Volume 79, Issue 8

The 19th International Conference on Chemical Thermodynamics (ICCT-19) took place as part of THERMO International 2006, together with the 16th Symposium on Thermophysical Properties and the 61st Calorimetry Conference, from 30 July to 4 August 2006 at the University of Colorado, Boulder, CO, USA. Dr. W. M. Haynes was President of the Executive Board of THERMO International 2006, and Drs. M. Frenkel, R. D. Chirico, and J. W. Magee were the organizers of ICCT. Overall, 768 speakers submitted the abstracts of their presentations, including about 30 students and 11 exhibitors, from 62 countries (235 from North America, 341 from Europe, 76 from Japan, and 33 from China). About 65 % of the participants were from academia and 15 % from industry, with 20 % from governmental and international organizations. These individual conferences have an overlap of areas of interest, but this was the first time that they have been held jointly at the same site. This provided a unique opportunity for researchers and practitioners worldwide to meet and discuss a broad range of scientific problems in the fields of thermodynamics and thermophysical properties for a wide variety of systems, with applications in chemistry and other scientific and engineering disciplines. After the official opening ceremony, there was an invited keynote presentation by Prof. W. A. Wakeham from the University of Southampton, Southampton, UK, entitled "Thermophysical property measurements: The journey from accuracy to fitness for purpose". The Rossini Award lecture was given by Prof. A. Navrotsky on "Calorimetry of nanoparticles, surfaces, interfaces, thin films, and multilayers". The ICCT program consisted of nine symposia, some of which were held jointly with the other conferences. The plenary lecturers and invited speakers in these symposia, and the titles of the plenary lectures, were as follows: Electrolyte and Non-Electrolyte Solution Thermodynamics: J. M. Prausnitz (plenary), "Some promising frontiers in the thermodynamics of protein solutions"; C. G. Panayiotou, P. R. Tremaine, and T. Kimura (invited) Ionic Liquids: K. Seddon (plenary); "The mark of an educated mind"; L. P. N. Rebelo and C. J. Peters (invited) Molecular Modelling, Including Simulation: D. Evans (plenary), "The fluctuation and non-equilibrium free energy theorems: Theory and experiment"; H. Tanaka, J. Errington, and A. Klamt (invited) Thermochemistry and Molecular Energetics: J. A. de Sousa Martinho Simões (plenary), "Energetics of free radicals: Bridges between gas-phase and solution data"; W. E. Acree, Jr. and J. S. Chickos (invited) Thermodynamics and Properties in the Biological, Medical, Pharmaceutical, Agricultural, and Food Sectors: P. L. Privalov (plenary), "Thermodynamic problems in structural molecular biology"; J. M. Sanchez-Ruiz and H. H. Klump (invited) Databases, Data Systems, Software Applications, and Correlations: M. Satyro (plenary), "Life, data and everything"; R. L. Rowley and R. Sass (invited) Phase Equilibrium, Supercritical Fluids, and Separation Technologies: S. Sandler (plenary), "Computational quantum mechanics: An under-utilized tool for applied thermodynamics"; L. F. Vega and R. P. Danner (invited) Colloid and Interface Science: L. Piculell (plenary), "Controlling structure in associating polymer-surfactant mixtures"; H. K. Yan and K. Lohner (invited) New Materials: V. K. Pecharsky (plenary), "Structure, mechanism, and thermodynamics of novel rare-earth-based inter-metallic materials"; C. Staudt-Bickel and J. Pons (invited) The plenary lectures, with the exception of the lecture by Prof. K. Seddon, are published in this issue. There were workshops on New Experimental Techniques, with Profs. C. Schick and J. P. M. Trusler as invited speakers, on Properties and Processes for a Hydrogen-Based Economy, where Prof. C. J. Peters was the invited speaker, and on Thermodynamic Frontiers and Education, with Profs. R. N. Lichtenthaler and R. Battino as invited speakers. In addition, there was a workshop on the Thermodynamic Properties of Hydration (with Prof. V. Majer as invited speaker), software demonstrations, and two afternoon poster sessions, with over 400 posters. The sessions were held in the well-appointed Stadium Club, against the beautiful backdrop of the Flatirons to the west and the plains stretching across to the east. IUPAC had donated three poster prizes, a framed certificate signed by IUPAC President Brian Henry, a copy of the IUPAC "Gold Book" and a two-year subscription to Chemistry International . These were awarded to Martinez-Herrera Melchor (Mexico), Lisa Ott (USA), and Isabel Marrucho (Spain). Doctorate awards were presented by the International Association of Chemical Thermodynamics (IACT), with sponsorship from Elsevier. The four recipients were M. Fulem (Prague, Czech Republic), Y. U. Paulechka (Minsk, Belarus), E. Asabina (Nizhni Novgorod, Russian Federation), and J. Xu (Trondheim, Norway). They each received a certificate, plus a cash prize of $500, and presented their papers at the conference. All the lectures demonstrated how chemical thermodynamics is making, and will continue to make, very significant contributions to the rapidly developing interdisciplinary fields such as the life sciences, new materials, medicine and pharmacy, new energy resources, the environment, separation technologies, agriculture, green chemistry, and so on. These are all extremely important issues for scientists worldwide, and particularly for those who are in developing or economically disadvantaged countries. The opportunity for face-to-face discussion and communication with scientists from developed countries was a great benefit, which will lead to further research and improved education. The weather was most pleasant for the conference. This, together with the attractive setting of the campus, the welcoming reception, the conference banquet at the National Center for Atmospheric Research, and the high standard of the presentations, made this a memorable conference. In addition, there was a full program of tours for accompanying persons, which included a visit to the mile-high city (Denver). Our thanks are extended to the Conference Chair and Co-chairs, and to all members of the local Organizing Committee, the members of the International Advisory Committee, and the members of the International Scientific Committee. We are most grateful to IUPAC, the International Association of Chemical Thermodynamics, the National Institute of Standards and Technology, the American Society of Mechanical Engineers, and the American Institute of Chemical Engineers, Elsevier, Honeywell, and Mettler Toledo for sponsoring THERMO International 2006. Thermodynamics will continue to be an important area of research for many years to come, with a wide range of applications from chemical engineering to the biosciences. We look forward to the presentation and discussion of the results of further advances in chemical thermodynamics at the next ICCT, which will take place in Warsaw, Poland in August 2008. John H. Dymond Conference Editor

