Investigating and understanding in detail the sol-to-gel transition in inorganic and hybrid systems is a very challenging task. The transition is a critical phenomenon that can only be described with statistical but not thermodynamic models. Graphic schemes, therefore, cannot easily represent such a complicated process. The sol-to-gel transition has been illustrated with the support of several drawings. Representing complex media, such as the sol and the gel, by a scheme, is however quite tricky. Using oversimplified pictures can mislead the comprehension of the process, which is difficult to describe in general terms, as it depends so much on the synthesis and processing conditions. In this short tutorial, a fault-finding discussion based on the most common pictures drawn to illustrate the sol-to-gel transition has been used for a critical description of the process.
Sol–gel transition is a critical phenomenon described by statistical models.
Description of sol–gel transition through pictures should be done with care, to avoid a misinterpretation of the process.
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Prof. Luca Malfatti is gratefully acknowledged for critival discussion. Mrs Lavinia Innocenzi for support in drawing the figures.
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Innocenzi, P. Understanding sol–gel transition through a picture. A short tutorial. J Sol-Gel Sci Technol 94, 544–550 (2020). https://doi.org/10.1007/s10971-020-05243-w
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