Immersion Calorimetry: Molecular Packing Effects in Micropores. Issue 18 (13th October 2015)

• Record Type: Journal Article
• Authors: Madani, S. Hadi; Silvestre‐Albero, Ana; Biggs, Mark J.; Rodríguez‐Reinoso, Francisco; Pendleton, Phillip
• Is Part Of: Chemphyschem. Volume 16:Issue 18(2015)
• Page Start: 3984
• Page End: 3991
• Publication Date: 2015-10-13
• Subjects: adsorption -- immersion calorimetry -- molecular packing -- nitrogen -- pore size distribution; Chemistry, Physical and theoretical -- Periodicals; 541.05
• DOI: 10.1002/cphc.201500580
• Languages: English
• ISSNs: 1439-4235

Abstract

Abstract: Repeated and controlled immersion calorimetry experiments were performed to determine the specific surface area and pore‐size distribution (PSD) of a well‐characterized, microporous poly(furfuryl alcohol)‐based activated carbon. The PSD derived from nitrogen gas adsorption indicated a narrow distribution centered at 0.57±0.05 nm. Immersion into liquids of increasing molecular sizes ranging from 0.33 nm (dichloromethane) to 0.70 nm (α‐pinene) showed a decreasing enthalpy of immersion at a critical probe size (0.43–0.48 nm), followed by an increase at 0.48–0.56 nm, and a second decrease at 0.56–0.60 nm. This maximum has not been reported previously. After consideration of possible reasons for this new observation, it is concluded that the effect arises from molecular packing inside the micropores, interpreted in terms of 2D packing. The immersion enthalpy PSD was consistent with that from quenched solid density functional theory (QSDFT) analysis of the nitrogen adsorption isotherm. Abstract : Pore analysis : Repeated and controlled immersion calorimetry experiments are performed to determine the specific surface area and pore‐size distribution of a well‐characterized, microporous poly(furfuryl alcohol)‐based activated carbon.