DR. R.K. KHANDAL
DIRECTOR
NANOCOMPOSITES FOR
OPTICAL PLASTIC
MATERIALS
SHRIRAM INSTITUTE FOR INDUSTRIAL RESEARCH
19, UNIVE...
OUTLINE OF
PRESENTATION
OPTICAL APPLICATIONS
OPTICAL PLASTICS
NANO COMPOSITES
METAL CONTAINING PLASTICS
FUTURE OF NANO TEC...
OPTICAL APPLICATIONS
BIOMEDICALS ENGINEERING INSTRUMENTATION INFRA STRUCTURE
OPHTHALMIC
LENSES
AUTOMOTIVE
AVIATION
SPACE
R...
BIO-MEDICAL APPLICATIONS
Optical Devices Parameters Materials Used
Spectacle lenses Refractive index, optical Glass, Polyt...
INSTRUMENTAL APPLICATIONS
Optical Device Parameters Materials Used
Binocular lenses Magnifying power, Glass, Polyacrylates...
INFRASTRUCUTRE APPLICATIONS
Optical Device Parameters Materials Used
Optical waveguides Refractive index, Lithium niobate ...
ENGINEERING APPLICATIONS
Optical Device Parameters Materials Used
Optical modulators Refractive index, Lithium niobate (Li...
GLOBAL STATUS : PLASTIC LENSES
CHARACTERISTICS
800-850 million lenses per year
∈ 7-8 billion in sales
Lens replacement fre...
10%
17%
33%
45%
55%
98%
0%
20%
40%
60%
80%
100%
120%
Latin America United States Canada Western Europe Asia Pacific Japan
...
Lens market breakdown by material
Plastic lenses,
medium, high
indexes
(>1.5 index)
22%
Plastic lenses
<1.5 index
42%
Glas...
INDIAN STATUS : LENSES
140 million pieces per year
Export = 112 million pieces per year
Domestic = 28 million pieces per y...
DESIGN CRITERIA FOR
OPTICAL PLASTICS
Evaluation of the environment in which the plastic
is to be used
Physical and optical...
CLASSIFICATION OF OPTICAL MATERIALS
Gradient index materials : Glass & Polyacrylates
Low Refractive Index : < 1.5 (CR 39, ...
OPTICAL PLASTICS
PAST
Material : Polymethyl methacrylate (PMMA)
Applications : Spectacle lenses, Contact lenses,
Camera le...
PRESENT
Material : Modified acrylates and silicones,
Thiourethanes, polycarbonatyes
Applications :  Flexible intraocular ...
FUTURE
Material : Organic/ Inorganic hybrid materials,
Polymer composites
Applications : Lenses, Optical waveguides,
Optic...
Advantages Disadvantages
Light weight Soft surface
Impact resistance Limitation of refractive index
Good machineability Ul...
NANO MATERIALS : CROSS-SECTIONAL AND
INTERDISCIPLINARY APPROACH
Automotive
Components
Paper
Cosmetics
Textiles
Displays
Co...
TYPES OF NANO-
COMPOSITES FOR OPTICAL
APPLICATIONS
METAL-GLASS COMPOSITES
METAL-POLYMER COMPOSITES
 Areas of application ...
TYPES OF NANOCOMPOSITES
FOR OPTICAL APPLICATIONS
METAL-GLASS COMPOSITES
Incorporation of metal nanoparticles (Ag, Au) in g...
METAL-POLYMER COMPOSITES
Transparency is achieved
Substantial reduction in intensity loss which is size
dependent
Refracti...
METAL CONTAINING GLASS
Chronology Materials
Potable gold, Potable silver
Prepn. of colored glass by the
incorporation of p...
PRESENT
Materials : Preparation of dichroic films of
gelatin and Os, Rh, Ag, Au, P, Hg, As, S,
etc. Dichroic films of PVA-...
FUTURE OF METAL-CONTAINING
POLYMERS
NANOPARTICLE
Electronics
Multiuse
Chemical Industries
Defence
OpticsConsumers
Medical/...
As the scale goes down, the activity rises mainly due to the lowering distances at which the
interparticle interactions oc...
