Synthesis and characterization of nanoapatites organofunctionalized with aminotriphosphonate agents

Abstract

Organofunctionalized apatite nanoparticles were prepared using a one step process involving dissolution/precipitation of natural phosphate rock and covalent grafting of nitrilotris(methylene)triphosphonate (NTP). The synthesized materials were characterized by Brunauer–Emmett–Teller (BET) surface measurement, thermogravimetry, inductively coupled plasma emission spectroscopy (ICP-ES), elemental analysis, multinuclear solid state cross-polarization/magic angle spinning (CP/MAS) and single-pulse NMR spectroscopy, transmission electron microscopy (TEM) and energy dispersive x-ray analysis (EDXA). After grafting BET measurements yielded particle specific surface areas ranging from 88 to 193 m2 g−1 depending on the grafted phosphonate. The results show that the surfaces of the nanoapatite particles can be covered with functional groups bound through a variable number of R-P-O-Ca bonds to render them organoapatites.

Proton conducting membranes in fully anhydrous conditions at elevated temperature: Effect of Nitrilotris(methylenephosphonic acid) incorporation into Nafion- and poly(styrenesulfonic acid)

“…The different protonated and complex forms after dehydration have been also investigated by means of 31 P solid-state NMR [33]. Moreover 31 P solid-state NMR, and in particular 31 P isotropic chemical shift, has been exploited for obtaining structural information on possible complexes between NTMPA and tin [34], calcium [35,36] and zirconium-titanate [37] in several organic-inorganic hybrid systems. To the best of our knowledge NMR studies on condensation of NTMPA P-OH groups have not been reported yet, while this and other structural and dynamic properties have been investigated in several works, mainly based on 31 P and 1 H solid-state NMR experiments, on polymeric organic phosphonic acids for applications in proton exchange membranes fuel cells [10,11,38,39], layered microporous tin biphosphonates [40] and mesoporous silica functionalized with phosphonic acids [41].…”

A new in situ enhancement of the hydroxyapatite surface by Tyramine: Preparation and interfacial properties

“…Hydroxyapatite Ca 10 (PO 4 ) 6 (OH) 2 (HAp) is a naturally occurring mineral widely used in development of bioceramics, environmental sorbents and heterogeneous catalysis [1][2][3][4]. Its reactivity depends on different parameters such as particles size, porosity and crystallinity [5][6][7]. In recent years, several studies have shown that the addition of a wide range of additives, such as silane [8] and titanate coupling agents [9], biomacromolecules [10] and polymers [11] can control the nucleation of hydroxyapatite and modify its surface properties.…”

Chemical bonding of polycaprolactone on the surface of hydroxyapatite via silanization and ring opening polymerization

“…(Douard et al 2010). Finally, a small loss was observed between 600 and 00 ºC assigned to the departure of water during structural transformation (Saoiabi et al 2012). The amount of PCL grafted on HAp was measured directly from the TGA curves, since it corresponds to the weight loss [%] in the range 200 -400 ºC as reported in the Table 1.…”