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Dr.CK_Unit- 1_Adv.Nano.pdf

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Karthikeyan Chelladurai

The document discusses advanced nanomaterials and their applications. It begins by defining the nanoscale as structures between 1-100 nanometers. It then discusses various types of nanocrystals from 0-dimensional to 3-dimensional. Metal nanoparticles are discussed in detail, including their synthesis methods and applications in catalysis, computing, photovoltaics, and biology. The document emphasizes that nanoparticles have unique properties compared to bulk materials due to their high surface area to volume ratio and quantum confinement effects.

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Advanced Nanomaterials and Their Applications Dr.C. Karthikeyan Dept. of Energy Science Alagappa University, Karaikudi CK 1
Content Significance of nanoscale Surface area, quantum confinement effect, penetration of a barrier Tunnel effect. Types of nanocrystals Zero dimensional One dimensional Two dimensional Three dimensional nanostructured materials Metals Semiconductors Ceramics Composites Size dependent properties Mechanical, physical and chemical Uniqueness in these properties compared to bulk and microscopic materials. CK 2
UNIT-I: INTRODUCTION The nanoscopic scale (or nanoscale) usually refers to structures with a length scale usually cited as 1100 nanometers (nm). A nanometer is a billionth of a meter. CK 3
CK 4
Mouse scan circulation by radiolabeled nanoparticle Molecular machine- nanotechnology CK 5
Nano scale materials often have very different properties from bulk materials Ex: Colour and reactivity Particle at nanometre size CK 6
At least one dimension (height, length or depth) is less than 100 nm Less than 100 nm thick, called nano film CK 7
CK 8
Natural nanomaterials Peacock feather Viral Capsid Lotus effect Brazilian Crystal Opal SEM micrograph of a butterfly wing CK 9
Unique Characteristics of Nanoparticles Large surface to volume ratio High percentage of atoms/molecules on the surface Surface forces are very important, while bulk forces are not as important. Metal nanoparticles have unique light scattering properties and exhibit plasmon resonance. Semiconductor nanoparticles may exhibit confined energy states in their electronic band structure (e.g., quantum dots) Can have unique chemical and physical properties Same size scale as many biological structures CK 10
Nanoparticles Synthesis Methods Physical processing methods Physical and chemical processing methods Top-Down: Start with bulk material and cut away materials to make Nanoparticles Bottom-Up: Building the materials to Nanoparticles. Atom by atom, molecule by molecule or cluster by cluster CK 11
CK 12
CK 13
CK 14
Significance of Nanoscale: The quantum mechanical properties of the particles influence at the nanoscale By nanoscale design it is possible to vary micro and macroscopic properties such as charge capacity, magnetization, melting temperature without changing their chemical composition. Creation of new improved products. Availability of stronger, tougher and lighter materials for construction and engineering. Nanoscale components have high surface area to volume ratio making them idle for the use in composite materials, drug delivery and chemical storage. CK 15
Significance of Nanoscale Nanosized metallic powders have been used for the production of the gas tight materials and porous coatings. Nanostructured metal clusters and colloids are used in the special catalytic applications. Nanostructured metal oxide films are used even as the gas sensors. Nanostructured metal oxide finds applications in rechargeable batteries for cars and consumer goods CK 16
Significance of Nanoscale: Sophisticated health treatment by using the nano particles in the drug delivery. Cheaper and cleaner energy production. Nanophase ceramics which are very ductile a elevated temperatures as compared to the normal ones. Nanostructured semiconductors are used as window layers in solar cells. Cleaner drinking water due to the creation of filters (made by nano) that can entrap organisms and toxins. Cleaner environment by removal of pollutants from the environment. CK 17
