Adsorption of Ag (I) Ions at the Zirconium Phosphate/KNO3 Aqueous Solution Interface

The paper presented the mechanical (MChT), microwave (MWT), and hydrothermal (HTT) methods of zirconium phosphate samples modification in order to improve its adsorption affinity for the Ag (I) ions. The FTIR studies proved that the modification of both gel and xerogel samples with the ultrasonic microwaves causes an increase in the concentration of phosphate groups on the surface of MWT-modified zirconium phosphate: the isoelectric point pHiep = 2.2–2.9 for these samples against 3.9 for the initial sample and pKa2 values were 4.7–5.6 and 6.3, respectively. As resulting from the Ag+ ion adsorption studies, the MWT treatment of zirconium phosphate samples caused the greatest affinity of Ag+ ions for the surface of MWT zirconium phosphate. Compared with the initial ZrP sample, the shift of the Ag (I) ion adsorption edge towards lower pH values was observed, e.g., with adsorption of Ag (I) ions from the solution with the initial concentration of 1 µmol/dm3 for the initial ZrP sample pH50% = 3.2, while for the sample MWT ZrPxero pH50% = 2.6

Some applications of barium titanate prepared by different methods

The paper presents some application of barium titanate synthesized by different methods. Barium titanate samples were prepared by four procedures: solid state, mechanochemical as direct synthesis and modification as well as hydrothermal and microwave. The obtained samples were systematically studied using X-ray diffraction, nitrogen adsorption, Fourier transform infrared spectroscopy (FTIR), potentiometric titration, and quasi-elastic light scattering and zeta potential measurements. The values of pHpzc (point of zero charge) and pHIEP (isoelectric point) characteristic of the electrical double layer were determined. The prepared samples were tested as photocatalysts under visible light. As a result, relationship between the conditions of barium titanate synthesis, its physicochemical and electrokinetic parameters, as well as photocatalytic activity under visible light was first established

Characterization of Multimodal Silicas Using TG/DTG/DTA, Q-TG, and DSC Methods

The formation of hierarchical, multimodal porosity materials with controlled shape and size of pores is the essential challenge in materials science. Properties of silica materials depend largely on different features: crystal structure, dispersity, surface composition, and porosity as well as the method of preparation and possible modification. In this paper, multimodal silicas obtained using different additives are presented. A-50 and A-380 aerosils and wide-porous SiO2 milled at 300 rpm were used as the additives in the sol stage at 20 °C, the sol–gel stage followed by hydrothermal modification (HTT) at 200 °C, or in the mechanochemical treatment (MChT) process. The characterizations were made by application of N2 adsorption/desorption, SEM imaging, quasi-isothermal thermogravimetry (Q-TG), dynamic thermogravimetry/derivative thermogravimetry/differential thermal analysis (TG/DTG/DTA), and cryoporometry differential scanning calorimetry (DSC) methods. Results showed that such a one-step preparation method is convenient and makes it possible to obtain multimodal silicas of differentiated porous structures and surface chemistry