Calorimetry at the Solid–Liquid Interface

Abstract

Broad principles of Solid-Liquid calorimetry together with some illustrative examples of its use in the field of catalysis are presented here. The first use is related to the determination of surface properties of catalysts, adsorbents and solid materials in contact with liquids. In particular, it is shown how to evaluate the capacity of a given solid to establish different types of interaction with its liquid environment or to calculate its specific surface area accessible to liquids. The second use includes the measurement of the heat effects accompanying catalytic reactions and the related interfacial phenomena at Solid-Liquid and Liquid-Liquid interfaces. Examples of competitive ion adsorption from dilute aqueous solutions, as well as the formation of surfactant aggregates either in aqueous solution or at the SolidLiquid interface are considered in view of potential applications in Environmental Remediation and Micellar Catalysis.

Micellization Behavior of Long-Chain Substituted Alkylguanidinium Surfactants

“…From this point of view, this micellization behavior is at variance with the endothermic micelle formation observed here for their alkyltrimethylammonium homologues. A more detailed comparison with the thermodynamic parameters reported in the literature for various ionic surfactant indicates that this behavior is rather similar to that exhibited by alkyltrimethylammonium bromides with the same hydrophobic tails, even though the micellization of the guanidinium cationics studied occurs at lower CMC values [ 44 ]. The latter conclusion may be easily rationalized since the degrees of counter-ion binding to the micelle are similar in both cases, and Cl − is known to be more effective than Br − in salting out the surfactant cation and thus depressing the CMC [ 2 ].…”

Sorption Dynamics and Energetics of Cinnamic Acid and Its Derivatives at the Ferrihydrite–Water Interface Determined by Flow-Adsorption Microcalorimetry

“…CIN, which had the fewest substituents, lowest molecular weight, and smallest volume, would encounter the least resistance during diffusion to the surface. The endothermic response would be reflective of a greater loss of hydration water at the mineral surface and/or the loss of confinement within a water cluster. , Furthermore, the hydrophobic effect of the unsubstituted phenyl ring in CIN would have larger endothermic and entropic contributions. , In contrast, the shift in electronic distribution from the para-positioned OH group in COU would increase its polarizability compared to CIN (Table ). This higher polarizability in COU would favor its interaction with the surface via dipole-type interactions and would explain the exothermic response in the hydroxycinnamates.…”

“…36,37 Furthermore, the hydrophobic effect of the unsubstituted phenyl ring in CIN would have larger endothermic and entropic contributions. 8,38 In contrast, the shift in electronic distribution from the para-positioned OH group in COU would increase its polarizability compared to CIN (Table 1). This higher polarizability in COU would favor its interaction with the surface via dipole-type interactions and would explain the exothermic response in the hydroxycinnamates.…”

Driving Forces of Cationic Dye Adsorption, Confinement, and Long-Range Correlation in Zeolitic Materials

“…The dilution effect was evaluated under similar conditions with only the solvent. The global heat effects were calculated after appropriate subtraction of the dilution effect and then for each injection have been related to the real adsorbed amount from the isotherm . The final results are represented as the cumulative displacement enthalpy since the enthalpy represents a global effect combining various contributions involved in the overall sorption process including adsorption/exchange, hydration, and displacement …”