caa a22 4500 46319179X CHVBK 20180406164911.0 cr unu---uuuuu 170326e20070801xx s 000 0 eng 10.1007/s10973-006-7524-3 doi (NATIONALLICENCE)springer-10.1007/s10973-006-7524-3 Calorimetric determination of activated carbons in aqueous solutions [Elektronische Daten] [Liliana Giraldo, J. Moreno-Piraján] The interactions among five samples of activated carbons, obtained from different lignocellulosic materials with different degrees of activation of approximately 20% and aqueous solutions of phenol and 4-nitro phenol are studied by means of the determination of immersion enthalpies. It is established that the obtained activated carbons are of a basic character and show values for the pH at the point of zero charge, pHPZC, that range from 7.4 to 9.7 and, in all cases, higher total basicity contents than the values obtained for total acidity. The immersion heat of the activated carbons in CCl4 and water is determined obtaining values which are higher for CCl4 immersion and vary from 31.4 to 48.6 J g−1. The hydrophobic factor, hf, it is calculated from the relation between of the immersion heat of the activated carbons in CCl4 and the immersion heat in water, the obtained values were 2.98 and 6.75, which are greater than 1 due to the greater values obtained in CCl4 when compared to the values obtained in water. Immersion enthalpies in phenol solution range from 7.6 to 13.9 J g−1 and for the case of 4-nitro phenol such enthalpies range from 12.7 to 20.5 J g−1; all the 5 samples studied showed a higher value for the heat of immersion in aqueous solutions of 4-nitro phenol. Springer Science+Business Media LLC, 2007 acidity nationallicence basicity nationallicence immersion calorimetry nationallicence immersion enthalpy nationallicence phenol adsorption nationallicence pzc nationallicence Giraldo Liliana Departamento de Quimica, Facultad de Ciencias, Universidad Nacional de Colombia, San Andrés, Columbia aut Moreno-Piraján J. Departamento de Quimica, Facultad de Ciencias, Grupo de Investigación en Sólidos Porosos y Calorimetría, Universidad de los Andes, San Andrés, Columbia aut Journal of Thermal Analysis and Calorimetry Kluwer Academic Publishers-Plenum Publishers; http://www.springer-ny.com 89/2(2007-08-01), 589-594 1388-6150 89:2<589 2007 89 10973 https://doi.org/10.1007/s10973-006-7524-3 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10973-006-7524-3 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Giraldo Liliana Departamento de Quimica, Facultad de Ciencias, Universidad Nacional de Colombia, San Andrés, Columbia aut NATIONALLICENCE 700 1- Moreno-Piraján J. Departamento de Quimica, Facultad de Ciencias, Grupo de Investigación en Sólidos Porosos y Calorimetría, Universidad de los Andes, San Andrés, Columbia aut NATIONALLICENCE 773 0- Journal of Thermal Analysis and Calorimetry Kluwer Academic Publishers-Plenum Publishers; http://www.springer-ny.com 89/2(2007-08-01), 589-594 1388-6150 89:2<589 2007 89 10973 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer