Fabrication of Electrospun Fibers Containing Ternary Eutectic Fatty Acid Mixture as Phase-Change Materials for Application in Textiles

Phase-change materials (PCMs) are utilized in energy conservation systems due to their outstanding merits including high energy storage capacity and small temperature variation in the phase transition interval. Fatty acids are the preferable kind of organic PCMs due to their features such as high latent heat capacity, environmental friendly, chemical resistance and non-corrosive properties. For practical applications, fatty acid PCM suffers from leakage during frequent storage/retrieval process. This flaw can be mitigated by encapsulation of PCM in a micro/nano-sized supporting matrix. Although PCM encapsulation can be accomplished in various ways, the polymeric holding structures are efficient methods. Electrospinning is a novel flexible technique which facilitates the fabrication of ultrafine polymeric fibers in large scale and wide range of diameters. Electrospinning of ternary eutectic fatty acid mixture was carried out to fabricate nanofibers with appropriate thermal properties. The phase-change materials (PCMs) used including capric acid (CA), palmitic acid (PA), lauric acid (LA) and their ternary eutectics were supported by polymeric matrix of polylactic acid (PLA) in production of nanofibers through the electrospinning technique. The fabricated composites have undergone various characterization tests including Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) to study their chemical, morphological and thermal properties. The FTIR analyses showed that no chemical reaction occurred by composite constituents. The SEM analysis showed that the fibers were formed smoothly and without beads. In addition, the formation of hydrogen bond between PLA and ternary eutectic fatty acid mixture (C-L-P) showed the capability to encapsulate PCMs into the PLA polymer matrix. It was also observed that the composite fibers have an appropriate phase transition temperature range of about 12˚C and are suitable fibers which contain PCM having capability in energy storage/retrieval systems (e.g. textiles) to operate at low temperatures.