Research Papers

Synthesis and Characterization of Solid-State Phase Change Material Microcapsules for Thermal Management Applications

[+] Author and Article Information
Fangyu Cao

Department of Mechanical Engineering,
University of Maryland,
College Park, MD 20740
e-mail: fycao@umd.edu

Jing Ye

Department of Mechanical Engineering,
University of Maryland,
College Park, MD 20740
e-mail: ppsi523@gmail.com

Bao Yang

Department of Mechanical Engineering,
University of Maryland,
College Park, MD 20740
e-mail: baoyang@umd.edu

1Corresponding author.

Manuscript received October 2, 2013; final manuscript received February 25, 2014; published online March 12, 2014. Assoc. Editor: Calvin Li.

J. Nanotechnol. Eng. Med 4(4), 040901 (Mar 12, 2014) (5 pages) Paper No: NANO-13-1070; doi: 10.1115/1.4026970 History: Received October 02, 2013; Revised February 25, 2014

Polyalcohols such as neopentyl glycol (NPG) undergo solid-state crystal transformations that absorb/release significant latent heat. These solid–solid phase change materials (PCM) can be used in practical thermal management applications without concerns about liquid leakage and thermal expansion during phase transitions. In this paper, microcapsules of NPG encapsulated in silica shells were successfully synthesized with the use of emulsion techniques. The size of the microcapsules range from 0.2 to 4 μm, and the thickness of the silica shell is about 30 nm. It was found that the endothermic phase transition of these NPG-silica microcapsules was initiated at around 39 °C and the latent heat was about 96.0 J/g. A large supercooling of about 43.3 °C was observed in the pure NPG particles without shells, while the supercooling of the NPG microcapsules was reduced to about 14 °C due to the heterogeneous nucleation sites provided by the silica shell. These NPG microcapsules were added to the heat transfer fluid PAO to enhance its heat capacity and the effective heat capacity of the fluid was increased by 56% with the addition of 20 wt. % NPG-silica microcapsules.

Copyright © 2013 by ASME
Your Session has timed out. Please sign back in to continue.


