title: Zirconium phosphate dispersed on a cellulose fiber surface: preparation, characterization, and selective adsorption of Li+, Na+, and K+ from aqueous solution.
abstract: Highly dispersed zirconium phosphate was prepared by reacting Cel/ZrO(2) (ZrO(2)=6.7 wt%; 0.56 mmol g(-1) of zirconium atom per gram of the material) with phosphoric acid. High power decoupling magic angle spinning (HPDEC-MAS)(31)P NMR and X-ray photoelectron spectroscopy data indicated that HPO(2-)(4) is the species present on the fiber surface. The X-ray diffraction patterns showed that zirconium hydrogen phosphate particles were amorphous and had an ion-exchange capacity, determined by ammonia gas adsorption, of 0.30 mmol g(-1). The ion-exchange capacities for Li(+), Na(+), and K(+) ions were determined from ion-exchange isotherms at 298 K and showed the following values (in mmol g(-1)): Li(+)=0.01, Na(+)=0.23, and K(+)=0.30. The higher affinity of the surface hydrogen phosphate particles for Na(+) and K(+) is due to its lamelar structure which permits easier diffusion of these two ions whose hydrated radii are smaller than that of Li(+).
authors.affiliation: Instituto de Química, Unicamp, P.O. Box 6154, 13083-970 Campinas, São Paulo, Brazil.
authors.forename: Claudemir A
authors.initials: CA
authors.lastname: Borgo
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Gushikem
mesh_terms: D000327:Adsorption; D002414:Cations, Monovalent / Q000493:pharmacokinetics; D002482:Cellulose; D008094:Lithium / Q000493:pharmacokinetics*; D011188:Potassium / Q000493:pharmacokinetics*; D012964:Sodium / Q000493:pharmacokinetics*; D012996:Solutions; D015040:Zirconium
chemical_list: D002414:Cations, Monovalent; D012996:Solutions; C027006:zirconium phosphate; D002482:Cellulose; D008094:Lithium; D012964:Sodium; D015040:Zirconium; D011188:Potassium