TY - JOUR
T1 - Preparation, purification, and characterization of aminopropyl-functionalized silica sol
AU - Pálmai, Marcell
AU - Nagy, Lívia Naszályi
AU - Mihály, Judith
AU - Varga, Zoltán
AU - Tárkányi, Gábor
AU - Mizsei, Réka
AU - Szigyártó, Imola Csilla
AU - Kiss, Teréz
AU - Kremmer, Tibor
AU - Bóta, Attila
PY - 2013/1/15
Y1 - 2013/1/15
N2 - A new, simple, and "green" method was developed for the surface modification of 20nm diameter Stöber silica particles with 3-aminopropyl(diethoxy)methylsilane in ethanol. The bulk polycondensation of the reagent was inhibited and the stability of the sol preserved by adding a small amount of glacial acetic acid after appropriate reaction time. Centrifugation, ultrafiltration, and dialysis were compared in order to choose a convenient purification technique that allows the separation of unreacted silylating agent from the nanoparticles without destabilizing the sol. The exchange of the solvent to acidic water during the purification yielded a stable colloid, as well. Structural and morphological analysis of the obtained aminopropyl silica was performed using transmission electron microscopy (TEM), dynamic light scattering (DLS) and zeta potential measurements, Fourier-transform infrared (FTIR), 13C and 29Si MAS nuclear magnetic resonance (NMR) spectroscopies, as well as small angle X-ray scattering (SAXS). Our investigations revealed that the silica nanoparticle surfaces were partially covered with aminopropyl groups, and multilayer adsorption followed by polycondensation of the silylating reagent was successfully avoided. The resulting stable aminopropyl silica sol (ethanolic or aqueous) is suitable for biomedical uses due to its purity.
AB - A new, simple, and "green" method was developed for the surface modification of 20nm diameter Stöber silica particles with 3-aminopropyl(diethoxy)methylsilane in ethanol. The bulk polycondensation of the reagent was inhibited and the stability of the sol preserved by adding a small amount of glacial acetic acid after appropriate reaction time. Centrifugation, ultrafiltration, and dialysis were compared in order to choose a convenient purification technique that allows the separation of unreacted silylating agent from the nanoparticles without destabilizing the sol. The exchange of the solvent to acidic water during the purification yielded a stable colloid, as well. Structural and morphological analysis of the obtained aminopropyl silica was performed using transmission electron microscopy (TEM), dynamic light scattering (DLS) and zeta potential measurements, Fourier-transform infrared (FTIR), 13C and 29Si MAS nuclear magnetic resonance (NMR) spectroscopies, as well as small angle X-ray scattering (SAXS). Our investigations revealed that the silica nanoparticle surfaces were partially covered with aminopropyl groups, and multilayer adsorption followed by polycondensation of the silylating reagent was successfully avoided. The resulting stable aminopropyl silica sol (ethanolic or aqueous) is suitable for biomedical uses due to its purity.
KW - 3-Aminopropyl(diethoxy)methylsilane
KW - Aminopropyl silica nanoparticles
KW - Silylation in sol
KW - Surface modification
UR - http://www.scopus.com/inward/record.url?scp=84868500532&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84868500532&partnerID=8YFLogxK
U2 - 10.1016/j.jcis.2012.09.025
DO - 10.1016/j.jcis.2012.09.025
M3 - Article
C2 - 23068887
AN - SCOPUS:84868500532
SN - 0021-9797
VL - 390
SP - 34
EP - 40
JO - Journal of Colloid And Interface Science
JF - Journal of Colloid And Interface Science
IS - 1
ER -