Nanoparticles (Edexcel GCSE Chemistry): Revision Notes

Nanoparticles

• Nanoparticles are larger than atoms, as they contain hundreds of atoms, but are much smaller than most visible particles or molecules.

High Surface Area to Volume Ratio

• As particles decrease in size, their surface area becomes large compared to their volume. This gives nanoparticles a high surface area to volume ratio.
• This high ratio allows nanoparticles to have different properties compared to larger particles of the same material, making them useful in various applications.
• Because of their large surface area, they can be used as catalysts, helping speed up reactions by providing more surface for the reaction to occur on.

Below is a table with multiple uses, advantages and disadvantages of nanoparticles:

Category	Advantages	Disadvantages	Uses
Medicine	• Can deliver drugs directly to cells, improving treatment effectiveness	• Potential unknown health risks as they could pass through biological barriers (e.g., skin, blood-brain barrier)	• Drug delivery systems (targeting specific areas in the body)
Electronics	• Improve the performance of electronic devices (e.g., faster processors, smaller components)	• Expensive to produce	• Used in transistors, circuits, and displays for smaller, more efficient devices
Sunscreens	• Better protection from harmful UV rays due to more even coverage	• Possible environmental damage (e.g., nanoparticles can accumulate in aquatic ecosystems)	• Used in sunscreens for UV protection
Cosmetics	• Improve texture and absorption of products	• Potential skin penetration and unknown long-term effects	• Found in makeup and anti-ageing creams
Catalysts	• Provide a larger surface area to speed up reactions	• Can be difficult to recover from the reaction mixtures after use	• Used in industrial chemical processes (e.g., speeding up reactions in the production of chemicals or fuels)
Clothing	• Antimicrobial properties help to reduce odour and kill bacteria	• Potential release of harmful particles into the environment during washing	• Used in fabrics for sportswear, socks, and other clothing
Construction	• Increased strength and durability in materials	• Costly and potentially toxic during manufacturing	• Used in concrete, paints, and coatings to enhance strength and water resistance
Environmental	• Can help clean up pollutants by breaking down harmful substances (e.g., in water treatment)	• Risk of nanoparticles contaminating ecosystems	• Used in water purification systems and environmental remediation projects
Food Packaging	• Can help to extend the shelf life of food by preventing bacterial growth	• Possible ingestion of nanoparticles with unknown health consequences	• Used in food packaging to improve preservation and freshness

Potential Risks of Nanoparticles

• Unknown health effects: Because of their small size, nanoparticles can easily move through the body, potentially causing long-term health problems, but the exact effects are still being researched.
• Environmental concerns: Once nanoparticles are part of the waste chain, they may enter the environment, potentially getting into microorganisms, the food chain, and eventually animals and plants.
• Their large surface area could also make them toxic in certain conditions, but more studies are needed.

Specific Types of Nanoparticles

1. Fullerenes:

• Fullerenes are used in lubricants for machinery, such as gears or artificial joints.

2. Silver Nanoparticles:

• Silver nanoparticles are added to polymer fibres for things like surgical masks and wound dressings.
• They provide antibacterial properties, helping prevent infections.