Download - The Case for Materials Characterization
The Case for Materials Characterization
Foothill College
NANO53
Overview
• The role of characterization
• PNPA model
• Types of information
• Example problems
• Materials analyzed
Why Characterize?
• Nanostructures are unknown
• QA/QC of fabrication process
• Failure analysis of products
• Materials characterization
• Process development / optimization
PNPA – Nanomaterials Engineering Rubric
• Applications drive requirements
• Requirements inform material selection
• Nanostructured materials engineering
• Process design and optimization
• Characterization tools and approach
PNPA – A Rubric for Training Technicians in Nanomaterials Engineering
PNPA - Characterization
Processing (P)
Properties (P)
Characterization
(N)Nanostructure
PLOs – Program Learning Outcomes – Integrated Materials Engineering Process
Stru
ctur
e pr
oper
ty re
latio
nshi
ps =
>
Fabrication property relationships => <= Nanostructure elucidation
<= Process tools / QA/QC monitoring
Fabr
ication
pro
perty
relati
onsh
ips =
><= Properties determ
ination
Nanostructural Information
• Morphology• Composition• Chemistry• Structure• Properties
Novel nanocarbon can store and sieve hydrogen - http://spie.org/x13545.xml?ArticleID=x13545
Process Optimization
• Relate structure to properties
• Relate structure to process
• Relate process to properties
• Optimize structure / property process / relationships
• Optimize process parameters for manufacturing / cost / safety etc.
Taguchi Methods
• Taguchi methods are statistical methods developed by Genichi Taguchi to improve the quality of manufactured goods, and more recently also applied to, engineering, biotechnology, marketing and advertising. Professional statisticians have welcomed the goals and improvements brought about by Taguchi methods, particularly by Taguchi's development of designs for studying variation, but have criticized the inefficiency of some of Taguchi's proposals.[5]
http://en.wikipedia.org/wiki/Taguchi_methods
Key Nanomaterials
• Polymers
• Metals/alloys
• Glasses/ceramics
• Nanocarbon
• Thin film coatings
• Silicon
• Particles
Energy of electrons in graphene in the tight-binding model, http://dx.doi.org/10.1103/PhysRev.71.622
What we Need to Know
• Surface finish
• Surface composition and chemistry
• Layer thickness
• Bulk composition and chemistry
• Material phase and structure
Types of Testing
• Materials characterization
• Process development support
• Failure analysis
• QA/QC
• Authenticity testing
Tools
• Image (SEM, AFM, TEM)• Surface (AES, XPS)• Organic (FTIR, Raman,
GC/MS, LC/MS, NMR• Chemical (ICP, XRF, TEM)• Structural (XRD, Raman)• Modeling and simulation
AFM Instrumentation
PNI Nano-R AFM Instrumentation as used at Foothill College
Surface Analysis Tools
SSX-100 ESCA on the left, Auger Spectrometer on the right
XPS Spectrum of Carbon
• XPS can determine the types of carbon present by shifts in the binding energy of the C(1s) peak. These data show three primary types of carbon present in PET. These are C-C, C-O, and O-C=O
Typical Problems
• Contamination
• Failure
• Process development
• Competitive analysis
• Research (R&D)
http://www.forensicinvestigation.com/
Nanocarbon
• Graphitic like structures – CNT, graphene, etc
• Soot that has been annealed (graphitized)
• Graphitic planes are observed by TEM
• No one knows what the 3D structure is
• Electron tomography might be useful
Biomedical Stents
• Surface finish is critical to patient outcomes, electropolishing etc.
• Multi-technique analysis– Image analysis– Surface analysis– Depth profiles
Identification of Contamination
• Organic contamination• Ionic residues• Cleaning residue• Process residue• Packaging transfer• Environmental
Surface Treatment of NiTi
Biomedical Devices and Biomedical Implants – SJSU Guna Selvaduray
Biomedical Devices and Biomedical Implants – SJSU Guna Selvaduray
Surface Treatment of NiTi
• XPS spectra of the Ni(2p) and Ti(2p) signals from Nitinol undergoing surface treatments show removal of surface Ni from electropolish, and oxidation of Ni from chemical and plasma etch. Mechanical etch enhances surface Ni.
Biomedical Devices and Biomedical Implants – SJSU Guna Selvaduray
Surface Treatment of NiTi
Multi-technique Analysis
• Image – surface morphology
• Surface – surface chemistry
• Structural – crystal domain
• Organic – molecular specific identification (separation)
• Chemical – elemental analysis
Modeling and Simulation
Not Being Blind
• Developing a process with NO characterization tools
• Using properties measurements only
• Not knowing why something is good
• Not knowing if you can do better
• Not having a baseline of quality