Reach Us +44-1522-440391
1H And 31P NMR Spectroscopy Of Dynamic Structures In Nano-and Mesostructured Hydroxyapatites | 35538
ISSN: 2169-0022

Journal of Material Sciences & Engineering
Open Access

OMICS International organises 3000+ Global Conferenceseries Events every year across USA, Europe & Asia with support from 1000 more scientific Societies and Publishes 700+ Open Access Journals which contains over 50000 eminent personalities, reputed scientists as editorial board members.

Open Access Journals gaining more Readers and Citations
700 Journals and 15,000,000 Readers Each Journal is getting 25,000+ Readers

This Readership is 10 times more when compared to other Subscription Journals (Source: Google Analytics)
All submissions of the EM system will be redirected to Online Manuscript Submission System. Authors are requested to submit articles directly to Online Manuscript Submission System of respective journal.

1H and 31P NMR spectroscopy of dynamic structures in nano-and mesostructured hydroxyapatites

International Conference and Exhibition on Mesoscopic & Condensed Matter Physics

Vytautas Balevicius, Laurynas Dagys and Vytautas Klimavicius

Vilnius University, Lithuania

ScientificTracks Abstracts: J Material Sci Eng

DOI: 10.4172/2169-0022.C1.031

The 1H spin-lattice and spin-spin relaxation time as well as high data point density 1H–31P cross-polarization kinetics (static and upon MAS) measurements have been carried out for calcium hydroxyapatite containing amorphous phosphate phase (ACP-CaHA) and nano-structured hydroxyapatite (CaHA). The chosen setting of the sampling frequency of 5×104 s–1 allowed to reveal all spin interactions having the dipolar splitting b≤25 kHz that in the case of 1H–31P interaction means the structures with the inter-nuclear distances r≥0.125 nm could be resolved. The advanced processing of CP MAS kinetic data has been developed introducing the variable cut-off distribution of the dipolar coupling. This procedure allows to describe the oscillatory kinetics and CP curves in nano-structured materials over a wide range of contact time and to determine the characteristic size profile and composition of the spin clusters. The characteristic size of 31P–(1H)n spin nano-cluster being within 0.3÷0.5 nm has been determined for nano-structured CaHA. The 1H spin-lattice and spin-spin relaxation time measurements revealed the fast spin motion takes place in ACP-CaHA. The effect of MAS rate on the 31P signal shape confirms that the correlation time of this motion gets into the time scale of microseconds or even nanoseconds. Such fast dynamics can be attributed to the rotational diffusion of adsorbed water molecules. The magnitude of the inhomogeneous anisotropic broadening of 1220±20 Hz determined for nano-structured sample is very close to 1185 Hz that corresponds to the maximum of Gauss distribution of dipolar 1H–31P coupling obtained using 31P–1H CP MAS kinetics. The dynamics of this interactions runs in the time scale of microseconds and it is much slower that in ACP-CaHA.

Vytautas Balevicius is a Physicist, Doctor of physical sciences and Professor. Currently he runs the Vilnius University Faculty of Physics dean's office.

Email: [email protected]