15

20

25

30

3 6 9 12 15 18

Ea

(kJ/m

ol)

λ

Dispersed

Phase-separated

30

25

20

153 6 12 15 189

15

20

25

30

35

40

0.0 5.0 10.0 15.0 20.0 25.0

Ea

(kJ/m

ol)

λ

LiOTf solution

Li-form Nafion

Liquid water

0 5 10 15 20 25

35

30

25

20

15

40

1.200 1.400 1.600 1.800 2.000

0

20

40

60

80

0

20

40

60

80

1.2 1.4 1.6 1.8 2.0

Ea

(kJ

/mo

l)

Nanotube diameter (nm)

Confined water

Liquid water

80

60

40

20

01.2 1.6 1.8 2.01.4

~1 nm

~10 nm

~1 mm

Drew Korovich, Curt Zanelotti, Rui Zhang, Deyang Yu, Shravan Uppala, Nick Pietra, Syeda Anam Bukhari, Alexis McCarthy

We measure and build ion conducting and nanostructured

materials, specifically involving multi-scale structure and

morphology.

Impacts: Clean energy, water, and nanomedicine applications

including batteries, fuel cells, and drug delivery. Determining

fundamental mechanisms of ion and water transport.

Who are we? Physical, analytical, and polymer chemists,

materials scientists.

Introduction

Multi-scale Transport , Dynamics, and Morphology in Materials

Multi-Modal NMR

Group & Funding Sources

Molecular Ionic Composites (MICs)Molecular Transport

In Polymer MembranesCombining a Kevlar-like polymer

with ionic liquids to enable safer

and higher density batteries

Problem:

Commercial organic electrolytes

safety concerns including

flammability, leaking, volatility

limited battery energy density

Solution:Composite electrolyte of PBDT and

ionic liquid features:

• High ionic conductivity (~1 mS*cm-1)

• Tunable modulus (0.03 – 3 GPa)

• Thermally stable (up to 300°C)

• Electrochemical window to 6 V

• Long cycling Li-metal batteries

Macromolecules (2017 x2, 2018, 3 in prep)

Block Copolymer

Micelles

Nanoconfined Transport

Polycaprolactone

(PCL):

Polyethylene oxide

(PEO)

Solute (salt, organic

molecules, etc.)Water

Reverse

osmosis

membrane

Macromolecules (2019)

Macromolecules (2018)

J Membrane Sci (2013)

Nature Materials (2011)

Macromolecules (2011)

Macromolecules (2010)

Macromolecules (2009)

+ 2 in prep

~ 20 nm ~ 2 nm~ 100 nm

Random copolymer membranes μm-scale heterogeneity observed! Change in diffusion behavior on different length scales

Hydration modulated tortuosity!

ℑ𝐿−𝐵 =𝐷𝑙𝑜𝑐𝐷∞

ℑ𝜇−𝐵 =𝐷0𝐷∞

+

+

Kevlar-like polymer forms double helix!

MICs held together by

collective electrostatic

interactions!XRD of PBDT

aqueous solution

• Diffusion coefficients measured from

NMR probes structure/environment

on micrometer lengthscale

• Activation energy probes local

molecular interactions and structure

Chem. Comm. (2013), +2 in prep

In review Macromolecules (2020)

Macromolecules (2015), JPCB (2014)

Arrhenius Equation

𝐷 = 𝐷0𝑒ൗ−𝐸𝑎𝑅𝑇

Lithium form Nafion

Lithium triflate

solutions

NMR diffusometry

Molecular dynamics simulations

Water confined in carbon nanotube

• Similar molecular/ionic environment

• Physically confined environment vs.

bulk

NMR spectroscopy: Molecular structure,

internal dynamics, associations, alignment

Å to nm, ps to days

NMR diffusometry: Species-specific and

phase-specific transport, confined motion

10s of nm to 10s of mm, ms to s

MicroMRI: Spatial resolution of molecular

structure, dynamics, transport

≥ 10 mm (devices, tissue…), t-resolved

C

H

H

Mechanisms of ion and water transport

Dw

ater

(10

-10

m2/s

)

Able to load MICs with Li+, Na+, Mg2+, etc.

Thin flexible films

Nature Comm (2019)

Advanced Materials

(2016)

Langmuir (2017)

ACS Appl. Mater.

Interfaces (2019)

Macromolecules (2020)Lithium-metal battery Li:MIC:LiFePO4

J Membrane Sci (2015)

Macromolecules (2014)

+5 in prep

Dispersed Phase-separated

Nanoconfinement leads to

higher energy barrier

Phase separation lead to

lower energy barrier

1

10

100

1000

10000

30:70 35:65 40:60 30:70 35:65 40:60

Tort

uosity

𝕴𝒍𝒐𝒄𝒂𝒍−𝒃𝒖𝒍𝒌 𝕴𝒎𝒊𝒄𝒓𝒐𝒏−𝒃𝒖𝒍𝒌

HEA:EA HEMA:MMA

Polyelectrolyte Molecular

Weight Determination

Lou Madsen Group

Collaboration with Prof.

Ralph Colby at Penn State

Collaboration with Prof. Diego Troya at VT

DMR

CHE

CBET

Collaboration

with Prof. Megan

Robertson at

U. Houston

Collaborations with Dingemans

(UNC), Colby (PSU), Forsyth (Deakin –

Australia), Qiao, Moore, and Lin (VT)

Collaborations with

Hickner (PSU), Geise

(UVA), Moore (VT)…