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A series of ZSM-5 samples were synthesized by template-free hydrothermal synthesis without adding seed crystals. When synthesis parameters such as temperature, duration, and molar ratio of components being equal, various silicas (specifically, Silica-Fumed from Sigma-Aldrich; Rosil-175 from the Bashkir Soda Company (BSC), Russia; Silica from the Salavat Catalyst Plant (SCP), Russia; and Aerosil-300 from Evonik, Germany) and of aluminum (Al(NO3)3∙9H2O and NaAlO2) were varied. In the presence of sodium aluminate, highly crystalline ZSM-5 samples were synthesized, whereas the use of aluminum nitrate led to an amorphous product due to accelerating aluminosilicate condensation. The ZSM-5 crystals prepared from various SiO2 sources have different morphology, including the crystal size (ranging from 5.9 to 12.2 µm) and the aspect ratio (from 1.9 to 2.6). The ZSM-5 samples synthesized from available Russian-manufactured SiO2 sources (Rosil-175 (BSC) and Silica (SCP)) in the presence of sodium aluminate consisted of crystals with average sizes of 5.9 and 6.9 μm, respectively, and a narrow particle size distribution (cv < 20%). [ABSTRACT FROM AUTHOR]

The paper is focused on the growth of polystyrene particles followed by optical microscopy during dispersion polymerization (DP) in the absence of crosslinking agents. In particular, we compared the growth kinetics of the particles and their tendency to coagulation in alcoholic media in the presence of a steric stabilizer, chosen from one of the following: polyvinylpyrrolidone (PVP-40, PVP-10, PVP-360), hydroxypropyl cellulose (HPC), poly(acrylic acid) (PAA), and polyvinyl alcohol (PVA). The particle size distributions from the optical microscopy images were obtained using trained neural network. To predict the particles' growth at the first few hours after microphase separation, we suggest to adopt a simple model describing the coalescence of liquid drops in immiscible fluids. Based on this model, we discuss the possible approaches for the preparation routes of the particles with non-spherical morphology. [ABSTRACT FROM AUTHOR]