effect of storage temperature on ti-6al-4v surface wettability caio peixoto*, arman butt** and...
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Effect of Storage Temperature on Ti-6Al-4V Surface Wettability
Caio Peixoto*, Arman Butt** and Christos Takoudis**
*Federal University of Rio Grande do Norte
**University of Illinois at Chicago
Outline
• Motivation and Background
• Sample Preparation
• Surface Characterization
– Roughness (Zygo)
– Chemistry (Fourier Transform Infrared Spectroscopy – FTIR)
– Wettability (Water Contact Angle)
• Conclusions
22
Motivation and Background
Titanium and Alloys
• Corrosion resistance, mechanical properties and biocompatibility
• Numerous biomedical applications– Dentistry– Orthopaedics– Cardiovascular– Ophthalmology
2Figure from Geetha Manivasagam et al. Biomedical Implants: Corrosion and its Prevention - A Review. Recent Patents on Corrosion Science. 2010, pp. 40-54. 3
Osseointegration
• Connection between the implant and the living bone• Prevention of implant loosening
3Figure adapted from M. Geetha et al. Ti based biomaterials, the ultimate choice for orthopaedic implants - A review. Pregress in Materials Science. 2009, pp. 397-425. 4
Water adsorption Proteins adsorption Cells adsorption
Water Dissociation on TiO2 Surface
3
Figure adapted from Z. Zhang et al. Imaging Water Dissociation on TiO2(110): Evidence for Inequivalent Geminate OH Groups J. Phys. Chem. B 2006, 110, 21840-21845 5
(a) TiO2 surface with oxygen vacancy
(b) Two hydroxyl groups HV (at a vacancy) and HB (protonation of neighbor oxygen atom) formed by water adsorption and dissociation
(c) HB diffusion
Motivation
• Current storage method: samples in air (Petri-dish or Kimwipe
• Decrease in wettability over time• Materials can be mistakenly classified as bad by further
tests
6
200 °C 400 °C 600 °C0
10
20
30
40
50
60
70
80
Samples stored in glass Petri-dish in air
Day 0
Day 1
Day 2
Day 3
Day 4
Day 5
Day 8
Day 9
Thermally oxidized samples
Ave
rage
Wat
er C
onta
ct A
ngle
(°)
Evolution of water contact angle – Samples stored in glass petri –dish in air (Data acquisition and graph preparation by
Sweetu Patel)
6
Samples in current storage conditions
Background
• Surface wettability decreases over time due to poor
storage methods1
• At 2x10-10 Torr, increase in temperature results in water
desorption and hydroxyl group loss2
7
[1] Jung Hwa Park et al. Effect of cleaning and sterilization on titanium implant surface properties and cellular response. Acta Biomaterialia, 2011
[2] Amy L. Linsebigler, et al. Photocatalysis on TiOn Surfaces: Principles, Mechanisms, and Selected Results . Chem. Rev. 1995, 95, 735-758. 7
Sample Preparation
Sample Preparation
• Sandblasting – 50 µm alumina grit particles– 517 kPa
28
• Acid Etching
Figure from L.G. Harris, et al.Staphylococcus aureus adhesion to titanium oxide surfaces coated with non-functionalized and peptide-functionalized poly(l-lysine)-grafted-poly(ethylene glycol) copolymers, Biomaterials, Volume 25, Issue 18, August 2004
H2SO4 + H2O2 → H2SO5 + H2O
Sample Preparation
• Sonication – 1 hour methanol (99.8%)
• Wash – 30 seconds deionized water (DI-water)
• Annealing – 3h in air
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AnnealingScheme (adapted from http://www.memsnet.org/mems/processes/deposition.html)
Not Annealed
400 ºC
600 ºC
Annealing Storage Condition
Group 1
Not Annealed
Kimwipe
Group 2 Room Temp. DI-Water
Group 3 Cold DI-Water*
Group 4
400 ºC
Kimwipe
Group 5 Room Temp. DI-Water
Group 6 Cold DI-Water*
Group 7
600 ºC
Kimwipe
Group 8 Room Temp. DI-Water
Group 9 Cold DI-Water*
10*Refrigerator temperature: 8 ± 2 ºC
Surface Characterization
Zygo
411
Roughness (µm)
Not Annealed 400 ºC 600 ºC
RMS 2.27 ± 0.27 2.57 ± 0.47 2.51 ± 0.56
Sample 45 surface
FTIR
412
• Infrared Spectrum (absorbance)
• Deconvolution using XPSpeak
Figure from http://www.bgtu.net/image/ik.jpg
13
14
15
Anatase
Ti-O bond
16
17
RutileV-O
Al2O3
18
Al2O3
Water Contact Angle
• Water contact angle measurements
– After 0h, 3h, 6h,12h, 1d, 2d, 6d, 9d,13d, 16d and 20d
• Cold water groups let to warm up to room temperature
– Measurements after 20d3h, 20d6h, 20d12h, 21d, 23d and
27d
• Warm up all the samples to 37 °C
– Measurements after 27d3h, 27d6h, 27d12h, 28d, 30d, 34d419
20
0 5 10 15 20 25 30 350
20
40
60
80
100
120
140
160
Samples Not AnnealedGroups 1, 2 and 3
Kimwipe Room Temperature Water Cold Water
Time (days)
Wa
ter
Co
nta
ct
An
gle
(º)
Cold water samples warmed up to room temperature
Samples immersed in water and warmed up to 37 ºC
21
0 5 10 15 20 25 30 350
20
40
60
80
100
120
140
160
Samples Annealed at 400 ºCGroups 4, 5 and 6
Kimwipe Room Temperature Water Cold Water
Time (Days)
Wa
ter
Co
nta
ct
An
gle
(º)
Cold water samples warmed up to room temperature
Samples immersed in water and warmed up to 37 ºC
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0 5 10 15 20 25 30 350
20
40
60
80
100
120
140
160
Samples Annealed at 600 ºCGroups 7, 8 and 9
Kimwipe Room Temperature Water Cold Water
Time (Days)
Wa
ter
Co
nta
ct
An
gle
(º)
Cold water samples warmed up to room temperature
Samples immersed in water and warmed up to 37 ºC
23
Conclusions
• Best annealing temperature: 600 ºC– Rutile formation– Signatures related to vanadium and aluminum oxides from FTIR
spectrum
Water Contact Angle After 34 Days (º)
Not Annealed 400 ºC 600 ºC
Kimwipe 61 ± 10 54 ± 10 31 ± 13
Room Temperature Water 12 ± 4 12 ± 4 7 ± 2
Cold Water 9 ± 3 12 ± 4 4 ± 2
24
Conclusions
• Best storage condition: immersed in DI-water– Storage temperature showed no major effect– Samples wrapped in Kimwipe decreased drastically when
immersed in DI-water– Water dissociation reaches equilibrium
Figure adapted from Z. Zhang et al. Imaging Water Dissociation on TiO2(110): Evidence for Inequivalent Geminate OH Groups J. Phys. Chem. B 2006, 110, 21840-21845
Acknowledgments
AMReLAdvanced Materials Research Laboratory
ORTHOPAEDIC AND DENTAL RESEARCH GROUP
RUSH, Michigan Tech and UIC
Dr. Gregory Jursich, Sweetu Patel, Azhang Hamlekhan and Dmitry Royhman
Questions? Comments?