Nano Materials Flashcards
Nanomaterials are the materials with at least one dimension measuring less than ___________
a) 1 nm
b) 10 nm
c) 100 nm
d) 1000 nm
100 nm
A material with one dimension in Nano range and the other two dimensions are large is called ___________
a) Micro-material
b) Quantum wire
c) Quantum well
d) Quantum dot
Quantum well
A material with two of the three dimensions in the nano range and third large is called quantum wire. When all the dimensions are in nano range, it is called quantum dot.
The colour of the nano gold particles is ___________
a) Yellow
b) Orange
c) Red
d) Variable
Variable
The colour of the nano gold particle varies with the size of the particles. It shows different colours like orange, red, purple, or greenish.
The melting point of particles in nano form ___________
a) Increases
b) Decreases
c) Remains same
d) Increases then decreases
Decreases
For the particles in the nano form, the melting point reduces significantly. Other chemical properties are also changed as the dimensions of the object comes in the nano range.
The first talk about nano-technology was given by ___________
a) Albert Einstein
b) Newton
c) Gordon E. Moore
d) Richard Feynman
Richard Feynman
In 1959, Richer Feynman gave a speech in which he spoke of nano-science and nano-technology. He talked about the possibility of manipulating individual atoms and molecules.
Which of the processes of materials was not described as Nanotechnology?
a) Separation
b) Creation
c) Processing
d) Consolidation
Creation
Nanotechnology, as defined by Professor N. Taniguchi, consists of the processing, separation, consolidation and deformation of materials by one atom or by one molecule. It is used exclusively for the nanomaterials.
The initial tools used to help launch the nanoscience revolution were ___________
a) Binoculars
b) Microscope
c) Scanning probe instruments
d) Interferometer
Scanning probe instruments
In these instruments, the probe slides along the surface of the specimen.
When semiconductors are reduced to nanometres they become pure conductors.
a) True
b) False
False
When semiconductors are reduced to the nano form their chemical properties change significantly and they become insulators, as there is no more space for free electrons to move.
The major difference between the nano materials compared to the bulk form is the big fraction of the total number of atoms on the surface.
a) True
b) False
True
As the bulk material is changed into nano form, the number of atoms on the surface turns out to be a large fraction of the total number of atoms present in the material. Due to this, the whole physical/chemical properties of the material changes.
The size of atoms is nearly ____________
a) 0.01 nm
b) 0.1 nm
c) 1 nm
d) 10 nm
0.1 nm
What’s the procedure in Top-down fabrication method?
a) Nano-particles -> Powder -> Bulk
b) Powder -> Bulk – > Nano-particles
c) Bulk -> Powder – > Nano-particles
d) Nano-particle – > Bulk -> Powder
Bulk -> Powder – > Nano-particles
In the bottom-up approach, the atoms are joined to form nano-particles.
Which of the following is an example of Bottom Up approach?
a) Attrition
b) Colloidal dispersion
c) Milling
d) Etching
Colloidal dispersion
Attrition, milling and etching are typical top down methods.
For milling operations, what kind of environment is preferred?
a) Acidic
b) Basic
c) Active
d) Inert
Inert
Milling is the process of particle size reduction with the objective of mixing or blending and change of particle size. An inert environment is preferred for this process.
What kind of metals are used for milling operations?
a) Soft and brittle
b) Soft and elastic
c) Hard and brittle
d) Hard and elastic
Hard and brittle
The water is prepared and then photoresist is applied. The product is exposed to the UV light which after a series of processes, results in the fabrication of nanomaterials.
What is the above method called
Microfabrication
CVD stands for ____________
a) Carbon vapour density
b) Chemical vapour density
c) Chemical vapour deposition
d) Carbon vapour deposition
Chemical vapour deposition
CVD, is a chemical process used to produce high-purity, high-performance solid materials. The process is often used to produce carbon nanotubes.
Photolithography is a type of patterning technique.
a) True
b) False
True
Chemical solution deposition is also known as ____________
a) Sol-gel
b) CVD
c) Plasma spraying
d) Laser pyrolysis
Sol-gel
Sol-gel, or chemical solution deposition, is used primarily for the fabrication of material starting from a chemical solution that acts as the precursor for an integrated network.
Typical precursor used in sol-gel are ____________
a) Metal oxides
b) Metal dioxides
c) Metal alkoxides
d) Metal fluorides
Metal alkoxides
Metal alkoxides and metal chlorides are basically used as precursors in sol-gel. Furthermore, a colloidal suspension is formed when they undergo hydrolysis or poly-condensation.
Particles of ZrO2, Y2O2 and Nano whiskers have been produced by __________
a) Sol-gel
b) CVC
c) Plasma spraying
d) Laser pyrolysis
CVC
CVC stands for chemical vapour condensation. It involves pyrolysis of vapours of metal organic precursors in a reduced pressure atmosphere.
