Date of Award

6-2015

Document Type

Open Access

Degree Name

Bachelor of Science

Department

Physics and Astronomy

First Advisor

Samuel Amanuel

Language

English

Keywords

fusion, heat, nano, annealing, apparent

Abstract

We studied melting and freezing of 2-decanol nano-crystals (100 Angstrom to 1000 Angstrom) using a Differential Scanning Calorimeter (DSC). In agreement with the Gibbs-Thompson equation, the melting temperature of nano crystals decreases with physical size and its change scales linearly with the inverse of physical size. The apparent heat of fusion of the nano scaled systems, however, has been found to be lower than the heat of fusion for the bulk. Although this is in agreement with previous experimental observations, it is in contradiction with the assumptions used to develop the Gibbs-Thompson equation. We believe that the apparent heat of fusion needs a correction since material at an interface may not crystallize under typical freezing conditions. We are able to demonstrate that we can increase the apparent heat of fusion by as much as 23% by annealing the nano scaled systems and that the heat of fusion increases with annealing time while the suppression of melting temperature due to confinement decreases with annealing time.

Download

Included in

Physics Commons

Share

COinS