Phase Change Materials PCMs

PCMs have high heats of fusion and so are capable of absorbing and storing large quantities of energy from the environment. The heat is re-released at low temperatures, and this leads to an active thermoregulation and insulation which is adapted to physical activity and to the ambient temperature. 

In addition to ice (water), more than 500 natural and synthetic PCMs are known. These materials differ one from another in terms of their phase change temperature range and their heat-storage capacities. 

A comparison between organic and salt-based PCMs is provided in Table 7.3. Today, most popular PCMs used in textile applications are based on paraffins (waxes). Compared to other PCMs, paraffins have high heat-storage capacities. 

Material Melting point rq Heat of fusion [kj k ] Latent heat [MJ m- ] 

Range of water/salt eutectics Oto-64 Wider range Wide range 

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Abstract. This section is an introduction into materials that can be used as Phase Change Materials (PCM) for heat and cold storage and their basic properties. At the beginning, the basic thermodynamics of the use of PCM and general physical and technical requirements on perspective materials are presented. Following that, the most important classes of materials that have been investigated and typical examples of materials to be used as PCM are discussed. These materials usually do not fulfill all requirements. Therefore, solution strategies and ways to improve certain material properties have been developed. The section closes with an up to date market review of commercial PCM, PCM composites and encapsulation methods. 

Phase-change materials (PCMs) represent another important application for metal chalcogenide films, as a result of emerging memory technologies, includ-... 

Microencapsulated phase-change-material (PCM) slurry, 13 276 Microencapsulation, 16 438-463. See also Encapsulation processes controlled release pesticide applications, 7 561-566... 

Smart textiles from chemical finishing Temperature protection by coating with phase change materials (PCMs) foam, quicker healing/recovery of wounds by moisture regulation, release of drugs on demand by signals from the skin... 

Materials used in latent heat storage are known as phase change materials (PCM). The requirements for a PCM to be used as latent heat storage material are... 

Tan, F.L. Hosseinizadeh, S.F. Khodadadi, J.M. Fan, L. Experimental and computational study of constrained melting of phase change materials (PCM) inside a spherical capsule. Int J Heat Mass Tran 52 (2009) 3464-3472. 

Bayes-Garcfa, L. Ventolh, L. Cordobilla, R. Benages, R. Calvet, T. Cuevas-Diarte, M.A. Phase change materials (PCM) microcapsules with different shell compositions Preparation, characterization and thermal stability. Sol Energ Mat Sol C 94 (2010) 1235-1240. 

The application of phase-changing materials (PCM) also involves certain problems. Entectic salts are snsceptible to phase separation [110,111]. To avoid this [38,112] it is desirable to make the PCM containers thin (Fignre 14.33). Another phase-change material is paraffin wax (A = 209 kJ/kg). Its disadvantage is inflammability. 

McCaim et al. recently introduced an approach that combined the process of melt co-axial electrospinning to encapsulate the phase change materials (PCMs) into polymer or composite sheath. PCM can help stabilize the temperature near its melting point as the material changes the state from a solid to liquid or vice versa and the enthalpy of fusion involved can absorb or release thermal energy. The nanofibers produced using such a material can be used in thermal insulation applications. The researchers used three PCMs, octadecane, hexadecane and eicosane, in melt forms as core solutions and demonstrated temperature stabilization at three different points, 17°C, 30°C and 37°C, respectively ... 

Shin Y, Yoo D-I and Son K (2005) Development of thermoregulating textile materials with microencapsulated phase change materials (PCM). II. Preparation and application of PCM microcapsules, I Appl Polym Sci., 96(6), pp. 2005-2010. 

Gao C, Kuklane K and Hohner I (2008), The heating effect of phase change material (PCM) vests on a thermal manikin in a subzero environment, 7th International Thermal Manikin and Modelling Meeting-Vniweisity of Coimbra, September 2008, USA. 

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