Departamento de Química, Facultad de Ciencias, Universidad Nacional de Colombia, Sede Bogotá, Carrera 30 No 45-03, Bogotá, 111321 Colombia.
Departamento de Química. Facultad de Ciencias. Universidad Nacional de Colombia. Sede Bogotá. Carrera 30 No 45-03, Bogotá, 111321 Colombia.
Molecules. 2018 Feb 22;23(2):476. doi: 10.3390/molecules23020476.
The study of aliphatic compounds adsorption on activated carbon can be carried out from the energetic change involved in the interaction; the energy values can be determined from isotherms or by the immersion enthalpy. Vapor phase adsorption isotherms of hexane at 263 K on five activated carbons with different content of oxygenated groups and the immersion enthalpy of the activated carbons in hexane and water were determined in order to characterize the interactions in the solid-liquid system, and for calculating the hydrophobic factor of the activated carbons. The micropore volume and characteristic energy from adsorption isotherms of hexane, the BET (Brunauer-Emmett-Teller) surface area from the adsorption isotherms of N₂, and the area accessible to the hexane from the immersion enthalpy were calculated. The activated carbon with the lowest content of oxygenated groups (0.30 µmolg¹) and the highest surface area (996 m²g¹) had the highest hexane adsorption value: 0.27 mmol g¹; the values for E were between 5650 and 6920 Jmol¹ and for ΔH were between -66.1 and -16.4 Jg¹. These determinations allow us to correlate energetic parameters with the surface area and the chemical modifications that were made to the solids, where the surface hydrophobic character of the activated carbon favors the interaction.
可以从相互作用中涉及的能量变化来研究脂肪族化合物在活性炭上的吸附；可以从吸附等温线或浸热焓来确定能量值。为了表征固-液体系中的相互作用，并计算活性炭的疏水性因子，测定了在 263 K 下五种不同含氧基团含量的活性炭对正己烷的气相吸附等温线和活性炭在正己烷和水中的浸热焓。从正己烷吸附等温线上计算了微孔体积和特征能，从 N₂吸附等温线上计算了 BET（Brunauer-Emmett-Teller）表面积，从浸热焓上计算了正己烷可及面积。含氧基团含量最低（0.30 µmolg¹）和比表面积最高（996 m²g¹）的活性炭对正己烷的吸附值最高：0.27 mmol g¹；E 值在 5650 到 6920 Jmol¹ 之间，ΔH 值在-66.1 到-16.4 Jg¹ 之间。这些测定结果使我们能够将能量参数与表面积和对固体进行的化学修饰相关联，其中活性炭的表面疏水性有利于相互作用。
