Nanoparticles

By Srivallabh Sabnivisu


A nanoparticle is an extremely small particle, with its size usually ranging between 1-100 nanometres in size. Nanoparticles exist naturally in the world and can also be artificially created. Invisible to the human eye, their physical and chemical properties are significantly different to their larger material counterparts. Their sub microscopic size and unique properties mean that they have many unique, practical applications in many industries such as medicine, engineering, catalysis, and environmental remediation. Most nanoparticles are made up of no more than 100 atoms.


Properties

The properties of a material change as their size increases closer to the atomic scale. Their surface area to volume ratio is already quite high. As the size is increasing, so is the ratio, resulting in the material’s surface atom’s dominating its performance. Their amazing properties can be explained in relation to their size. Their small size enables them to confine their electrons and produce quantum effects.

Figure (1) shows a nanoparticle under an extremely powerful microscope


For example, copper is considered a soft material, with bulk copper bending when its atoms cluster at the 50nm scale. Consequently, copper nanoparticles smaller then 50nm are considered a very hard material, with drastically different malleability and ductility performance when compared to bulk copper. The change in size can also affect the melting characteristics; gold nanoparticles melt at much lower temperatures (300 °C for 2.5 nm size) than bulk gold (1064 °C). Moreover, absorption of solar radiation is much higher in materials composed of nanoparticles than in thin films of continuous sheets of material.

Measuring concentration

Validated ways to accurately measure nanoparticle number concentrations are important for optimising the manufacture, performance, and safety of nanomaterials, and for compliance with forthcoming EU regulations. Some instruments are capable of measuring nanoparticle number concentrations, but no documentary standards nor certified reference materials are available for calibration and validation.


There are 4 main instruments used in measuring nanoparticle number concentrations:

- Welding fume by use of a Metal Inert Gas (MIG) welding robot

- Welding fume by PVC welding

- Cooking fume

- Candle-burning

Nanoparticles in everyday life

Waking up in the morning, nanoparticles are probably one of the furthest things from our minds. Yet, throughout the day, at every step we have unknowingly encountered it. From the wrinkle-free shirt and sunglasses we wear to computer hard drives and even cosmetic products, to the way to work or school, we use nanotechnology.

Nanotechnology is an advanced technique which has progressively entered everyday life, conquering an increased importance in many fields. As an emerging strategy for development, nano-based ingredients have found a place as consumer products in the market such as paints, building materials, cosmetics and in medical treatment, the food industry and so much more. In fact, it's becoming increasingly harder to keep track of where nanotech isn't. We are using it in our daily lives and not even realizing it.

Conclusion

Nanoparticles is an area of technology that is increasing rapidly and incorporating into our daily lives. Further advancements of technology such as this can improve our quality of lives.

Sources and Bibliography:

- What are Nanoparticles? Definition, Size, Uses and Properties - TWI (twi-global.com)

- nanoparticle | Definition, Size Range, & Applications | Britannica