© 2010 Anasys InstrumentsI N S T R U M E N T S

Transition Temperature MicroscopyNano-scale Thermal Analysis Technique

Khoren SahagianAnasys Instruments

Steven Goodman10H Technology Inc.

I N S T R U M E N T S© 2010 Anasys Instruments

Outline

• Introduction to Nano ThermalAnalysis (NanoTA)

• Technology Overview• Transition Temperature

Microscopy (TTM)• Applications in materials

science and engineering

I N S T R U M E N T S© 2010 Anasys Instruments

About Anasys Instruments

• Founded in 2005 to expand the capabilitiesof probe microscopy and nanoscalecharacterization

• Over 100 years of combined experience inSPM, spectroscopic and thermal sciences

• Pioneers in– nanoscale thermal analysis– nanoscale IR spectroscopy

I N S T R U M E N T S© 2010 Anasys Instruments

Sample Limitations for Normal Thermal Analysis

• TMA – 500um diameter/5um thickness(minimum quartz probe dia. of 200um)

• DSC – 0.100mg highly crystalline materials,2-10 mg amorphous

• TGA – 5-10mg depending on maximumloss anticipated

• DMA – sample geometry is mode specific

I N S T R U M E N T S© 2010 Anasys Instruments

Temperature

Def

lect

ion

Tg = 152.4 °C

Nano Thermal Analysis

Sample

ThermaLever™ Probe

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Atomic Force Microscope

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Enabling technology

VI

I

* Developed incollaboration with

inventor Prof. W. King,UIUC

700 nm Scan on Rubber Blend

AFM Phase Image

•Controllable probe temperatures up to 450˚C

•Heating rates up to 600,000˚ C/min

ThermaLevers™ Probes*

<30 nmend radius

* Manufactured in partnership with

I N S T R U M E N T S© 2010 Anasys Instruments

Correlation to Bulk Thermal Analysis

Three crystalline samples and three amorphous samples were measured bybulk ThermoMechanical Analysis (TMA) and compared against LTAmeasurements.

y = 1.0088x - 3.8173

R2 = 0.9811

y = 1.0027x + 0.2778

R2 = 0.9701

y = 1.0047x + 2.9657

R2 = 0.95810

50

100

150

200

250

300

0.0 100.0 200.0 300.0

TMA onset

Na

no

Ta

On

se

t

0.1°C/s

1°C/s

10°C/s

Slopes: 1.003 - 1.009Offsets: -4 to +3ºC

Data courtesy of G. Meyers and A. Pasztor, DOW

I N S T R U M E N T S© 2010 Anasys Instruments

Technology Platforms

VESTAStand-alone Localized Thermal Analysis

nanoTA2Add-on accessory for AFM users

AFM+

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An optical image and nano-TA measurement on the fourlayers in a multilayer film composed of Nylon, PET andtwo forms of low density polyethylene.

94˚ C

88˚ C

180˚ C 218˚ C++ +

+

Example: Multilayer Film

100um

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BrightfieldOptical

Microscope

MotorizedXY and ZStages

VESTA head

- Point & Click Nanothermal Analysis

•Rapid, automated nano-TAmeasurements

•No AFM expertise required

•Transition TemperatureMicroscopy (TTM)

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Transition Temperature Microscopy

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Example TTM: LCD Multilayer Film

• High resolutionthermal imagingand analysis

• Automated pixel bypixel analysis

100um

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Selected Medical Device Applications

• UHMWPE Orthopaedic Bearings• Polyurethane Stress Corrosion Cracking• Drug Coated Stents• Extruded Catheters• Contact Lenses

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Example – Orthopaedic UHMWPE

PE (GUR 1050) 5 x 106 MW:• Virgin• Radiation cross-linked

100kGyLess alpha-tocopherol

More alpha-tocopherol

Vitamin E = alpha tocopherol:• Plasticization effect

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Example Explant UHMWPE Knee Bearing

Examine 2 specimen regions:• Multiple thermal transitions in damaged region• Undamaged region LTA like virgin material

Figure 1.3: Photograph of an explanted UHMWPE

knee bearing (a) and two regions of LTA analysis as

indicated with the arrows. Region shown in b and

indicated with upper blue arrow shows no visible

damage. Region c indicated with lower red arrow is

in the small pit. Local thermal analysis curves (e) are

shown for the two regions: Region b (blue curves

with 108ºC peak) and region c (red curves with

118ºC peaks, one of which has a second 176ºC peak.

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Selected Medical Device Applications

• UHMWPE Orthopaedic Bearings• Polyurethane Stress Corrosion Cracking• Drug Coated Stents• Extruded Catheters• Contact Lenses

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Example: Polyurethane Stress Corrosion

Environmental aginggreatly lowers Tm

SEM

Aged96.2 C

Intrinsic128.4 C

Melting deformation

nano-TA

Andy Hung(1) , Khoren Sahagian(2) , Mike Colvin(1) , Roshan Shetty(2)

1) Boston Scientific, Valencia, CA, 2)Anasys Instruments, Santa Barbara, CA

• 0.1 M CoCl2, 20% H2O2• 37°C• Constant 250 g pull• H2O2 changed 3X/week• 1 month

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ESC Region

Polyurethane

•ESCdomain122.5°C•Polyurethane135.2°C

100um

Example: Polyurethane Stress Corrosion

StressedRegion

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Selected Medical Device Applications

