The Synthesis, Structures, and Chemical Properties of Macrocyclic Ligands Covalently Bonded into Layered Arrays
- Texas A & M Univ., College Station, TX (United States)
In this part of the proposal we have concentrated on the surface functionalization of α-zirconium phosphate of composition Zr(O3POH)2•H2O. It is a layered compound that can be prepared as particles as small as 30 nm to single crystals in the range of cm. This compound is an ion exchanger with a capacity of 6.64 meq per gram. It finds use as a catalyst, proton conductor, sensors, biosensors, in kidney dialysis and drug delivery. By functionalizing the surface additional uses are contemplated as will be described. The layers consist of the metal, with 4+ charge, that is positioned slightly above and below the mean layer plane and bridged by three of the four phosphate oxygens. The remaining POH groups point into the interlayer space creating double rows of POH groups but single arrays on the surface layers. The surface groups are reactive and we were able to bond silanes, isocyanates, epoxides, acrylates ` and phosphates to the surface POH groups. The layers are easily exfoliated or filled with ions by ion exchange or molecules by intercalation reactions. Highlights of our work include, in addition to direct functionalization of the surfaces, replacement of the protons on the surface with ions of different charge. This allows us to bond phosphates, biophosphates, phosphonic acids and alcohols to the surface. By variation of the ion charge of the ions that replace the surface protons, different surface structures are obtained. We have already shown that polymer fillers, catalysts and Janus particles may be prepared. The combination of surface functionalization with the ability to insert molecules and ions between the layers allow for a rich development of numerous useful other applications as well as nano-surface chemistry.
- Research Organization:
- Texas A & M Univ., College Station, TX (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), Basic Energy Sciences (BES)
- DOE Contract Number:
- FG02-03ER15420
- OSTI ID:
- 1164084
- Report Number(s):
- DOE-TAMU-15420; DOE Proposal 202679
- Country of Publication:
- United States
- Language:
- English
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