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Author(s): Filipa Castro
Simon Kuhn
Klavs Jensen
António Ferreira
Fernando Rocha
António Vicente
José António Teixeira
Title: Continuous-flow precipitation of hydroxyapatite in ultrasonic microsystems
Issue Date: 2013
Abstract: This paper describes the continuous-flow precipitation of hydroxyapatite Ca-5(PO4)(3)OH (HAp) in two ultrasonic microreactors using diluted aqueous solutions of calcium and phosphate at 37 degrees 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 100 nm in length and around 20 nm 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.
Subject: Engenharia química, Engenharia química
Chemical engineering, Chemical engineering
Scientific areas: Ciências da engenharia e tecnologias::Engenharia química
Engineering and technology::Chemical engineering
Related Information: info:eu-repo/grantAgreement/FCT - Fundação para a Ciência e Tecnologia/Projetos Estratégicos/PEst-C/EQB/UI0511/2013/PROJECTO ESTRATÉGICO - UI 511 - 2013-2014/UI0511
Document Type: Artigo em Revista Científica Internacional
Rights: restrictedAccess
Appears in Collections:FEUP - Artigo em Revista Científica Internacional

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