CHANGE OF PROPERTIES AT
THE NANOMETER SCALE
Chemical reactivity
Electronic properties
Optical properties (absorption, scat...
INCREASE IN SURFACE AREA
(at constant volume fraction)
1 µm 100 nm 10 nm
o. of particles 1 10
3
10
6
face Area
unit volume...
 Combination of two or more phases where at
least one phase is in nanometer range
TYPICAL MORPHOLOGIES
FEATURES OF NANOCOMPOSITES FOR
OPTICAL APPLICATIONS
 Particle size less than 50-100nm leads to less scattering of
light a...
WORK CARRIED OUT AT SRI
 Selection of suitable metal salts for dispersion
 Ba(OH)2, BaSO4, Ba(NO3)2, BaCl2,
 PbO, (CH3C...
 Characterization of cast lenses for various opto-
mechanical properties
 Colour
 Refractive index
 Abbe number
 Shor...
1.39
1.4
1.41
1.42
1.43
1.44
1.45
1.46
1.47
1.48
0 3 6 9 12 15 18 21 24
% age of metal salt
Refractiveindex
M-1
 M-2
♦ M-...
EFFECT OF CO-MONOMER 1 ON REFRACTIVE
INDEX OF METAL DISPERSED ACRYLIC PLASTICS
1.4
1.42
1.44
1.46
1.48
1.5
1.52
0 2 4 6 8 ...
1.38
1.4
1.42
1.44
1.46
1.48
1.5
1.52
1.54
1.56
0 2 4 6 8 10 15 20 25 30 35 40 45 50
%age of comonomer-2
Refractiveindex
E...
PROPERTIES OF GAMMA RADIATIATED
SAMPLES CO-MONOMER 1
 Dispersion of metal salts resulted in improved optical and mechanic...
0.1592
90
1.23
>120.0
Good
Pass
3H
---
Grade-B
88-90
38-39
1.5603
0.13920.1263Yellowness index14.
8987Spectral Transmittan...
STANDARD MATERIAL Vs METAL
CONTAINING SAMPLES
>2.02.03.0<1.01-2< 1.0Haze,%7.
>9092> 908990-9290-95Transmittance6.
1.20-1.3...
STANDARD MATERIAL Vs METAL
CONTAINING SAMPLES
0.12-1.20.022750.170.07860.00740.0087Yellowness
index
13.
0.5533-0.61520.584...
CONCLUSIONS
Materials can be designed for desired characteristics
Lenses have been cast successfully with barium ,lead
and...
FUTURE OF NANOTECHNOLOGY
Structure
sizes
2040 year1960 1980 2020Based on Bachmann, VDI
0.1 nm
0.1 µm
0.1 mm
Nano
Micro
Mac...
THANK YOU
of 41

Nano baroda

Published on: Mar 3, 2016
Published in: Education      Technology      Business      
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Transcripts - Nano baroda

  • 1. DR. R.K. KHANDAL DIRECTOR NANOCOMPOSITES FOR OPTICAL PLASTIC MATERIALS SHRIRAM INSTITUTE FOR INDUSTRIAL RESEARCH 19, UNIVERSITY ROAD, DELHI - 110007
  • 2. OUTLINE OF PRESENTATION OPTICAL APPLICATIONS OPTICAL PLASTICS NANO COMPOSITES METAL CONTAINING PLASTICS FUTURE OF NANO TECHNOLOGY  An overview presenting, past, present and future options in novel materials
  • 3. OPTICAL APPLICATIONS BIOMEDICALS ENGINEERING INSTRUMENTATION INFRA STRUCTURE OPHTHALMIC LENSES AUTOMOTIVE AVIATION SPACE RADIATION SHIELDING TELESCOPE BINOCCULAR CAMERA SENSORS OPTICS COMMUNICATION (Fibre Optics) SIGNALS (Railways, Aviation, Road, transport etc.) SHIELDING  Glass is the most conventional material used in all the above applications; Plastics are viable alternatives SPECTCLE CONTACT INTRAOCULAR
  • 4. BIO-MEDICAL APPLICATIONS Optical Devices Parameters Materials Used Spectacle lenses Refractive index, optical Glass, Polythiourethanes clarity, Abbe number, Polyacrylates, Polycarbonates Sun glasses Refractive index, UV- Glass, Polyacrylates resistance, aesthetics Contact lenses Refractive index, clarity, Polyacrylates and modified biocompatibility, softness/ acrylates, silicones and rigidity modified silicones Intraocular lenses Refractive index, Polyacrylates and modified transparency acrylates and silicones biocompatibility,  Glass has been completely replaced by plastics  Development of newer plastics is the key
