1. Do you expect that cube -shaped Ag NPs exhibit stronger or weaker anti -bacterial activity than sphere -shaped Ag NPs with the same particle volume? Explain your answer. 2. Graphite is a solid lubricant while CNTs can be used for armor. CNTs can be made from graphite . Explain why their mechanical properties are so different ? 3. What is the signal of carbon nanotubes when used for sensors ? Explain the general mechanism responsible for sensing a specific substance using a sensor made of CNTs 4. The following figures show the growth of carbon nanotube on metal nanoparticles (catalyst , e.g., Fe, Co ) in tip growth mode during a CVD process , involving diffusion of carbon atoms on surface and through the metal nanoparticle CNT - Tip growth Growth stops Hat Metal Support Answer the following questions Based on the figures, explain how the metal nanoparticle helps the formation of CNTs. b) Do you expect that the nanoparticle size influences the CNT's outer and internal diameters ? Explain your reasons ? c) Later studies show that ceramic c nanoparticles , e.g., SiO 2: Al203, may also play a similar role . Compared to a metal nanoparticle , do you expect that a S102 nanoparticle of the same size result in CNTs with a smaller or lager internal diameter ? Why ? It is known that the diffusion of carbon in ceramics is slower than in metals