title: Application of pH-responsive poly(2-dimethyl-aminoethylmethacrylate)-block-poly(acrylic acid) coatings for the open-tubular capillary electrochromatographic analysis of acidic and basic compounds.
abstract: A new type of stimuli-responsive polymeric (SRP) coating has been prepared for use in open tubular capillary electrochromatography (OT-CEC), by grafting poly(2-dimethylaminoethylmethacrylate)-block-poly(acrylic acid) (PDMAEMA-b-PAA) as a Y-shaped block copolymer with two dissimilar chain compositions onto the inner walls of aminopropyl-modified silica capillaries. The grafting process introduced weakly charged functional groups from the PAA and PDMAEMA, enabling the generation of electroendosmotic flow with magnitude and direction adjustable by changing the pH of the running buffer electrolyte. This stimuli-responsive PDMAEMA-b-PAA block copolymer was found to provide excellent resolution of various acidic and basic compounds, leading to efficient analyte separation. When operated in the OT-CEC mode, separation selectivities could be readily manipulated via differential contributions from chromatographic and electrophoretic mechanisms, simply by changing the pH or the ionic strength of the running buffer electrolyte.
authors.affiliation: Australian Centre for Research on Separation Science (ACROSS), School of Chemistry, Monash University, Melbourne, VIC, 3800, Australia.
authors.forename: Roshanak
authors.initials: R
authors.lastname: Sepehrifar
authors.affiliation: Australian Centre for Research on Separation Science (ACROSS), School of Chemistry, Monash University, Melbourne, VIC, 3800, Australia.
authors.forename: Reinhard I
authors.initials: RI
authors.lastname: Boysen
authors.affiliation: Australian Centre for Research on Separation Science (ACROSS), School of Chemistry, Monash University, Melbourne, VIC, 3800, Australia.
authors.forename: Basil
authors.initials: B
authors.lastname: Danylec
authors.affiliation: Australian Centre for Research on Separation Science (ACROSS), School of Chemistry, Monash University, Melbourne, VIC, 3800, Australia.
authors.forename: Yuanzhong
authors.initials: Y
authors.lastname: Yang
authors.affiliation: Australian Centre for Research on Separation Science (ACROSS), School of Chemistry, Monash University, Melbourne, VIC, 3800, Australia.
authors.forename: Kei
authors.initials: K
authors.lastname: Saito
authors.affiliation: Australian Centre for Research on Separation Science (ACROSS), School of Chemistry, Monash University, Melbourne, VIC, 3800, Australia. Electronic address: milton.hearn@monash.edu.
authors.forename: Milton T W
authors.initials: MT
authors.lastname: Hearn
keywords: Ionic strength effects; Open-tubular capillary electrochromatography; Zwitterion properties; pH effects; pH-responsive polymers