  • 5. INSTRUMENTAL APPLICATIONS Optical Device Parameters Materials Used Binocular lenses Magnifying power, Glass, Polyacrylates, Refractive index, clarity Polycarbonates Telescopes lenses Magnifying power, Glass, Polyacrylates, Refractive index, clarity Polycarbonates Magnifying glass Magnifying power, Glass, Polyacrylates, Refractive index, clarity Polycarbonates  Tailoring of available materials for achieving varying refractive index Plastics  Plastics provide flexibility and options
  • 6. INFRASTRUCUTRE APPLICATIONS Optical Device Parameters Materials Used Optical waveguides Refractive index, Lithium niobate (LiNbO3), absorbance / Potassium titanyl transmittance phosphate (KTiOPO4) in polyacrylate Optical fibres Refractive index, Glass, Polyacrylates rate of light Metals transmission  Research is going on for alternate plastic materials for the above applications  Conventional materials would not have been adequate to meets the demand
  • 7. ENGINEERING APPLICATIONS Optical Device Parameters Materials Used Optical modulators Refractive index, Lithium niobate (LiNbO3), total internal reflection, Potassium titanyl phosphate infrared absorbance (KTiOPO4) Optical demodulators Refractive index, Lithium niobate (LiNbO3), total internal reflection, Potassium titanyl phosphate infrared absorbance (KTiOPO4) Optical interconnectors Refractive index, Lithium niobate (LiNbO3), total internal reflection, Potassium titanyl phosphate infrared absorbance (KTiOPO4) Liquid crystal dislays Refractive index, Glass, Polyacrylates (LCD) absorbance / transmittance  Use of plastic materials leads to the development of effective, less cumbersome technology
  • 8. GLOBAL STATUS : PLASTIC LENSES CHARACTERISTICS 800-850 million lenses per year ∈ 7-8 billion in sales Lens replacement frequency : 2-3 years  Indian requirement is met by imports only
  • 9. 10% 17% 33% 45% 55% 98% 0% 20% 40% 60% 80% 100% 120% Latin America United States Canada Western Europe Asia Pacific Japan Countries %asshareoftotallenses MARKET FOR ANTI-REFLECTING LENSES
  • 10. Lens market breakdown by material Plastic lenses, medium, high indexes (>1.5 index) 22% Plastic lenses <1.5 index 42% Glass lenses 36% MATERIALS USED : LENSES  Clear picture of the gaining popularity for optical plastics  Major plastics is polycarbonate
  • 11. INDIAN STATUS : LENSES 140 million pieces per year Export = 112 million pieces per year Domestic = 28 million pieces per year  Complete requirement is met by imports  Indigenous technologies are required for increase in Indian market demand  Optical plastic industry is engaged in job work
  • 12. DESIGN CRITERIA FOR OPTICAL PLASTICS Evaluation of the environment in which the plastic is to be used Physical and optical properties of the plastics Physical properties to be considered are density, hardness, rigidity Service temperature, thermal expansion, electrical and thermal conductivity
  • 13. CLASSIFICATION OF OPTICAL MATERIALS Gradient index materials : Glass & Polyacrylates Low Refractive Index : < 1.5 (CR 39, PMMA & Crown glass) Medium Refractive Index : 1.5-1.6 (Polycarbonates) High Refractive Index : > 1.6 (Polythiourethane) Infrared refractive materials : Fused silica and polycarbonates Ultra-violet refractive index : Fused silica, polycarbonates materials and Glass  Materials used are fused silica, polycarbonates and glass
