Phase change materials textile applications

Boh, B. and E. Knez, 2006. Microencapsulation of essential oils and phase change materials for application in textile products. Ind. J. Fibre Text. Res., 31 72-82. 

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. 

Another application of smart materials for PPE concerns thermoregulating phase change materials. Based on microencapsulation, macroencapsulation, or solid—solid transition, this technology allows a certain level of on-demand, immediate, and powerless cooling and warming with possible recharge at room temperature. Several fiber, textile, and PPE products are already commercially available, with the addition of a fire-resistant functionality soon to come. 

Microcapsules loaded with phase change materials (PCMs) have been incorporated into various textiles (83). They provide enhanced heat capacity not easily achieved in other ways. Nelson (84) discusses a variety of textile applications of microcapsules including encapsulated PCMs. Encapsulated PCMs offer much promise as a means of improving the thermal capacity of various heat-transfer fluids (85). 

Gateway Technologies has reported the application of heneicosane, eicosane, nonadecane, octadecane, and heptadecane as phase change materials for insulative fabrics. This material can be 425% as warm as a high bulk wadding. Schoeller Textil AG Switzerland has also explored the application of micro-encapsulated phase change materials like waxes, which offer interactive insulation for skiwear, snowboarding and ski boats. They store surplus heat and the wax liquefies when temperatures drop, the microcapsules release the stored heat. 

There are many thermal benefits of treating textile structures with PCM microcapsules such as cooling, insulation and thermo regulating effect. Without phase change materials the thermal insulation capacity of clothing depends on the thickness and the density of the fabric (passive insulation). The application of PCM to a garment provides an active thermal... 

Sarier N, Onder E. Organic phase change materials and their textile applications an overview. Thermochim... 

The coupled heat and liquid moisture transport of nano-porous material has wide industrial applications in textile engineering and functional design of apparel products. Heat transfer mechanisms in nano-porous textiles include conduction by the solid material of fibers, conduction by intervening air, radiation, and convection. Meanwhile, liquid and moisture transfer mechanisms include vapor diffusion in the void space and moisture sorption by the fiber, evaporation, and capillary effects. Water vapor moves through textiles as a result of water vapor concentration differences. Fibers absorb water vapor due to their internal chemical compositions and structures. The flow of liquid moisture through the textiles is caused by flber-liquid molecular attraction at the surface of fiber materials, which is determined mainly by surface tension and effective capillary pore distribution and pathways. Evaporation and/or condensation take place, depending on the temperature and moisture distributions. The heat transfer process is coupled with the moisture transfer processes with phase changes such as moisture sorption and evaporation. 

Shape-memory alloys (e.g. Cu-Zn-Al, Fe-Ni-Al, Ti-Ni alloys) are already in use in biomedical applications such as cardiovascular stents, guidewires and orthodontic wires. The shape-memory effect of these materials is based on a martensitic phase transformation. Shape memory alloys, such as nickel-titanium, are used to provide increased protection against sources of (extreme) heat. A shape-memory alloy possesses different properties below and above the temperature at which it is activated. Below this temperature, the shape of the alloy is easily deformed due to its flexible structure. At the activation temperature, the alloy can be changed by applying a force, but the structure resists this deformation and returns back to its initial shape. The activation temperature is a function of the ratio of nickel to titanium in the alloy. In contrast with Ni-Ti, copper-zinc alloys are capable of a two-way activation, and therefore a reversible variation of the shape is possible, which is a necessary condition for protection purposes in textiles used to resist changeable weather conditions. 

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