Which gas serves as buffer gas in Laser ablation?
a) Nitrogen
b) Oxygen
c) Helium
d) Neon
Helium
Laser ablation has been extensively used for the preparation of nanoparticles. In the device, there is a pulsed flow of Helium gas. It serves as a buffer gas in which clusters of the target material form, thermalize.
- The configuration of Buckminsterfullerene is ____________
a) 12 Hexagons and 22 Pentagons
b) 18 Hexagons and 15 Pentagon
c) 20 Hexagon and 12 Pentagon
d) 15 Hexagon and 15 Pentagon
20 Hexagon and 12 Pentagon
C60 is soluble in ____________
a) Water
b) Ammonia
c) HCl
d) Benzene
Benzene
C60 molecules are held together by weak Van der Waal’s forces. They are insoluble in ionic solvents like water, ammonia and HCl, as it is non-ionic. As it is an organic molecule, it is soluble in Benzene.
CNTs are capped on both ends with which carbon nanostructure?
a) Graphite
b) Diamond
c) C60
d) Benzene
C60
Carbon Nanotubes are basically a single sheet of graphite, which is rolled into a tube. The ends of the CNTs are covered by the C60 hemispheres.
For the synthesis of CNTs, the quartz tube is heated up to ____________
a) 1000℃
b) 1200℃
c) 1400℃
d) 1600℃
1200℃
For the synthesis of CNTs, a quartz tube containing argon gas and a graphite target are heated to 1200o C. This process takes place by the use of lasers.
The metallic tubes have which kind of structure?
a) Armchair
b) Chiral
c) Boat
d) Achiral
Armchair
The CNTs are often a mixture of semiconducting and metallic tubes. While the metallic tubes have armchair structure, the semiconducting tubes have a chiral structure.
The carbon tubes have high conductivity.
a) True
b) False
True
The reason for the high conductivity of the carbon nanotubes is that they have very few defects to scatter electrons and therefore show very low resistance.
Carbon nanotubes display magnetoresistance at low temperature.
a) True
b) False
True
Magnetoresistance is the phenomenon in which the resistance of a material changes on the application of a magnetic field. Carbon nanotubes display this property at low temperature. In fact, it shows negative magnetoresistance as the resistance decreases with an increasing magnetic field.
The main purpose of CNTs in fuel cells is ___________
a) Production of energy
b) Active medium
c) Catalyst
d) Storage
Storage
Carbon nanotubes are useful in fuel cells as well as in batteries, primarily for storage purposes of hydrogen. The tubes need to hold 6.5% hydrogen by weight.
Carbon nanotubes are poor transmitters of electromagnetic radiations due to their ____________
a) High conductivity
b) Large surface area
c) High porosity
d) Chemical Stability
High conductivity
Carbon nanotubes have very high electrical conductivity. Due to this, they are poor transmitters of electromagnetic radiations. A plastic composite of CNTs could provide lightweight shielding material for electromagnetic radiation.
The four types of Artificial nanomaterials are __________
a) Carbon-based, non-metallic, composites and ceramics
b) Carbon-based, metallic, composites and ceramics
c) Carbon-based, non-metallic, composites and dendrimers
d) Carbon-based, metallic, composites and dendrimers
Carbon-based, metallic, composites and dendrimers
olution of pure buckminsterfullerene has a colour of ___________
a) Green
b) Purple
c) Pink
d) Yellow
Purple
HyFn stands for __________
a) Hydrated Fluorine
b) Hydrolysed Fluorine
c) Hydrolysed Fullerene
d) Hydrated Fullerene
Hydrated Fullerene
HyFn stands for Hydrated fullerene. It is a stable, highly hydrophilic, super-molecular complex consisting of C60 molecules.
Nano sized polymers built from branched units are called __________
a) Dendrimers
b) Composites
c) Carbon-based materials
d) Metal-based materials
Dendrimers
Which property of nanoparticles provides a driving force for diffusion?
a) Optical Properties
b) High surface area to volume ratio
c) Sintering
d) There is no such property
High surface area to volume ratio
Quantum dots can be used in _________
a) Crystallography
b) Optoelectronics
c) Mechanics
d) Quantum physics
Optoelectronics
Quantum dots are basically semiconductor nanoparticles that show a particular colour on illumination by a light. They have unique electrical and optical properties. Due to this, they are widely used in optoelectronics.
Vesicle is a type of __________
a) Nanostructure
b) Nanoparticle
c) Nanocrystal
d) Supramolecular system
Supramolecular system
Vesicle is a bubble of liquid within another liquid, a supramolecular assembly made up of man different molecules. They can be formed naturally as well as artificially.
