Keith E. Gubbins教授学术报告通知

美国North Carolina State University, Keith E. Gubbins教授学术报告通知报告题目：PHASE CHANGE AND CHEMICAL REACTIONS AT THE NANOSCALE: EFFECTS OF CONFINEMENT报告人：美国工程院院士，美国 North Carolina State University, Keith E. Gubbins教授报告时间：2006年10月16日下午14:30-16:00报告地点: 浙江大学玉泉校区教八-107Keith E. Gubbins教授简介:W.H. Clark Distinguished University ProfessorNational Academy of Engineering (1989)B.Sc., Chemistry, University of London, (1958)Ph.D., Chemical Engineering, University of London (1962)Areas of Interest: Confined materials; adsorption; molecular simulation; surface properties. Email: keg@ncsu.eduResearch Group: http://chumba.che.ncsu.edu/Phone: 919-513-2262欢迎全校师生踊跃参加！Keith E. Gubbins教授欢迎有兴趣到North Carolina State University去攻读博士学位的同学与他面谈。理学院2006年10月8日 附：Abstract of the Lecture: Over the past decade there has been an outpouring of reports of new, syntheticnano-porous materials, with pores of various shapes, surface chemistries andtopologies, with sizes ranging from a few tenths of a nanometer up to tens of nm. These include some materials that are crystalline (e.g. fluorinated aluminophosphates, gallophosphates, metal-organic framework materials), some that are disordered (e.g. activated carbons, carbide-derived carbons), and others that are regular but not crystalline (e.g. mesoporous templated materials, periodic mesoporous organosilicas and mesoporous carbons (CMKs)). These materials have potential applications in new technologies, including energy storage devices, sensors, controlled drug release, microcircuits, as photonic crystals and lasers, and as templates to grow nanostructures such as nanowires and ordered mesoporous carbons that are of interest as potential fuel cell electrodes. By introducing guest nano-phases into these materials it is possible to produce a wide range of nano-structured materials and devices. In addition to these emerging applications, nano-porous solids play a central role as adsorbents and catalysts in many traditional industries and processes, including chemicals, petrochemicals, oil refining, fine chemicals, pharmaceuticals, catalysts, separations and environmental, technologies representing a world turnover of more than 1000 billion dollars per year. Of particular interest is the behaviour of host nanophases (fluid or solid) confined within these pore structures. The very large surface to volume ratios (some carbons exhibit surface areas of 2000m2/g), strong adsorbate-adsorbent interactions, chemical heterogeneity of pore walls, and reduced dimensionality can lead to very large confinement effects on physical and chemical property behaviour. This lecture will address two such classes of phenomena, namely phase transitions and chemical reactions. In the case of phase transitions, confinement leads to shifts in transition temperatures and pressures from the values in the bulk, and also in some cases to new surface-driven transitions. In the case of reactive mixtures, the effects of confinement, interaction of the reactive mixture with the pore walls of the material, defects, etc., can lead toenhancement or inhibition of the reaction. An experimental investigation of the role of each possible catalytic effect is challenging, since experimental measurements reflect an integration over multiple catalytic effects. Theoretical calculations also face difficulties. In particular, ab initio methods to determine the potential energy surface, and hence reaction mechanism, are computationally very demanding. In addition, reaction events are rare, and special “rare event” molecular dynamics methods are needed to sample the reaction. In many applications a combination of ab initio and semi-classical atomistic simulations will be needed. Examples of cases where such effects have a large influence on reaction yield, reaction rate and reaction mechanism will be shown.