Article
Biomimetic self-assembling copolymer-hydroxyapatite nanocomposites with the nanocrystal size controlled by citrate
Chemistry of Materials
Document Type
Article
Disciplines
Publication Date
1-1-2011
DOI
10.1021/cm200355n
Abstract
Citrate binds strongly to the surface of calcium phosphate (apatite) nanocrystals in bone and is thought to prevent crystal thickening. In this work, citrate added as a regulatory element enabled molecular control of the size and stability of hydroxyapatite (HAp) nanocrystals in synthetic nanocomposites, fabricated with self-assembling block copolymer templates. The decrease of the HAp crystal size within the polymer matrix with increasing citrate concentration was documented by solid-state nuclear magnetic resonance (NMR) techniques and wide-angle X-ray diffraction (XRD), while the shapes of HAp nanocrystals were determined by transmission electron microscopy (TEM). Advanced NMR techniques were used to characterize the interfacial species and reveal enhanced interactions between mineral and organic matrix, concomitant with the size effects. The surface-to-volume ratios determined by NMR spectroscopy and long-range 31P{1H} dipolar dephasing show that 2, 10, and 40 mM citrate changes the thicknesses of the HAp crystals from 4 nm without citrate to 2.9, 2.8, and 2.3 nm, respectively. With citrate concentrations comparable to those in body fluids, HAp nanocrystals of sizes and morphologies similar to those in avian and bovine bones have been produced.
Copyright Owner
American Chemical Society
Copyright Date
2011
Language
en
File Format
application/pdf
Citation Information
Y.-Y. Hu, X. P. Liu, X. Ma, A. Rawal, et al.. "Biomimetic self-assembling copolymer-hydroxyapatite nanocomposites with the nanocrystal size controlled by citrate" Chemistry of Materials Vol. 23 Iss. 9 (2011) p. 2481 - 2490 Available at: http://works.bepress.com/mallapragada_surya_k/29/
Reprinted (adapted) with permission from Chemistry of Materials, 23 (2011), pp. 2481-2490. doi: 10.1021/cm200355n. copyright 2011 American Chemical Society.