Investigation of Enantioselective Adsorption on Chiral Mineral Surfaces

提案标题：手性矿物表面对映选择性吸附的研究提案编号：CTS-0521719主要研究员：Paul Sides机构：卡内基梅隆大学本提案的目的是证明矿物的手性表面可以作为对映选择性分析和分离介质。许多常见的无机材料具有手性体相结构。 将产生单晶石英和方解石上氨基酸对映体特异性吸附的基本证据。 超高真空表面科学工具将被用来量化的R-和S-氨基酸的吸附能量的差异到石英和方解石的手性表面。吸附程度将在真空中通过程序升温脱附进行评价，并在水溶液中通过检测吸附氨基酸时相反手性表面之间的ζ电位差进行评价。zeta电位测量将使用卡内基梅隆大学最近开发的一种新技术进行。该技术将适用于R-和S-表面上的对映选择性吸附的差分测量。 矿物表面的对映选择性吸附以前从未在微真空条件下进行过研究。第二个新的特点是使用一个旋转的磁盘方法最近发明的测量与吸附的带电分子，如氨基酸的无机表面的zeta电位的变化，这种方法使得可能的对映体选择性的真正的差分测量。 该研究将有助于对手性化合物在无机手性表面上的对映体专一性吸附的基本认识。 就更广泛的影响而言，拟议的调查将促进手性知识的传播，手性是分子结构的一个微妙方面，材料科学和化学工程等工程学科在很大程度上忽略了这一点。一个新的实验的基础上对映体吸附将被纳入现有的实验室课程。 这项工作可能会导致更好的过程中进行分离手性分子用于药物，人工香料和农用化学品。

Proposal Title: Investigation of Enantioselective Adsorption on Chiral Mineral SurfacesProposal Number: CTS-0521719Principal Investigator: Paul SidesInstitution: Carnegie Mellon UniversityThe objective of this proposal is to demonstrate that chiral surfaces of minerals can function as enantioselective analysis and separations media. Many common inorganic materials have chiral bulk structures. Fundamental evidence for the enantiospecific adsorption of amino acids on single crystalline quartz and calcite will be produced. Ultra-high vacuum surface science tools will be used to quantify the differences in the adsorption energies of R- and S- amino acids onto chiral surfaces of quartz and calcite. The extent of the adsorption will be evaluated in vacuum by temperature programmed desorption and in aqueous solutions by detection of the zeta potential differences between surfaces of opposite handedness when amino acids are adsorbed. The zeta potential measurements will be made using a novel technique recently developed at Carnegie Mellon University. This technique will be adapted to make a differential measurement of enantioselective adsorption on R- and S- surfaces. Enantioselective adsorption on mineral surfaces has never before been studied under the controlled conditions possible in ultrahigh vacuum. The second novel feature is the use of a rotating disk method recently invented for measuring changes in zeta potential of inorganic surfaces associated with adsorption of charged molecules such as amino acids; this method makes possible a true differential measurement of enantioselectivity. The proposed investigation will contribute to the fundamental understanding of the enantiospecific adsorption of chiral compounds on inorganic chiral surfaces. In terms of the broader impacts, the proposed investigation will foster dissemination of knowledge about chirality, a subtle aspect of molecular structure that engineering disciplines such as materials science and chemical engineering have largely ignored. A new experiment based on enantiospecific adsorption will be incorporated in an existing laboratory course. This work could lead to better processes for performing separations of chiral molecules for use in pharmaceuticals, artificial flavors, and agrochemicals.