Jump to main content
Jump to site search

Issue 3, 2014
Previous Article Next Article

Flow of suspensions of carbon nanotubes carrying phase change materials through microchannels and heat transfer enhancement

Author affiliations

Abstract

This work explores the potential of nano-encapsulated phase change materials (PCMs) in applications related to microelectronics cooling. PCMs (wax or meso-erythritol) were encapsulated in carbon nanotubes (CNTs) by a method of self-sustained diffusion at room temperature and pressure. These nano-encapsulated wax nanoparticles alone allowed heat removal over a relatively wide range of temperatures (different waxes have melting temperatures in the range 40–80 °C). On the other hand, nano-encapsulated meso-erythritol nanoparticles allowed heat removal in the range 118–120 °C. The combination of these two PCMs (wax and meso-erythritol) could extend the temperature range to 40–120 °C, when both types of nanoparticles (wax and meso-erythritol intercalated) would be suspended in the same carrier fluid (an oil). The nanoparticles possess a short response time of the order of 10−7 s. Such nano-encapsulation can also prevent the PCM from sticking to the wall. In this work, experiments with wax-intercalated CNTs, stable aqueous suspensions of CNTs with concentrations up to 3 wt% with and without nano-encapsulated wax were prepared using a surfactant sodium dodecyl benzene sulfonate (NaDDBS). These suspensions were pumped through two channels of 603 μm or 1803 μm in diameter subjected to a constant heat flux at the wall. It was found that the presence of the surfactant in CNT suspensions results in a pseudo-slip at the channel wall which enhances the flow rate at a fixed pressure drop. When aqueous solutions of the surfactant were employed (with no CNTs added), the enhanced convection alone was responsible for a ~2 °C reduction in temperature in comparison with pure water flows. When CNTs with nano-encapsulated wax were added, an additional ~1.90 °C reduction in temperature due to the PCM fusion was observed when using 3 wt% CNT suspensions. In addition, suspensions of meso-erythritol-intercalated CNTs in alpha-olefin oil were used as coolants in flows through the 1803 μm-diameter microchannel. These suspensions (1.5 wt% CNT) revealed a temperature reduction due to the PCM fusion of up to 3.2 °C, and a fusion temperature in the range 118–120 °C.

Graphical abstract: Flow of suspensions of carbon nanotubes carrying phase change materials through microchannels and heat transfer enhancement

Back to tab navigation

Publication details

The article was received on 15 Aug 2013, accepted on 07 Oct 2013 and first published on 09 Oct 2013


Article type: Paper
DOI: 10.1039/C3LC50949D
Citation: Lab Chip, 2014,14, 494-508
  •   Request permissions

    Flow of suspensions of carbon nanotubes carrying phase change materials through microchannels and heat transfer enhancement

    S. Sinha-Ray, S. Sinha-Ray, H. Sriram and A. L. Yarin, Lab Chip, 2014, 14, 494
    DOI: 10.1039/C3LC50949D

Search articles by author

Spotlight

Advertisements