Kinetics of Resorcinol-Formaldehyde Condensation-Comparison of Common Experimental Techniques

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61988987%3A17310%2F22%3AA2302CQV" target="_blank" >RIV/61988987:17310/22:A2302CQV - isvavai.cz</a>

Výsledek na webu

<a href="https://www.mdpi.com/2310-2861/8/1/8/htm" target="_blank" >https://www.mdpi.com/2310-2861/8/1/8/htm</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.3390/gels8010008" target="_blank" >10.3390/gels8010008</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Kinetics of Resorcinol-Formaldehyde Condensation-Comparison of Common Experimental Techniques

Popis výsledku v původním jazyce

Porous carbons, originated from resorcinol-formaldehyde (RF) gels, show high application potential. However, the kinetics and mechanism of RF condensation are still not well described. In this work, different methods (dynamic light scattering-DLS, Fourier transform infrared spectroscopy-FTIR, low field H-1 nuclear magnetic resonance relaxometry-H-1-NMR, and differential scanning calorimetry-DSC) were used to follow the isothermal RF condensation of mixtures varying in catalyst content (Na2CO3) and reactant concentration. The applicability and results obtained by the methods used differ significantly. The changes in functional groups can be followed by FTIR only at very early stages of the reaction. DLS enables the estimate of the growth of particles in reaction solution, but only before the solution becomes more viscous. Following the relaxation of H-1 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. From this side, the process behaves similarly to the nucleation reaction, which is in contradiction to the n-order mechanism confirmed by other techniques. 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. Furthermore, this approach enables us to follow the gradual formation and development of the gel through the intermediate undergoing glass transition.

Název v anglickém jazyce

Kinetics of Resorcinol-Formaldehyde Condensation-Comparison of Common Experimental Techniques

Popis výsledku anglicky

Porous carbons, originated from resorcinol-formaldehyde (RF) gels, show high application potential. However, the kinetics and mechanism of RF condensation are still not well described. In this work, different methods (dynamic light scattering-DLS, Fourier transform infrared spectroscopy-FTIR, low field H-1 nuclear magnetic resonance relaxometry-H-1-NMR, and differential scanning calorimetry-DSC) were used to follow the isothermal RF condensation of mixtures varying in catalyst content (Na2CO3) and reactant concentration. The applicability and results obtained by the methods used differ significantly. The changes in functional groups can be followed by FTIR only at very early stages of the reaction. DLS enables the estimate of the growth of particles in reaction solution, but only before the solution becomes more viscous. Following the relaxation of H-1 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. From this side, the process behaves similarly to the nucleation reaction, which is in contradiction to the n-order mechanism confirmed by other techniques. 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. Furthermore, this approach enables us to follow the gradual formation and development of the gel through the intermediate undergoing glass transition.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10404 - Polymer science

Projekt

—

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2022

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

GELS

ISSN

2310-2861

e-ISSN

2310-2861

Svazek periodika

—

Číslo periodika v rámci svazku

1

Stát vydavatele periodika

CH - Švýcarská konfederace

Počet stran výsledku

15

Strana od-do

1-15

Kód UT WoS článku

000747514700001

EID výsledku v databázi Scopus

2-s2.0-85121772669