title: Physicochemical aspects of epoxide driven nano-ZrO2 hydrogel formation: milder kinetics for better properties.
abstract: Robust and highly transparent quasi amorphous ZrO2-water-glycerol hydrogels were obtained in a mild one pot procedure, based on the 2,3-epoxy-1-propanol driven alkalinization. SAXS-based characterization of the sol-gel transition revealed that an homogeneously nucleated sol composed of 2 nm primary particles continuously grows up to a critical size of 5-6 nm, when gelation takes place. These particles reach a size of 8-10 nm, depending on the Zr(iv) concentration. Conductivity measurements offer an overall in situ assessment of the reaction rate. The gelled samples share a common trend: once the conductivity decays to 40% of the starting value, the primary particles nucleate and when this decay reaches 20%, the sol-gel transition takes place. The mild conditions employed herein prevent massive ripening and recrystallization leaving hydrogels with extremely low undesired visible light scattering. This suitable nanostructure was achieved in a wide range of total Zr(iv) concentrations or water to glycerol ratios.
authors.affiliation: INQUIMAE, DQIAQF, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Pabellón II, Ciudad Universitaria, C1428EHA-Buenos Aires, Argentina. mercedesp@qi.fcen.uba.ar jobbag@qi.fcen.uba.ar.
authors.forename: V
authors.initials: V
authors.lastname: Oestreicher
authors.affiliation: INQUIMAE, DQIAQF, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Pabellón II, Ciudad Universitaria, C1428EHA-Buenos Aires, Argentina. mercedesp@qi.fcen.uba.ar jobbag@qi.fcen.uba.ar.
authors.forename: M
authors.initials: M
authors.lastname: Perullini
authors.affiliation: INQUIMAE, DQIAQF, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Pabellón II, Ciudad Universitaria, C1428EHA-Buenos Aires, Argentina. mercedesp@qi.fcen.uba.ar jobbag@qi.fcen.uba.ar and Centro Interdisciplinario de NanoCiencia y NanoTecnología, Argentina.
authors.forename: M
authors.initials: M
authors.lastname: Jobbágy