Significance of Nanoscale Composite made by nanoparticle become more stronger (ie: grain size (10 nm) 7 times harder and tougher than grain size (100 nm) Large surface area Chemically more active Properties change at nanoscale CK 18
Significance of Nanoscale- Surface area Generally, surface area to volume ratio has a significant effect on the properties of the material Firstly, materials made up of nanoparticles have a relative larger surface area when compared to the same volume of material made up of bigger particles (bulk). What is surface area to volume ratio? Amount of surface area or total exposed area of a body relative to its volume or size. CK 19
Significance of Nanoscale- Surface area Nanoparticles shows different properties compared to large particles of the same materials. Force of attraction is weak in large scale but in nanoscale are strong In nanoparticle surface to volume ratio is large Generally, atom in the surface more reactive than centre, so large surface area means the materials is more active. CK 20
Colour change at nanoscale Cu- transparent at nano scale Au nanosphere (50 nm) green in colour Au (100 nm) Orange in colour Au Bulk yellow CK 21
CK 22
Quantum confinement effects Quantum confinement effects describe electrons in terms of energy levels, potential wells, valence bands, conduction bands, and electron energy band gaps. The quantum confinement effect is observed when the size of the particle is too small to be comparable to the wavelength of the electron potential well is region surrounding a local minimum of potential energy. CK 23
The synthesis of nanomaterials, including 1. Top-down and 2. Bottom-up approaches, CK 24
Types of nanocrystals What do you mean by nanocrystals? Nanocrystals are aggregates of atoms that combine into a cluster (less than 1 亮m in size). particle having at least one dimension smaller than 100 nanometres Typical sizes range between 10 and 400 nm. Have unique physical and chemical properties than bulk solids and molecules. They play an important role in the fabrication of many devices and modified materials because of their unique physical and chemical properties, such as a large surface-area-to- volume ratio, and their high mechanical strength CK 25
Nanoparticles CK 26
Types of nanocrystals Nanomaterials can be categorized into four types such as: (1) inorganic-based nanomaterials; - different metal and metal oxide nanomaterials. (2) carbon-based nanomaterials; - Fullerenes, carbon nanotubes, graphene and its derivatives, graphene oxide, nanodiamonds, and carbon-based quantum dots. (3) organic-based nanomaterials; - liposomes, micelles, and polymer nanoparticles, (4) composite-based nanomaterials. (nanomaterials with composite structure) - nanofibers, nanorods, nanoparticles, and carbon nanotubes. CK 27
Nanocrystals in drug delivery systems CK 28
CK 29
CK 30
Quantum dot Quantum dot is nanocrystals 2 to 10 nm Made by Semiconductor It is also called fluorescent semiconductor nanocrystals, once it excited with UV light, they emit particular fluorescent colour, depending on the dots size Have unique optical and electronic properties that differ from bulk Ex: CdSe, PbSe, PbTe CK 31
CK 32
Computing Q-LED Photovoltaics devices increase efficiency made by simple chemical method Solar cells Cancer cell imageing CK 33
https://www.youtube.com/watch?v=S-SOEBTplOM CK 35
0D, 1D, 2D and 3D According to dimensions, 0 D nanoparticle 1 D- nanotube, nanorods 2D-Nanothinfilm, nanocoating, nanolayers 3D- nanoprisms, nanoflowers CK 36
0D: All the dimensions in nanoscale, no dimension other than nano Ex: Quantum dot, nanoparticle, nanocluster, nanodots 1D: One dimension larger than nano Major growth in one dimension & growth is limited other 2 dimensions. Ex: nanowire, nanorod, CNT CK 37
2D: Two dimension larger than nano Plat-like shape Ex: graphene, nanofilms, nanoplates, nanonetworks 3D: Not confined nanoscale in any dimensions All the 3 dimensions larger than nano Major growth in all the 3 dimensions More complicated structure Ex: Graphite, Diamond, nanocomposite bundle of nanowires CK 38
CK 39
METAL NANOPARTICLE The term metal nanoparticle is used to described nanosized metals with dimensions (length, width or thickness) within the size range 1100 nm. The existence of metallic nanoparticles in solution was first recognized by Faraday in 1857 and a quantitative explanation of their colour was given by Mie in 1908. Usually: Au, Ag, Cu, Pt, Pd, Ru, Re - but: Fe, Ni.. (very reactive, very explosive) CK 40
