Frit inlet field-flow fractionation techniques for the characterization of polyion complex self-assemblies

Ugo Till (1, 2, 3, 4) , Mireille Gaucher (3, 4) , Baptiste Amouroux (1, 2) , Stéphane Gineste (1, 5) , Barbara Lonetti (1, 5) , Jean-Daniel Marty (1, 2) , Christophe Mingotaud (1, 5) , Carmen R.M. Bria (6) , S. Kim Ratanathanawongs Williams (6) , Frédéric Violleau (7) , Anne-Françoise Mingotaud (1, 5)

1 IMRCP - Interactions moléculaires et réactivité chimique et photochimique
2 CNRS - Centre National de la Recherche Scientifique
3 Département Sciences Agronomiques et Agroalimentaires - EI Purpan
4 UT - Université de Toulouse
5 UT3 - Université Toulouse III - Paul Sabatier
6 Department of Chemistry, Laboratory for Advanced Separations Technologies
7 CAI - Chimie Agro-Industrielle

Polymer self-assemblies joining oppositely charged chains, known as polyion complexes (PICs), have been formed using poly(ethyleneoxide – b – acrylic acid)/poly(l-lysine), poly(ethyleneoxide-b-acrylic acid)/dendrigraft poly(l-lysine) and poly[(3-acrylamidopropyl) trimethylammonium chloride – b – N – isopropyl acrylamide]/poly(acrylic acid). The self-assemblies have been first characterized in batch by Dynamic Light Scattering. In a second step, their analysis by Flow Field-Flow Fractionation techniques (FlFFF) was examined. They were shown to be very sensitive to shearing, especially during the focus step of the fractionation, and this led to an incompatibility with asymmetrical FlFFF. On the other hand, Frit Inlet FlFFF proved to be very efficient to observe them, either in its symmetrical (FI-FlFFF) or asymmetrical version (FI-AsFlFFF). Conditions of elution were found to optimize the sample recovery in pure water. Spherical self-assemblies were detected, with a size range between 70–400nm depending on the polymers. Compared to batch DLS, FI-AsFlFFF clearly showed the presence of several populations in some cases. The influence of salt on poly(ethyleneoxide-b-acrylic acid) (PEO-PAA) 6000-3000/dendrigraft poly(l-lysine) (DGL 3) was also assessed in parallel in batch DLS and FI-AsFlFFF. Batch DLS revealed a first process of swelling of the self-assembly for low concentrations up to 0.8M followed by the dissociation. FI-AsFlFFF furthermore indicated a possible ejection of DGL3 from the PIC assembly for concentrations as low as 0.2M, which could not be observed in batch DLS.

Mots clés: Flow field-flow fractionation; Frit inlet flow field-flow fractionation; Polyion complex micelles; Polymers; Self-assembly

Mots clés: polymère

Domaines: Autre; Sciences agricoles

Ugo Till, Mireille Gaucher, Baptiste Amouroux, Stéphane Gineste, Barbara Lonetti, et al.. Frit inlet field-flow fractionation techniques for the characterization of polyion complex self-assemblies. Journal of Chromatography A, 2017, 1481, pp.101-110. ⟨10.1016/j.chroma.2016.12.050⟩. ⟨hal-01595439⟩