Prakash, J., Garg, H. P., and Datta, G., 1985, “A Solar Water Heater With a Built-In Latent-Heat Storage,” Energy Convers. Manage., 25(1), pp. 51–56. [CrossRef]
Buddhi, D., Sawhney, R. L., Sehgal, P. N., and Bansal, N. K., 1987, “A Simplification of the Differential Thermal-Analysis Method to Determine the Latent-Heat of Fusion of Phase-Change Materials,” J. Phys. D: Appl. Phys., 20(12), pp. 1601–1605. [CrossRef]
Shaikh, S., and Lafdi, K., 2010, “C/C Composite, Carbon Nanotube and Paraffin Wax Hybrid Systems for the Thermal Control of Pulsed Power in Electronics,” Carbon, 48(3), pp. 813–824. [CrossRef]
Mondal, S., 2008, “Phase Change Materials for Smart Textiles—An Overview,” Appl. Therm. Eng., 28(11-12), pp. 1536–1550. [CrossRef]
Han, Z. H., Yang, B., Qi, Y., and Cumings, J., 2011, “Synthesis of Low-Melting-Point Metallic Nanoparticles With an Ultrasonic Nanoemulsion Method,” Ultrasonics, 51(4), pp. 485–488. [CrossRef] [PubMed]
Han, Z. H., Cao, F. Y., and Yang, B., 2008, “Synthesis and Thermal Characterization of Phase-Changeable Indium/Polyalphaolefin Nanofluids,” Appl. Phys. Lett., 92(24), p. 243104. [CrossRef]
Baetens, R., Jelle, B. P., and Gustavsen, A., 2010, “Phase Change Materials for Building Applications: A State-of-the-Art Review,” Energy Build., 42(9), pp. 1361–1368. [CrossRef]
Farid, M. M., Khudhair, A. M., Razack, S. A. K., and Al-Hallaj, S., 2004, “A Review on Phase Change Energy Storage: Materials and Applications,” Energy Convers. Manage., 45(9-10), pp. 1597–1615. [CrossRef]
Zhao, C. Y., and Zhang, G. H., 2011, “Review on Microencapsulated Phase Change Materials (MEPCMs): Fabrication, Characterization and Applications,” Renewable Sustainable Energy Rev., 15(8), pp. 3813–3832. [CrossRef]
Wang, X. W., Lu, E. R., Lin, W. X., Liu, T., Shi, Z. S., Tang, R. S., and Wang, C. Z., 2000, “Heat Storage Performance of the Binary Systems Neopentyl Glycol/Pentaerythritol and Neopentyl Glycol/Trihydroxy Methyl-Aminomethane as Solid-Solid Phase Change Materials,” Energy Convers. Manage., 41(2), pp. 129–134. [CrossRef]
Yan, Q., and Liang, C., 2008, “The Thermal Storage Performance of Monobasic, Binary and Triatomic Polyalcohols Systems,” Sol. Energy, 82(7), pp. 656–662. [CrossRef]
Chandra, D., Chellappa, R., and Chien, W. M., 2005, “Thermodynamic Assessment of Binary Solid-State Thermal Storage Materials,” J. Phys. Chem. Solids, 66(2-4), pp. 235–240. [CrossRef]
O'Sullivan, M., and Vincent, B., 2010, “Aqueous Dispersions of Silica Shell/Water-Core Microcapsules,” J. Colloid Interface Sci., 343(1), pp. 31–35. [CrossRef] [PubMed]
Wang, J.-X., Wang, Z.-H., Chen, J.-F., and Yun, J., 2008, “Direct Encapsulation of Water-Soluble Drug Into Silica Microcapsules for Sustained Release Applications,” Mater. Res. Bull., 43(12), pp. 3374–3381. [CrossRef]
Almeida, R. M., and Pantano, C. G., 1990, “Structural Investigation of Silica-Gel Films by Infrared-Spectroscopy,” J. Appl. Phys., 68(8), pp. 4225–4232. [CrossRef]
Divi, S., Chellappa, R., and Chandra, D., 2006, “Heat Capacity Measurement of Organic Thermal Energy Storage Materials,” J. Chem. Thermodyn., 38(11), pp. 1312–1326. [CrossRef]
Ruckenstein, E., and Djikaev, Y. S., 2005, “Recent Developments in the Kinetic Theory of Nucleation,” Adv. Colloid Interface Sci., 118(1-3), pp. 51–72. [CrossRef] [PubMed]
Santiso, E., and Firoozabadi, A., 2006, “Curvature Dependency of Surface Tension in Multicomponent Systems,” AIChE J., 52(1), pp. 311–322. [CrossRef]
Gibout, S., Jamil, A., Kousksou, T., Zeraouli, Y., and Castaing-Lasvignottes, J., 2007, “Experimental Determination of the Nucleation Probability in Emulsions,” Thermochim. Acta, 454(1), pp. 57–63. [CrossRef]
Cao, F., and Yang, B., 2014, “Supercooling Suppression of Microencapsulated Phase Change Materials by Optimizing Shell Composition and Structure,” Appl. Energy, 113, pp. 1512–1518. [CrossRef]
Synfluid PAO Databook, Chevron Phillips Chemical Company LP, Chevron Phillips Chemical LP, 2002, Synfluid PAO Databook, The Woodlands, TX.


Grahic Jump Location
Fig. 2

(a) SEM and (c) TEM images of as-synthesized microcapsules of NPG in silica shell, and (b) SEM and (d) TEM images of wrinkled silica shell after NPG is removed. Inserted in (a) is a histogram of the particle size distribution of the NPG-silica microcapsules.

Grahic Jump Location
Fig. 1

Process of synthesizing NPG in silica microcapsules. (a) Mixing water phase into cyclohexane with surfactant; (b) adding TEOS to the mixture; (c) hydrolysis of TEOS to form silica shell; and (d) collection of microcapsules.

Grahic Jump Location
Fig. 3

FT-IR spectra of sample (a) silica, (b) NPG, and (c) NPG-silica microcapsules

Grahic Jump Location
Fig. 4

Atomic distribution of the NPG-silica microcapsules measured using the EDS technique

Grahic Jump Location
Fig. 5

DSC heating and cooling curves of samples, (a) pure, bulk NPG, (b) dispersions of pure NPG micro-particles in PAO, and (c) dispersions of 20 wt. % NPG-silica microcapsules in PAO

Grahic Jump Location
Fig. 6

Calculated effective heat capacity of dispersion of NPG particles and dispersions of NPG-silica microcapsules

Grahic Jump Location
Fig. 7

Dynamic viscosities of pure PAO and PAO containing 20 wt. % microcapsules in versus temperature




Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In