Micro- and nanoscale modifications for polymer …2010/10/11 · 3-D resist preform Therm. post-processing PMMA resist layer (1050 nm high) after development and thermal treatment

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Micro- and nanoscale modificationsfor polymer functionalization

Prof. Dr. Per Magnus Kristiansen

Prof. Dr. P.M. Kristiansen Micronarc Industrial Forum - 10.11.2010 2

Outline

• Introduction– INKA ; from polymer nanotechnology to functionalization

• Physical surface modification – micro/nanostructuring– Towards industrially feasible micro/nanostructured polymer surfaces

• Chemical functionalization - patterned surface grafting– selective tuning of surface chemistry

• Bulk modification of polymers – morphology control– From traditional fillers to nanoscaled or supramolecular additives

• Summary

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Who is INKA?Das Institut ist eine gemeinsame Einrichtung der Fachhochschule

Nordwestschweiz und des Paul Scherrer Instituts

Inst. f. Kunststoff-technik der HTNW

Labor für Mikro- undNanotechnologie LMN

Ressourcen INKA:Prof. Dr. Ing. Jens Gobrecht, LeiterProf. C. Dransfeld, Stv. FHProf. Dr. M. KristiansenDr. H. Schift, Leiter INKA-PSI4 Assistenten @ FH2 Wissensch. + 1 Techniker @ PSI1 Ing. + 3 Doktoranden @PSITechniker-pools IKT und LMN

Zugriff auf: Kunststofflabors im IKT,im KATZ, auf Reinraumlabors undGrossanlagen im PSI

IKT


IKTInstitut fürKunststofftechnik

INKAInstitut fürnanotechnischeKunststoffanwendungen

INKA-PSI

LMN - Labor für Mikro- und Nanotechnologie

Vorteile für INKA• Zugriff auf volle Infrastruktur des PSI und der HT (inkl. KATZ)• Zugriff auf knowhow auf beiden Seiten• „Pooling“ der Personalressourcen INKA/IKT und INKA/LMN

IKT & INKA

Differenzen• Unterschiedliche Prioritäten betr. Output• Unterschiedliche Kulturen• Priorisierung der Forschung

Röntgen-optik

Nano-Magnetics etc.

Technologie-entwicklung

Die volle Durchlässigkeit der Grenzen zur HTNW und zum PSI macht INKA einzigartig!

I N K A

10 km

INKA – a „joint venture“ between FHNW & PSI

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Scientific and technological vision

year

0.1 nm

0.1 µm

0.1 mm

1960 1980 2000 2020 2040

Nano

Micro

Macro

Dim

ensi

ons

Future: Bridging the gap between nano‐ and macroscale, and building with nanoobjects by design

Cellbiology

Molecularbiology Molecular

design

Electricalengineering

Electronics

Nano-devices

Micro-electronics

Top-

dow

nPolymer

Chemistry SupramolecularChemistry

ComplexChemistry

Bot

tom

-up

Self-assembly

Nanotechnology

Mesotechnology

Courtesy of H.-W. Schmidt, Uni Bayreuth


PS, ABS, SAN PE, PP, PVC

PMMA

PPE mod.

PAPBTPOMPMPPUR

PC

PBIPITPIPAI

PES, PPSUPEI, PSUPC‐HT

PEKPEEKLCP, PPSPTFE, PFAETFE, PCTFEPVDF

High performancepolymers

Engineeringplastics

Commodityplastics

amorphous semi-crystalline

< 1%

< 15%

> 85%

PET

The world of plastics

Major challenge in polymer science, with respect to novel functional and even multifunctional materials, is the understanding and control of hierarchical functional polymer structures created by (macro)molecular self-assembly.