In this paper, we highlight the various ways computational quantum mechanics (QM) can be used in applied thermodynamics. We start with the most rigorous procedures of calculating the interactions between molecules that can then be used in simulation and progress, in steps, to less rigorous but easily used methods, including the very successful continuum solvation models.

The Evans-Searles fluctuation theorem (ESFT) has been shown to be applicable in the near- and far-from-equilibrium regimes for systems with both constant and time-dependent external fields. The derivations of the ESFT have assumed that the external field has a definite parity under a time-reversal mapping. In the present paper, we confirm that the time-reversibility of the system dynamics is a necessary condition for the ESFT to hold. The manner in which the ESFT fails for systems that are not time-reversible is presented, and results are shown which demonstrate that systems which fail to satisfy the ESFT may still satisfy the Crooks relation (CR).

Solvent effects are responsible for the difference between gas- and solution-phase bond-dissociation enthalpies (BDEs), and are thus crucial for understanding reactivity in solution. While solvation effects can be negligible (e.g., in reactions involving carbon-centered radicals), they may be rather significant (e.g., when oxygen-centered radicals are formed). This paper reviews a number of models which have been proposed to deal with the difference between the solvation energetics of a radical and its parent molecule. It is concluded that the radical-solvent interaction may be larger than previously anticipated.

