Open Access Repository

Development of novel polymer monoliths for fast ion chromatography

Downloads

Downloads per month over past year

Schaller, D (2012) Development of novel polymer monoliths for fast ion chromatography. PhD thesis, University of Tasmania.

[img]
Preview
PDF (Front matter)
front-schaller-...pdf | Download (425kB)
Available under University of Tasmania Standard License.

[img]
Preview
PDF (Chapters 1-2)
ch1-2-schaller-...pdf | Download (646kB)
Available under University of Tasmania Standard License.

[img]
Preview
PDF (Chapters 3-4)
ch3-4-schaller-...pdf | Download (10MB)
Available under University of Tasmania Standard License.

[img]
Preview
PDF (Chapter 5)
ch5-schaller-th...pdf | Download (19MB)
Available under University of Tasmania Standard License.

[img]
Preview
PDF (Chapters 6-8)
ch6-8-schaller-...pdf | Download (310kB)
Available under University of Tasmania Standard License.

[img]
Preview
PDF (Whole thesis)
whole-schaller-...pdf | Download (30MB)
Available under University of Tasmania Standard License.

Abstract

This thesis focuses on the development of latex agglomerated ion-exchange
materials for applications in capillary ion chromatography (IC). The
continuous rod, monolithic polymer columns were predominantly synthesised
in-situ in micro-format – within capillaries of 1 mm internal diameter and
below - useable in traditional as well as current high-end capillary IC
instruments. Recent developments in monolithic stationary phases for the
fast analysis of inorganic ions and other small molecules in IC and capillary
electrochromatography (CEC) concentrate in particular on the properties of
organic (polymer) monolithic materials and inorganic (silica-based) monoliths
and specific applications.
The project path has encompassed fabrication, characterisation and
chromatographic investigation of monolayer AS18 latex-coated, sulfonated
poly(chloromethylstyrene-co-divinylbenzene) (poly(CMS-co-DVB)) monoliths
and their commercial counterpart – the Dionex IonswiftTM Max Series.
Subsequent to the synthesis work, the non-destructive morphology and
capacity assessment by capacitively-coupled contactless conductivity
detection (C4D) and the comprehensive study of this technique in relation to
methacrylate based, strong anion-exchanger (SAX) polymer monoliths in
capillary format revealed the potential and shortfalls of the detection
technique to predict monolithic column performance. Monolayer latex-coated,
functionalised poly(CMS-co-DVB) monolithic porous polymer scaffolds were
measured with capacities of 34 μequiv/g and plate heights of 26,000
plates/m. The direct surface functionalised (non-coated) SAX version
exhibited values in both capacity and plate number more than double in
magnitude, which is ascribed to the actual surface and pore morphology of
the polymer materials with different levels of hydrophobicity.
C4D was used to non-invasively evaluate the internal make-up of the
capillary columns, consisting of a combination of morphology and surface
chemistry. Measurements were made by scanning the conductance of the
mobile phase filling the pores of the substrate, with and without the surface
functional conductivity of the scaffold, over the length of the capillary section
using an automated, motorized stage. The findings were well matched with
scanning electron microscopy (SEM) images of the capillary cross-sections
at discrete locations and further confirmed with chromatographic testing,
such that higher conducting, smooth profile yielding columns were
predictably exhibiting better separation performance over versions that
yielded more irregular conductivity profiles.
The extension of this work on latex-coated, functionalised poly(CMS-co-
DVB) monoliths in capillary format to coatings with differently sized AS11
latex particles showed that the extent and type of coating are of lower
influence on the chromatographic performance in comparison to well defined,
uniformly porous morphology of the polymer substrate. Other material
surface effects, such as gel porosity and the level of hydrophobicity in
relation to the eluents and solvents used, appear to have significant effects
on both the synthesis process and the final column chromatographic
performance.

Item Type: Thesis (PhD)
Keywords: Ion-chromatography (IC), functional polymer monoliths, capacitively coupled contactless conductivity detection (C4D), morphology characterisation, latex nanoparticle coatings
Additional Information:

Copyright The Author

Date Deposited: 22 Jan 2013 02:02
Last Modified: 15 Sep 2017 00:59
Item Statistics: View statistics for this item

Actions (login required)

Item Control Page Item Control Page
TOP