Interfacial interactions between calcined hydroxyapatite nanocrystals and substrates

Masahiro Okada, Keiko Furukawa, Takeshi Serizawa, Yoshihiko Yanagisawa, Hidekazu Tanaka, Tomoji Kawai, Tsutomu Furuzono

Research output: Contribution to journalArticle

29 Citations (Scopus)

Abstract

Interfacial interactions between calcined hydroxyapatite (HAp) nanocrystals and surface-modified substrates were investigated by measuring adsorption behavior and adhesion strength with a quartz crystal microbalance (QCM) and a contact-mode atomic force microscope (AFM), respectively. The goal was to develop better control of HAp-nanocrystal coatings on biomedical materials. HAp nanocrystals with rodlike or spherical morphology were prepared by a wet chemical process followed by calcination at 800 °C with an antisintering agent to prevent the formation of sintered polycrystals. The substrate surface was modified by chemical reaction with a low-molecular-weight compound, or graft polymerization with a functional monomer. QCM measurement showed that the rodlike HAp nanocrystals adsorbed preferentially onto anionic COOH-modified substrates compared to cationic NH2- or hydrophobic CH 3-modified substrates. On the other hand, the spherical nanocrystals adsorbed onto NH2- and COOH-modified substrates, which indicates that the surface properties of the HAp nanocrystals determined their adsorption behavior. The adhesion strength, which was estimated from the force required to move the nanocrystal in contact-mode AFM, on a COOH-grafted substrate prepared by graft polymerization was almost 9 times larger than that on a COOH-modified substrate prepared by chemical reaction with a low-molecular-weight compound, indicating that the long-chain polymer grafted on the substrate mitigated the surface roughness mismatch between the nanocrystal and the substrate. The adhesion strength of the nanocrystal bonded covalently by the coupling reaction to a Si(OCH3)-grafted substrate prepared by graft polymerization was approximately 1.5 times larger than that when adsorbed on the COOH-grafted substrate.

Original languageEnglish
Pages (from-to)6300-6306
Number of pages7
JournalLangmuir
Volume25
Issue number11
DOIs
Publication statusPublished - Jun 2 2009
Externally publishedYes

ASJC Scopus subject areas

  • Materials Science(all)
  • Condensed Matter Physics
  • Surfaces and Interfaces
  • Spectroscopy
  • Electrochemistry

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    Okada, M., Furukawa, K., Serizawa, T., Yanagisawa, Y., Tanaka, H., Kawai, T., & Furuzono, T. (2009). Interfacial interactions between calcined hydroxyapatite nanocrystals and substrates. Langmuir, 25(11), 6300-6306. https://doi.org/10.1021/la804274q