A problem in materials design is that in natural as well as artificial materials, volume occasionally drops, or surges, with rising temperature. While there are mechanical reasons for this occurrence for certain materials, a general insight into why this occasionally occurs is still lacking. However, a group of Penn State scientists has formulated a theory to elucidate and then forecast it: Zentropy.
Zentropy is a kind of entropy, a concept fundamental to the second law of thermodynamics that states the measure of the disorder of a system that takes place over a certain duration when no energy is applied to maintain order in the system.
The theory of Zentropy observes that the thermodynamic relationship of thermal expansion, when the volume rises because of higher temperature, is equal to the negative derivative of entropy concerning pressure, i.e., the entropy of most material systems reduces with a rise in pressure.
This allows Zentropy theory to have the ability to estimate the alteration of volume as a function of temperature at a multiscale level, meaning the various scales within a system. All states of matter have their own entropy, and different components of a system possess their own entropy.
Macroscopic functionalities of materials arise from groups of microscopic states (microstates) at all scales at and below the scale of the macroscopic state of investigation (macrostate).
These functionalities are tough to estimate as only one or a few microstates can be taken into consideration in a standard computational method such as the predictive ab initio calculations, which help establish the key properties of materials.
Zentropy has the prospect of altering the way materials are developed, particularly those that are part of systems that are subjected to increasing temperatures. These temperatures, specific thermal expansion, could cause problems if the materials expand.
While there are advantages for society overall, scientists could apply Zentropy to numerous fields. This is on account of how entropy exists in each system.
For more information: Penn State University
