Colloidal Titration of Aqueous Zirconium Solutions with Poly(vinyl sulfate) by Potentiometric Endpoint Detection Using a Toluidine Blue Selective Electrode

Abstract

Zirconium chemicals are used in a wide range of industries, and with advances in modern technology, the diversity of their applications has increased. 1 In particular, tetragonal zirconia is one of the most important zirconium compounds for ceramic use, with excellent mechanical properties, such as high structure toughness, strength, and hardness. 2 We have studied the effective use of some zirconium oxy-salts as a depressive and fluidizing material of ceramic slurries, 3,4 and have developed a new direct-casting method based on aqueous-acidic high solids loading alumina slurries stabilized with zirconium acetate. 5When the slurries were prepared, the concentration of zirconium oxy-salt was an important factor, and a simple and convenient determination of aqueous zirconium was required. However, the determination of zirconium is not very easy because zirconium(IV) has a marked tendency to form polynuclear hydroxy group-bridged zirconium species (polymerization) in aqueous solutions.6 Pilkington et al. mentioned that accurate results in EDTA titration of zirconium could only be obtained after zirconium ions were converted to a depolymerized form. Therefore, we studied a colloidal titration method as a means to measure the concentration of zirconium conveniently as it exists in the aqueous solution in a polynuclear configuration.Colloidal titration is an excellent measurement method for determining the concentration of natural and synthetic polyelectrolytes. [8][9][10][11][12] Titration is based on the reaction between a positively charged polyelectrolyte (polycation) and a negatively charged one (polyanion).When the charges of the polyelectrolytes are neutralized by the addition of oppositely charged polyelectrolytes, the two ployelectrolytes tend to associate and eventually precipitate. According to Terayama, who was the first proposer of colloidal titration, the colloidal titration method has been applied to several poly-charged species, such as proteins and cells. 8 However, their stoichiometries are still not clear. Regarding the reaction between oppositely charged polyelectrolytes, most of the reaction is accurately stoichiometric. As a typical case, an aqueous solution of poly(diallyldimethyl ammonium) chloride (PDADMAC) can be titrated with an aqueous solution of potassium poly(vinyl sulfate) (KPVS) of known concentration. The reaction between oppositely charged polyelectrolytes has been studied on stoichiometry, 9,13-16 the stability constant, 17,18 and the effect of the polymerization degree. 19 A few colloidal titrations were applied to measure metal ions in hydrolyzed, polymeric forms. Kikuchi and Kubota have investigated a chemical reaction of KPVS with a mixture of poly(aluminum chloride), PAC, ([Al2(OH)nCl6-n]m, n = 3, m = 2.5) as an inorganic macromolecule and [2-(diethylamino)ethyl]dextran hydrochloride.The general characteristics of the resultant polyelectrolyte complexes were also studied. 20 Tajima has reported that undeca(11-)tungstocobalt(II)phosphate, [PW11O39Co(H2O)] 5-, was a useful standa...

Investigating the Kinetics and Structure of Network Formation in Ultraviolet-Photopolymerizable Starch Nanogel Network Hydrogels via Very Small-Angle Neutron Scattering and Small-Amplitude Oscillatory Shear Rheology

“…To determine the amount of charge per gram of material (meq/g) on the functionalized SNPs, a particle charge detector (BTG Mutek) was used. Poly­(diallyldimethyl­ammonium chloride) (PDADMAC, 0.001 mol/L) was used as the cationic titrant, and poly­(vinyl sulfate) (PVSK, 0.001 M) was used as the anionic titrant, both consistent with reported methods. , The sample was suspended in MQW at concentrations of 10–30 mg/mL in a total volume of 10 mL, after which the oppositely charged titrant was added incrementally to the sample using an autotitrator until the effective surface charge was 0 mV (i.e., all charged groups were titrated).…”

Electrochemical Sensing of Anions and Heparin by an Alkyl-chain Ferrocene Cationic Surfactant

“…Excess heparin formed an ion-pair complex FcMDDMA and then adsorbed the CPE electrode (Scheme 1C). The method is one of colloidal titration [31][32][33][34] on which the selective ion association between polyanion (heparin) and polycation (protamine) occurs. Since the stability of the polycation-polyanion complex was larger than that between FcMDDMA and heparin, the interference with co-existence of many inorganic salts can be ignored.…”

Dispersion and Fluidity of Aqueous Aluminum Oxide Suspension with Titanate Aqueous Solution

“…We also studied the hydrolytic behavior of zirconium IV in aqueous solution, and reported a new method for determination of zirconium in aqueous solution by colloidal titration. 10 Ohya et al reported that very stable aqueous titanate solution could be prepared by direct reaction of titanium IV tetraisopropoxide Ti=OCH CH 3 2 ? 4 , TIP with ahydroxycarboxylic acids HOCR 1 R 2 CO 2 H , such as lactic acid CH 3 CH OH CO 2 H, Lac in water, and that 004 -oriented anatase film with a high refractive index of 2.54 was obtained from the stable titanate solutions via the spincoating method.…”