CK 43
Metallic Nanoparticles Synthesis Ideally, metallic nanoparticles should be prepared by a method which: reproducible May control the shape of the particles Yields monodisperse metallic nanoparticles easy, cheap Use less toxic precursors: in water or more environmentally benign solvents (e.G. Ethanol) Use the least number of reagents Use a reaction temperature close to room temperature With as few synthetic steps as possible (onepot reaction) Minimizing the quantities of generated byproducts and waste. CK 44
Influence of reducing reagents CK 45
Influence of reducing reagents Sodium citrate Citric acid SEM- Gold nanoparticles CK 46
TEM- Gold nanoparticles various pH range a) 4.0 b) 4.5 c) 5.0 d) 5.5 e) 6.0 f) 6.5 CK 47
CK 48
CK 49
In Catalysis: Catalysts based on metal NPs are: Highly active Selective Exhibit long lifetime for several kind of reactions Applications of homogenous catalysts: Olefin hydrogenation Nitrile hydrogenation Photoinduced electron transfer Applications of heterogeneous catalysts: Oxidation reactions Hydrogenation Hydrodechlorination Synthesis of H2O2 Water gas shift Colloidal Pt/Ru catalysts are used in direct methanol fuel cells DMFCs Uniform metal nanoparticles used to design of new supercomputers having a superior data storage capacity Nickel NPs are used as magnetic recording medium, electrical conductive pastes, battery materials, etc. Applications of Metal Nanoparticles CK 51
Applications of Metal Nanoparticles Biological Applications Magnetic nanoparticles used as For binding BSA (Bovine Serum Albumin) For drug delivery For biosensing For bioseparations Sensors 1. Electrochemical sensors the introduction of metal NPs (mostly supported) on the electrode can: decrease the overpotentials of many electrochemical reactions turn into reversible some redox reactions that are normally irreversible in conventional unmodified electrodes Examples: sensitive NO, H2O2and sugar and amino sacid sensors 2. Biosensors: can enhance the electron transfer between biomolecules Ag NPs supported on glass used as selective biosensors for the biotinstreptavidin system Photocatalysis (Ag Nps) water splitting degradation of organic pollutants Biology and Medicine:Ag is a highly antimicrobial material used in: water purification wound care medical devices drog delivery CK 52

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Dr.CK_Unit- 1_Adv.Nano.pdf

  • 1. Advanced Nanomaterials and Their Applications Dr.C. Karthikeyan Dept. of Energy Science Alagappa University, Karaikudi CK 1
  • 2. Content Significance of nanoscale Surface area, quantum confinement effect, penetration of a barrier Tunnel effect. Types of nanocrystals Zero dimensional One dimensional Two dimensional Three dimensional nanostructured materials Metals Semiconductors Ceramics Composites Size dependent properties Mechanical, physical and chemical Uniqueness in these properties compared to bulk and microscopic materials. CK 2
  • 3. UNIT-I: INTRODUCTION The nanoscopic scale (or nanoscale) usually refers to structures with a length scale usually cited as 1100 nanometers (nm). A nanometer is a billionth of a meter. CK 3
  • 5. Mouse scan circulation by radiolabeled nanoparticle Molecular machine- nanotechnology CK 5
  • 6. Nano scale materials often have very different properties from bulk materials Ex: Colour and reactivity Particle at nanometre size CK 6
  • 7. At least one dimension (height, length or depth) is less than 100 nm Less than 100 nm thick, called nano film CK 7
  • 9. Natural nanomaterials Peacock feather Viral Capsid Lotus effect Brazilian Crystal Opal SEM micrograph of a butterfly wing CK 9
  • 10. Unique Characteristics of Nanoparticles Large surface to volume ratio High percentage of atoms/molecules on the surface Surface forces are very important, while bulk forces are not as important. Metal nanoparticles have unique light scattering properties and exhibit plasmon resonance. Semiconductor nanoparticles may exhibit confined energy states in their electronic band structure (e.g., quantum dots) Can have unique chemical and physical properties Same size scale as many biological structures CK 10
