Precise Acid Copolymer Exhibits a Face-Centered Cubic Structure

Buitrago, C. Francisco; Opper, Kathleen L.; Wagener, Kenneth B.; Winey, Karen I.

doi:10.1021/mz2000237

Cited by 30 publications

(50 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…One zinc-neutralized system additionally displays long range cubic ordering of ionic aggregates [10]. A cubic ordering of aggregates has also recently been observed in a precise polyethylene copolymer with pendant phosphonic acid groups [4].…”

Section: Atomistic MD Simulationsmentioning

confidence: 80%

Effects of morphology on ion transport in ionomers for energy storage.

Frischknecht¹,

Alam²,

Azoulay³

et al. 2012

View full text Add to dashboard Cite

Polymer electrolytes are essential elements of current and next-generation energy storage applications. An important class of polymer electrolytes is ionomers, in which one of the ions is covalently bound to the polymer backbone. Ionomers are currently used in fuel cells, and show extraordinary promise as solid electrolytes in batteries for transportation and portablepower applications. Solid electrolytes are desirable for a variety of reasons. A primary one is safety: the lack of solvent leads to fewer electrochemical reactions (e.g. with the electrodes) and the absence of flammable liquids. Solvent-free electrolytes allow for less packaging (and hence higher energy density batteries) and easier manufacture. Single-ion conductors such as ionomers also have the advantage of higher efficiency (high lithium transference numbers), since the anions are bound to the polymer backbone and the current is primarily due to the cations that actively participate in the electrochemical reactions. However, to date ionomeric materials do not have sufficiently high conductivities. Ion transport mechanisms in ionomers and their relation to molecular structure are poorly understood, although it is known that ion transport is coupled to polymeric motion and to the nanoscale morphology of ionic aggregates that often self-assemble in the polymer matrix. In this project we investigate the morphology and ion dynamics in ionomer melts using ab initio calculations, NMR experiments, and both atomistic and coarse-grained molecular dynamics simulations. We find that the aggregate morphology depends strongly on polymer architecture, neutralizing cation, and degree of neutralization. This morphology in turn affects the counterion dynamics; we find that counterions diffuse more quickly in systems with percolated aggregates than in systems with discrete aggregates. AcknowledgmentsWe thank Prof. Karen I. Winey for getting us interested in this topic initially and for a strong collaboration throughout the project. We thank Michelle Seitz, Francisco Buitrago, Ken Wagener, and John McCoy for many insightful conversations, emails, and meetings. We also thank Ralph

show abstract

Section: Atomistic MD Simulationsmentioning

confidence: 80%

Effects of morphology on ion transport in ionomers for energy storage.

Frischknecht¹,

Alam²,

Azoulay³

et al. 2012

View full text Add to dashboard Cite

show abstract

“…An isotropic PA polymer film displayed uniform scattering rings at the 2D X‐ray scattering detector (Figure via X‐ray scattering profile at room temperature). Winey and co‐workers confirmed that the behavior was not consistent with the previously accepted modified liquid‐like scattering model of monodisperse spheres …”

Section: Functionalized Admet–pementioning

confidence: 86%

“…Recent advances in catalyst chemistry have enabled synthesis of linear polyethylenes via ADMET with precisely placed functional groups . For example, polyethylenes with acidic side groups form various polymer architectures (Figure ) such as acid dimers, ionic and/or neutral aggregates, and polymer nanocrystals . Commercial preparations of acid copolymers typically exhibit unpredictable degrees of microstructural irregularities leading to a diverse assortment of bulk properties and potential applications .…”

Section: Functionalized Admet–pementioning

confidence: 99%

“…Production of ion‐transport membranes is one of the many applications of PA containing polymers . Recent findings that relate proton mobility to order and crystallinity through generation of defined proton pathways have led to investigation of well‐defined functionalized polymer architectures synthesized by ADMET …”

Section: Functionalized Admet–pementioning

confidence: 99%

“…Phosphonic groups have three hydrogen bonding sites that can lead to larger assemblies, unlike most substituted PE's, which predominantly form triclinic or orthorhombic crystals. The germinal PA polyethylene exhibits a face‐centered cubic (FCC) structures, as described below . On the other hand, other acid groups like COOH possess two hydrogen bonding sites that form dimers (Figure ).…”

Section: Functionalized Admet–pementioning

confidence: 99%

See 2 more Smart Citations

Systematic Studies of Morphological Changes of Precision Polyethylene

Few

Wagener

Thompson

2013

Macromol. Rapid Commun.

Self Cite

View full text Add to dashboard Cite

The morphological changes of polyethylenes bearing precisely spaced "defects" are reviewed, focusing on the effects of defect frequency, size, and functionality on crystallization and crystalline structure. The precise defect interval is imparted through acyclic diene metathesis polymerization of structurally symmetric diene monomers. Studies have included structural characterization by differential scanning calorimetry, wide-angle X-ray scattering, small-angle X-ray scattering (SAXS), and infrared spectroscopy. The collective results are presented separately for functionalized polyethylenes and for those containing alkyl chain branches, as these two classes of polymers vary greatly in morphology.

show abstract

Extending the Methylene Spacer Length of ADMET Hydroxy‐Functionalized Polymers

Thompson

Yamakado

Wagener

2014

Macro Chemistry & Physics

Self Cite

View full text Add to dashboard Cite

Solution acyclic diene metathesis (ADMET) polymerization using Grubbs' fi rst-generation catalyst leads to the direct synthesis of polymers containing hydroxyl groups. Secondary alcohols are placed precisely at specifi c intervals on an unsaturated hydrocarbon backbone. Increasing the number of methylene spacers decreases the frequency of the pendant groups from every 15th carbon to every 21st carbon. The complete hydrogenation of the unsaturated polymers yields model representatives of well-defi ned ethylene-vinyl alcohol copolymers. Despite the decrease in branch frequency in both the homopolymers and randomized versions of such polymers, surprisingly, the precision does not have an infl uence on the thermal properties, and they are all similar in nature. It is concluded that hydrogen bonding dominates the polymer behavior, rather than the precision in hydroxyl-group placement along the polyethylene chain.

show abstract

Precise Acid Copolymer Exhibits a Face-Centered Cubic Structure

Cited by 30 publications

References 8 publications

Effects of morphology on ion transport in ionomers for energy storage.

Effects of morphology on ion transport in ionomers for energy storage.

Systematic Studies of Morphological Changes of Precision Polyethylene

Extending the Methylene Spacer Length of ADMET Hydroxy‐Functionalized Polymers

Contact Info

Product

Resources

About