Definitions [15]
Define Green chemistry.
Green Chemistry is the use of chemistry for pollution prevention by environmentally conscious design of chemical products and processes that reduce or eliminate the use or generation of hazardous substances.
Define atom economy.
Atom economy is a measure of the amount of atoms from the starting materials that are present in the useful products at the end of the chemical process.
Define the Nanochemistry.
Nanochemistry:
Nanochemistry is the combination of chemistry and nanoscience which deals with designing and synthesis of materials of nanoscale with different sizes and shape, structure and composition, and their organization into functional architectures.
Answer the following
Define the following term: Nanomaterial
Nanomaterial:
The nanomaterial is a material having structural components with at least one dimension in the nanometer scale, that is, 1-100 nm.
Answer the following
Define the following term: Nanotechnology
Nanotechnology:
Nanotechnology is the design, characterization, production and application of structures, devices and systems by controlling shape and size at nanometer scale.
Define the following term:
Nanoscience
Nanoscience is the study of phenomena and manipulation of materials at atomic, molecular, and macromolecular scales where properties differ significantly from those at a larger scale.
The use of chemistry for pollution prevention through environmentally conscious design of chemical products and processes that reduce or eliminate the use and generation of hazardous substances is called green chemistry.
Development that meets the needs of the present without compromising the ability of future generations to meet their own needs is called sustainable development.
The study of phenomena and manipulation of materials at atomic, molecular and macromolecular scales where properties differ significantly from bulk materials is called nanoscience.
The design, characterization, production and application of structures, devices and systems by controlling shape and size at the nanometer scale is called nanotechnology.
The branch of science dealing with the design and synthesis of materials at the nanoscale with controlled size, shape, structure and composition is called nanochemistry.
A material having structural components with at least one dimension in the nanometer range (1–100 nm) is called nanomaterial.
A nanostructure in which all three dimensions are in the nanometer scale is called a zero-dimensional nanostructure.
A nanostructure in which two dimensions are in the nanometer scale is called a one-dimensional nanostructure.
A nanostructure in which one dimension is in the nanometer scale is called a two-dimensional nanostructure.
Formulae [1]
Write the formula to calculate the % atom economy.
% atom economy = `" Formula weight of the desired product"/"Sum of formula weight of all the reactants used in the reaction" xx 100`
Key Points
- Nanoparticles are used to develop stronger, lighter and smarter materials such as scratch-proof eyeglasses, crack-resistant paints and advanced transport materials.
- Nanomaterials are widely used in electronic devices, for example in Magnetoresistive Random Access Memory (MRAM).
- Nanotechnology plays an important role in water purification, where silver nanoparticles are used as effective disinfectants to remove bacteria like E. coli.
- Nanostructures are used in self-cleaning materials based on the lotus effect, which helps surfaces repel water and dirt.
- Nanotechnology has revolutionized electronics and computing by improving performance and efficiency of devices.
- In the energy sector, nanotechnology makes solar power more economical and improves energy storage systems.
- In the medical field, nanotechnology helps in manufacturing smart drugs and in treating serious diseases like cancer and diabetes with fewer side effects.
- Despite its advantages, nanotechnology can cause nano pollution and health risks such as lung damage due to inhalation of nanoparticles.
| No. | Principle | Main Idea | Key Objective | Example / Focus |
|---|---|---|---|---|
| 1 | Prevention of Waste | Avoid formation of waste instead of treating it later | Minimize waste generation | Zero Waste Technology (ZWT) |
| 2 | Atom Economy | Maximize incorporation of reactant atoms into final product | Reduce by-products | Higher % atom economy |
| 3 | Less Hazardous Chemical Synthesis | Use safer reaction pathways | Reduce toxic waste | Replace harmful chemicals like DDT |
| 4 | Designing Safer Chemicals | Design products with minimum toxicity | Protect human health | Develop low-toxicity chemicals |
| 5 | Use of Safer Solvents and Auxiliaries | Use safer solvents and minimize auxiliary substances | Reduce environmental impact | Use water or supercritical CO₂ |
| 6 | Design for Energy Efficiency | Minimize energy requirements | Reduce energy consumption | Reactions at room temperature and pressure |
| 7 | Use of Renewable Feedstocks | Prefer renewable raw materials | Conserve non-renewable resources | Plant-based raw materials |
| 8 | Reduce Derivatives | Avoid unnecessary protection/deprotection steps | Improve atom economy | Minimize blocking groups |
| 9 | Use of Catalysis | Use catalysts instead of stoichiometric reagents | Increase selectivity and efficiency | Industrial catalysts (e.g., Ni, Ziegler–Natta) |
| 10 | Design for Degradation | Design products that break down safely | Prevent environmental persistence | Biodegradable materials |
| No. | Characteristic Feature | Description | Key Effect at Nanoscale | Example |
|---|---|---|---|---|
| 1 | Colour | Optical properties change at nanoscale | Materials show different colours than bulk form | Gold nanoparticles appear red instead of yellow |
| 2 | Surface Area | Surface-to-volume ratio increases as particle size decreases | Higher reactivity due to more exposed surface atoms | Small cubes have greater total surface area than a large cube |
| 3 | Catalytic Activity | Catalysts become more active due to larger surface area | Increased reaction rate and efficiency | Pt nanoparticles in hydrogenation; TiO₂, ZnO in photocatalysis |
| 4 | Thermal Property (Melting Point) | Melting point changes with particle size | Smaller particles melt at lower temperatures | Sodium clusters melt at lower temperature than bulk sodium |
| 5 | Mechanical Properties | Strength and hardness increase at nanoscale | Enhanced mechanical performance | Nano copper and palladium show higher hardness |
| 6 | Electrical Conductivity | Electrical behaviour differs at nanoscale | May behave as conductor or semiconductor | Carbon nanotubes show varied conductivity |
Important Questions [15]
- Define Green chemistry.
- Explain any three principles of green chemistry.
- Name the γ-isomer of BHC.
- Define the following term: Nanoscience
- Write the reaction involved in sol-gel process during hydrolysis.
- Write the name of the technique used to know geometry of nanoparticles.
- What is nano material?
- Answer the following Which nanomaterial is used for tyres of the car to increase the life of tyres?
- Write the name of metal nanoparticle used to remove E.coli bacteria from water.
- Which flower is an example of self-cleaning?
- The name of metal nanoparticle which acts as highly effective bacterial disinfectant in water purification process is ______.
- Explain any two applications of nanomaterials.
- Write any three advantages of nanoparticles and nanotechnology.
- Write two disadvantages of nanotechnology.
- State Disadvantages of nanoparticles and nanotechnology.
Concepts [10]
- Green Chemistry and Nanochemistry
- Principles of Green Chemistry
- The Role of Green Chemistry
- Introduction to Nanochemistry
- Characteristic Features of Nanoparticles
- Synthesis of Nanomaterials
- History of Nanotechnology
- Applications of Nanomaterials
- Nanoparticles and Nanotechnology
- Overview of Green Chemistry and Nanochemistry
