title: Dissolution studies on TiO2 with organics.
abstract: In this work the effect of organic reducing reagents, namely, ascorbic acid, oxalic acid and L-cysteine on dissolution of commercial TiO(2) has been investigated. Kinetic studies showed that a maximum of about 45% of TiO(2) was dissolved by ascorbic acid in 4h when oxide:acid molar ratio was kept at 1:2. The dissolution of TiO(2) increased with increase in ascorbic acid and oxalic acid concentration up to 0.15M in 4h (corresponding to molar ratio of oxide to acid of 1:3) and further addition did not affect the dissolution. Nearly 45% TiO(2) dissolution was obtained with ascorbic acid alone while oxalic acid yielded 40% dissolution. When oxalic acid was added along with ascorbic acid in equi-molar concentrations, dissolution of TiO(2) was enhanced to 60% in 2.5h but when cysteine was added to ascorbic acid the dissolution was about 50% in just 1h.
authors.affiliation: Department of Metallurgy, Indian Institute of Science, Bangalore 560012, India.
authors.forename: Amitava
authors.initials: A
authors.lastname: Mukherjee
authors.forename: Ashok M
authors.initials: AM
authors.lastname: Raichur
authors.forename: Jayant M
authors.initials: JM
authors.lastname: Modak
mesh_terms: D001205:Ascorbic Acid / Q000737:chemistry*; D003545:Cysteine / Q000737:chemistry*; D019815:Oxalic Acid / Q000737:chemistry*; D010084:Oxidation-Reduction; D012995:Solubility; D014025:Titanium / Q000737:chemistry*
chemical_list: C009495:titanium dioxide; D019815:Oxalic Acid; D014025:Titanium; D003545:Cysteine; D001205:Ascorbic Acid