Polymers & Nanotechnology

Polymers & Nanotechnology

1. Polymers:A substance which has a molecular structure built up chiefly or completely from a large number of similar units bonded together, e.g. many synthetic organic materials used as plastics and resins

2. Nanotechnology:The branch of technology that deals with dimensions and tolerances of less than 100 nanometres, especially the manipulation of individual atoms and molecules.

3. These particles are measured in nanometres (nm). A nanometre is one billionth of a metre (0.000 000 001m). Nanotechnology is concerned with the use and control of structures that are 1-100 nanometres in size.

4. Nanoparticles of a material show different properties compared to larger particles of the same material. Forces of attraction between surfaces can appear to be weak on a larger scale, but on a nanoscale they are strong.

5. Nanoparticles are used in products that are currently available. sports equipment: nanoparticles are added to materials to make them stronger whilst often being lighter. They have been used in tennis rackets, golf clubs and shoes clothing: silver nanoparticles have been added to socks. This stops them from absorbing the smell of sweaty feet as the nanoparticles have antibacterial properties healthcare: nanoparticles are used in sunscreens. They offer protection and can be rubbed in so there are no white marks.

6. There are some concerns that nanoparticles may be toxic to people. They may be able to enter the brain from the bloodstream and cause harm. Some people think more tests should take place before nanoparticles of a material are used on a wider scale.

7. Alkenes can be used to make polymers. Polymers are very large molecules made when many smaller molecules join together, end-to-end. The smaller molecules are called monomers.

8. Alkenes can act as monomers because they have a double bond: Ethene can polymerise to form poly(ethene), which is also called polythene. Propene can polymerise to form poly(propene), which is also called polypropylene.

9. Polymers have properties that depend on the chemicals they are made from, and the conditions in which they are made. Modern polymers have many uses, including: waterproof coatings, fillings for teeth dressings for cuts, hydrogels for making soft contact lenses and disposable nappy liners, shape memory polymers for shrink-wrap packaging

10. Plasticisers are substances that let the polymer molecules slide over each other more easily. This makes the polymer softer and more flexible. For example, poly(chloroethene) or PVC is a hard polymer. Unplasticised PVC, usually called uPVC, is used to make pipes and window frames. PVC with plasticisers is soft and flexible. It is used for floor coverings, raincoats and car dashboards.

11. One of the useful properties of polymers is that they are unreactive, so they are suitable for storing food and chemicals safely. Unfortunately, this property makes it difficult to dispose of polymers.

12. Many polymers can be recycled. This reduces the disposal problems and the amount of crude oil used. But the different polymers must be separated from each other first, and this can be difficult and expensive to do.

13. Toxic gases are produced unless the polymers are incinerated at high temperatures.

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