  • 14. OPTICAL PLASTICS PAST Material : Polymethyl methacrylate (PMMA) Applications : Spectacle lenses, Contact lenses, Camera lenses, Binocular lenses Features : High rigidity leading to eye-discomfort in internal wear such as contact lenses. Poor aesthetics leading to bulge eye look. Poor shatter resistance leading to delicate handling  Availability of the right type of materials was a constraint
  • 15. PRESENT Material : Modified acrylates and silicones, Thiourethanes, polycarbonatyes Applications :  Flexible intraocular lenses,  Extended wear contact lenses  Contact lenses of variable wear Features :  Fixed optical properties  Easy to use  Economic  Better customer appeal OPTICAL PLASTICS  With newer materials, novel applications have become possible
  • 16. FUTURE Material : Organic/ Inorganic hybrid materials, Polymer composites Applications : Lenses, Optical waveguides, Optical fillers, Optical transmitters Features : Wide range of refractive index, Improved stability and hardness, Tailor-making of optical properties possible OPTICAL PLASTICS  Nano composites have a great potential for future
  • 17. Advantages Disadvantages Light weight Soft surface Impact resistance Limitation of refractive index Good machineability Ultra high & low refractive index not possible Good aesthetics Good processability  All the above disadvantages can be overcome by only nanocomposites OPTICAL PLASTICS  Nanocomposites can be designed
  • 18. NANO MATERIALS : CROSS-SECTIONAL AND INTERDISCIPLINARY APPROACH Automotive Components Paper Cosmetics Textiles Displays Coatings Emulsions Dispersions Plastics Films Powders Science Chemistry Physics Analytics Material Science Biology Applications End Products Materials/ Intermediates Nano- materials  Developing Nanomaterials is a challenge !
  • 19. TYPES OF NANO- COMPOSITES FOR OPTICAL APPLICATIONS METAL-GLASS COMPOSITES METAL-POLYMER COMPOSITES  Areas of application include sensors, wave guides, optical fibres, etc.  Complementary and synergistic compositions for extraordinary effect
  • 20. TYPES OF NANOCOMPOSITES FOR OPTICAL APPLICATIONS METAL-GLASS COMPOSITES Incorporation of metal nanoparticles (Ag, Au) in glass leading to colored glass Good absorption of incident light: negligible scattering Concept used since 15th century  Colloidal dispersions of metals in inorganics was an established way
  • 21. METAL-POLYMER COMPOSITES Transparency is achieved Substantial reduction in intensity loss which is size dependent Refractive index above 2.5 (ultra-high) and refractive index below 1.25 (ultra-low) is possible only with nanocomposites TYPES OF NANOCOMPOSITES FOR OPTICAL APPLICATIONS  A novel idea of imparting advantageous features of metals to plastics for better
  • 22. METAL CONTAINING GLASS Chronology Materials Potable gold, Potable silver Prepn. of colored glass by the incorporation of purple, violet, brown or black colloidal powders Use of colloidal gold powders for the painting of enamel Detailed analysis of color of gold colloids Formation of ruby glass using gold particles Coloured glass with unique features 15th Century 16th Century 17th Century 18th Century 19th Century 20th Century
  • 23. PRESENT Materials : Preparation of dichroic films of gelatin and Os, Rh, Ag, Au, P, Hg, As, S, etc. Dichroic films of PVA-Au, Ag & Hg Silver add crystallites in ramie, hemp, bamboo, silk, wool, viscose, (5-14nm) Applications : Eye-wear lenses, cameras, binoculars, sensors, solar applications, filters, transmitters, wave guides, reflectors, etc. METAL CONTAINING POLYMERS  Metal containing polymers are a novel idea !