  • 11. Nanoparticles Synthesis Methods Physical processing methods Physical and chemical processing methods Top-Down: Start with bulk material and cut away materials to make Nanoparticles Bottom-Up: Building the materials to Nanoparticles. Atom by atom, molecule by molecule or cluster by cluster CK 11
  • 12. CK 12
  • 13. CK 13
  • 14. CK 14
  • 15. Significance of Nanoscale: The quantum mechanical properties of the particles influence at the nanoscale By nanoscale design it is possible to vary micro and macroscopic properties such as charge capacity, magnetization, melting temperature without changing their chemical composition. Creation of new improved products. Availability of stronger, tougher and lighter materials for construction and engineering. Nanoscale components have high surface area to volume ratio making them idle for the use in composite materials, drug delivery and chemical storage. CK 15
  • 16. Significance of Nanoscale Nanosized metallic powders have been used for the production of the gas tight materials and porous coatings. Nanostructured metal clusters and colloids are used in the special catalytic applications. Nanostructured metal oxide films are used even as the gas sensors. Nanostructured metal oxide finds applications in rechargeable batteries for cars and consumer goods CK 16
  • 17. Significance of Nanoscale: Sophisticated health treatment by using the nano particles in the drug delivery. Cheaper and cleaner energy production. Nanophase ceramics which are very ductile a elevated temperatures as compared to the normal ones. Nanostructured semiconductors are used as window layers in solar cells. Cleaner drinking water due to the creation of filters (made by nano) that can entrap organisms and toxins. Cleaner environment by removal of pollutants from the environment. CK 17
  • 18. Significance of Nanoscale Composite made by nanoparticle become more stronger (ie: grain size (10 nm) 7 times harder and tougher than grain size (100 nm) Large surface area Chemically more active Properties change at nanoscale CK 18
  • 19. Significance of Nanoscale- Surface area Generally, surface area to volume ratio has a significant effect on the properties of the material Firstly, materials made up of nanoparticles have a relative larger surface area when compared to the same volume of material made up of bigger particles (bulk). What is surface area to volume ratio? Amount of surface area or total exposed area of a body relative to its volume or size. CK 19
  • 20. Significance of Nanoscale- Surface area Nanoparticles shows different properties compared to large particles of the same materials. Force of attraction is weak in large scale but in nanoscale are strong In nanoparticle surface to volume ratio is large Generally, atom in the surface more reactive than centre, so large surface area means the materials is more active. CK 20
  • 21. Colour change at nanoscale Cu- transparent at nano scale Au nanosphere (50 nm) green in colour Au (100 nm) Orange in colour Au Bulk yellow CK 21
  • 22. CK 22
  • 23. Quantum confinement effects Quantum confinement effects describe electrons in terms of energy levels, potential wells, valence bands, conduction bands, and electron energy band gaps. The quantum confinement effect is observed when the size of the particle is too small to be comparable to the wavelength of the electron potential well is region surrounding a local minimum of potential energy. CK 23
  • 24. The synthesis of nanomaterials, including 1. Top-down and 2. Bottom-up approaches, CK 24
  • 25. Types of nanocrystals What do you mean by nanocrystals? Nanocrystals are aggregates of atoms that combine into a cluster (less than 1 亮m in size). particle having at least one dimension smaller than 100 nanometres Typical sizes range between 10 and 400 nm. Have unique physical and chemical properties than bulk solids and molecules. They play an important role in the fabrication of many devices and modified materials because of their unique physical and chemical properties, such as a large surface-area-to- volume ratio, and their high mechanical strength CK 25
  • 27. Types of nanocrystals Nanomaterials can be categorized into four types such as: (1) inorganic-based nanomaterials; - different metal and metal oxide nanomaterials. (2) carbon-based nanomaterials; - Fullerenes, carbon nanotubes, graphene and its derivatives, graphene oxide, nanodiamonds, and carbon-based quantum dots. (3) organic-based nanomaterials; - liposomes, micelles, and polymer nanoparticles, (4) composite-based nanomaterials. (nanomaterials with composite structure) - nanofibers, nanorods, nanoparticles, and carbon nanotubes. CK 27
