This question is about the properties of materials. Aerospace drone components can be manufactured from Titanium alloy or Carbon Fiber Reinforced Epoxy (CFRE). The table below shows some properties of Titanium alloy and CFRE:
| Property | Titanium Alloy | CFRE |
|---|---|---|
| Density (g/cm3\text{g/cm}^3g/cm3) | 4.50 | 1.55 |
| Relative strength-to-weight | 1 | 4 |
| Fatigue resistance | moderate | high |
| Resistance to corrosion | high | outstanding |
Describe and explain two reasons why high-performance drone components are made from CFRE instead of Titanium alloy.
Kevlar-49 is a high-strength polymer used in advanced aerospace composites. Look at the repeating unit of Kevlar-49:
[−NH−C6H4−NH−CO−C6H4−CO−]n\left[ -\text{NH}-\text{C}_6\text{H}_4-\text{NH}-\text{CO}-\text{C}_6\text{H}_4-\text{CO}- \right]_n[−NH−C6H4−NH−CO−C6H4−CO−]n
What type of polymer is Kevlar-49?
Nanoparticles of titanium dioxide are used to make self-cleaning coatings for drone sensors. A titanium dioxide nanoparticle has a diameter of 42 nm42\text{ nm}42 nm. The diameter of a titanium atom is 0.22 nm0.22\text{ nm}0.22 nm.
Estimate how many times larger the titanium dioxide nanoparticle is, compared to a titanium atom. Give your answer to 1 significant figure.
Titanium dioxide is used as a photocatalyst. Suggest why 1 g1\text{ g}1 g of titanium dioxide is more effective as a catalyst when used as nanoparticles rather than as a bulk powder.