Physicochemical aspects of epoxide driven nano-ZrO2 hydrogel formation: Milder kinetics for better properties
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...
| Authors: | ; ; |
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| Format: | Article |
| Status: | Published version |
| Publication date: | 2016 |
| Country: | Argentina |
| Institution: | Consejo Nacional de Investigaciones Científicas y Técnicas |
| Repository: | CONICET Digital (CONICET) |
| Language: | English |
| OAI Identifier: | oai:ri.conicet.gov.ar:11336/59003 |
| Online Access: | http://hdl.handle.net/11336/59003 |
| Access Level: | Open access |
| Keyword: | Hydrogels Saxs Gelification https://purl.org/becyt/ford/1.4 https://purl.org/becyt/ford/1 |
| Summary: | 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. |
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