Synthesis and Properties of Microencapsulated Solid Paraffin Phase Change Materials

Abstract:

To prepare the phase change materials for efficient low-temperature latent heat storage, microcapsules with commercial solid paraffin were synthesized by using in-situ polymerization process. Liquid paraffin was used first as core materials since it facilitates the direct observation of containment by the shell of melamine-formaldehyde resin (MF resin), and examines easily the optimal synthesizing condition. The effects of emulsion processes, pre-polymerization conditions, shell material content and reaction time on the quality of microcapsules were investigated. The experimental investigations show that the optimal process of synthesizing liquid paraffin microcapsules is adoptable to that of solid paraffin microcapsules. The as-prepared solid paraffin microcapsules show high quality. The microcapsules surface was smooth and dense, and be free of any adhesion. The measurements show that in the microcapsules solid paraffin was well encapsulated by MF resin. The microcapsule size was almost within the range of 6~33 μm and most intense distribution at 23 μm. DSC measurements gave two endothermic peaks with initial phase change temperature at 35°C and 50°C respectively, and the total enthalpy was above 134 J/g.

• Periodical: Key Engineering Materials (Volume 519)
• Pages: 1-5
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.519.1
• Online since: July 2012
• Authors: Zhe Xu, Jian Qiang Li, Guo Cai Zhang
• Keywords: Microencapsulation, Paraffin, Phase Change Materials (PCM), Thermal Energy Storage

References

[1] A. Abhat, Low temperature latent heat thermal energy storage: heat storage materials, J. Solar. Energy. 30 (1983) 313-332.

DOI: 10.1016/0038-092x(83)90186-x

[2] M.M. Farid, A.M. Khudhair, S.A.K. Razack, et al, A review on phase change energy storage: materials and applications, J. Energy Convers. Manage. 45 (2004) 1597-1615.

DOI: 10.1016/j.enconman.2003.09.015

[3] M.M. Farid, A.K. Mohamed, Effect of Natural convection on the process of melting and solidification of paraffin wax, J. Chem. Eng. Commun. 57 (1987) 297-316.

DOI: 10.1080/00986448708960492

[4] M.M. Farid, A. Kanzawa, Thermal performance of a heat storage module using PAMs with different melting temperatures-mathematical modeling, J. J. Solar. Energy. Eng. 111 (1989) 152-157.

DOI: 10.1115/1.3268301

[5] F. Wang, G. Maidment, J. Missenden, et al, A review of research concerning the use of PCMs in air conditioning and refrigeration engineering, J. Adv. Build. Technol. 2 (2002) 1273-128.

DOI: 10.1016/b978-008044100-9/50158-3

[6] V.V. Tyagi, D. Buddhi, PCM thermal storage in buildings: a state of art, J. Renew. Sustain. Energy. Rev. 11 (2007) 1146-1166.

DOI: 10.1016/j.rser.2005.10.002

[7] D. Saihi, I. Vroman, S. Giraud, et al, Microencapsulation of ammonium phosphate with a polyurethane shell. Part II. Interfacial polymerization technique, J. React. Funct. Polym. 66 (2006) 1118-1125.

DOI: 10.1016/j.reactfunctpolym.2006.02.001

[8] H.Y. Lee, C.A. Kim, W.H. Jang, et al, Synthesis and electrorheological characteristics of micro-encapsulated polyaniline particles with melamine-formaldehyde resins, J. Polymer. 42 (2001) 8277-8283.

DOI: 10.1016/s0032-3861(01)00342-1

[9] G. Sun, Z. Zhang, Mechanical properties of melamine-formaldehyde microcapsules, J. J. Microencapsul. 18 (2001) 593-602.

[10] G. Sun, Z. Zhang, Mechanical strength of microcapsules made of different wall materials, J. Int. J. Pharm. 242 (2002) 307-311.

[11] B. Boh, E. Knez, M. Staresinic, Microencapsulation of higher hydrocarbon phase change materials by in situ polymerization, J. J. Microencapsul. 22 (2005) 715-735.

DOI: 10.1080/02652040500162139

[12] W.J. Luo, W. Yang, S. Jiang, et al, Microencapsulation of decabromodiphenyl ether by in situ polymerization: Preparation and characterization, J. Polym. Degrad. Stab. 92 (2007) 1359-1364.

DOI: 10.1016/j.polymdegradstab.2007.03.004

[13] F. Salaun, E. Devaux, S. Devaux, et al, Influence of process parameters on microcapsules loaded with n-hexadecane prepared by in situ polymerization, J. Chem. Eng. J. 155 (2009) 457-465.

DOI: 10.1016/j.cej.2009.07.018

[14] Q.Y. Yan, C. Liang, L. Zhang, Experimental study on the thermal storage performance of paraffin mixtures used in the phase change wall, J. Sol. Energy Mater. Sol. Cells. 92 (2008) 1526-1532.

DOI: 10.1016/j.solmat.2008.07.002

[15] S. Fabien, V. Isabelle, Influence of core materials on thermal properties of melamine-formaldehyde microcapsules, J. Euro. Poly. J. 44 (2008) 849-860.

DOI: 10.1016/j.eurpolymj.2007.11.018

[16] X.X. Zhang, X.M. Tao, K.L. Yick, et al, Structure and thermal stability of microencapsulated phase-change materials, J. Collid. Polym. Sci. 88 (2004) 330-336.

DOI: 10.1007/s00396-003-0925-y