Non-Exclusion Effects in Aqueous SEC: Behavior of Some Polyelectrolytes Using On-Line Mass Detectors

Volet, Gisèle; Lesec, James

doi:10.1080/10826079408013160

Cited by 20 publications

(9 citation statements)

References 10 publications

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“…Gel permeation chromatography (GPC) of charged polymers is challenging due to the likelihood of large aggregate formation or interactions with the stationary phase of the chromatographic column . It requires specialized columns and an aqueous mobile phase.…”

Section: Resultsmentioning

confidence: 99%

Dual-Functional ROMP-Based Betaines: Effect of Hydrophilicity and Backbone Structure on Nonfouling Properties

2011

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Foundational materials for nonfouling coatings were designed and synthesized from a series of novel dual-functional zwitterionic polymers, Poly[NRZI], which were easily obtained via ring-opening metathesis polymerization (ROMP) followed by a single step transformation of the cationic precursor, Poly[NR(+)], to the zwitterion, Poly[NRZI]. The resulting unique dual-functional structure contained the anion and the cation within the same repeat unit but on separate side chains, enabling the hydrophilicity of the system to be tuned at the repeat unit level. These dual-functional zwitterionic polymers were specifically designed to investigate the impact of structural changes, including the backbone, hydrophilicity, and charge, on the overall nonfouling properties. To evaluate the importance of backbone structure, and as a direct comparison to previously studied methacrylate-based betaines, norbornene-based carbo- and sulfobetaines (Poly[NCarboZI] and Poly[NSulfoZI]) as well as a methacrylate-based sulfobetaine (Poly[MASulfoZI]) were synthesized. These structures contain the anion-cation pairs on the same side chain. Nonfouling coatings were prepared from copolymers, composed of the zwitterionic/cationic precursor monomer and an ethoxysilane-containing monomer. The coatings were evaluated by using protein adsorption studies, which clearly indicated that the overall hydrophilicity has a major influence on the nonfouling character of the materials. The most hydrophilic coating, from the oligoethylene glycol (OEG)-containing dual-functional betaine, Poly[NOEGZI-co-NSi], showed the best resistance to nonspecific protein adsorption (Γ(FIB) = 0.039 ng/mm(2)). Both norbornene-based polymers systems, Poly[NSulfoZI] and Poly[NCarboZI], were more hydrophilic and thus more resistant to protein adsorption than the methacrylate-based Poly[MASulfoZI]. Comparing the protein resistance of the dual-functional zwitterionic coatings, Poly[NRZI-co-NSi], to that of their cationic counterparts, Poly[NR(+)-co-NSi], revealed the importance of screening electrostatic interactions. The adsorption of negatively charged proteins on zwitterionic coatings was significantly less, despite the fact that both coatings had similar wetting properties. These results demonstrate that the unique, tunable dual-functional zwitterionic polymers reported here can be used to make coatings that are highly efficient at resisting protein adsorption.

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Section: Resultsmentioning

confidence: 99%

Dual-Functional ROMP-Based Betaines: Effect of Hydrophilicity and Backbone Structure on Nonfouling Properties

2011

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“…GPC of charged polymers is challenging due to ionic aggregations or interactions with the stationary phase of the chromatographic column. 37 Careful sample preparation is needed in order to obtain accurate data. A high salt concentration aqueous solution, 0.1 M NaBr, was used as the eluent and the samples were stirred overnight to dissolve any possible aggregates.…”

Section: Resultsmentioning

confidence: 99%

Synthesis and Solution Properties of Norbornene Based Polybetaines

Çolak

Tew

2008

Macromolecules

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Ring-opening metathesis polymerization (ROMP) was used to synthesize novel norbornene based polycarboxy- (d-Poly 3a and d-Poly 3b) and polysulfobetaines (Poly 3c) using the third generation Grubbs’ catalyst (G3) as the initiator. Hydrophobicity of the polycarboxybetaines was varied by changing the bridging group of the norbornene backbone. A protective group approach was utilized to prevent any possible retardation in the polymerization due to interactions of the carboxylate functionality with the catalyst and to provide ease of characterization. The tert-butyl ester protected precursor polymers (Poly 3a and Poly 3b) were deprotected under acidic conditions to yield the corresponding polycarboxybetaines with very narrow polydispersity indices, ranging from 1.03 to 1.15. This method allowed excellent control over the molecular weight distributions compared to the direct polymerization approach. When molecular weight was plotted against the theoretical degree of polymerization (DP), linear relationships were obtained for both 1H NMR and GPC-MALLS data. Oxanorbornene based polycarboxybetaine (d-Poly 3a) was studied in aqueous 0.1 M NaBr solution by dynamic light scattering (DLS) and no significant aggregation was observed. An attempt was made to determine the acid ionization constant (K a) of the carboxylate group, which led to the discovery that the cyclic imide of these particular monomers is easily ring opened under basic conditions.

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“…They may occur in SEC separations where at least one of the components (stationary phase, mobile phase, or polymers that are being separated) is highly polar or ionic [61]. The occurrence of nonsize exclusion effects can be discovered by utilizing viscometry and light scattering independently [62,63]. These effects can be controlled by changing the pH and/or ionic strength of mobile phase [64,65].…”

Section: Viscosity Detectorsmentioning

confidence: 97%