Date of Degree
PhD (Doctor of Philosophy)
Ned B. Bowden
Macroscopic, hollow thimbles were synthesized from dicyclopentadiene with the Grubbs second generation catalyst at a monomer:catalyst loading of 10,000:1. A series of Buchwald-Hartwig and Sonogashira coupling reactions were completed on the interior of the thimbles followed by extraction of the product to the exterior using hexane. In all examples, palladium was retained by the membranes at ≥99.9% levels. Both polar and apolar molecules with molecular weights from 101 to 583 g mol-1 permeated these thimbles with values for flux of 10-5 to 10-6 mol cm-2 h-1, but selected molecules did not permeate them and had flux values 104 to 105 times slower. The difference in flux was large between molecules that permeated and those that did not permeate, but no trend was observed that correlated flux with molecular weight or hydrophobicity. Rather, molecules that did not permeate the membranes had large cross-sectional areas that led to low rates of diffusion within the highly cross-linked polydicyclopentadiene membranes.
Membranes were fabricated from the ring opening metathesis polymerization of dicyclopentadiene with the Grubbs first generation catalyst at a monomer:catalyst loading of 5,000:1. Mixtures of fatty acid salts were separated using polydicyclopentadiene membranes. Mixtures of fatty acids could not be separated by the membranes, but when triisobutylamine was added to the fatty acids, cis-fatty acid salts had slower permeation though the membranes than saturated and trans-fatty acid salts. Oleic, petroselinic, vaccenic, linoleic, and linolenic acid salts with triisobutylamine had slower permeation relative to the permeation of stearic and elaidic acid salts.
Organic catalysts were retained from organic molecules using nanoporous polydicyclopentadiene membranes. Acid or base was added to organic catalysts that increased the critical areas of the organic catalysts to the size range (>0.5 nm2) where PDCPD membranes could retain them. The catalysts by themselves were too small to be retained by the membrane, but the salts were in the range where PDCPD retains molecules.
xiv, 152 pages
Includes bibliographical references (pages 143-152).
Copyright 2012 Abhinaba Gupta