Enhanced Thermal Buffering of Phase Change Materials by the Intramicrocapsule Sub per Mille CNT Dopant

Alexey A Mikhaylov; Sergey Sladkevich; Alexander G Medvedev; Petr V Prikhodchenko; Jenny Gun; Konstantin A Sakharov; Zhichuan J Xu; Vladimir Kulish; Vitaly A Nikolaev; Ovadia Lev

doi:10.1021/acsami.9b21205

Enhanced Thermal Buffering of Phase Change Materials by the Intramicrocapsule Sub per Mille CNT Dopant

ACS Appl Mater Interfaces. 2020 Apr 8;12(14):16227-16235. doi: 10.1021/acsami.9b21205. Epub 2020 Mar 26.

Authors

Alexey A Mikhaylov^{1

2

3}, Sergey Sladkevich¹, Alexander G Medvedev^{1

2

3}, Petr V Prikhodchenko³, Jenny Gun¹, Konstantin A Sakharov^{1

2}, Zhichuan J Xu², Vladimir Kulish^{4

5}, Vitaly A Nikolaev^{1

2}, Ovadia Lev^{1

2}

Affiliations

¹ The Institute Chemistry, The Casali Center of Applied Chemistry, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Jerusalem 9190401, Israel.
² Singapore HUJ Alliance Research & Enterprise, New CREATE Campus for Research Excellence and Technological Enterprise (CREATE), 1 CREATE Way, Singapore 138602, Singapore.
³ Kurnakov Institute of General and Inorganic Chemistry, Russian Academy of Sciences, Leninskii prosp. 31, Moscow 119991, Russia.
⁴ Faculty of Mechanical Engineering, Czech Technical University in Prague, Technická 4, Prague 166 07, Czech Republic.
⁵ Madanapalle Institute of Technology & Science, Post Box No: 14, Kadiri Road, Angallu (Village), Chittoor District, Madanapalle 517325, Andhra Pradesh, India.

PMID: 32167739
DOI: 10.1021/acsami.9b21205

Abstract

Microencapsulation of a carbon nanotube (CNT)-loaded paraffin phase change material, PCM in a poly(melamine-formaldehyde) shell, and the respective CNT-PCM gypsum composites is explored. Although a very low level (0.001-0.1 wt %) of intramicrocapsule loading of CNT dopant does not change the thermal conductivity of the solid, it increases the measured effusivity and thermal buffering performance during phase transition. The observed effusivity of 0.05 wt % CNT-doped PCM reaches 4000 W s^-0.5 m^-2 K^-1, which is higher than the reported effusivity of alumina and alumina bricks and an order of magnitude larger than the solid, CNT-free PCM powder. The CNT dopant (0.015 wt %) in a 30 wt % PCM-plaster composite improved the effusivity by 60% compared to the CNT-free composite, whereas the addition of the same amount of CNTs to the bulk of the plaster does not improve either the effusivity or the thermal buffering performance of the composite. The thermal enhancement is ascribed to a CNT network formation within the paraffin core.

Keywords: CNT; energy storage; microencapsulation; phase change materials (PCM); thermal buffering; transient plane source method.