000063247 001__ 63247
000063247 005__ 20190709135523.0
000063247 0247_ $$2doi$$a10.1021/acsomega.7b00975
000063247 0248_ $$2sideral$$a101996
000063247 037__ $$aART-2017-101996
000063247 041__ $$aeng
000063247 100__ $$aGavilán, H.
000063247 245__ $$aFormation Mechanism of Maghemite Nanoflowers Synthesized by a Polyol-Mediated Process
000063247 260__ $$c2017
000063247 5060_ $$aAccess copy available to the general public$$fUnrestricted
000063247 5203_ $$aMagnetic nanoparticles are being developed as structural and functional materials for use in diverse areas, including biomedical applications. Here, we report the synthesis of maghemite (¿-Fe2O3) nanoparticles with distinct morphologies: single-core and multicore, including hollow spheres and nanoflowers, prepared by the polyol process. We have used sodium acetate to control the nucleation and assembly process to obtain the different particle morphologies. Moreover, from samples obtained at different time steps during the synthesis, we have elucidated the formation mechanism of the nanoflowers: the initial phases of the reaction present a lepidocrocite (¿-FeOOH) structure, which suffers a fast dehydroxylation, transforming to an intermediate "undescribed" phase, possibly a partly dehydroxylated lepidocrocite, which after some incubation time evolves to maghemite nanoflowers. Once the nanoflowers have been formed, a crystallization process takes place, where the ¿-Fe2O3 crystallites within the nanoflowers grow in size (from ~11 to 23 nm), but the particle size of the flower remains essentially unchanged (~60 nm). Samples with different morphologies were coated with citric acid and their heating capacity in an alternating magnetic field was evaluated. We observe that nanoflowers with large cores (23 nm, controlled by annealing) densely packed (tuned by low NaAc concentration) offer 5 times enhanced heating capacity compared to that of the nanoflowers with smaller core sizes (15 nm), 4 times enhanced heating effect compared to that of the hollow spheres, and 1.5 times enhanced heating effect compared to that of single-core nanoparticles (36 nm) used in this work.
000063247 536__ $$9info:eu-repo/grantAgreement/ES/MINECO/RYC-2014-15512
000063247 540__ $$9info:eu-repo/semantics/openAccess$$aby-nc$$uhttp://creativecommons.org/licenses/by-nc/3.0/es/
000063247 592__ $$a0.749$$b2017
000063247 593__ $$aChemical Engineering (miscellaneous)$$c2017$$dQ1
000063247 593__ $$aChemistry (miscellaneous)$$c2017$$dQ2
000063247 655_4 $$ainfo:eu-repo/semantics/article$$vinfo:eu-repo/semantics/publishedVersion
000063247 700__ $$aSánchez, E.H.
000063247 700__ $$aBrollo, M.E.F.
000063247 700__ $$0(orcid)0000-0003-0641-3407$$aAsín, L.$$uUniversidad de Zaragoza
000063247 700__ $$aMoerner, K.K.
000063247 700__ $$aFrandsen, C.
000063247 700__ $$0(orcid)0000-0003-3130-4237$$aLázaro, F.J.$$uUniversidad de Zaragoza
000063247 700__ $$aSerna, C.J.
000063247 700__ $$aVeintemillas-Verdaguer, S.
000063247 700__ $$aMorales, M.P.
000063247 700__ $$0(orcid)0000-0003-2366-3598$$aGutiérrez, L.$$uUniversidad de Zaragoza
000063247 7102_ $$12009$$2750$$aUniversidad de Zaragoza$$bDpto. Química Analítica$$cÁrea Química Analítica
000063247 7102_ $$15001$$2065$$aUniversidad de Zaragoza$$bDpto. Ciencia Tecnol.Mater.Fl.$$cÁrea Cienc.Mater. Ingen.Metal.
000063247 773__ $$g2, 10 (2017), 7172-7184$$pACS Omega$$tACS Omega$$x2470-1343
000063247 8564_ $$s1192174$$uhttp://zaguan.unizar.es/record/63247/files/texto_completo.pdf$$yVersión publicada
000063247 8564_ $$s124781$$uhttp://zaguan.unizar.es/record/63247/files/texto_completo.jpg?subformat=icon$$xicon$$yVersión publicada
000063247 909CO $$ooai:zaguan.unizar.es:63247$$particulos$$pdriver
000063247 951__ $$a2019-07-09-11:58:20
000063247 980__ $$aARTICLE