Structural Evolution of Porous Coordination Polymers upon Chemical Exposure

技术摘要：这项研究的总体目标是对一种名为微孔配位聚合物(MCPs)的新兴超高性能吸附剂发展一个详细的、分子水平的了解。MCP吸着剂的性能源于其高体积分数(孔隙率)的微小、纳米大小的孔隙，从而产生极高的比表面积。了解这些材料如何吸附如此大量的气体以及选择性吸收的化学/物理基础是拟议研究的主要推动力。特别是，在实际的气体吸附和溶剂去除过程中，将首次观察到孔大小、孔结构和孔相互连通性的基本作用。这一独特的观点是正电子湮没寿命谱在MCP中的首次应用，正电子湮没寿命谱是最近开发的一种用于表征微电子器件中微孔薄膜介质绝缘体的反物质探测器。这项技术的采用有可能改变研究人员探测吸附剂中孔隙率的方式。只有了解微尺度和纳米尺度上的变化对表观孔隙率的影响，才能实现开发现有MCP的最佳模式。最终，这些结果将对指导新材料的合成具有实际意义。MCP？S有望在能源研究(气体储存)和环境研究(气体净化)中得到广泛的应用，由于MCP现在正在商业化，它们已经能够并将对社会产生直接影响。非技术总结这项研究汇集了化学家和物理学家，努力改变超高性能吸附剂的研究--纳米材料本身正在改变化学分离领域。这一独特的合作寻求使用最近开发的强大的反物质探测器技术来研究微芯片中新设计的多孔绝缘体，以提供前所未有的结构表征。这些高度多孔的吸附剂有望在替代能源(气体储存)和工业过程(气体净化)中得到广泛应用，由于它们现在开始商业化，它们将对社会产生直接影响。这项研究的影响完全取决于化学家和物理学家的成功互动。研究生和本科生将跨越学科界限，在一个广泛多样和合作的环境中学习，包括与行业的频繁互动。出于这些原因，获得变革性研究成果的潜力很大。然而，只有充分了解材料的性质，以便在新的更有效的工艺中广泛应用，才有可能做到这一点。很明显，吸附剂技术还没有达到这一点，但拟议的研究将大大有助于实现这一目标。

TECHNICAL SUMMARY:The over-arching goal of this research is to develop a detailed, molecular level understanding of an emerging class of ultrahigh performance sorbents named Microporous Coordination Polymers (MCPs). MCP sorbent performance derives from their high fractional volume (porosity) of tiny, nanometer-sized pores resulting in exceedingly high specific surface areas. An understanding of how these materials can adsorb such enormous amounts of gases and the chemical/physical basis for selective uptake are the major thrusts of the proposed research. In particular, the fundamental role of pore size, pore architecture, and pore interconnectedness will be observed for the first time during the actual processes of gas adsorption and solvent removal. Enabling this unique viewpoint is the first use in MCPs of positron annihilation lifetime spectroscopy, an antimatter probe of porous materials recently developed to characterize microporous thin film dielectric insulators in microelectronic devices. Adoption of this technique has the potential to transform how researchers probe porosity in sorbents. Only by understanding how changes on the microscale and nanoscale exert an effect on apparent porosity can the best modes of exploiting existing MCPs be realized. Ultimately these results will be of practical use to guide the synthesis of new materials. MCP?s are expected to find broad application in energy research (gas storage) and environmental research (gas purification) and since MCPs are now being commercialized they are at the point where direct impact on society can and will be felt.NON-TECHNICAL SUMMARYThis research brings together chemists and physicists in an effort to transform the study of ultrahigh performance sorbents?the nanomaterials that are themselves transforming the field of chemical separations. This unique collaboration seeks to use powerful antimatter probe techniques recently developed to study newly engineered porous insulators in microchips to provide unprecedented structural characterization. These highly porous sorbents are expected to find broad application in alternative energy (gas storage) and industrial processes (gas purification) and since they are now beginning to be commercialized they are at the point where direct impact on society will be felt. The impact of this research is totally dependent on the successful interaction of chemists and physicists. Graduate and undergraduate students will cross discipline boundaries to learn in a broadly diverse and collaborative environment involving frequent interaction with industry. For these reasons the potential for obtaining transformative research results is high. However, this will only be possible if the properties of the materials are sufficiently well understood to allow widespread deployment in new more efficient processes. It is clear that sorbent technology has not yet achieved this point, but the proposed research will do much to enable reaching this goal.