TY - JOUR

T1 - Ionic clathrate hydrates loaded into a cryogel – halloysite clay composite for cold storage

AU - Stoporev, Andrey

AU - Mendgaziev, Rais

AU - Artemova, Maria

AU - Semenov, Anton

AU - Novikov, Andrei

AU - Kiiamov, Airat

AU - Emelianov, Dmitrii

AU - Rodionova, Tatyana

AU - Fakhrullin, Rawil

AU - Shchukin, Dmitry

N1 - Publisher Copyright: © 2020 Elsevier B.V. Copyright: Copyright 2020 Elsevier B.V., All rights reserved.

PY - 2020/6/15

Y1 - 2020/6/15

N2 - Mixed type phase change material (PCM) based on the tetra-n-butylammonium bromide (TBAB) hydrate loaded in a composite matrix included poly(vinyl alcohol) (PVA) and natural halloysite clay nanotubes can be used for the cold storage. Poly(vinyl alcohol) provides the formation of a cryogel, while the clay nanotubes promote the hydrate nucleation reducing the supercooling of the formed hydrate. At the same time, the cryogel formation ensures the sedimentation stability of halloysite inside the dispersion. The relationship between the concentration of the target compound in the initial solution, the presence/absence of halloysite, and specific enthalpy of the phase transition made it possible to optimize the properties of this material for cold storage. The formation of two hydrates in the systems under study with different water content as well as the possibility of recrystallization of the low content water hydrate into the high content water one and during the melting of ice was experimentally revealed. The obtained PCM melted at a temperature of 9–13 °C and had a melting enthalpy up to 196 J/g. It was shown that the halloysite is a nucleator for TBAB hydrates. Adding 1 mass% of halloysite to the composite increases the temperature of hydrate onset by 2 °C. The best thermal stability in an open system was shown for the 1:50 M ratio. The energy capacity of such material does not decrease during 50 cycles of the reversible melting-crystallization phase transition, which indicates the stability of the TBAB-PVA-halloysite system. As both halloysite clay nanotubes and poly(vinyl alcohol) cryogel are biocompatible, encapsulation of tetra-n-butylammonium bromide hydrate in such material will protect the environment from harmful effects of a quaternary ammonium salt and expand the scope of this cold accumulator. The halloysite as an additive for phase change composites is also low-cost, readily available from natural mineral deposits, and non-toxic.

AB - Mixed type phase change material (PCM) based on the tetra-n-butylammonium bromide (TBAB) hydrate loaded in a composite matrix included poly(vinyl alcohol) (PVA) and natural halloysite clay nanotubes can be used for the cold storage. Poly(vinyl alcohol) provides the formation of a cryogel, while the clay nanotubes promote the hydrate nucleation reducing the supercooling of the formed hydrate. At the same time, the cryogel formation ensures the sedimentation stability of halloysite inside the dispersion. The relationship between the concentration of the target compound in the initial solution, the presence/absence of halloysite, and specific enthalpy of the phase transition made it possible to optimize the properties of this material for cold storage. The formation of two hydrates in the systems under study with different water content as well as the possibility of recrystallization of the low content water hydrate into the high content water one and during the melting of ice was experimentally revealed. The obtained PCM melted at a temperature of 9–13 °C and had a melting enthalpy up to 196 J/g. It was shown that the halloysite is a nucleator for TBAB hydrates. Adding 1 mass% of halloysite to the composite increases the temperature of hydrate onset by 2 °C. The best thermal stability in an open system was shown for the 1:50 M ratio. The energy capacity of such material does not decrease during 50 cycles of the reversible melting-crystallization phase transition, which indicates the stability of the TBAB-PVA-halloysite system. As both halloysite clay nanotubes and poly(vinyl alcohol) cryogel are biocompatible, encapsulation of tetra-n-butylammonium bromide hydrate in such material will protect the environment from harmful effects of a quaternary ammonium salt and expand the scope of this cold accumulator. The halloysite as an additive for phase change composites is also low-cost, readily available from natural mineral deposits, and non-toxic.

KW - Cold storage

KW - Cryogel

KW - DSC

KW - Halloysite nanotubes

KW - Ionic clathrate hydrate

KW - Nucleation

KW - SYSTEM

KW - PERFORMANCE

KW - CO2

KW - RELEASE

KW - PHASE-CHANGE MATERIALS

KW - THF HYDRATE

KW - LATENT-HEAT

KW - NANOTUBES

KW - NUCLEATION

UR - http://www.scopus.com/inward/record.url?scp=85083336264&partnerID=8YFLogxK

U2 - 10.1016/j.clay.2020.105618

DO - 10.1016/j.clay.2020.105618

M3 - Article

AN - SCOPUS:85083336264

VL - 191

JO - Applied Clay Science

JF - Applied Clay Science

SN - 0169-1317

M1 - 105618

ER -