Which property of Nanomaterials make them suitable to be used for elimination of pollutants?
a) High purity
b) Better thermal conductivity
c) Enhanced chemical activity
d) Small size
Enhanced chemical activity
Nano crystalline materials synthesised by sol-gel technique results in a foam like structures called ___________
a) Gel
b) Aerosol
c) Foam
d) Aerogel
Aerogel
The foam-like material formed is called aerogel. They are porous and extremely lightweight, yet they can load equivalent to 100 times their weight. They are used as insulation materials.
Which nanomaterial is used for cutting tools?
a) Fullerene
b) Aerogel
c) Tungsten Carbide
d) Gold
Tungsten Carbide
Aerogels can hold more energy than the separators in batteries.
a) True
b) False
True
The energy density of a conventional battery is quite low. The Nano crystalline materials, as aerogels, have considerably more energy holding capacity.
A Carbon monoxide sensor made of zirconia uses which characteristic to detect any change?
a) Capacitance
b) Resistivity
c) Activity
d) Permeability
Activity
Zirconia uses its chemical activity to sense the presence of CO. In case CO is present, the oxygen atoms in zirconia would react with the carbon in CO to partially reduce Zirconium oxide.
Which components of an automobile are envisioned to be coated with zirconia?
a) Spark plugs
b) Liners
c) Tyres
d) Brakes
Liners
Zirconia is a hard and brittle ceramic. Its use in the coating of liners in an automobile is envisioned, as it can heat up the engine more effectively. Alumina can also be used for coating.
The main purpose of CNTs in fuel cells is __________
a) Production of energy
b) Active medium
c) Catalyst
d) Storage
Storage
Nanoscale aluminium oxide increases the _________
a) Conductivity
b) Resistance
c) Ductility
d) Stability
Resistance
Nanoscale aluminium oxide and titanium oxide are optically transparent and they greatly increase abrasion resistance of traditional coatings.
Which one of the following is an example for top-down approach?
Ball milling technique
Sol-gel process
Both a and b
None of the above
Ball milling technique
The measurement range of electron microscopy is around _____________ meters?
a. 1 m
b. 1 nm
c. 10 m
d. 12 mm
1 nm
Which one of the following neurotoxic effects comes under gold nanoparticles?
a. Cognition defects
b. Necrosis
c. Genotoxicity
d. None of the above
Cognition defect
What is the dimensional classification of quantum dots?
0D
What is the dimensional classification of quantum dots?
0D
Which nanomaterial classification refers to nanosheets?
2D
A bulk material with nanostructures inside is classified as?
3D
Nanoparticles belong to which dimensional classification?
0D
Which dimensional nanomaterials have length, width, and height all in the nanoscale?
0D
What is the typical size range of nanomaterials?
1 to 100 nanometers
Match the following
a. CNT 1. 0D
b. Fullerene 2. 1D
c. Graphene 2. 2D
CNT - 1D
Fullerene - 0D
Graphene - 2D
What kind of materials are typically synthesized using the sol-gel method?
Metal oxides
In the sol-gel method, what is the role of water in the hydrolysis process?
It helps in the breakdown of the precursor compound.
What is a common precursor used in the sol-gel synthesis of titanium dioxide?
Titanium alkoxide
Which type of nanoparticles are commonly synthesized via chemical reduction?
Metal nanoparticles
What is the diameter range of a single-walled carbon nanotube (SWCNT)?
1-2 nanometers
Which type of carbon nanotube has superior electrical conductivity?
Single-walled carbon nanotubes (SWCNTs)
What is the role of a stabilizing agent in the chemical reduction method?
a) It accelerates the reduction reaction
b) It prevents the aggregation of nanoparticles
c) It increases the oxidation of metal ions
d) It enhances the growth of nanoparticles
It prevents the aggregation of nanoparticles
Which metal salt is commonly used as a precursor for the synthesis of silver nanoparticles via chemical reduction
a) Silver nitrate (AgNO₃)
b) Silver chloride (AgCl)
c) Silver sulfate (Ag₂SO₄)
d) Silver oxide (Ag₂O)
Silver nitrate (AgNO₃)
What is a common characteristic of nanoparticles synthesized by the chemical reduction method?
a) Large size variation
b) Homogeneous particle distribution
c) Irregular shapes
d) High agglomeration
Homogeneous particle distribution
Which of the following is a method used to synthesize carbon nanotubes?
a) Sol-gel method
b) Arc discharge method
c) Ball milling
d) Thermal evaporation
Arc discharge method
What is the structure of graphene?
a) 1D chain of carbon atoms
b) 2D single layer of carbon atoms
c) 3D crystalline form of carbon
d) Spherical cluster of carbon atoms
2D single layer of carbon atoms
What is the hybridization of carbon atoms in graphene?
a) sp
b) sp²
c) sp³
d) sp⁴
Sp2
Graphene is known for having which of the following properties?
