis processes. Due to such a large number of factors that affect the process, zeolite synthesis has been undergoing constant development. Nowadays, researchers focus on the methods of synthesizing zeolites at ambient temperature and pressure. Metakaolin and tuff are natural raw materials which can be turned into a brand new class of synthetic zeolites. However, each requires different method of synthesis in order to obtain a material with best physical properties. This paper discusses the process of alkaline activation of synthetic zeolites from natural raw materials: volcanic tuff excavated in Filipowice and metakaolin obtained from Rominco company. Two methods: fusion and low-temperature synthesis, were used in the presented research. Moreover, the physical properties of raw materials and zeolites obtained were shown. Based on the XRD analysis, it was verified that materials after the synthesis process contained zeolites A, Na-X and faujasite-Na. Furthermore, the dehydration and thermal decomposition phenomena of the tuff and metakaolin before and after the synthesis process were determined by coupled TG/MS techniques. [ABSTRACT FROM AUTHOR]

Thermal analysis has a wide range of applications in pharmaceutical industry, in designing new molecules, control of raw materials, stability, compatibility studies, and development of new formulations. This paper evaluates the thermodynamic properties of two second generation G2 carbosilane dendrimers with peripheral ammonia groups by differential scanning calorimetry and TG/FTIR coupled techniques. The physical transformations have been detected and their thermodynamic characteristics have been estimated and analyzed. Both dendrimers are stable up to 150 °C, have the Tg at 75 and 59 °C and melting temperatures at 113 and 128 °C, respectively. The decomposition process proved to be very complex and takes place in three steps in nitrogen atmosphere and four steps in air, for both types of dendrimers. IR spectroscopic analysis was used to observe the evolution of the gaseous products versus temperature. [ABSTRACT FROM AUTHOR]

Thermal treatment of torasemide form A resulted in several effects which were divided into five steps. These were investigated and discussed applying TG-MS and TG-FTIR with additional information derived from SEM, hot-stage and FTIR microscopy. The investigated crystal form of torasemide represents a mixed solvate including ethanol and water. Its desolvation, the solid-solid transformation into the anhydrate mod. II and the melting of this anhydrate is elucidated using thermal analysis and microscopic observations (FTIR and hot-stage microscopy). The released and evaporated solvents were determined with coupled techniques. On further heating the structural identification of evolved gases allowed the analysis of the degradation pathway of torasemide up to 340°C. [ABSTRACT FROM AUTHOR]