Advanced functional polymers


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Polymer functionalization – modifications on the micro- & nanoscale

Surface modification Bulk modification

Processing

topographic chemical

Self‐assembly

ordered disordered

morphology

particlesphasesorientation

„buckling“

fillers

fibers

Injection & other molding, extrusion (e.g. films), spinning, etc.

grafting

coating

Hot embossing

additives

compoundingblending

compounding

After‐treatment: metallization, CVD/PVD, particle or biochemical modification


Contents

Physical surface modification – micro/nanostructuring

Chemical functionalization ‐ patterned surface grafting

Bulk modification – morphology control

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Tooling problem: Machining technologies with resolution < 1 mm

milli micro nano

10-3 10-6 10-9

Tech

nol o

gies

for

patte

rnde

finiti

o nTy

pica

lob

ject

s

mechanicalmachining

optical lithography

beam lithography

SPM lithpography

R e p l i c a t i o nm

Auflösung

LIGA gears chip Quantum devices moleculeswatch parts

light e- beam

Self-organisation

Tech

nolo

gica

lGap

erosionlaser ablation


Nanopatterning Production and Applications based on NanoimprintingLithographyThe project targets scalablenanomanufacturing processes forarbitrary 3-dimensional surfaces

Industrial Demonstrators–Planar Diffractive Optical Element

(PDOE)–Emissive Head-Up Display (eHUD)–Light Directional Elements (LDIR)

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Silicon mold masters made by lithographic processes

Advantage: extremely precise, tolerances << 1 µm (microelectronic process), very hard material, i.e. low wear; durable mold inserts nickel copies

Disadvantage: very brittle (breakage risk), only planar geometries, direct moldingfrom silicon requires glueing or clamping (both not ideal but sufficient forprototyping)


Towards super-small structural features

exposure station at SLS-XIL beamline

• X-ray interference lithography–Resolution ~10nm

• e-beam lithography–Resolution ~20nm

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Hot embossing Technology

Tight process control:

Temperature and T-profiles, Vacuum, clamping force, speed of closing/ emolding

Both sides of tool adjustable withina few micrometers laterally

Optional possibilities

• device for measuring demolding forces

• UV-assisted nanoimprint lithography

Jenoptik Hex03


Replication of Micro- and Nanostructures by Injection Molding

• Interest from vastly different industries– Optics, Security, Decoration– Life science, Bioanalytics

• Entire value chain in-house– Lithography (e-beam, XIL), etch processes– Tool design: construction, CAD, FEM– Laser machining at IPPE

• Present research focus– Optimisation of super-fine structure replication– Variotherm-concepts ; 2-side structured molding– Alternative mold insert materials– Hierarchical structures (nano+micro)– Microfluidics and human liquid handling

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INKA Reference Activities (1)

period 200 nm

AFM calibration chips madeof plasticsPSI – FHNW – Nanosurf AG

Replication of sub-micronstructures by inj. moldingKATZ – FHNW – PSI – Bayer AG

CD-injection molding ofnanostructuresPSI – FHNW – KATZ –AWM Moldtech AG – Netstal AG

Main focus:Master creation (Si, Ni, ..), Replication processes,Tooling developmentPolymer processing

One-way cuvette, nanostructured on inside improvesde-wettingproperties forautomatizedbioanalytics

World record in controlled replicationof nanostructureswith injectionmolding17 nm channels in COC

Microcantilevers withd=20µm for Bionalyticts.top: Laserstructured mold


Application example: Dewetting surfaces for bioanalytics

Problem: structuring of non-planar surfacessolution 1 (Microstructures): Laser Micromachiningsolution 2 (sub-micron structures): Photolithography Nickel foil

Injection molded part (PP)

Kooperationspartner: Roche Diagnostics AG und 3D AG

liquid 1 liquid 2

planar surface 66° 70°

100 nm lines 120° 134°

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Injection molded micro-cantilevers

Nominal cantilever dimensions:Width: 100µmLength: 500µmThickness: currently 30µm

Target 10µm

PVDF COC

Laser-machined mold insert


15min / 110 °C

15min / 115 °C 15min / 120 °C

no reflow !resist pattern / molecular weights

Thermal post-processing of 3-D resist patternPMMA resist layer (500 nm high) after development

Reference: A. Schleunitz and H. Schift, J. Micromech. Microeng. 20 (2010) 095002.

slope inclination~ 11 °

reflow

AFM analysis

2 umselective melting !

not exposed during EBL

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Variation of slope inclination by no. of steps

angle ~ 12.5° angle ~ 17.5°

5-level pattern 4-level PMMA pattern

3-D

resi

st p

refo

rmTh

erm

. pos

t-pro

cess

ing

PMMA resist layer (1050 nm high) after development and thermal treatment

transforming multi-level structures to continuous slopes

Reference: A. Schleunitz and H. Schift, submitted to Microelectronic Engineering (2011).


