A Simple and Universal Gel Permeation Chromatography Technique for Precise Molecular Weight Characterization of Well-Defined Poly(ionic liquid)s

Abstract

Poly(ionic liquid)s (PILs) are an important class of technologically relevant materials. However, characterization of well-defined polyionic materials remains a challenge. Herein, we have developed a simple and versatile gel permeation chromatography (GPC) methodology for molecular weight (MW) characterization of PILs with a variety of anions. PILs with narrow MW distributions were synthesized via atom transfer radical polymerization, and the MWs obtained from GPC were further confirmed via nuclear magnetic resonance end group analysis.

All Poly(ionic liquid)-Based Block Copolymers by Sequential Controlled Radical Copolymerization of Vinylimidazolium Monomers

“…In contrast, styrenic-type ILMs featuring this anion have been polymerized by ATRP. 37 In a first step, ILMs with different alkyl groups (VRImTf 2 N; R = Et, Me, Bu) were thus tested under OMRP conditions, before studying the block copolymerization. As expected, ILMs exhibit marked differences of solubility, according to the counteranion.…”

“…N-Vinyl-3-ethylimidazolium bis(trifluoromethylsulfonyl)-imide (VEtImTf 2 N) and N-vinyl-3-buthylimidazolium bis(trifluoromethylsulfonyl)imide were prepared via anion-exchange following the procedure described in the literature. 37 The synthesis as well as the complete characterization of the alkyl−cobalt(III) adduct (R-Co-(acac) 2 ) is prepared according to our previously described procedure. 83 The alkyl-cobalt(III) adduct was stored as a CH 2 Cl 2 solution at −20°C under argon.…”

“…37 A PSS SDV analytical linear S 5 μm column (molar mass range: 100−150 000 Da), protected by a PL gel 5 μm guard column, was calibrated with PS standards. Samples of polymers bearing Tf 2 N − (∼10−15 mg), dried under reduced pressure overnight at 50°C, were dissolved with 1.5 mL of THF containing LiTf 2 N (10 mM) and filtered two times with nylon membrane filter (size 0.45 and 0.20 μm, respectively).…”

Structural evolution of imidazolium-based poly (ionic liquid) assemblies during solvent evaporation

“…It should be pointed out that the presence of charged groups in PILs would result in electrostatic repulsions and accordingly polymer chain aggregation in GPC measurement, which could be screened by the addition of a small amount of LiTf 2 N as proposed by Nulwala [27]. Therefore, we changed the Br -as LiTf 2 -and then conducted the GPC measurement using tetrahydrofuran (THF) containing 10 mM LiTf 2 N as eluent at a flow rate of 0.8 mL/min at 30°C.…”

Modeling polymeric gels: The role of chain fexibility on the structure of physical gels

“…Gels undergo extraordinarily large volume changes as a reaction to different types of stimuli like changes of temperature, pH and ionic concentration [23][24][25][26] and this property is exploited for many applications such as absorbent materials, separation agents, drug delivery systems [27,28] , polymer dosimetry [29], actuators [30] and sensors [31] among many other. The phenomenon of contraction or dilatation of polymer gels induced by external stimuli can be used to make controllable membranes, as is the case in gel permeation chromatography [32]. Without going to the particular factors that induce the changes of volume, it is clear that the size of the porous in a polymer gel is a determining factor for many practical applications [33,34].…”