Influence of Copper on the Isomerization of Eugenol for as-Synthesized NiCuAl Ternary Hydrotalcites: An Understanding Through Physicochemical Study

30 Years of Vicente Rives’ Contribution to Hydrotalcites, Synthesis, Characterization, Applications, and Innovation

Hydrotalcite is the name of a mineral discovered in Sweden in 1842 whose formula is Mg6Al2(OH)16CO3·4H2O and presents a layered crystal structure that consists of positively charged hydroxide layers neutralized by interlayer anions as carbonate, also containing water molecules. The ease of their synthesis and the possibility of incorporating other layer cations and interlayer anions have made this type of layered double hydroxides (LDH) a group of very interesting materials for industry. In addition to LDH and due to the name of the most representative mineral, this group of compounds is commonly called hydrotalcite-like materials, or simply hydrotalcites. Another way of referring to them is as anionic clays because of their layered structure but, unlike classical clays, their layers are positive and their interlayers are anionic. The main fields of application of these solids comprise catalysis, catalyst support, anion scavengers, polymer stabilizers, drug carriers, or adsorbents. This paper briefly summarizes some of the work carried out by Professor Rives over more than thirty years, focused, among other topics, on the study of the synthesis, characterization, and applications of hydrotalcites. This research has led him to train many researchers, to collaborate with research groups around the world and to publish reference papers and books in this field. This contribution, written to be included in the Special Issue “A Themed Issue in Honor of Prof. Dr. Vicente Rives”, edited on the occasion of his retirement, only shows a small part of his scientific research and intends to value and recognize his cleverness and his enormous scientific and human quality.

Improving the NOx decomposition and storage activity through co-incorporating ammonium and copper ions into Mg/Al hydrotalcites

We report a 40% and 70% improvement of NO_x decomposition and storage rate based on synthetic Mg/Al/Cu/NH₄⁺ hydrotalcites (HT), compared with Mg/Al/NH₃ and Mg/Al/Cu HTs. TGA and DTG show that ammonium has been released from HT below 160 °C.

Layered double hydroxides as drug carriers and for controlled release of non-steroidal antiinflammatory drugs (NSAIDs): a review

Non-steroidal anti-inflammatory drugs constitute one of the groups most widely currently used, but show several problems for administration due to low solubility and delivery control. For this reason, several matrices have been tested to support them in order to overcome these drawbacks. Among them, layered double hydroxides have been used in recent years. The aim of this review is to update the current knowledge and findings on this hybrid system, namely, layered double hydroxides intercalated with different NSAIDs. The basic nature of the matrix introduces an additional advantage, i.e., to decrease ulceration damages. We have focused our review mostly on the preparation procedures, as these control, define and determine the performance of the systems in vitro and also in living organisms.