• Current members– Jeff Easley, PhD Candidate– Josh Katzenstein, PhD Candidate– Alfredo Clemente Cruz, Masters Candidate– Bobby Sankhagowit, Undergraduate– Amanda Beck, Undergraduate

• Looking to add 1 or more PhD student

Ellison LabOverview

anionic, RAFT,ATRP, NMRP,new functional

monomers

1 Å – 100’s nmmonomer

macromolecularbulk

shear and extensional flows

electric and magnetic fields

mechanical electromagnetic

conductivethermalbarrier

Synthesis Structure Processing Properties

Ellison ResearchOverview

Our research theme is connecting nanoscale / molecular level detail to macroscopic function for designing next

generation materials.

Nanostructured Polymers: Technological Impact

• Asymmetric membranes for gas separation– Koros and Pasek (J. Membr. Sci. 1993)

• Polysulfone (Udel) skin layers 20-80 nm thick

• Photoresist, production of microelectronics– Okoroanyanwu (J. Vac. Sci. Tech. B 2000)

• Understanding properties of polymer confined to feature sizes < 100 nm needed for future devices

• Nanocomposites– Vaia and Giannelis (MRS Bulletin 2001)

• Low loading levels (~several vol%), all polymer lies < 100 nm from composite interface

Hinsberg, et al. IBMJ. Vac. Sci. Tech. B 1998

Li, et al. J. Membr. Sci. 2002

Ellison Lab: “Active” Projects• New “Designer” Materials – molecular design via synthesis for tailored

properties (responsive, conductive, mechanical, separations, etc)

Project 1: Directing Nanoscale Fillers for Recyclable Barrier Materials, Nanocomposite Solar Cells, etc.

• Novel Characterization Tech. – attaining critical pieces of information others cannot using fluorescence approaches (focused on surfaces and interfaces and in-situ)

Project 2: Understanding the “Interphase” in Nanocomposites, Polymer Self-Diffusion in Thin Films

• “Green” Polymer Strategies – processing in the absence of volatile solvents, additives, etc., renewable materials

Project 3: “Green” Processing Route to Polymer Nanofibers, Designer Materials from Renewable Resources, etc.

Polymer Diffusion Near Surfaces / Interfaces

• Why is it important?

Disk Drive Lubricant Recovery

www.phi.com

Latex Film Formationhttp://www.chem.utoronto.ca/staff/MAW/

Nanocomposite Exfoliation

Fluorescence Recovery After Photobleaching (FRAP)

• Model geometry of thin and ultrathin films: In-plane diffusion– Demonstrated as viable approach, single MW and temp.1

• Start with simple system: anthracene labeled homopolymer

Fra

ctio

nal

Rec

ove

red

Flu

ore

scen

ce In

ten

sity

f(t) e It

It

t r / D

D /t D D

D i

20 1

2

2 2

4

characteristic diffusion time

t = 0

t = t1

t = t2

Photobleaching

Recovery

2ri

1 Frank B., et al, Macromolecules 29, 1996.

Melt Blowing: Green Polymer Nanofibers

Tg or Tc

Processing variables:• Polymer and air temperatures (Tp, Ta)• Polymer and air flow rates

• Solventless, environmentally benign process• Method of choice for many nonwoven products – low cost, high prod. rates• Produces microfibers with diameter > 2 μm

Fiber formation:• Hot air jet draws fiber• Active T window: Tg or Tc < T < Tp

Compared to electrospinning:• Higher production rate• No solvent

PBT

PP

PS

PBT

PP

Ellison, Phatak, Giles, Macosko, BatesPolymer 48, 2007.