11

Novel Applications of Nano-composites and Multiscale Composites Through

Case Studies

Dr. K. PadmanabhanDr. K. Padmanabhan Asst. Director and ProfessorAsst. Director and Professor

School of Mechanical EngineeringSchool of Mechanical Engineering VIT-University, Vellore-632014VIT-University, Vellore-632014

Email: padmanabhan.k@vit.ac.inEmail: padmanabhan.k@vit.ac.in

22

HistoryHistory

33

Indus Valley and Natural Indus Valley and Natural CompositesComposites

Mud Composite Figurines and Sun Baked Mud Composite Bricks Were Produced by The Indus Valley People from 5000 BC It was not the Egyptians first- A myth !

44

Kajal or Mai- the home made Kajal or Mai- the home made nanocarbon from castor oil ! nanocarbon from castor oil !

Nanocarbon structures are present in the soot !

55

Nanotechnology of Delhi Iron PillarNanotechnology of Delhi Iron PillarThe external rust layer on the fracture surface of the pillar iron was heavily cracked. The flowery needle-like nano rust can also be seen in the upper right portion of the figure.

Microstructure of the pillar iron showing the presence of a larger fraction of miniscule pearlite near some slag particles.

-Prof. R Balasubramaniam, IITK

66

Samurai SwordSamurai Sword

Microstructure showing nanocarbonand nanoparticles in the sword.

77

Sword of DamascusSword of Damascus

The sword of Damascus that can slicethrough falling silk and cut stoneswith out dulling contains carbon nanotubes and nanophases

Novel Applications of Nano-composites and Multiscale Composites Through Case

Studies

88

99

Abstract Nanocomposites and multiscale composites find wide applications in structures, electronics, biomedical fields, automobiles and aviation. This invited lecture illustrates

some of these applications through five case studies that the investigator has carried out.

1. Nanostructuring of Kevlar fibres through chemical modification of the surface for better interfacial properties

with epoxy matrices in composite applications.

1010

2. Multiscale composites for manufacturing restoratives for dental applications.

3. Novel fabrication methods and uses of nano-steel and nano cast iron containing nano phases of carbon.

4. Novel applications of a glass fabric /epoxy composite containing a centroidal layer of multiwalled carbon nanotubes, in electronic circuit boards, packaging, cladding and structural applications .

1111

5. The synthesis and characterization of a bio-resin based nano-composite containing nano-silica and carbon black is vividly described. Here, the Cashew Nut Shell Oil (CNSL) is converted in to a usable plastic matrix with which a nano-composite is synthesized and characterized for applications in electronic packaging.

The lecture concludes by summing up some novel applications of nano-composites and multi-scale composites

1212

1. Nano Structuring of 1. Nano Structuring of KevlarKevlar

0.51 nm

Schematic diagram of Kevlar® 49 fibershowing the radially arranged

pleated sheets

Microstructure of aramid fiber

Kevlar fibers

Kevlar-49 Structure

1515

Kevlar Fibre Nano Kevlar Fibre Nano StructuringStructuring

1616

Kevlar Fibre Nano Kevlar Fibre Nano StructuringStructuring

10 Min Methanol And water Washing

1717

XPS of Treated Kevlar XPS of Treated Kevlar SurfacesSurfaces

1818

SEM of Treated Kevlar SEM of Treated Kevlar SurfacesSurfaces

1919

Multiple Fibre Pullout TestsMultiple Fibre Pullout Tests

Ref: K. Padmanabhan , Composites B, 30(1999) p205 ( Citation Classic )

Ref: K. Padmanabhan , Toyobo Confidentiality Report, 2002

2020

Kevlar Fibre/ Epoxy Kevlar Fibre/ Epoxy CompositesComposites

- Interfacial Results- Interfacial Results

2121

2. Multiscale Composites in 2. Multiscale Composites in DentistryDentistry

2222

Composites in DentistryComposites in Dentistry

Acrylics, Acrylic esters, Bis-GMA, PMMA derivatives, Ceramic filled composites

Can you make out the difference ?

Ref: K. Padmanabhan , Comment on 'standards on restoratives' 2009 ,  Volume : 20 , Issue : 4 ,  Page : 516, 1000 + downloads

2323

Composites in ProsthodonticsComposites in Prosthodontics

Tooth is a functionally gradedcomposite material with enameland dentin. In the third maxillary molar the occlusal stress can be 2-3 MPa.

