Modification of different zirconium propoxide precursors with H(2)dea was investigated by characterization of the isolated modified species. Upon modification of zirconium n-propoxide and [Zr(O(n)Pr)(O(i)Pr)(3)((i)PrOH)](2) with (1/2) a mol equivalent of H(2)dea the complexes [Zr(2)(O(n)Pr)(6)(OCH(2)CH(2))(2)NH](2) (1) and [Zr(2)(O(n)Pr)(2)(O(i)Pr)(4)(OCH(2)CH(2))(2)NH](2) (2) were obtained. However, (1)H-NMR studies of these tetranuclear compounds showed that these are not time-stable either in solution or solid form. The effect of this time instability on material properties is demonstrated by light scattering and TEM experiments. Modification of zirconium isopropoxide with either (1/2) or 1 equivalent mol of H(2)dea results in formation of the trinuclear complex, Zr{eta(3)mu(2)-NH(C(2)H(4)O)(2)}(3)[Zr(O(i)Pr)(3)](2)(iPrOH)(2) (3) countering a unique nona-coordinated central zirconium atom. This complex 3 is one of the first modified zirconium propoxide precursors shown to be stable in solution for long periods of time. The particle size and morphology of the products of sol-gel synthesis are strongly dependent on the time factor and eventual heat treatment of the precursor solution. Reproducible sol-gel synthesis requires the use of solution stable precursors.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2808018 | PMC |
http://dx.doi.org/10.3390/ijms10114977 | DOI Listing |
Environ Pollut
January 2025
College of Safety and Environmental Engineering, Shandong University of Science and Technology, Qingdao 266590, Shandong Province, China; State Key Laboratory of Mining Disaster Prevention and Control Co-found by Shandong Province and the Ministry of Science and Technology, Shandong University of Science and Technology, Qingdao 266590, China.
Red mud (RM), an iron oxide-rich solid waste, shows potential as a catalyst for selective catalytic reduction in denitrification processes. This study investigates the catalytic performance and mechanism of metal-modified RM in reducing NO from diesel vehicle exhaust. Acid-washed RM catalysts were impregnated with varying ratios of cerium (Ce) and zirconium (Zr).
View Article and Find Full Text PDFInt J Clin Pediatr Dent
November 2024
Department of Pharmacology, Saveetha Dental College and Hospitals, Saveetha Institute of Medical and Technical Sciences, Saveetha University, Chennai, Tamil Nadu, India.
Aim And Background: Glass ionomer cement (GIC) serves as a widely used restorative dental material, known for its direct bonding to tooth structures and fluoride-releasing properties. This study aims to investigate the enhancement of GIC through the incorporation of a green-mediated nanocomposite comprising chitosan, titanium, zirconium, and hydroxyapatite, with a focus on evaluating the wear resistance of the modified GIC.
Materials And Methods: A one-pot synthesis technique was utilized to prepare a green-mediated nanocomposite incorporating chitosan, titanium, zirconium, and hydroxyapatite nanoparticles.
Chem Commun (Camb)
January 2025
Department of Chemistry, Indiana University, Bloomington, Indiana 47405, USA.
This manuscript explores the post-synthetic modification (PSM) of amine-functionalized porous coordination cages, specifically focusing on the formation of imine bonds through reactions with aldehydes. Targeting various cage topologies, including zirconium-, magnesium-, and molybdenum-based structures, we demonstrate the tunability of cage solubility and porosity through selective functionalization where the proximity of amine groups on the parent cage impacts the extent of modification. The work highlights the reversible nature of imine formation, offering potential applications in solubility switching and mixed-metal solid synthesis.
View Article and Find Full Text PDFEnviron Technol
December 2024
School of Materials Science and Engineering, Yancheng Institute of Technology, Yancheng, People's Republic of China.
In order to achieve the goal of phosphate removal from glyphosate by-product salts, zirconium and zinc ions were successfully loaded onto D202 resin by co-precipitation modification method in this study, and their effectiveness in phosphate removal was evaluated under various conditions. The results of static adsorption experiments showed that the Zr/Zn@D202 resin effectively reduced the phosphate concentration in the glyphosate by-product salts from 10 mg/L to less than 0.1 mg/L, which met the national level emission standard ( < 0.
View Article and Find Full Text PDFAnal Chim Acta
January 2025
Food Inspection and Quarantine Technology Center of Shenzhen Customs, Shenzhen Academy of Inspection and Quarantine, Shenzhen, 518045, PR China. Electronic address:
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!