2 um

3-D grating pattern transferred into silicon

25.7° 27.7°

PMMA resist after reflow and corresponding silicon pattern after dry-etching

silicon

cross section 26.6° -

pattern transfer by dry-etching

PMMA pattern on silicon 3-D silicon structures

2 um

Reference: A. Schleunitz and H. Schift, Proceedings of the 9th International Conference on Nanoimprint and Nanoprint Technology (NNT 2010), Oresund & Copenhagen, October 13-15, 2010.

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Reflow of polymer microstructures

substratewithout surfactant coating

(hydrophilic)

substratewith surfactant coating

(hydrophobic)

17 µm

24h

2h

11 µm

2h

6.7 µm

2.8 µm

24h

2.8 µm

6.7 µm

3 µm

3.5 µm

Ridge-type PMMA preforms after annealing at 160 °C for various times

Courtesy of A. Schleunitz, H. Schift, INKA-PSI


nucleation point120 nm

100 nm

polymer lines with nodes

hydrophobic surface

regularly ordered nanospheres

silicon stamp AFM measurement

x 2 um / divz 500 nm / div

controlling dewetting effect !

Modified silicon stamp for controlled coagulationExpended lines width (node) provoke nucleation points during reflow (16h @ 160 °C)

Courtesy of A. Schleunitz, H. Schift, INKA-PSI

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Contents





Grafting of polymer brushes on polymers

Exposure to particlesor photons e.g. EUV

degassing

heating

Pattern of radicals, stabilised as hydroperoxides

Immersion intomonomer solutione.g. acrylic acid

Polymer film (e.g. ETFE)

Pattern of polymer brushes

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XIL: EUV interferencelithography

Beamlines at the Swiss Light Source


area of high radical density

area of high radical density

direct beam

direct beam

Creation of radicals using EUV interference lithography

membrane mask

beam stop ETFE film

periodic patternof radicals

1st order diffracted beams

incoming beam(synchrotron light)

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ETFE irradiated at the XIL-Beamline(92eV Photons) grafted with 5 % acrylic acid

Non-contact AFM images → topography

Surface microstructures: EUV exposure through TEM grids

Courtesy of C. Padeste, INKA-PSI


Examples of grafted brush structures

4 interfering beams, 283 nm period dot structure

Nanostructuring: Poly-GMA grafted onto ETFE after EUV interference exposure

106º

91º

10º

Adaptation of surface propertieslarge area, un-structured brush

ETFE substrate:low surface energy

GMA-brush

Sulfonated brush

Ar-plasma exposure, grafting with GMA

NaHSO3Grafted 2µm period structure after binding of fluorescent labelled streptavidin

Bio-functional Brush

Courtesy of S. Neuhaus & C. Padeste, INKA-PSI

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Contents





Highly oriented polymers for structural applications

• special processing technologies–Solvent-borne processing

yields super-strong fibers

• Further processing of said fibers–Keep orientation !– Introduce as layers in CF-composites

• Mechanical properties–Outstanding tensile properties–Interesting damping characteristics

Ref: J. Lefèvre, Ultra-high performance polymer foils, Diss ETH Nr. 17603 (2008)

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Polymeric foams – main interest: structural foams

• Batch foaming as R&D tool– Saturation at high pressures– Separate foaming

• Morphology & Properties– Control cell density, size & form– Improved mechanics of cell walls through

nanoscale reinforcement & nucleation

• Modification of melt strength as key– Additives, Nanoparticles, fibrillar fillers– MW build-up, Polymer blends– Rheotens characterization


Functionalization of polymers by nanofillers or specialty additives

• Processing of nanocomposites–Ultrasonic, Dispenser, ball mill,

extruders, kneaders–Safety aspects important!