• UHMWPE Orthopaedic Bearings• Polyurethane Stress Corrosion Cracking• Drug Coated Stents• Extruded Catheters• Contact Lenses

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Example: Drug Coated Stents

Local Thermal Analysis Maps of Drug Distribution

S t e n tType Formulation Solvent

Brand X PDLLA + Drug A + excipients Solvent 1Brand Y PDLLA + Drug B + excipients Solvent 2Brand Z PDLLA + Drug C + excipients Solvent 3

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Selected Medical Device Applications

• UHMWPE Orthopaedic Bearings• Polyurethane Stress Corrosion Cracking• Drug Coated Stents• Extruded Catheters• Contact Lenses

I N S T R U M E N T S© 2010 Anasys Instruments

Example: Extruded Catheters, Contacts

Catheter LTA - Tm

Catheter Tm - very uniform

Contact Lens LTA – Tg(dry hydrogel)

Contact lens Tg - not consistent

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Additional Applications

• Thermal mapping of composites andpolymer blends

• Characterizing defects• Mapping film heterogeneity• In situ analysis of coating/thin film• Detecting weathering/degradation

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Applications

• Thermal mapping of composites andpolymer blends

• Characterizing defects• Mapping film heterogeneity• In situ analysis of coating/thin film• Detecting weathering/degradation

I N S T R U M E N T S© 2010 Anasys Instruments

Sample: Polypropylene,Polyethylene and“rubbery” phase

Impact Modified Polymers

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TTM - Polymer Blend

100 x 100 um TTM image

Polystyrene andPoly(methyl methacrylate)polymer blend

Scan size100 x 100microns.

TTM clearly differentiatesthe different Tg values ofthe two materials

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TTM: Fiber Reinforced Composites

Epoxy

• Interfacial bonding is critical toperformance

Contributed by Khoren Sahagian, Anasys Instruments

Temperature

100um

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Applications

• Thermal mapping of composites andpolymer blends

• Characterizing defects• Mapping film heterogeneity• In situ analysis of coating/thin film• Detecting weathering/degradation

I N S T R U M E N T S© 2010 Anasys Instruments

Sidewall Haze

• Analyze amorphous/crystallinecontent across the sample

Data courtesy of L.Germinario, Eastman

Chemical

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Defects in Extruded Film- Blood Bag

100um

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Applications

• Thermal mapping of composites andpolymer blends

• Characterizing defects• Mapping film heterogeneity• In situ analysis coating/thin film• Detecting weathering /degradation

I N S T R U M E N T S© 2010 Anasys Instruments

Measurement of thetransition temperaturegradient across a thin

film

Thin Film Heterogeneity

Film

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Mapping across PET bottle wall

Across wall

Bottom

inside outside

Measurements by K. Sahagian

PET Bottle Cross Sections

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Polyolefin Blown Film

TTMs showinhomogeneous

crystallinity

Histogram of transitiontemperatures

Bad!

Good!

LESS crystalline

MORE crystalline

I N S T R U M E N T S© 2010 Anasys Instruments

Applications

• Thermal mapping of composites andpolymer blends

• Characterizing defects• Mapping film heterogeneity• In situ analysis coating/thin film• Detecting Weathering/degradation

I N S T R U M E N T S© 2010 Anasys Instruments

TTM: Solid Lubricant Coating

Measurement of coatinguniformity of lubricant

100um

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Fiber Coupler-Mounting

129 ° C

205 ° C

Fiber

Substrate

Epoxy

Tg measurement of the thin epoxy layerholding the fiber to the substrate

100um

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Applications

• Thermal mapping of composites andpolymer blends

• Characterizing defects• Mapping film heterogeneity• In site analysis coating/thin film• Detecting weathering/degradation

I N S T R U M E N T S© 2010 Anasys Instruments

TTM: Weathering of PET Sheet

Exposed

Transition Temperature Microscopy Images

Transition Temperature peak shifted by ~ 90ºC due to weathering

Unexposed

Exposed to UV light

Unexposed to UV light

~125°C

~215°C

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Summary

• Nanothermal analysis enables measurements ofthermal properties on the micro and nanoscale

• Material characterization & identification• Spatially and time-resolved measurements• Transition Temperature Microscopy allows

automated visualization of structure andheterogeneity

• Broad applicability in material science andengineering

I N S T R U M E N T S© 2010 Anasys Instruments

Correlation to Bulk Thermal Analysis

Three crystalline samples and three amorphous samples were measured bybulk ThermoMechanical Analysis (TMA) and compared against LTAmeasurements.

y = 1.0088x - 3.8173

R2 = 0.9811

y = 1.0027x + 0.2778

R2 = 0.9701

y = 1.0047x + 2.9657

R2 = 0.95810

50

100

150

200

250

300

0.0 100.0 200.0 300.0

TMA onset

Na

no

Ta

On

se

t

0.1°C/s

1°C/s

10°C/s

Slopes: 1.003 - 1.009Offsets: -4 to +3ºC

Data courtesy of G. Meyers and A. Pasztor, DOW

I N S T R U M E N T S© 2010 Anasys Instruments

Polymer Standard Based CalibrationThree crystalline polymer samples are used to calibrate

the tip-sample interface temperature

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Advantages of tip heating

•Heating rates up to 600,000 C/min•Wide range of rate dependent studies

•Avoid re-crystallization

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Pharmaceutical Tablets

100x100 micron Acetaminophen-HPMC mixture