  • 24. FUTURE OF METAL-CONTAINING POLYMERS NANOPARTICLE Electronics Multiuse Chemical Industries Defence OpticsConsumers Medical/Biology Solar Cells Sensors Electrocatalysis Photocatalysis  For any application, nanotechnology is a blend of the science of physics, chemistry and biology  Field of optics has seen a lot success with nanotechnology; coatings and diagnostics
  • 25. As the scale goes down, the activity rises mainly due to the lowering distances at which the interparticle interactions occur leading to evolution of energy. Emulsion High surface energy, Non-homogeneous, unstable Thermodynamically Extremely High Irreversible System Scale Activity Remarks Mixtures >micrometer Low Suspension Dispersion micrometer Medium kinetically stable unstable Microemulsion Solubilised nanometer Moderately High stability probable Thermodynamic Macromolecular angstrom High Molecular Atomic Very High Nuclear Spontaneous atomic sub-atomic Thermodynamically stable Basis for new materials Source of energy SIZE - DEPENDENT PROPERTIES OF MATERIALS
  • 26. CHANGE OF PROPERTIES AT THE NANOMETER SCALE Chemical reactivity Electronic properties Optical properties (absorption, scattering) Mechanical properties (hardness) Transport properties (heat, current) Bioavailability In addition to quantum effects, the increased surface-volume ratio at the nanometer scale bring improvements in ;  Nanomaterials have extraordinary features
  • 27. INCREASE IN SURFACE AREA (at constant volume fraction) 1 µm 100 nm 10 nm o. of particles 1 10 3 10 6 face Area unit volume 1X 10X 100X Decreasing Particle Size
  • 28.  Combination of two or more phases where at least one phase is in nanometer range TYPICAL MORPHOLOGIES
  • 29. FEATURES OF NANOCOMPOSITES FOR OPTICAL APPLICATIONS  Particle size less than 50-100nm leads to less scattering of light and therefore improves transparency  By incorporation of inorganic colloids with extreme refractive index in organic polymers ultra high refractive is possible  High surface to volume ratio improves reduces scattering losses  Drawbacks of plastics can be eliminated  Tailor-making of refractive index possible
  • 30. WORK CARRIED OUT AT SRI  Selection of suitable metal salts for dispersion  Ba(OH)2, BaSO4, Ba(NO3)2, BaCl2,  PbO, (CH3COO)2Pb, PbNO3,  LaCl3, La2O3, La(NO3)3,  TiO2  Nb2O3, NbC  Acrylic acid as monomer  Selection of polymerization technique Thermal, Gamma Selection of suitable initiator for thermal polymerization Benzoyl peroxide, Azo bis-isobutyronitile (AIBN)  Selection of suitable dose for polymerization by Gamma radiation  Casting of lenses  Eight patents on the product & process
  • 31.  Characterization of cast lenses for various opto- mechanical properties  Colour  Refractive index  Abbe number  Shore-D hardness  Scratch resistance  Haze  Pencil hardness  Impact resistance  Machinability  Heat distortion (° C)  Specific gravity  Transmittance (%)  Yellowness index  LAB value
  • 32. 1.39 1.4 1.41 1.42 1.43 1.44 1.45 1.46 1.47 1.48 0 3 6 9 12 15 18 21 24 % age of metal salt Refractiveindex M-1  M-2 ♦ M-3 EFFECT OF METAL SALTS ON REFRACTIVE INDEX OF ACRYLIC PLASTICS  Metal salts are effective in improving the refractive index of acrylic plastics
  • 33. EFFECT OF CO-MONOMER 1 ON REFRACTIVE INDEX OF METAL DISPERSED ACRYLIC PLASTICS 1.4 1.42 1.44 1.46 1.48 1.5 1.52 0 2 4 6 8 10 12 14 %age of comonomer-1 Refractiveindex  Significant increase in refractive index of acrylic plastic is obtained with co-monomer 1 ♦ M-1  M-2 M-3
