Continuous-flow precipitation of hydroxyapatite in ultrasonic microsystems
Name
Continuous-flow_precipitation_of_hydroxyapatite_in.pdf
Description
Accepted version
Size
1.36 MB
Format
Adobe PDF
Checksum (MD5)
b28bee9e956693bc00bb4b406a512435
Author(s)
Castro, Filipa
Kuhn, Simon
Jensen, Klavs
Ferreira, Antonio
Rocha, Fernando
Vincente, Antonio
Teixeira, Jose Antonio
Date Issued
November 2012
Journal
Chemical Engineering Journal
Publisher
Elsevier BV
Citation
Castro, Filipa, et al. “Continuous-Flow Precipitation of Hydroxyapatite in Ultrasonic Microsystems.” Chemical Engineering Journal 215–216 (January 2013): 979–87.
Version
Author's final manuscript
Abstract
This paper describes the continuous-flow precipitation of hydroxyapatite Ca[subscript 5](PO[subscript 4])[subscript 3]OH (HAp) in two ultrasonic microreactors using diluted aqueous solutions of calcium and phosphate at 37°C. Precipitation of HAp was first carried out in a tubular microreactor immersed in an ultrasonic bath, where single-phase (laminar) flow and segmented gas-liquid flow were both evaluated. The single-phase flow study was then conducted in a novel microfluidic device developed at MIT. It consists of a Teflon stack microreactor with an integrated piezoelectric element (Teflon microreactor), thereby allowing the direct transmission of ultrasound to the reactor. Both microsystems produce single-phased calcium-deficient carbonated HAp under near-physiological conditions of temperature and pH. In addition, particle aggregation and primary particle size were significantly reduced in the segmented-flow tubular microreactor and in the Teflon microreactor. The as-prepared particles mostly consisted of rod-like shape nanoparticles with dimensions below 100nm in length and around 20nm in width. Further, the microreactors used yielded HAp particles with improved characteristics, namely higher crystallinity and less carbonate contamination, when compared to the HAp particles produced in a stirred tank batch reactor. Keywords: microfluidics; ultrasound; nanoparticles; hydroxyapatite; aggregation
MIT Department
Massachusetts Institute of Technology. Department of Chemical Engineering
Terms of Use
Creative Commons Attribution-NonCommercial-NoDerivs License
Persistent DSpace Link
DOI of Published Version
https://doi.org/10.1016/j.cej.2012.11.014
