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Topic Review
Synthesis of Ferrocenyl Phosphorhydrazone Dendrimers
The discovery of ferrocene is often associated with the rapid growth of organometallic chemistry. Dendrimers are highly branched macromolecules that can be functionalized at will at all levels of their structure. The functionalization of dendrimers with ferrocene derivatives can be carried out easily as terminal functions on the surface, but also at the core, or at one or several layers inside the structure. Depending on the desired location of the ferrocenes in the structure of phosphorhydrazone dendrimers, the ferrocenes should be functionalized differently. For the grafting to the surface, the ferrocene should bear a phenol group, suitable to react in substitution reactions with the P(S)Cl2 terminal groups of the dendrimers. To be used as core, the ferrocene should have two aldehyde functions, from which the synthesis of the dendrimer will be carried out. To be introduced in the branches, at all layers or within a single layer, the ferrocene should replace hydroxybenzaldehyde; thus, it should bear both a phenol and an aldehyde.
  • 792
  • 06 Jun 2022
Topic Review
Application of Geopolymers in Adsorption
Geopolymer is a porous inorganic material with a three-dimensional mesh structure, good mechanical properties, a simple preparation process (no sintering) and a low economic cost, and it is environmentally friendly. Geopolymer concrete has been widely used in the construction field, and many other studies have revealed that geopolymer will become one of the most promising inorganic materials with unique structure and properties. Geopolymer has a three-dimensional mesh structure that provides the geopolymer with high porosity and a significant number of mesopores that enhance the adsorption capacity by providing more exposed binding sites on the surface. The high mesoporous structure, high porosity, and three-dimensional mesh structure give geopolymers a larger specific surface area, which increases the contact sites with pollutants and impurities. 
  • 792
  • 14 Sep 2022
Topic Review
Plants with Antiviral Properties
Phytochemicals have been used as antiviral agents against several viruses since they could inhibit via different mechanisms, either at the viral entry point or the replication stages and also immunomodulation potentials. 
  • 792
  • 19 May 2021
Topic Review
CO2 Hydrogenation to Methanol
High-efficiency utilization of CO2 facilitates the reduction of CO2 concentration in the global atmosphere and hence the alleviation of the greenhouse effect. The catalytic hydrogenation of CO2 to produce value-added chemicals exhibits attractive prospects by potentially building energy recycling loops.
  • 792
  • 15 Apr 2022
Topic Review
Cadmium Recovery from Spent Ni-Cd Batteries
The significant increase in the demand for efficient electric energy storage during the last decade has promoted an increase in the production and use of Cd-containing batteries. On the one hand, the amount of toxic Cd-containing used batteries is growing, while on the other hand, Cd is on a list of critical raw materials (for Europe). Both of these factors call for the development of effective technology for Cd recovery from spent batteries. Alkaline nickel-cadmium (Ni-Cd) batteries are widely used as autonomous sources of industrial and household current (power banks) due to a successful combination of feasibility studies and achieved sustainable electrical characteristics. In recent decades, the market of secondary current sources for portable equipment has undergone significant changes, which leads to an intensive replacement of Ni-Cd batteries with lithium-ion (LIB) and nickel-metal-hydride.
  • 791
  • 07 Feb 2022
Topic Review
Catalytic Activity of Zeolite
Zeolites are microporous aluminosilicates with high surface area and crystallinity. They have been widely applied in many different fields, such as gas storage, water treatment, biomass upgrading, and oil refining, because of their strong acidity, excellent catalytic activity, shape selectivity, and hydrothermal stability. In the past decades, one of the most important applications of zeolites is in fluidized catalytic cracking (FCC) in the petrochemical industry, which accounts for more than 95% of the global zeolite catalyst consumption. It is reported that 400 million tons of olefins are produced annually, and about 59% of olefins are produced by FCC units. Light olefins are critical building blocks in the petrochemical industry, and the demand for olefins and their derivatives has continuously increased over the last decade. Therefore, it is important to understand how to improve the catalytic performance of zeolites. Studies have shown that the performance of zeolite catalysts for cracking reactions is determined by various factors, including the porous size and composition, e.g., the Si/Al ratio and the presence of other heteroatoms or extra-framework aluminum (EFAL) species. Since the range of possible combinations of zeolite structures and compositions is exceedingly large, it is highly desirable to understand the effects of zeolite topology and composition on hydrocarbon cracking in order to improve their activity and selectivity to desired products.
  • 791
  • 09 Oct 2021
Topic Review
Sharpless Asymmetric Dihydroxylation
Sharpless asymmetric dihydroxylation is an important reaction in the enantioselective synthesis of chiral vicinal diols that involves the treatment of alkene with osmium tetroxide along with optically active quinine ligand. Sharpless introduced this methodology after considering the importance of enantioselectivity in the total synthesis of medicinally important compounds.
  • 791
  • 03 Apr 2023
Topic Review
Electrodeposited Multilayer Metal Nanowires
Because of having high aspect ratio nanowires(NWs) structures offer great advantages in many sensing and biological systems.  Magnetic/non-magnetic multilayered NWs  were fabricated by electrochemical deposition, usually by using potentiostatic, galvanostatic techniques, and they were seen to be kinetic or diffusion control. By using optimized deposition parameters i.e presence of additives, potential, solution concentration, hydrogen evolution and confinement effect of nanopore wall, one can successfully fabricate NWs with well-defined segmented structures for single, bilayer or even tri layer thickness. Structural and chemical compositional of the multilayer NWs was observed by using various characterization techniques i.e electron microscopy, spectroscopy, and x-ray diffraction. Studying the kinetics of the phase transformation of NWs between stable or metastable phases reveals basic thermodynamical information and essential for future various applications.
  • 791
  • 23 Oct 2020
Topic Review
Molecular Sensing with Hyperpolarized 129Xe
Hyperpolarized noble gases have been used early on in applications for sensitivity enhanced NMR. 129Xe has been explored for various applications because it can be used beyond the gas-driven examination of void spaces. Its solubility in aqueous solutions and its affinity for hydrophobic binding pockets allows "functionalization" through combination with host structures that bind one or multiple gas atoms. Moreover, the transient nature of gas binding in such hosts allows the combination with another signal enhancement technique, namely chemical exchange saturation transfer (CEST). Different systems have been investigated for implementing various types of so-called Xe biosensors where the gas binds to a targeted host to address molecular markers or to sense biophysical parameters.
  • 791
  • 19 Oct 2020
Topic Review
Electrostatic Repulsion Reversed-Phase Liquid Chromatography
Electrostatic Repulsion Reversed-Phase Liquid Chromatography (ERRP) allows the elution of bases in protonated form without peak distorsion (as commonly happen in reversed phase) due to the presence of positive charges in the chromatographic system. 
  • 790
  • 05 Aug 2021
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