  • 34. 1.38 1.4 1.42 1.44 1.46 1.48 1.5 1.52 1.54 1.56 0 2 4 6 8 10 15 20 25 30 35 40 45 50 %age of comonomer-2 Refractiveindex EFFECT OF CO-MONOMER 2 ON REFRACTIVE INDEX OF METAL DISPERSED ACRYLIC PLASTIC ♦ M-1  M-2 M-3  Significant increase in refractive index of acrylic plastic is obtained with co-monomer 2
  • 35. PROPERTIES OF GAMMA RADIATIATED SAMPLES CO-MONOMER 1  Dispersion of metal salts resulted in improved optical and mechanical properties of polyacylates 1.1581.2181.044Yellowness index14. 858287Spectral Transmittance (%)12. 1.281.301.31Specific gravity11. >120>120120.0Heat distortion (0C)10. GoodGoodGoodMachinability9. PassPassPassImpact resistance8. 4H3H3HPencil hardness7. 6.80-7.0710.7-10.88.24-8.29Haze6. Grade-BGrade-BGrade-BScratch resistance5. 78-8070-7570-72Shore-D hardness4. 343435Abbe No.3. 1.581.591.56Refractive index2. Light YellowDark YellowLight YellowColour1. M-1 M-2 M-3 Metal dispersed polyacrylateAnalysisS. No. 13. Integrated transmittance 0.5563 0.5575 0.5679
  • 36. 0.1592 90 1.23 >120.0 Good Pass 3H --- Grade-B 88-90 38-39 1.5603 0.13920.1263Yellowness index14. 8987Spectral Transmittance (%)12. 1.291.24Specific gravity11. 130>120.0Heat distortion (0 C)10. GoodGoodMachinability9. PassPassImpact resistance8. 3H3HPencil hardness7. ---2.75-2.84Haze6. Grade-BGrade-BScratch resistance5. 80-8285-88Shore-D hardness4. 30-3134Abbe No.3. 1.5741.570Refractive index2. colourlesscolourlessLight yellowColour1. M-1 M-2 M-3 Metal dispersed polyacrylateAnalysisS. No. 13. Integral Transmittance 0.5933 0.5822 0.7795 PROPERTIES OF GAMMA RADIATIATED SAMPLES CO-MONOMER 2
  • 37. STANDARD MATERIAL Vs METAL CONTAINING SAMPLES >2.02.03.0<1.01-2< 1.0Haze,%7. >9092> 908990-9290-95Transmittance6. 1.20-1.301.241.331.201.322.0-5.0Specific gravity5. GoodPoorModerateModerateGoodPoorImpact resistance 4. >85< 65>757588-89>90Shore-D Hardness 3. 35-385726355850-55Abbe number2. 1.56-1.591.451.661.581.491.80Refractive index1. PA (SRI) PAPTU (SRI) PCCR-39GlassPropertiesS.No  Modified polyacrylates can be a good replacement to the conventional optical materials
  • 38. STANDARD MATERIAL Vs METAL CONTAINING SAMPLES 0.12-1.20.022750.170.07860.00740.0087Yellowness index 13. 0.5533-0.61520.58450.58580.59060.57911.1548Integrated Transmittance 12. GoodGoodGoodGoodGoodGoodMachinability11. 3H-4H3H6H3H4H>6HPencil hardness 10. Grade-BGrade-DGrade-BGrade-BGrade-BGrade-AScratch resistance 9. L=51.38-77.05 a=-6.25-7.50 b = 23.7-25.50 L=67.50 a=6.30 b=20.30 L=67.90, a = 5.50, b = 23.2 L=67.68, a = 6.15, b = 21.8 L=67.44, a = 6.35, b=20.32 L=67.46, a = 6.35, b=20.48 LAB value8. PA (SRI) PAPTU (SRI) PCCR-39GlassPropertiesS.No  Modified polyacrylates can be a good replacement to the conventional optical materials
  • 39. CONCLUSIONS Materials can be designed for desired characteristics Lenses have been cast successfully with barium ,lead and lanthanum salts. Tailor making of refractive index of polyacrylates have been achieved between 1.550-1.575 using barium salts; 1.560-1.595 using lead salts; 1.550-1.565 using lanthanum salts. SRI team has been successful in developing metal dispersed nano-composites of polyacrylate with improved Abbe no., hardness, & scratch resistance.
  • 40. FUTURE OF NANOTECHNOLOGY Structure sizes 2040 year1960 1980 2020Based on Bachmann, VDI 0.1 nm 0.1 µm 0.1 mm Nano Micro Macro Integrated use of biological principles, physical laws and chemical know-howComplex chemistry Electrical engin. Electronics Micro-electronics Material design Supramolecular chemistry Quantum effects Cell biology Molecular biology Functional molecule design Applications of nano- technology bottom upbottom up  top down top down  Chemistry Coatings, cleaning agents, composite materials, textiles, cosmetics, displays Physics Biology
  • 41. THANK YOU