After approximately 30 years of dormancy, the binary, ternary, and multicomponent intermetallic compounds of rare earth metals ( R ) with the group 14 elements ( T ) at the R 5 T 4 stoichiometry have become a goldmine for materials science, condensed matter physics, and solid-state chemistry. In addition to providing numerous opportunities to clarify elusive structure-property relationships, the R 5 T 4 compounds may soon be developed into practical materials by exploiting their unique sensitivity toward a variety of chemical and physical triggers. The distinctiveness of this series is in the remarkable flexibility of the chemical bonding between well-defined, self-assembled, subnanometer-thick slabs and the resultant magnetic, transport, and thermodynamic properties of the R 5 T 4 compounds that can be controlled by varying either or both R and T , including mixed rare earth elements on the R -sites and different group 14 (and 13 or 15) elements occupying the T -sites. In addition to chemical means, the interslab interactions are tunable by temperature, pressure, and magnetic field. Presently, a substantial, yet far from complete, body of knowledge exists about the Gd compounds with T = Si and Ge. In contrast, only a little is known about the physics and chemistry of R 5 T 4 alloys with other lanthanides, while compounds with T = Sn and Pb remain virtually unexplored.

The use of thermodynamics for the solution of chemical and process engineering problems is determined by a blend of science, engineering, art, and grit. Although chemical engineering thermodynamics benefits from an ever-increasing body of basic scientific knowledge, the solution of real problems still depends very much on the knowledge of individuals, their creativity, and their determination to recommend solutions. The essence of success is determined by a combination of two apparently simple components-physical property data and how they are used.

Structures of concentrated mixtures of associating polymer-surfactant mixtures are important in many technical applications. Yet an in-depth understanding of how molecular parameters affect these structures is lacking. We here summarize the results of ongoing work using a novel simplified approach to the study of associating oppositely charged polymer-surfactant mixtures, introducing a minimum number of components to the various mixtures. The results illustrate the relations between systems with and without polyions, as well as effects of systematic changes of parameters such as surfactant chain length, polyion length, polyion charge density, and the charge density of the surfactant aggregate.

Three examples illustrate the versatility and usefulness of biothermodynamics. The first example concerns calculation of a phase diagram for aqueous lysozyme with a new potential of mean force that takes the Hofmeister effect into account; such calculations may be useful for design of a separation process where addition of a salt to an aqueous protein mixture precipitates a target protein. The second example concerns thermodynamic studies to elucidate the effect of an organic cosolvent on the mechanism of crystallizing aqueous insulin. The final example concerns a thermodynamic contribution to mitigating the AIDS epidemic; it indicates how isothermal-titration-calorimetry studies are helpful for choosing an optimum inhibitor that is effective not only for the wild-type HIV protease but also for at least some of its mutants.

The most essential feature of living biological systems is their high degree of structural organization. The key role is played by two linear heteropolymers, the proteins and nucleic acids. Under environmental conditions close to physiological, these biopolymers are folded into unique native conformations, genetically determined by the arrangement of their standard building blocks. In their native conformation, biological macromolecules recognize their partners and associate with them, forming specific, higher-order complexes, the "molecular machines". Folding of biopolymers into their native conformation and their association with partners is in principle a reversible, thermodynamically driven process. Investigation of the thermodynamics of these basic biological processes has prime importance for understanding the mechanisms of forming these supra-macromolecular constructions and their functioning.

Critically evaluated propagation rate coefficients, k p , for free-radical polymerization of methacrylic acid, MAA, in aqueous solution are presented. The underlying k p values are from two independent sources, which both used the IUPAC-recommended technique of pulsed-laser-initiated polymerization (PLP) in conjunction with molar mass distribution (MMD) analysis of the resulting polymer by size-exclusion chromatography (SEC). Different methods of measuring the MMD of the poly(MAA) samples have, however, been used: (i) direct analysis via aqueous-phase SEC and (ii) standard SEC with tetrahydrofuran as the eluent carried out on poly(methyl methacrylate) samples obtained by methylation of the poly(MAA) samples from PLP. Benchmark k p values for aqueous solutions containing 15 mass % MAA are presented for temperatures between 18 and 89 °C. The Arrhenius pre-exponential and activation energy of k p at 15 mass % MAA are 1.54 × 10 6 L mol -1 s -1 and 15.0 kJ mol -1 , respectively. Also reported are critically evaluated k p values for 25 °C over the entire MAA concentration range from dilute aqueous solution to bulk polymerization.