Formation of hydrotalcite in aqueous solutions and intercalation of ATP by anion exchange

Abstract

The formation reaction and the intercalation of adenosine triphosphate (ATP) were studied for hydrotalcite (HT), a layered double hydroxide (LDH) of magnesium and aluminum. Hydrotalcite with nitrate ions in the interlayer (HT-NO 3 ) was formed (A) by dropwise addition of a solution of magnesium and aluminum nitrates (pH ca. 3) to a sodium hydroxide solution (pH ca. 14) until the pH decreased from 14 to 10 and (B) by dropwise addition of the NaOH solution to the solution of magnesium and aluminum nitrates with pH increasing from 3 to 10. The precipitate obtained with method (B) was contaminated with aluminum hydroxide and the crystallinity of the product was low, possibly because aluminum hydroxide precipitates at pH 4 or 5 and remains even after HT-NO 3 forms at pH above 8. With method (A), however, the precipitate was pure HT-NO 3 with increased crystallinity, since the solubility of aluminum hydroxide at pH above and around 10 is high as dissolved aluminate anions are stable in this high pH the triphosphate group, the adenosine group bends owing to its bond angles and projects into the interlayer to a height of 1 nm, and the adenosine groups aligned in the interlayer support the interlayer distance.

Stability and inter-conversion of synthetic dawsonites in aqueous media

“…Dissolution of Al in the aqueous medium leads to the formation of distinctive Al-ionic species depending on the pH (Tamura et al, 2006;Bénézeth et al, 2007), which further evolve into dawsonite and/or (oxy)hydroxides. This behavior was reported previously with dawsonite-derived aluminas, which transformed into dawsonite uniquely in (NH 4 ) 2 CO 3 solution, whereas other media originated various forms of aluminum hydroxides and (oxy)hydroxides (Stoica and Pérez-Ramírez, 2007;Stoica et al, 2008).…”

Phosphate uptake behavior of ZnAlZr ternary layered double hydroxides through surface precipitation

“…During the last three decades, extensive research has been done on the synthesis and applications of hydrotalcitelike materials. Recently the LDHs are received incisive attention in catalysis [16,17], pharmaceuticals [18,19], polymer blends [20,21], adsorbents [22,23] and ion-exchangers [24,25]. Hydrotalcite-like materials were found to be selective adsorbents for the removal of phosphate from sea water [26,27].…”

Organic-Inorganic Nanohybrids of Biologically Important Molecules and Layered Double Hydroxides

“…The ZnAl-LDH/biopolymer nanocomposites have been incorporated in carbon paste or PVC matrices for the aim of developing potentiometric sensors [64]. Here again, I start with the brief description with findings concerning nucleotide-LDH nanobiohybrids [65][66][67][68][69][70][71][72]. the various nucleotides.…”

“…They are as follows: adenosine 5'-monophosphate (AMP) [65,[67][68][69]71], adenosine 5'-diphosphate (ADP) [71], adenosine 5'-triphosphate (ATP) [66,67,[70][71][72], guanosine 5'-monophosphate (GMP) [65,[67][68][69]71], cytidine 5'monophosphate (CMP) [65,[67][68][69]71] and uridine 5'-monophosphate [71]. They are as follows: adenosine 5'-monophosphate (AMP) [65,[67][68][69]71], adenosine 5'-diphosphate (ADP) [71], adenosine 5'-triphosphate (ATP) [66,67,[70][71][72], guanosine 5'-monophosphate (GMP) [65,[67][68][69]71], cytidine 5'monophosphate (CMP) [65,[67][68][69]71] and uridine 5'-monophosphate [71].…”