Thermal Gravimetric Analysis question.

[KKAK]

Hello,
how do we determine the metal weight percent of gold nanopartilces that are coated organic thin films by using thermal gravimetric analysis ?

 

[chem_tr]

I think thermal gravimetric analysis include combustion of organic substances in high temperature like 1500 degrees celsius, and gravimetric determination of the inorganic ones. As nanogold particles are of sufficiently high purity, it would not be difficult to determine them after combustion; to be sure, wash the residue with some polar organic solvents like acetic acid, acetonitrile, dimethyl formamide, then water, and dry the gold bulk again.

To do the gravimetric analysis, you will need to find an appropriate reactant for gold (I think gold is in elemental state here). So, it is likely that you can directly weigh the gold particles, or dissolving them with Aqua Regia (3HCl+1HNO₃) and finally reacting with, say, pyrophosphate.

 

[ravenprp]

Thermal gravimetric analysis (TGA) is a useful technique for determining the weight percent of a metal in a sample. In the case of gold nanoparticles coated with organic thin films, TGA can be used to determine the weight percent of gold in the sample by measuring the change in weight as the sample is heated.

To determine the metal weight percent of gold nanoparticles coated with organic thin films using TGA, you will need to follow these steps:

1. Prepare the sample: The first step is to prepare the sample for analysis. This involves accurately weighing a known amount of the sample, which should include both the gold nanoparticles and the organic thin films.

2. Conduct the TGA analysis: The sample is then heated at a constant rate in a controlled atmosphere. As the temperature increases, the organic thin films will start to decompose and evaporate, leaving behind the gold nanoparticles. This will result in a decrease in the sample's weight, which can be measured by a balance connected to the TGA instrument.

3. Analyze the data: The TGA instrument will generate a plot of weight versus temperature. The weight loss observed during the analysis is due to the evaporation of the organic thin films. The weight percent of gold can be calculated by dividing the weight loss due to the evaporation of the organic films by the initial weight of the sample.

4. Consider the factors that may affect the results: It is important to note that there are some factors that may affect the accuracy of the results. These include the purity and homogeneity of the sample, the heating rate, and the atmosphere used during the analysis.

In conclusion, TGA is a useful technique for determining the weight percent of gold in nanoparticles coated with organic thin films. By following the steps outlined above and considering any potential factors that may affect the results, you can accurately determine the metal weight percent of your sample.