Surface properties of various powdered hydroxyapatites

Calcium, Barium and Strontium apatites: A new generation of catalysts in the Biginelli reaction

“…The reaction between benzaldehyde (1), ethyl acetoacetate (2) and urea (3) afforded dihydropyrimidinone [31,32]. If their specific activity is low, it increases during acid-base catalysis as it is the case in the Michael reaction [37].…”

“…It has also been shown that non-modified hydroxy-and fluorapatites are less active than modified apatites for the Biginelli reaction in refluxing toluene [29,30]. ) sites [31]. Due to its diverse properties, it can be used as a heterogeneous catalyst for various reactions, such as Knoevenagel condensation [32], Diels-Alder reaction [33], Friedel-Crafts reaction [34], oxidation of propargylic alcohols [34], aldol reaction [36].…”

EDTA impact on Cd2+ migration in apatite–water system

“…[22,23]. pH of water-apatite suspensions stabilizes at 6.9-7.2, independently on the value of pH in due to amphoteric properties of apatite surface [23,24].…”

“…[22,23]. pH of water-apatite suspensions stabilizes at 6.9-7.2, independently on the value of pH in due to amphoteric properties of apatite surface [23,24]. In Cd(NO 3 ) 2 , EDTA and Cd(II)EDTA complex solutions, the equilibrium pH value depends on pH in and Ca/P ratio of the apatite (Tables 2 and 3) and is the lowest (5.0-6.1) in Cd(NO 3 ) 2 -containing solution.…”

Calcium Modulates Interactions between Bacteria and Hydroxyapatite

“…Fourier Transform Infrared spectra showed the presence of small quantities of carbonate (weak band at 1460 cm -1 ). [For further details on the properties of the hydroxyapatite, see García Rodenas et al (2005) salivarius ATCC11741, and Lactobacillus fermentum ATCC14932 from the oral cavity, and Lactobacillus casei ATCC393 from cheese. The behavior of hydrophilic bacteria was explored with this latter strain representative of micro-organisms entering the oral cavity with food intake.…”