studied the kinetics of reaction between R and F under alkaline conditions (Na 2CO 3) by 1H NMR and 13C NMR. The second most used technique for investigating sol-gel RF polycondensation is nuclear magnetic resonance spectroscopy ( 1H NMR or 13C NMR). investigated the kinetics of cluster growth with the use of various carbonates as catalysts and reached similar findings as the previous researchers. However, a higher catalyst concentration led to an increase in the number of clusters. On the contrary, Gaca and Sefcik concluded that the size of primary clusters in the early gelation stages was independent of the R/C ratio and the reactant concentration (R and F). , the growth rate of primary clusters in the early gelation stage was particularly dependent on the catalyst concentration (R/C molar ratio). A significant number of researches have been carried out in this area. The structure formation during sol-gel transition of the RF solution has been the most investigated by light scattering methods, dynamic light scattering (DLS), and static light scattering (SLS). However, the progress of the restriction comes with the reaction progress when the sol develops through various polymeric intermediates into a three-dimensional polymer network (gel). To a lesser degree, the problem is not at the beginning, when the reaction starts from the RF polycondensation mixture (sol), which can be examined by various techniques. Moreover, only a limited number of techniques allow for the investigation of the whole course of the sol-gel reaction. The probable reason why this issue is relatively poorly explored is in technical matters. Therefore, its understanding is necessary for the effective tailoring of the properties of final gels. This lack of mechanistic or kinetic studies is in clear contradiction with the generally adopted fact that RF condensation is the crucial step of RF based carbons. In fact, only five contributions have attempted to study and explain the course and mechanism of the kinetics of resorcinol-formaldehyde polycondensation. Nevertheless, most of these ‘kinetic’ papers follow the kinetics of adsorption in RF-based carbon adsorbents. Six hundred and sixteen studies are found on the Web of Science that have in the title concept resorcinol-formaldehyde, and only 15 of them contain kinetic in the title. Over the last 30 years, a large number of investigations have been performed focusing on the study of the properties of RF gels. The preparation of these materials is based on the sol-gel polycondensation of the precursors (R and F) under alkaline or acidic conditions. The exceptional properties predetermine their use as adsorbents, catalyst supports, electrodes for supercapacitors, batteries or fuel cells, and column packing materials for chromatography. Resorcinol (R) and formaldehyde (F) are precursors for the preparation of highly porous and chemically resistant carbon materials. Furthermore, this approach enables us to follow the gradual formation and development of the gel through the intermediate undergoing glass transition. The widest range of applicability was found for DSC measurement of the freezing/melting behavior of the reaction mixture, which is possible to use without any limitations until full solidification. From this side, the process behaves similarly to the nucleation reaction, which is in contradiction to the n-order mechanism confirmed by other techniques. Following the relaxation of 1H nuclei in water during RF condensation brings a different view on the system-this technique follows the properties of the present water that is gradually captured in polymeric gel. DLS enables the estimate of the growth of particles in reaction solution, but only before the solution becomes more viscous. The changes in functional groups can be followed by FTIR only at very early stages of the reaction. The applicability and results obtained by the methods used differ significantly. In this work, different methods (dynamic light scattering–DLS, Fourier transform infrared spectroscopy–FTIR, low field 1H nuclear magnetic resonance relaxometry– 1H-NMR, and differential scanning calorimetry–DSC) were used to follow the isothermal RF condensation of mixtures varying in catalyst content (Na 2CO 3) and reactant concentration. However, the kinetics and mechanism of RF condensation are still not well described. Porous carbons, originated from resorcinol-formaldehyde (RF) gels, show high application potential.
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