Pillared Layered Compounds: Their Synthesis, Structure and Properties

柱柱层状化合物：其合成、结构和性能

• 批准号: 0652166
• 负责人: Abraham Clearfield
• 金额: $ 45万
• 依托单位: Texas A&M Research Foundation
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-05-15 至 2012-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0652166&HistoricalAwards=false
• 关键词: Pillared; Layered; Compounds; Their; Synthesis

There is great current interest to design multifunctional micro- or mesoporous materials. A main goal of this project is the synthesis of organic-inorganic hybrid materials Most of the research is directed towards carboxylic acids as the organic complexing agent. The effort also involves the more complex phosphonic acids. The strategy is to prepare pillared layered materials in which the inorganic portion constitutes the layer and the organic the pillars. The products can have high surface areas (~400m2/g), with small pores (~7-8 diameter) up to mesopores (~25 diameter). The pillars can be functionalized with sulfonic acid, carboxylic acid, amino, etc. groups. Furthermore, the pillars can be further separated by small spacers which themselves carry functional groups. Thus, they can be prepared as ion exchangers, as specific complexants, catalysts and as luminescent materials. When the metal is four valent, the particles formed are nanoparticles in which insufficient Bragg reflections to solve their crystal structures are obtained. The mystery of their structure is further compounded by the fact that the pores grow without the use of templates or spacer groups and are often larger than the interlayer distances and yield type I gas sorption isotherms. This is unprecedented as the pore formation depends upon the solvent used. Therefore, we employ a variety of tools such as extended x-ray absorption fine structure and high resolution electron microscopy as well as in-situ methods to probe their structures along with the more usual infra-red, visible, nuclear magnetic resonance, and neutron scattering and gas sorption methods to characterize the pores. The research is also directed towards molecules that breathe by using flexible alkyl, polyether and polyimine pillars separated by high levels of spacer groups. Thus students learn to synthesize unusual materials and employ cutting edge spectroscopic tools as well as the latest crystal structure methodology. %%%Research in chemistry often leads to unexpected results. There exist a large number of mineral-like compounds that contain pores. These pores are of the order of 4-13 Angstroms, where one Angstrom is about a hundred-millionth of an inch. So these pores are the sizes of small molecules. These mineral-like materials are principal catalysis used in petroleum refining and many other useful reactions. Therefore, they are of great interest to chemists and chemical engineers. This project aims to produce porous materials from layers of inorganic material bonded together with organic (carbon based) pillars. Visualize a parking garage with the floor and ceiling made of inorganic minerals connected by the pillars that are carbon based. Samples with pores that range from 7 angstroms to 25 angstroms are synthesized. The pillars can be made highly reactive by attaching acid or basic groups. They can be made to conduct protons for use in fuel cell membranes and to carry out a variety of useful reactions. One such reaction converts relatively useless compounds to those useful to the pharmaceutical industry. They can also separate molecules by size and finally a variety that breathes by using flexible pillars I sbeing synthesized. They swell when taking up solvent and deflate when emptied. A large number of uses for these fascinating materials is predicted. Research on these materials provides students with special skills in synthesis and techniques of handling nano-sized particles and state of the science spectroscopic X-ray, neutron and electron microscopy methodology. A partnership with a historically African-American University augments the already high diversity (Hispanic, women, Puerto Rican) of our research group.

目前人们对设计多功能微孔或介孔材料非常感兴趣。 该项目的主要目标是有机-无机杂化材料的合成，大部分研究都针对羧酸作为有机络合剂。这项工作还涉及更复杂的膦酸。该策略是制备有柱层状材料，其中无机部分构成层，有机部分构成柱。 该产品可以具有高表面积（〜400m2/g），具有小孔（〜7-8直径）到中孔（〜25直径）。 柱可以用磺酸、羧酸、氨基等基团官能化。 此外，柱可以通过本身带有官能团的小间隔物进一步分开。 因此，它们可以被制备为离子交换剂、特定络合剂、催化剂和发光材料。当金属为四价时，形成的颗粒是纳米颗粒，其中获得的布拉格反射不足以解析它们的晶体结构。 它们的结构之谜进一步复杂化，因为孔在不使用模板或间隔基团的情况下生长，并且通常大于层间距离和产量 I 型气体吸附等温线。 这是前所未有的，因为孔的形成取决于所使用的溶剂。 因此，我们采用多种工具，如扩展X射线吸收精细结构和高分辨率电子显微镜以及原位方法来探测其结构，以及更常用的红外、可见光、核磁共振、中子散射和气体吸附方法来表征孔隙。 该研究还针对通过使用由高水平间隔基团分隔的柔性烷基、聚醚和聚亚胺柱进行呼吸的分子。因此，学生学习合成不寻常的材料并使用尖端的光谱工具以及最新的晶体结构方法。 %%%化学研究常常会带来意想不到的结果。 存在大量含有孔隙的类矿物化合物。 这些孔隙的大小约为 4-13 埃，其中一埃约为亿分之一英寸。 所以这些孔隙是小分子的大小。 这些类矿物材料是石油精炼和许多其他有用反应中使用的主要催化剂。 因此，它们引起了化学家和化学工程师的极大兴趣。 该项目旨在利用与有机（碳基）柱粘合在一起的无机材料层生产多孔材料。 想象一个停车场，其地板和天花板由无机矿物制成，通过碳基柱子连接。 合成了孔径范围为 7 埃至 25 埃的样品。通过连接酸或碱基团可以使柱具有高反应性。 它们可以传导质子，用于燃料电池膜并进行各种有用的反应。 一种这样的反应将相对无用的化合物转化为对制药工业有用的化合物。 他们还可以根据大小来分离分子，最后通过使用正在合成的柔性柱来分离出可以呼吸的分子。 它们在吸收溶剂时膨胀，在排空时收缩。 预计这些令人着迷的材料将有大量用途。对这些材料的研究为学生提供了合成和处理纳米粒子的特殊技能以及光谱 X 射线、中子和电子显微镜方法的科学状态。 与一所历史悠久的非裔美国大学的合作增强了我们研究小组本已高度的多样性（西班牙裔、女性、波多黎各人）。