Sorption of Cu(II) from Ammoniacal Solutions into α-Zirconium(IV) bismonohydrogenphosphate (α-ZrP) Intercalated with Butylamine

Abstract

Studies on the sorption of tetraamminecopper(II) complex from ammoniacal solutions of various compositions into α-ZrP modified with butylamine were performed in the temperature range of 40 to 80°C. The experimental results were discussed in terms of first-order reaction kinetics. The activation energy of sorption of Cu(II) into modified α-ZrP was found to be equal to 46.1 ± 3 kJ/mol. The effects of the concentrations of ammonia and ammonium sulfate were also examined. Pure and modified α-ZrP loaded with tetraamminecopper(II) were characterized by means of elemental analysis, X-ray diffractometry, FTIR, and Raman spectroscopy. Copper was recovered quantitatively from pure and modified α-ZrP at room temperature using 0.5 M HCl solution.     

Microscopic observations of self‐healing products in calcareous fly ash mortars

The results of microstructural characterization of mortars containing fly ash class C (High Calcium Fly Ash) from combustion of lignite are presented. The evaluation of the microstructure was performed using scanning electron microscope, optical, and confocal microscope. The tested beams were bent till the crack and microcracks opening, which were healed during the different curing time. The results showed that the replacement of cement with fly ash class C influenced the process of crack healing. The addition of HCFA, at both 30% and 60%, speeds up the self‐healing process in cracks and particularly in micro‐cracks. In the research, the completely filling up of the cracks by new phases has not been observed, only the beginning of such process has been noticed. Microsc. Res. Tech., 78:22–29, 2015. © 2014 Wiley Periodicals, Inc.     

Characterization and use of ultraviolet‐reactive low‐molecular‐weight polyhydroxybutyrate to prepare biodegradable acrylates

The characterizations of prepared low‐molecular‐weight polyhydroxybutyrate (LMWPHB) and the properties of LMWPHB photopolymerized with hydrophilic and hydrophobic acrylic monomers were studied with ¹H‐NMR spectroscopy, Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy, Instron tensile testing, and biodegradation tests. The results of ¹H‐NMR and FTIR spectroscopy confirmed that the prepared LMWPHB had transformed unsaturated ends that were photoreactive under UV light. The tensile strengths of the LMWPHB/acrylates decreased with increasing content of the added biodegradable LMWPHB because of the relatively long chains and large equivalent molar weights of LMWPHB. However, the flexibility of LMWPHB/acrylates changed differently with the type of acrylic monomer used. The LMWPHB/hydrophilic acrylate had a much more rapid biodegradation rate than the LMWPHB/hydrophobic acrylate because of the fast penetration of microorganisms. We demonstrated that the prepared LMWPHB could be used to control the biodegradation properties of acrylates and then could potentially be applied in biomedical fields. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 39501.     

Determination of Thermal-Diffusivity Dependence on Temperature of YAG Single Crystals with Different Concentrations of Yb<Superscript>3+</Superscript> and V<Superscript>3+</Superscript> Doping Ions

Thermal diffusivities of pure and doped yttrium aluminum garnet single crystals were measured as a function of temperature. Samples doped with rare earth ions (3 at% and 25 at% of Yb ³⁺, and 0.8 at% and 2.1 at% of V ³⁺) were investigated in the temperature range from 34 °C to 300 °C. Determination of the thermal diffusivity was based on an analysis of propagation of a thermal wave in the sample. The frequency of the thermal wave was 100 mHz. A temperature disturbance connected with the thermal wave propagating in the sample was detected using the mirage effect. The results showed that the thermal diffusivity of all investigated samples decreases with an increase of sample temperature. A drop in the thermal diffusivity is more pronounced for pure and low-doped crystals.     

Comparison of hazelnut and peanut shells combustion in bubbling fluidized-bed combustor

The combustion of peanut and hazelnut shells was studied in an atmospheric bubbling fluidized bed. The impact of the enrichment of air with oxygen and the flow rate of fluidizing gas on CO₂ and CO concentrations was analyzed. It was stated that in air enriched with oxygen up to 25% the mole ratios of CO₂ to CO were improved by 15–30%, depending on the flow rate used. For the peanut shell the combustion of volatiles with a hematite as an oxygen carrier was also studied. The effects were observed above ~ 450°C.     

The transformation of coal fly ash deposited on wet landfills

The stability of the ashes taken from the three heat-power plants showed that each day of storage in wet landfill causes transformation in their physical and chemical composition. At low temperatures, the spherical grains become brittle and consequently undergo cracking. The studies with a laser diffractometer have shown changes in particle size distribution during the experiment. The pozzolanic activity of the studied ashes significantly decreased under the weathering impact.