The masticatory heavy chewing stress will be around 193 MPa.A composite restorative must with stand this with an FOS and with constant hygrothermal attack.

2424

Multi Scale Composites for Multi Scale Composites for DentistryDentistry

Bis GMA, UDMA, Methacrylic Esters Bis GMA, UDMA, Methacrylic Esters contain glassy particles that are mostly contain glassy particles that are mostly less than 1 micron in sizeless than 1 micron in size

Esters and acrylates/ceramic filler Esters and acrylates/ceramic filler (barium alumina silica glass, glassy (barium alumina silica glass, glassy microfillers, 0.1 to 10 microns size) microfillers, 0.1 to 10 microns size) restorative composites.restorative composites.

Multi scale composites are also useful Multi scale composites are also useful as luting cements, crown and bridge as luting cements, crown and bridge materials and cements and veneer materials and cements and veneer materialsmaterials..

2525

Wear Data for RestorativesWear Data for Restoratives Aesthetics, Shade, ReliabilityAesthetics, Shade, Reliability Most of the composites show a logarithmic Most of the composites show a logarithmic

wear rate, linear wear rate is unwelcome !wear rate, linear wear rate is unwelcome ! Wear of less than 200 microns in 10 years Wear of less than 200 microns in 10 years

is acceptable.is acceptable. Wear volume will be 0.5 to 0.8 cu. mm per Wear volume will be 0.5 to 0.8 cu. mm per

annum, enamel annum, enamel vsvs restoratives. restoratives. Coeff of Friction is ~ 0.1 to 0.35.Coeff of Friction is ~ 0.1 to 0.35.

Hygrothermal BehaviourHygrothermal Behaviour Fibre reinforced plastics are known for Fibre reinforced plastics are known for environmental attacks that reduce their function.environmental attacks that reduce their function.Mechanical properties degrade over time !Mechanical properties degrade over time !Moisture plays havoc at elevated temperatures, Moisture plays havoc at elevated temperatures, in the presence of voids, defects and in low Tin the presence of voids, defects and in low Tgg plastics .plastics .Diffusion and osmotic pressure are the driving Diffusion and osmotic pressure are the driving mechanisms for hygrothermal attackmechanisms for hygrothermal attackEvaluation methods and surface preservation Evaluation methods and surface preservation Important in marine, biomedical, aeronautical, Important in marine, biomedical, aeronautical, electronic and automobile applications electronic and automobile applications

27

Variation of strength with temperature

Glass Transition Temperature

ASTM STP D 5229 M RuleASTM STP D 5229 M RuleThe MOT( Maximum Operating Temperature) The MOT( Maximum Operating Temperature) of the material, device/component should be of the material, device/component should be at least at least 25 º Celsius lower than the lowest Tg (normally wet) of the material attained after hygrothermal equillibration. All the polymeric . All the polymeric materials and their composites must satisfy materials and their composites must satisfy this rule in order to qualify for certification for this rule in order to qualify for certification for reliability and durability.reliability and durability.

The need to revise The need to revise standardsstandards

2929K. Padmanbhan,

3030

Nano Cast Iron and Nano Nano Cast Iron and Nano SteelSteel

3131

Iron-iron carbide phase Iron-iron carbide phase diagramdiagram

3232

AFM of MWCNTAFM of MWCNT

K. Padmanabhan & Sai Sirisha, Procedia Engineering , 97 ( 2014 ) 1422 – 1433.

3333

XRD of As Cast Nano Cast XRD of As Cast Nano Cast IronIron

XRD DiscussionXRD Discussion

3434

Figure reveals that the 1.57116, 2.27751 and the 2.89858 d spacing MWCNT peaks were seen in the as cast nano cast iron. However, a very minor shift was also recorded in these peaks which could be attributed to the copper coating on the MWCNTs prior to stir casting and the mild solubility of the same in cast iron. It is clear from the x-ray of the as cast nano iron that the MWCNT d spacing peaks appear at 1.58433, 2.26832 and 2.87563 values among the other peaks that are typically representative of a grey cast iron. The 2.26832 peak is common to both the Quantum MWCNT and a conventional unfilled grey cast iron as it is most likely that it is Fe5C2 phase which is present as an impurity in both.

