Change search
ReferencesLink to record
Permanent link

Direct link
Polyhydroxyl and Polyphosphorylcholine functionalized Silica for Hydrophilic interaction liquid Chromatography- Synthesis, characterization and application
Umeå University, Faculty of Science and Technology, Department of Chemistry. (Professor Knut Irgum)
2012 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

This thesis focuses on the development of new stationary phases for use in hydrophilic interaction liquid chromatography using TRIS-based and phosphorylcholine typed monomers and porous silica particles as starting substrates. In this thesis, several ways of polymerizing highly hydrophilic mono­mers onto pore surfaces of silica supports are described, based on several “grafting from” schemes. “Controlled/living” radical polymerizations including atom transfer radical polymerization (ATRP) and iniferter-mediated polymerization in conjunction with conventional free radical polymerization are demonstrated to be successful tools for grafting different hydrophilic monomers (polyhydroxyl and phosphorylcholine [meth]acrylamide/acrylates) onto the silica surfaces. Reaction solvents are proven to play an essential role to achieve efficient graft polymerization of activated silica surfaces with these amphiphilic vinylic monomers, which is difficult because of their restricted access to the activated surface in solvents that can be used because of solubility constraints.

Two tentacle TRIS-based polymer grafted silica, namely TRIS-WAX – TRIS functionality bonded to silica via a C–N–C imine bond and TRIS-Amide – TRIS bonded to silica via an amide bond, prove to be useful as stationary phases for hydrophilic interaction chromatography (HILIC).The TRIS-WAX exhibits a mixed mode hydrophilic partitioning and weak anion exchange (HILIC/WAX) retention mechanism while retention by hydrophilic partitioning is the dominant mechanism on the neutral TRIS-Amide phase which lacks weak anion exchange (WAX) properties. Interestingly, both these phases have selectivities that are radically different from most commercial HILIC stationary phases.

Finally, a method is demonstrated for synthesizing a stratified (graft-copolymerized) silica material based on N,N′-methylenebisacrylamide and 2-methacryloyloxyethyl phosphorylcholine (MPC) using a “controlled/living” photoiniferter-mediated polymerization from the N,N-diethyldithiocarbamate iniferter moiety immobilized silica surfaces. This polymerization method proves to be successful for graft-blockcopolymerization of different highly hydrophilic monomers onto the activated surfaces of porous silica. In this way, silica surfaces are grafted with a cross-linked amide-based hydrogel, on top of which a tentacle zwitterionic phosphorylcholine-typed layer is synthesized. The resulted material proves to be useful for HILIC separations and possesses different selectivity for the tested organic acids compared to that of commercial ZIC-cHILIC stationary phase.

Place, publisher, year, edition, pages
Umeå: Umeå Universitet , 2012. , 80 p.
Keyword [en]
Hydrophilic Interaction Chromatography, HILIC, silica, TRIS, acrylamide/acrylate, ATRP, iniferter, “controlled/ living’’ radical polymerization, N, N′-methylenebisacrylamide, MPC, stationary phase
National Category
Natural Sciences Analytical Chemistry
Research subject
Analytical Chemistry
URN: urn:nbn:se:umu:diva-60600ISBN: 978-91-7459-507-9OAI: diva2:561440
Public defence
2012-11-09, KBC building, KB3A9, Umeå universitet, Umeå, 10:00 (English)
Available from: 2012-10-19 Created: 2012-10-18 Last updated: 2012-10-19Bibliographically approved
List of papers
1. Tris(hydroxymethyl)aminomethane-functionalized silica particles and their application for hydrophilic interaction chromatography
Open this publication in new window or tab >>Tris(hydroxymethyl)aminomethane-functionalized silica particles and their application for hydrophilic interaction chromatography
2010 (English)In: Journal of Separation Science, ISSN 1615-9306, E-ISSN 1615-9314, Vol. 33, no 19, 2965-2976 p.Article in journal (Refereed) Published
Abstract [en]

A new method is presented for synthesizing a highly hydrophilic silica-based material for use in hydrophilic interaction chromatography. Porous silica particles used as a starting substrate were modified with 3-bromopropyl trichlorosilane and grafted with glycidyl methacrylate by controlled (“living”) atom transfer radical polymerization in order to introduce an oxirane-carrying reactive tentacle layer on the silica surface. The grafted material was thereafter subject to an oxirane ring opening reaction with tris(hydroxy-methyl)aminomethane in dimethylformamide to yield a polymer-bound equivalent of the well known and highly hydrophilic “TRIS” buffering substance. Chemical characterization was done by diffuse reflectance FT-IR, X-ray photoelectron spectroscopy, elemental analysis, and 1H NMR. Porosity and surface area examination was done with Brunauer–Emmett–Teller. Chromatographic application of the material was evaluated by separations of nucleic bases, small organic acids, and common nucleotides under mixed hydrophilic interaction chromatography and weak anion exchange conditions.

Place, publisher, year, edition, pages
John Wiley & Sons, 2010
Hydrophilic interaction chromatography, Silica, Trishydroxymethyl aminomethane
National Category
Chemical Sciences
urn:nbn:se:umu:diva-37267 (URN)10.1002/jssc.201000154 (DOI)000283201900007 ()
Available from: 2010-10-25 Created: 2010-10-25 Last updated: 2012-10-18Bibliographically approved

Open Access in DiVA

FULLTEXT(2320 kB)776 downloads
File information
File name FULLTEXT01.pdfFile size 2320 kBChecksum SHA-512
Type fulltextMimetype application/pdf

Search in DiVA

By author/editor
Bui, Nhat Thi Hong
By organisation
Department of Chemistry
Natural SciencesAnalytical Chemistry

Search outside of DiVA

GoogleGoogle Scholar
Total: 776 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Total: 755 hits
ReferencesLink to record
Permanent link

Direct link