Session: ASME Undergraduate Student Design Expo

Paper Number: 173471

Enhancement of Thermal Functionality in Phase Change Materials Using Nitrogen-Doped Graphene Support Materials 

The growing demand for sustainable energy solutions has increased research into advanced thermal energy storage systems, with phase change materials (PCMs) emerging as a promising class due to their ability to store and release significant amounts of latent heat during phase transitions. This unique property enables their use in a wide array of applications, including building thermal regulation, electronics cooling, cold-chain logistics, and solar thermal energy systems. However, despite their advantages, PCMs face major drawbacks such as low thermal conductivity and thermal instability during repeated heating and cooling cycles, which hinder their performance in practical energy systems. To address these limitations, this study aims to focus on developing composite PCMs by incorporating nitrogen-doped graphene (N-G) into paraffin wax (melting point 53–58 °C) to enhance both thermal conductivity and phase stability. Graphene, known for its exceptional thermal conductivity and high surface area, serves as an ideal candidate for improving thermal transport properties, while nitrogen doping introduces active functional groups and lattice defects that improve certain aspects of PCMs. For this study, N-G was synthesized using graphene oxide (GO) and melamine via a nanoscale high-energy wet (NHEW) ball milling technique, which not only reduced the material to nanoscale dimensions but also enabled the introduction of functional sites and structural defects. Following synthesis, the N-G was incorporated into paraffin wax at varying mass ratios using a controlled probe sonication process to ensure uniform dispersion and maximize interaction between the filler and matrix. The resulting N-G/PCM composites were then characterized through multiple methods to evaluate both thermal and structural properties. Differential Scanning Calorimetry (DSC) was used to assess latent heat and phase transition behavior, while complementary techniques such as Raman spectroscopy, Fourier Transform Infrared Spectroscopy (FTIR), X-ray Photoelectron Spectroscopy (XPS), and Transmission Electron Microscopy (TEM) provided insight into microstructural features, bonding mechanisms, and other physiochemical attributes. Notably, composites containing 2–3% N-G demonstrated significant improvement in thermal conductivity along with a roughly 5% increase in latent heat compared to pure paraffin, which is particularly remarkable given that many thermally conductive fillers, such as other carbon-based materials, often increase thermal conductivity but significantly diminish latent heat capacity. However, the enhancement in this work is attributed to favorable interactions between nitrogen and oxygen-containing groups on N-G and the hydrocarbon chains of the PCM matrix, which facilitate efficient thermal transport and stabilize phase change behavior. Overall, this research offers a better way to improve PCM performance and contributes to a deeper scientific understanding of the relationship between chemical structure and material properties at the nanoscale. These findings lay the groundwork for developing more durable, efficient, and energy-dense materials for next-generation thermal energy storage systems.

Presenting Author: Andrew Jiang New Jersey Institute of Technology

Presenting Author Biography: Andrew Jiang is an undergraduate student in the Albert Dorman Honors College at New Jersey Institute (NJIT) of Technology studying Mechanical Engineering graduating in May 2028. He conducts research at NJIT's Advanced Energy Systems and Microdevices Laboratory, focusing on nanomaterials as well as phase change materials (PCMs). He is interested in the use of AI-driven models to anticipate and optimize the functionality of PCMs.

Authors:

Andrew Jiang New Jersey Institute of Technology
Niladri Talukder New Jersey Institute of Technology
Eon Soo Lee New Jersey Institute of Technology