Читать книгу Introduction to Nanoscience and Nanotechnology - Chris Binns - Страница 23

1 1 Silver, whose density is 10 490 kg/m3, is used to form spheres of different diameters. Calculate the surface area in m2 of 1 g of Ag spheres of diameter:1 mm10 μm10 nm

2 2 Calculate the proportion of atoms on the surface atomic layer of Ag spheres with the diameters below given that the thickness of the surface atomic shell is 0.289 nm, stating any assumptions made.1 μm10 nm5 nm

3 3 In a magnetic material, the energy of the exchange interaction between neighboring atoms is about 1 eV/atom whereas the magnetic dipolar interaction between neighboring assemblies of atoms averages at 10−5 eV/atom. Use the data to estimate the maximum size of a spherical single‐domain particle. (Hint: assume the exchange interaction only operates between atomic neighbors, whereas in a small particle the dipolar interaction affects all atoms equally. In addition, for an estimate, assume the atoms are cubes with a width of 0.2 nm).⁶

4 4 An HIV virus with a diameter of 100 nm has 50 glycoprotein extrusions over its surface, each one of which will bind a 5 nm diameter Ag nanoparticle. You are provided with a suspension of 5 nm diameter Ag nanoparticles containing 1 μg Ag per milliliter of liquid. What volume of the suspension is required to saturate 107 viruses in a test tube?