a) Poor electrical conductivity
b) Exceptional electron mobility
c) High density
d) Low mechanical strength
Exceptional electron mobility
What is a significant potential application of graphene in electronics?
a) Superconducting materials
b) Flexible touchscreens
c) Photovoltaic cells
d) Magnetic storage devices
b) Flexible touchscreens
Fullerenes have potential applications in:
a) Battery electrodes
b) Superconductors
c) Drug delivery systems
d) All of the above
All of the above
What makes fullerenes unique compared to other carbon allotropes?
a) They have a two-dimensional structure
b) They have a hollow, cage-like structure
c) They are arranged in layers
d) They have a hexagonal lattice
They have a hollow, cage-like structure
Which property of fullerenes makes them suitable for drug delivery?
A:
a) High mechanical strength
b) Ability to trap other atoms inside their structure
c) High electrical conductivity
d) High surface area
Ability to trap other atoms inside their structure
The discovery of fullerenes was awarded the Nobel Prize in Chemistry in which year?
a) 1980
b) 1996
c) 2000
d) 2010
1996
Who is credited with the discovery of carbon nanotubes?
a) Sumio Iijima
b) Richard Smalley
c) Andre Geim
d) Harold Kroto
Sumio Iijima (1991)
In which year were carbon nanotubes first observed by Sumio Iijima?
a) 1985
b) 1991
c) 2004
d) 1996
1991
What was the method used by Sumio Iijima to first observe carbon nanotubes?
a) Chemical vapor deposition
b) Arc discharge method
c) Laser ablation
d) Sol-gel process
Arc discharge method
Who are the scientists credited with the isolation of graphene?
a) Sumio Iijima and Richard Smalley
b) Andre Geim and Konstantin Novoselov
c) Harold Kroto and Robert Curl
d) Thomas Swan and Richard Feynman
Andre Geim and Konstantin Novoselov
In which year was graphene first isolated?
a) 2000
b) 1991
c) 2004
d) 1996
2004
What simple technique was used by Andre Geim and Konstantin Novoselov to isolate graphene?
a) Chemical vapor deposition
b) Electrochemical exfoliation
c) Mechanical exfoliation (Scotch tape method)
d) Ball milling
Mechanical exfoliation (Scotch tape method)
For their groundbreaking work on graphene, Andre Geim and Konstantin Novoselov were awarded the Nobel Prize in Physics in:
a) 2008
b) 2010
c) 2012
d) 2014
2010
Who is credited with the discovery of fullerenes (C60)?
a) Andre Geim
b) Sumio Iijima
c) Harold Kroto, Robert Curl, and Richard Smalley
d) Konstantin Novoselov
arold Kroto, Robert Curl, and Richard Smalley
In which year were fullerenes (C60) first discovered?
a) 1985
b) 1991
c) 1996
d) 2000
1985
Fullerenes were discovered using which technique?
a) Chemical vapor deposition
b) Arc discharge method
c) Laser ablation
d) Mechanical exfoliation
Laser ablation
Harold Kroto, Robert Curl, and Richard Smalley received the Nobel Prize in Chemistry for their discovery of fullerenes in:
a) 1985
b) 1996
c) 2004
d) 2010
1996
What inspired the name “fullerene” for the C60 molecule?
a) The structural similarity to geodesic domes designed by architect Buckminster Fuller
b) Its ability to conduct electricity
c) Its spherical shape
d) Its high carbon content
The structural similarity to geodesic domes designed by architect Buckminster Fuller
Which of the following is a commonly used reducing agent in the chemical reduction method?
a) Sodium hydroxide (NaOH)
b) Sodium borohydride (NaBH₄)
c) Hydrochloric acid (HCl)
d) Ethanol
b) Sodium borohydride (NaBH₄)
Which of the following is NOT a commonly used reducing agent in nanomaterial synthesis?
a) Ascorbic acid
b) Sodium borohydride
c) Hydrogen peroxide
d) Hydrazine
Hydrogen peroxide
Why is sodium borohydride commonly used as a reducing agent in the synthesis of nanoparticles?
a) It is inexpensive
b) It provides strong reducing power
c) It acts as both a reducing and stabilizing agent
d) It can be used at high temperatures
It provides strong reducing power
What is the main purpose of using a surfactant in the chemical reduction method?
a) To increase the reaction temperature
b) To reduce the metal ions
c) To control nanoparticle size and morphology
d) To stabilize the metal ions
To control nanoparticle size and morphology
What are the reagent used for chemical reduction method for producing Molybdenum Nano Particles
Molybdenum Chloride + Toluene + Sodium Borohydride
What are the reagent used for chemical reduction method for producing Silver Nano Particles
Ascorbic acid as reducing agent and Sodium polyacrylate as protective agent
