2024-03-29T06:03:18Zhttps://eprints.lib.hokudai.ac.jp/dspace-oai/requestoai:eprints.lib.hokudai.ac.jp:2115/329852022-11-17T02:08:08Zhdl_2115_20045hdl_2115_139Cation Exchange Properties of Tetratitanic Acid with Interlayer Protons and of Titania with Surface Hydroxyl ProtonsSvojstva izmjene kationa tetratitanske kiseline s međuslojnim protonima i svojstva izmjene titanijeva oksida s površinskim hidroksilnim protonimaTamura, HirokiNakamura, KyosukeKikkawa, Shinichilayered tetratitanic acidhydroxyl groupinterlayerion exchangeFrumkin equation431Cation exchange properties of tetratitanic acid with interlayer protons were measured and compared to those of titania with surface hydroxyl protons using the Frumkin equation. Tetratitanic acid showed larger ion-exchange capacity and much higher activity than titania. The characteristics of exchangeable protons and intercalated cations are discussed to explain the different ion-exchange properties. The interlayer protons of tetratitanic acid can be regarded as acid functional groups of an oxoacid of TiIV, and acid functional groups dissociate much more easily than the surface hydroxyl groups on titania that are formed by hydration. The cations intercalated into tetratitanate are sandwiched between opposing titanate layers with negative charges and are better stabilized than the cations adsorbed on the outer surfaces of titania owing to better neutralization of cationic charges.Mjerena su svojstva izmjene kationa tetratitanske kiseline s međuslojnim protonima i rezultati su, pomoću Frumkinove jednadžbe, uspoređeni s rezultatima dobivenima za svojstva izmjene kationa titanijeva oksida s površ inskim hidroksilnim protonima. Tetratitanska kiselina pokazala je veći kapacitet ionske izmjene i znatno veću aktivnost od titanijeva oksida. Kako bi se objasnila različita svojstva ionske izmjene, raspravljena su svojstva izmjenjivih protona i interkalarnih kationa. Međuslojni protoni tetratitanske kiseline mogu se promatrati kao kisele funkcionalne skupine oksokiseline titanija(IV), a takve kisele funkcionalne skupine znatno lakše disociraju nego površinske hidoksilne skupine na titanijevu oksidu koje nastaju hidratacijom. Kationi interkalirani u tetratitanate smješteni su između titanatnih slojeva s negativnim nabojem i bolje su stabilizirani nego kationi adsorbirani na vanjsku površinu TiO2 zbog bolje neutralizacije kationskih naboja.Croatian Chemical SocietyJournal Articleapplication/pdfhttp://hdl.handle.net/2115/32985https://eprints.lib.hokudai.ac.jp/dspace/bitstream/2115/32985/1/cca_80_2007_no3-4_351-356_Tamura.pdf0011-1643AA00620408Croatica chemica acta803-43513562007-11engpublisher