3535

XRD of Heat Treated NCCIXRD of Heat Treated NCCI

XRD Discussion XRD Discussion

3636

Small amounts of impurities present seem to dissolve in the NCCI due to heat treating thereby suppressing the impurity peaks. However, the two α-ferrite peaks at a 2θ value of 44.981 º and 65 º in Figure show that the phase evolved is a (110) ferrite . Heat treatment at 550 º C appears to improve , solid solubility. Copper found in trace amounts ( because of coating the MWCNT) naturally leads to better corrosion resistance and strength in the NCCI in addition to protecting the MWCNT in the as cast NCCI. However, solid solubility of copper and MWCNT in the NCCI appear to take place as a result of heat treatment which is evident from Figure . This ferritizing anneal reduces the hardness of the NCCI as seen later.

3737

Micrograph of NCCIMicrograph of NCCI

3838

Micrograph of HTNCCIMicrograph of HTNCCI

MWCNT/ Glass Fabric /Epoxy MWCNT/ Glass Fabric /Epoxy Multiscale CompositesMultiscale Composites

3939

40

Glass/ Epoxy MWCNT Multiscale Composites

These sandwich structures find wide applications in electronic packaging, thermal insulation, structural members and products with cladding.

Specimen and Testing

AA Ravindra, Razim Refai, Aman Nigam, Siddarth Kumar, Padmanabhan. K, Procedia Engineering 97 ( 2014 ) 449 – 458, About 200 downloads !

Parameters for Evaluation

• ILSS- Interlaminar Shear Strength• Mode II Strain Energy Release Rate

•Russell’s Theory• Direct Beam Theory

42

Micrographs of Fracture

43

4444

Nano Bio Composites in Nano Bio Composites in Microsystems and Microsystems and

Nanosystems PackagingNanosystems Packaging

4545

Microsystems and Microsystems and Nanosystems Packaging Nanosystems Packaging

RoadmapRoadmap

4646

AnalysisAnalysis Electric-Thermal AnalysisElectric-Thermal Analysis Thermal – Structural AnalysisThermal – Structural Analysis

– Materials usedMaterials used Lead Frame and LeadsLead Frame and Leads - Copper- Copper Wire bondingWire bonding - Gold- Gold DieDie - Silicon- Silicon Adhesive for lead frame Adhesive for lead frame

and dieand die - Silver Epoxy- Silver Epoxy EncapsulationEncapsulation - - Carbon black and fused silicaCarbon black and fused silica

particles filled epoxy andparticles filled epoxy and phenolic resinphenolic resin –a multiscale –a multiscale

composite !composite !

K. Padmanabhan, D. Sanjay and S. Subeesh, International Jl. of Micro and Nano Electronics , Circuits and Systems, 1(2), 2009, pp 67-76

47

FUNCTIONS OF PACKAGES

1. Shut out environmental influences

2. Enable electrical connectivity

3. Dissipate heat

4. Improve handling & assembly

Applications of IC Packages• Mobile Phones• PDA s• Automotive Electronics• Digital Cameras and Camcorders• TVs and Monitors• Signal Transmission and Reception ICs• Aviation, Marine and Biotechnology

48

49

Electric and Thermal Results

Electric plot Temperature distribution

Ref: K. Padmanbhan, A multiphysics based finite element approach to evaluate the reliability of IC packages, Book chapter in IGI Global Handbook, USA, 2016.

05/02/23 50

Cashew Nut Shell Oil as Composite Matrix Material

• Cashew nut shell oil can be polymerized using acids, toluene as inhibitor and formaldehyde at 120 celsius.

• A tough and strong maroon coloured matrix !

05/02/23 51

Composition of CNSL

05/02/23 52

CNSL Matrix Material

Hygrothermally Very Stable and Termite Resistant

53

• Dielectric Constant• Coefficient of Thermal expansion • Thermal conductivity • Specific Heat Capacity• Vibration tests

1) Carbon Black powder under an SEM VS Nanosilica powder under SEM 2) EDS of carbon black powder VS EDS of nanosilica powder 3) Formaldehyde phenol curedCNSL and the nanocomposite4) Microstructure of Nanocomposite5) EDS of nanocomposite 6) DSC/TGA plot of CNSL resin VS DSC/TGA plot of nanocomposite7) The Dielectric Permittivity

05/02/23 55

CNSL COMPOSITES AND THEIR DYNAMIC APPLICATIONS

CNSL MATRIX/ GLASS FABRIC LAMINATE. FRF and FFT of CNSL a Composite

5656

Cosmic CreationCosmic CreationThe most elegant and sublime of creation is a representation of the creation of the universe at the beginning of each cosmic cycle, a motif known as the cosmic dance of Lord Shiva. In the upper right hand is a drum whose sound is the sound of creation -

Thank You All