7803-63-6Relevant articles and documents
1H Spin-Lattice Relaxation in a NH4HSO4 Single Crystal
Lim, Ae Ran,Han, Tae Jong,Jung, Jae Kap,Park, Hyun Min
, p. 2268 - 2270 (2002)
The proton NMR line width and spin-lattice relaxation times for the NH 4HSO4 single crystal were studied over a wide temperature range. The proton spin-lattice relaxation time for NH4HSO 4 has a minimum value, which is attributed to the effect of molecular motion. The 1H spin-lattice relaxation times occurring in phases I and III are attributed to the same motions of NH4 ions. The activation energies for the reorientation motions in phases I and III are 0.98 and 4.61 kcal/mol, respectively. In phase II, the activation energy is 5.92 kcal/mol. The large change in the activation energy between phases I and II indicates that the NH4 groups are affected during this transition; however, the motion of the NH4+ ions between phases II and III does not play an important role in the phase change.
On the high-temperature phase transitions of NH4HSO4
Diosa,Fernandez,Vargas,Torijano,Mellander
, p. 1891 - 1895 (2005)
Modulated differential scanning calorimetry (MDSC), thermogravimetric analysis (TGA) and X-ray diffraction (XRD) were used to study the phase behaviour of NH4HSO4 (AHS) above room temperature. For powder AHS measured during successive thermal cycles, the MDSC curves show an endothermic peak at 147°C on heating scans and an exothermic peak at about 115°C on subsequent cooling runs. However, after the second thermal cycle, a second endothermic peak starts to appear at about 135°C on heating runs whose intensity increases on subsequent cycles. The thermogravimetric measurements on powder AHS show weight loss above 135°C. X-ray powder diffraction data for AHS heated to 140°C during 24 hours, show the diffraction pattern for (NH4)2S2O7. We discuss the endothermic effect at 135°C in terms of a partial dehydration setting in at reaction sites distributed on the surface of the crystals.
Physicochemical properties of a microelement fertilizer with amino acids
Paleckiene,Sviklas,Slinksiene
, p. 352 - 357 (2008/02/03)
The physicochemical properties of the initial components and products were studied with the aim of production of a microelement fertilizer with an amino acid concentrate. The physicochemical properties of the amino acid concentrate and its influence on the stability and sorption properties of fertilizers enriched in microelements were studied.