scholarly journals The Model of Metal Oxide Particle Formation from Water Solutions of Salts

2010 ◽  
Vol 4 (2) ◽  
pp. 95-100 ◽  
Author(s):  
Volodymyr Kislenko ◽  
◽  
Liliya Oliynyk ◽  
Svyatoslav Ivanyshyn ◽  
◽  
...  

The model describing the formation of metal oxide particles from water solutions of salts was suggested. Dependence of instability constants of metal complexes and ionization constants of oxygen containing inorganic acids on the electron density upon the central ion or atom allows to calculate these values for metal hydroxides. Equations describing the number of metal ions in polyion, the concentration of polyions in solution, the number of metal ions in primary metal oxide particles and their concentration in the system were suggested.

1995 ◽  
Vol 10 (5) ◽  
pp. 1327-1336 ◽  
Author(s):  
Chin-Lin Huang ◽  
Egon Matijevic

Five kinds of uniform metal oxide particles (α-Fe2O3, CeO2, CuO, NiO, and SiO2) were coated with polypyrrole by reacting the dispersed solids with pyrrole in a water/ethanol medium without the use of a soluble oxidant. When the process was carried out in air, all particles were coated with the polymer, although the thickness of the layer varied on different cores. In CuO dispersions, independent polypyrrole particles were produced in addition to coated spheres. While oxygen is the major oxidant that initiates the polymerization of pyrrole, some metal oxides may also affect the reaction both in terms of the amount and the composition of the shell. Thus, α-Fe2O3 and SiO2 were found to be inactive in the polymerization, while CeCh and CuO react with the adsorbed pyrrole molecules through a reductive-dissolution process, in which the monomers are oxidized, causing a release of reduced metal ions.


ACS Omega ◽  
2020 ◽  
Vol 5 (11) ◽  
pp. 5601-5607
Author(s):  
Vahid Saadattalab ◽  
Xia Wang ◽  
Anthony E. Szego ◽  
Niklas Hedin

Author(s):  
E. R. Kimmel ◽  
H. L. Anthony ◽  
W. Scheithauer

The strengthening effect at high temperature produced by a dispersed oxide phase in a metal matrix is seemingly dependent on at least two major contributors: oxide particle size and spatial distribution, and stability of the worked microstructure. These two are strongly interrelated. The stability of the microstructure is produced by polygonization of the worked structure forming low angle cell boundaries which become anchored by the dispersed oxide particles. The effect of the particles on strength is therefore twofold, in that they stabilize the worked microstructure and also hinder dislocation motion during loading.


2018 ◽  
Vol 69 (7) ◽  
pp. 1678-1681
Author(s):  
Amina Mumtaz ◽  
Tariq Mahmud ◽  
M. R. J. Elsegood ◽  
G. W. Weaver

New series of copper (II), cobalt (II), zinc (II), nickel (II), manganese (II), iron (II) complexes of a novel Schiff base were prepared by the condensation of sulphadizine and pyridoxal hydrochloride. The ligand and metal complexes were characterized by utilizing different instrumental procedures like microanalysis, thermogravimetric examination and spectroscopy. The integrated ligand and transition metal complexes were screened against various bacteria and fungus. The studies demonstrated the enhanced activity of metal complexes against reported microbes when compared with free ligand.


2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Anh Thi Le ◽  
Swee-Yong Pung

Purpose This paper aims to investigate the reusability of metal/metal oxide-coupled ZnO nanorods (ZnO NRs) to degrade rhodamine B (RhB). Design/methodology/approach ZnO NRs particles were synthesized by precipitation method and used to remove various types of metal ions such as Cu2+, Ag+, Mn2+, Ni2+, Pb2+, Cd2+ and Cr2+ ions under UV illumination. The metal/metal oxide-coupled ZnO NRs were characterized by scanning electron microscope, X-ray diffraction and UV-Vis diffuse reflectance. The photodegradation of RhB dye by these metal/metal oxide-coupled ZnO NRs under UV exposure was assessed. Findings The metal/metal oxide-coupled ZnO NRs were successfully reused to remove RhB dye in which more than >90% of RhB dye was degraded under UV exposure. Furthermore, the coupling of Ag, CuO, MnO2, Cd and Ni particles onto the surface of ZnO NRs even enhanced the degradation of dye. The dominant reactive species involved in the degradation of RhB dye were •OH- and •O2−-free radicals. Research limitations/implications The coupling of metal/metal oxide onto the surface of ZnO NRs after metal ions removal could affect the photocatalytic performance of ZnO NRs in the degradation of organic pollutants in subsequent stage. Practical implications A good reusability performance of metal/metal oxide-coupled ZnO NRs make ZnO NRs become a desirable photocatalyst material for the treatment of wastewater, which consists of both heavy metal ions and organic dyes. Originality/value Metal/metal oxide coupling onto the surface of ZnO NRs particles improved subsequent UV-assisted photocatalytic degradation of RhB dye.


1999 ◽  
Vol 6 (2) ◽  
pp. 67-73 ◽  
Author(s):  
Claudiu T. Supuran ◽  
Andrea Scozzafava ◽  
Luca Menabuoni ◽  
Francesco Mincione ◽  
Fabrizio Briganti ◽  
...  

Metal complexes of a heterocyclic sulfonamides possessing very strong carbonic anhydrase (CA) inhibitory properties, i.e., 5-(p-fluorobenzenesulfonylamido)-1,3,4-thiadiazole-2-sulfonamide (p-fluorobenzolamide) were prepared. The new complexes contained metal ions such as Zn(II), Cu(II), Co(II), Ni(II), Cd(II) and Mn(II). The new compounds were characterized by standard physico-chemical procedures, and assayed as inhibitors of three CA isozymes, CA I, II and IV. Very good inhibition has been evidenced both for the parent sulfonamides as well as for the prepared complexes, against all three investigated isozymes. Some of these new complexes as well as the parent sulfonamide, strongly lowered intraocular pressure (IOP) in normotensive rabbits when administered as a 2% solution into the eye.


1990 ◽  
Vol 212 ◽  
Author(s):  
Johan Byegård ◽  
Gunnar Skarnemark ◽  
Mats Skålberg

ABSTRACTA radioactive tracer experiment has been performed in a highly conductive fracture zone, using a dipole geometry. Anions (131I− and 82Br−) and complexed metal ions (51Cr-EDTA, 58Co-EDTA, 111In-EDTA, 140La-DOTA, 160Tb-EDTA, 169Yb-EDTA and 177Lu-DOTA) have been injected and their properties as non-sorbing tracers were evaluated. Besides, studies of slightlysorbing cations (24Na+, 58Co2+, 86Rb+ and 201T1+) were performed. 99mTcO4 and its chemical analogue 186ReO4 were also injected to study the behaviour of Tc at low redox-potentials. Breakthrough was obtained for Re and for all metal complexes and anions. Some differences in the recovery yields could be seen. No transport of cations, except for Na, could be measured. No breakthrough of Tc could be observed. This indicates that TcO4− was reduced and sorbed.


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