Hydrotalcites with heterogeneous anion distributions: a first approach to producing new materials to be used as vehicles for the successive delivery of compounds

Abstract

Hydrotalcites with heterogeneous distributions of anions between their layers were synthesized. Some synthesis parameters were studied to verify their influence on the anionic segregation properties of the hydrotalcites. The nature of the divalent cation and the crystallization method were most relevant. Zinc, in contrast to magnesium, assisted in discriminating carbonates and attracting nitrates to form hydrotalcites with heterogeneous distributions using microwave irradiation. Furthermore, the identification of this kind of hydrotalcite could be easily verified by determining the presence of a double reflection in the 003 X-ray diffraction (XRD) maximum, which definitively characterized a heterogeneous anion distribution. Finally, the reason as to why in some cases the hydrotalcite presented two reflections in the 003 XRD peak was elucidated.

Effect of copper and eucalyptol on the bactericidal activity of ZnAl- and MgAl-LDH clays

“…This difference may be attributed to the presence of mostly interlayered nitrates rather than carbonates in the sample containing zinc, while the sample containing magnesium is richer in carbonates. [14] The peaks appearing at 61-63° (2θ), corresponding to the 110 and 113 reflections, are not well resolved. This could be due by the presence of copper, which introduces serious deformations in the octahedron coordination structure leading to a reduction of crystallinity [15] mostly in presence of magnesium.…”

Continuous production of 1,4-pentanediol from ethyl levulinate and industrialized furfuryl alcohol over Cu-based catalysts

“…37 In order to further prove the presence of anion species in the intercalation of hydrotalcite materials and the structural when Na 2 CO 3 was used as the precipitant during the coprecipitation process, but no NO 3 À decomposition was observed in the calcination process, which showed that CO 3 2À anions were easier to enter the interlayer of hydrotalcite than NO 3 À ions. 35,40 On the other hand, in the samples prepared with mixed alkali as the precipitant, only a small amount of NO 2 was released at near 330 C, indicated that only a trace amount of NO 3 À ions existed in the CuMgAl-Mix and the NO 3 À can be completely decomposed below 330 C. From the mass spectrum signal of CO 2 in Fig. 4C, it can be seen that CO 2 was released in all samples during high-temperature decomposition.…”

Conjugation strategies on functionalized iron oxide nanoparticles as a malaria vaccine delivery system

“…The Coprecipitation technique is the most common method to prepare iron oxide nanoparticles. Both sodium hydroxide (NaOH) and ammonium hydroxide (NH 4 OH) have been used to detect whether the basicity manipulates the crystallization process during particle formation 8,32 . Various surface modification techniques have been used to enhance nanoparticles' diagnosis and therapeutics potential in biomedicine applications 6 .…”