Nanoparticles

Question 1

What are some applications of nanoparticles?

Answer 1

1. Modern surgical practice
2. Invasive imaging techniques
3. Drug delivery systems
4. Development of engineered organs

Question 2

What is one property of nanoparticles?

Answer 2

They have a high surface area to volume ratio.

Question 3

What are the three categories of nanoparticles?

Answer 3

1. Fullerenes (carbon allotropes) - adopt different shapes, e.g. carbon nanotubes.
2. Au as contrast agent in non-invasive cell tracking with CT imaging.
3. Synthetic polyhedral oligomeric silsesquioxane (POSS) nanoparticles.

Question 4

Where do the reactions of nanoparticles happen?

Answer 4

Reactions take place at the surface of a chemical or material.

Question 5

How does the surface area affect the reactivity of a nanoparticle?

Answer 5

1. Larger surface area, larger reactivity
2. Smaller particles - surface area to volume ratio increases.

Question 6

What are nanocomposites?

Answer 6

Multiphase solid materials with one phase having 1, 2, or 3 dimensions less than 100 nm.

Question 7

How are scaffolds used in tissue engineering?

Answer 7

Enhanced by nanoparticulate fillers:
1. intercalated between layers
2. distributed evenly throughout to maximize surface area for component interaction.

Question 8

What do fillers include?

Answer 8

1. Silicones
2. carbon nanotubes
3. nano clays
4. synthetic nanocomposites, including oligomeric silsesquioxane (POSS) nanoparticles

Question 9

What is amphiphilic nature?

Answer 9

Molecules containing both hydrophilic and lipophilic regions

Question 10

What is the method of preparation of colloidal Au nanoparticles?

Answer 10

By reduction of Au (III) chloride trihydrate (HAuCl4.3H2O) using sodium citrate (Na3C6H5O7) as the reductant:
Au+3 + citrate ions [C3H5OCOO3.3-] -> Au0

Question 11

What methods are used for the characterization of AuNPs?

Answer 11

1. UV-visible spectroscopy, obtaining adsorption spectra using 2ml 1% wt sodium citrate
2. TEM