Ammonium Sulfate Chloride Research Articles

Acmonidesite, a new ammonium sulfate chloride from La Fossa crater, Vulcano, Aeolian Islands, Italy

AbstractThe new mineral acmonidesite, (NH4,K,Pb2+,Na)9Fe42+(SO4)5Cl8, was found in an active fumarole (fumarole FA, temperature ~250°C) at La Fossa crater, Vulcano, Aeolian Islands, Sicily, Italy. It occurs on a pyroclastic breccia as brown prismatic crystals up to 0.10 mm long, in association with salammoniac, alunite and adranosite. The mineral is orthorhombic, space group C2221 (no. 20) with a = 9.841(1), b = 19.448(3) c = 17.847(3) Å, V = 3415.7(9) Å3 and Z = 4. The six strongest reflections in the powder X-ray diffraction pattern are: [dobs in Å(I)(hkl)] 8.766(100)(110), 1.805(88)(390), 5.178(45)(131), 4.250(42)(221), 2.926(42)(330) and 2.684(32)(261). The empirical formula (based on 28 anions per formula unit [pfu]) is (NH4)5.77K1.42Pb0.62Na1.24Fe3.96Mn0.08S5.04O20.16Cl7.97Br0.08. The idealised formula is (NH4,K,Pb2+,Na)9Fe42+(SO4)5Cl8. The calculated density is 2.551 g cm–3. Using single-crystal diffraction data, the structure was refined to a final R(F) = 0.0363 for 4614 independent observed reflections [I > 2σ(I)]. The structure contains two independent, distorted octahedral iron sites, Fe1 and Fe2, with the iron atoms in the 2+ oxidation state, as confirmed by the interatomic distances and bond-valence calculations (2.06 and 1.94 vu, respectively). Fe1 is surrounded by two chlorine atoms and four oxygens of the sulfate ions, with the following average distances (Å): Fe1–O 2.125 and Fe1–Cl 2.472; and Fe2 is surrounded by three chlorine atoms and three oxygens of the sulfate ions, with the following average distances (Å): Fe2–O 2.110 and Fe2–Cl 2.531. Three independent sulfate anions are also present and are connected with the iron polyhedra to form a three-dimensional structure containing voids occupied by four independent ammonium ions (two of them partially replaced by K+), one Na+/Pb2+ site and one Cl– ion.

Screening, Identification and Dissolving Characteristics of a Strong Phosphorus Solubilizing Fungi in Calcareous Soil

In order to improve phosphorus utilization in calcareous soil, a fungi Z60 with strong phosphate-solubilizing activity was isolated from crop rhizosphere of Shanxi calcareous soil by tablet separation. According to its morphological properties and ITS rDNA sequence, its position in phylogenetic development tree was defined, then dissolving characteristics and acid production were further studied. The strain was identified as Aspergillus sp., with maximum activity of phosphatedissolving reaching 714.4, 624.1, 305.2, 108.3 mg L-1respectively in tricalium phosphate, aluminum phosphate, ferric phosphate and phosphate rock liquid culture. For different C and N sources sucrose and sodium nitrate were optimum for Z60, with the C source sequence as mannitose glucose mannitose lactose starch; for N source the order was potassium nitrate ammonium nitrate ammonium chloride ammonium sulfate sodium nitrate. HPLC analysis showed that Z60 produced oxalic acid in all kinds of N source, formic acid in ammonium nitrogen as N source, lactic acid in ammonium nitrate as N source, and tartaric acid in ammonium chloride or potassium nitrate as N source. Z60 has a strong ability to dissolve hard-tosolve phosphate, therefore is a promising microbial resource of high efficiency biological phosphorus fertilizer for calcareous soil.

Characterization of a “Smart” Hybrid Varnish Electrospun Nylon Benzotriazole Copper Corrosion Protection Coating

This work presents the electrochemical evaluation of a proposed copper corrosion protection hybrid coating acting as asmartcorrosion protection system. This consists of an alkyd varnish, painted over electrospun nylon fibers acting as a secondary diffusion barrier and also as a benzotriazole (BTAH) inhibitor nanocontainer. Submicron diameter electrospun nylon 6-6 fiber nanocontainers were prepared from a polymeric solution containing BTAH at different concentrations, and Cu samples were coated with the electrospun fibers and painted over with an alkyd varnish by the drop method. Functional groups in fibers were determined through FTIR spectroscopy. Optical and SEM microscopies were used to characterize the nanocontainer fibers. Samples were evaluated using electrochemical impedance and noise, during six weeks of immersion, in a chloride-ammonium sulfate solution. Excellent response was obtained for thesmartinhibitor coating system. For long periods of immersion good corrosion protection performance was observed. The results presented demonstrate the good barrier properties of the hybrid coating, obstructing the diffusion of aggressive species, through the electrospun structure. Furthermore the nanocontainer functionality to store and liberate the corrosion inhibitor, only when it is needed, was also proved.