2024-03-29T06:54:28Zhttp://digital.csic.es/dspace-oai/requestoai:digital.csic.es:10261/1323072022-12-14T14:06:57Zcom_10261_84com_10261_5col_10261_337
The enhancement of porosity of carbon xerogels by using additives
Rey Raap, Natalia
Rodríguez-Sánchez, Sandra
Díaz Alonso-Buenaposada, Isabel
Gómez Calvo, Esther
Menéndez Díaz, José Ángel
Arenillas de la Puente, Ana
Ministerio de Economía y Competitividad (España)
Microwave heating
Carbon xerogels
Porosity
Additives
Resorcinol-formaldehyde carbon xerogels were synthesized by means of microwave heating by using precursor solutions with pH values ranging from 3 to 7 and adding various amounts of sodium sulfate, hexadecyltrimethylammonium bromide and Span80. It was found that the amount of additive that can be introduced depends to a large extent on the final pH of the precursor solution. Characterization of the porous structure of the carbon xerogels thus synthesized demonstrated that their porosity was modified by interactions between the additives and the polymeric structure of the xerogels. It is worth noting that carbonaceous materials with a pore size that could not be obtained by merely modifying the pH could be synthesized by adding different types of additive, with the result that a significant improvement of the porous properties of the carbon xerogels was achieved. The addition of sodium sulfate increased the size of the clusters and pores due to repulsive forces created between the additive and resorcinol anions. Hexadecyltrimethylammonium bromide gave rise to a dense branched structure with pores of a small size attributable to forces of attraction between the cations of the additive and resorcinol anions. In contrast, the presence of Span80 in the precursor solution produced a condensation reaction between the resorcinol and the additive, as a result of which the amount of resorcinol available for the sol-gel reaction was reduced.
2015
2016-05-18T11:23:13Z
artículo
Microporous and Mesoporous Materials 217: 39-45 (2015)
http://hdl.handle.net/10261/132307
10.1016/j.micromeso.2015.06.003
http://dx.doi.org/10.13039/501100003329
eng
Postprint
http://dx.doi.org/10.1016/j.micromeso.2015.06.003
Sí
http://creativecommons.org/licenses/by-nc-nd/4.0/
openAccess
Elsevier