• Characterization–Dispersion quality / QC methods

Effects:–Antimicrobial, functional– Improvements in mechanical,

(di)electric & thermal properties–Modified melt properties–Enabler for certain technologies

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Antimicrobial Polymer Composites using HeiQ Additives

H2OBacteriaFiber or plastic

Fiber or plastic article

Silver additive H2O

AgAg+



Silver additive H2O

AgAg+



Silver additive H2O

AgAg+

Mechanism of functionalisation and of Ag+ release

HeiQ

INKA

HLS-FHNW EMPA

Plastics Textiles

Antimicrobial nanopowders

Masterbatch

Plastic test plates

Anti-microbial testing

Antimicrobial nanopowders

Surface-functionalized nanopowders

Ion release quantification

Fiber & textile test plates

CTI Project structure

Effect of Nano-Silber-Composites on growthof Escheria coli bacteria after 24 h

Partner:HeiQ Materials AGBad Zurzach


“Plastics without additives are not viable. Additives are essential to make plastic processable and assure the end-use properties.” (*)

ExamplesAntioxidantsLight-stabilizers Acid scavengersLubricantsProcessing aidsAntistatic additivesAntimicrobialsColorantsOptical brighteners Fillers and ReinforcementsFlame retardantsSmoke suppressantsNucleating agentsClarifying agents

* Plastics Additives Handbook, Hanser (2001)

World of plastic additives

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central core with 1,3,5‐substitutionsymmetry and planarity

moieties forming hydrogen bondsone dimensional crystal growth self assembly

peripheral apolar substituentsmanipulation of crystallographic order dissolution in polymer melt

H.‐W. Schmidt et al., Europ. Pat. Appl. EP 0940 431 A1 (1998): nucleators for crystallizable thermoplastic polymersH.‐W. Schmidt et al., US Pat. Appl. 60/251,396 (1999): polypropylene resin composition

Concept – molecular structure of 1,3,5-Trisamide derivatives


Dissolved additive in polymer melt Primary aggregation

Nucleation of polymer Supramolecular nanoobjects

10 ‐ 20nm

1 ‐ 2nm

Cooling

self assembly under cooling

Ø 0.02 ‐ 2µm

Cooling

heating

Supramolecular additives - concept

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High‐efficiency, next generation clarifier for polypropylene

Ciba® IRGACLEAR® XT 386

introduced to market 27.09.2006


Trisamide additive - platform

70nm

α‐Nucleation and clarification of i‐PP

1 µm1 cm

β‐Nucleationof i‐PP

1 µm

NH

RO N

H R

O

NH

OR

Modification ofPP and PE waxes

PP electrets

Processing aidsfor LLDPE

Nucleation of PBT and PVDF

Nanofilters

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Summary

• A large toolbox of modifications is available for polymer functionalization–Let‘s try to make use of it to enable novel solutions for specific needs

• Increasing importance of joining forces between academia and industry–Pioneering approaches for innovative companies

• Applications are there, but yet much more to come–The potential is huge but only fractions are used today

• Functional polymer systems will continue to grow–Joined forces between physics, chemistry, biology & polymer science


Acknowledgements

Physical surface modification – micro/nanostructuringArne Schleunitz, Christian Spreu, Helmut Schift, PrabithaUrwyler (PSI), Christian Rytka, Mirco Altana, Armin Stumpp, Beat Lüscher (FHNW)

Chemical functionalization – patterned surface graftingSonja Neuhaus, Celestino Padeste

Bulk modification – morphology controlMirco Altana, Giovanni Conigliaro (FHNW), Murray Height (HeiQ), Hans‐Werner Schmidt (Uni Bayreuth), Paul Smith (ETH), Daniel Müller (BASF)

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Point of contact – Polymer Technology

Institut für nanotechnische Kunststoffanwendungen (INKA)Institute of Polymer Nanotechnology

Prof. Dr. Per Magnus Kristiansen

Klosterzelgstrasse 25210 WindischT +41 56 462 45 41M +41 76 432 01 28F +41 56 462 45 [email protected]/technik/inka

Documents

Micro- and nanoscale modifications for polymer …2010/10/11 · 3-D resist preform Therm. post-processing PMMA resist layer (1050 nm high) after development and thermal treatment