  • 28. Nanocrystals in drug delivery systems CK 28
  • 29. CK 29
  • 30. CK 30
  • 31. Quantum dot Quantum dot is nanocrystals 2 to 10 nm Made by Semiconductor It is also called fluorescent semiconductor nanocrystals, once it excited with UV light, they emit particular fluorescent colour, depending on the dots size Have unique optical and electronic properties that differ from bulk Ex: CdSe, PbSe, PbTe CK 31
  • 32. CK 32
  • 33. Computing Q-LED Photovoltaics devices increase efficiency made by simple chemical method Solar cells Cancer cell imageing CK 33
  • 35. 0D, 1D, 2D and 3D According to dimensions, 0 D nanoparticle 1 D- nanotube, nanorods 2D-Nanothinfilm, nanocoating, nanolayers 3D- nanoprisms, nanoflowers CK 36
  • 36. 0D: All the dimensions in nanoscale, no dimension other than nano Ex: Quantum dot, nanoparticle, nanocluster, nanodots 1D: One dimension larger than nano Major growth in one dimension & growth is limited other 2 dimensions. Ex: nanowire, nanorod, CNT CK 37
  • 37. 2D: Two dimension larger than nano Plat-like shape Ex: graphene, nanofilms, nanoplates, nanonetworks 3D: Not confined nanoscale in any dimensions All the 3 dimensions larger than nano Major growth in all the 3 dimensions More complicated structure Ex: Graphite, Diamond, nanocomposite bundle of nanowires CK 38
  • 38. CK 39
  • 39. METAL NANOPARTICLE The term metal nanoparticle is used to described nanosized metals with dimensions (length, width or thickness) within the size range 1100 nm. The existence of metallic nanoparticles in solution was first recognized by Faraday in 1857 and a quantitative explanation of their colour was given by Mie in 1908. Usually: Au, Ag, Cu, Pt, Pd, Ru, Re - but: Fe, Ni.. (very reactive, very explosive) CK 40
  • 40. CK 43
  • 41. Metallic Nanoparticles Synthesis Ideally, metallic nanoparticles should be prepared by a method which: reproducible May control the shape of the particles Yields monodisperse metallic nanoparticles easy, cheap Use less toxic precursors: in water or more environmentally benign solvents (e.G. Ethanol) Use the least number of reagents Use a reaction temperature close to room temperature With as few synthetic steps as possible (onepot reaction) Minimizing the quantities of generated byproducts and waste. CK 44
  • 42. Influence of reducing reagents CK 45
  • 43. Influence of reducing reagents Sodium citrate Citric acid SEM- Gold nanoparticles CK 46
  • 44. TEM- Gold nanoparticles various pH range a) 4.0 b) 4.5 c) 5.0 d) 5.5 e) 6.0 f) 6.5 CK 47
  • 45. CK 48
  • 46. CK 49
  • 47. In Catalysis: Catalysts based on metal NPs are: Highly active Selective Exhibit long lifetime for several kind of reactions Applications of homogenous catalysts: Olefin hydrogenation Nitrile hydrogenation Photoinduced electron transfer Applications of heterogeneous catalysts: Oxidation reactions Hydrogenation Hydrodechlorination Synthesis of H2O2 Water gas shift Colloidal Pt/Ru catalysts are used in direct methanol fuel cells DMFCs Uniform metal nanoparticles used to design of new supercomputers having a superior data storage capacity Nickel NPs are used as magnetic recording medium, electrical conductive pastes, battery materials, etc. Applications of Metal Nanoparticles CK 51
  • 48. Applications of Metal Nanoparticles Biological Applications Magnetic nanoparticles used as For binding BSA (Bovine Serum Albumin) For drug delivery For biosensing For bioseparations Sensors 1. Electrochemical sensors the introduction of metal NPs (mostly supported) on the electrode can: decrease the overpotentials of many electrochemical reactions turn into reversible some redox reactions that are normally irreversible in conventional unmodified electrodes Examples: sensitive NO, H2O2and sugar and amino sacid sensors 2. Biosensors: can enhance the electron transfer between biomolecules Ag NPs supported on glass used as selective biosensors for the biotinstreptavidin system Photocatalysis (Ag Nps) water splitting degradation of organic pollutants Biology and Medicine:Ag is a highly antimicrobial material used in: water purification wound care medical devices drog delivery CK 52