Heat Capacity of Nanoparticles - Experimental Determination

In summary, the difficulties of measuring heat capacities in nanoparticles are due to the small size and the fact that it is an important topic.
  • #1
acb
10
1
I know little about the experimental measurements of heat capacity. I can see you'd need to know both how much energy you've transferred to a nanoparticle, and measure the temperature change resulting to ascertain it. This brings me to my questions:

How effective is laser heating of nanoparticles for determining heat capacity?
How is temperature of the nanoparticle measured? An infrared thermometer like device?

I'm guessing the answers are "Not very", and "No", because otherwise many mysteries in materials science would have already been solved. To reframe my question:

Would someone like to tell me about the difficulties of measuring heat capacities in nanoparticles?
 
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  • #2
What makes you think there's any more difficulty to measurement of heat capacity of nanoparticles than there is of any other material?
 
  • #3
A few reasons:

1) It's very small, and so insulating it might be difficult while also keeping it from aggregating with something else.
2) This is a very important topic. I know that in hydrogen storage, for example, people would very much like to know the heat capacity of nanoparticles they attempt to hydride, as that would allow them to separate the components of a (hydrogen) desorption reaction free energy. That is, if say: metal-hydride -> hydrogen + metal, then you're very interested in what the heat capacity of the metal is vs. the metal-hydride, as that will dominate the thermodynamics. Medical applications seem abundant for nanoparticles also. Basically this point summarised is: "If it's so important, where are the numbers?"
3) Back to (1) - how do you measure the temperature of a nanoparticle? Measuring its emitted radiation might work, but then how do you heat it (a laser would surely mess with that reading)? Then if you try heating it an insulator, via convection (like in an oven), how do you keep it from reacting with its container? It seems like there would be temperatures beyond which the entire exercise was fraught with difficulty.

I really don't know though. Is it harder?
 
  • #4
Heat capacities are commonly measured calorimetrically, X moles (or mass) of material are raised from an initial T to a final T and necessary heat measured, or measured heat is applied and temperature difference is measured. Single atom/molecule heat capacities can be determined spectroscopically, but I don't think I'd try it for nanoparticles.
 

Related to Heat Capacity of Nanoparticles - Experimental Determination

What is the purpose of determining the heat capacity of nanoparticles?

The heat capacity of nanoparticles is an important physical property that can provide insight into the thermal behavior and stability of these materials. It is also essential for understanding and designing various applications of nanoparticles, such as in nanoelectronics and nanomedicine.

How is the heat capacity of nanoparticles experimentally determined?

The heat capacity of nanoparticles can be experimentally determined using various techniques, such as differential scanning calorimetry (DSC), isothermal calorimetry, and temperature modulated DSC. These methods involve measuring the heat flow or temperature change of the nanoparticles as they are subjected to controlled heating or cooling.

What factors can affect the heat capacity of nanoparticles?

The heat capacity of nanoparticles can be influenced by several factors, including the size, shape, and composition of the nanoparticles, as well as the surrounding environment and any surface modifications. Additionally, the heat capacity may also vary depending on the temperature range and measurement technique used.

How do nanoparticles differ in heat capacity from bulk materials?

Nanoparticles often exhibit different heat capacities compared to their bulk counterparts due to their smaller size and unique surface properties. These differences can be attributed to the increased surface-to-volume ratio and the presence of surface effects, which can affect the vibrational and electronic contributions to the heat capacity.

Why is it important to accurately determine the heat capacity of nanoparticles?

An accurate determination of the heat capacity of nanoparticles is crucial for understanding their thermal behavior, predicting their stability, and optimizing their performance in various applications. It can also provide valuable information for designing and controlling the synthesis and processing of nanoparticles with desired thermal properties.

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