After the increase in energy consumption, the use of phase change material (PCM) has become the focus of attention. When ambient temperature increases or decreases such that PCMs can storage high latent heat at melting point and these can be salt hydrates, paraffins, fatty acids, fatty acid esters and their triple mixtures [1, 2]. Latent heat energy storage allows a high rate of energy to be storaged and released per unit weight of PCM during phase change [1, 3] and considering the phase change temperature range, a 5mm thick plate containing PCM can return the latent heat energy it has storaged to environment for 4 to 8 hours [4]. With the application of different methods, the technology of storing heat energy can increase efficiency and energy resources can be used effectively [5]. Polyethylene glycol (PEG) is a polymer used in the development of biocompatible and biodegradable tissue engineering scaffolds [6]. PEGs have a wide molecular weight range from 200 g/mol to 35,000 g/mol [7]. Although synthetic polymers are preferred as support materials in the production of PCM compounds in the literature, the use of natural polymers is less. High molecular weight PEGs are considered environmentally safe materials for latent heat energy storage and use [8].
Some pain relievers may have side effects, but herbal treatments have less negative aspects [9]. The highest concentrations in clove essential oil were eugenol (88.58%), eugenyl acetate (5.62%) and β-caryophyllene (1.38%), respectively, and showed antibacterial activity against staphylococcus epidermidis strain [10]. In addition, eugenol can show antifungal, antiallergic and antioxidant properties [11, 12, 13] and has a local numbing and pain-relieving effect, especially in tooth and gingival pain [14]. Clove and thyme oils are also known to be highly effective repellent agents against insects [10, 15].
Polylactic acid (PLA) is a linear polyester with biocompatibility that can be obtained by catalytic ring opening and condensation polymerization of lactic acid produced from corn, beet and cane sugar [16]. PLA-based nanofibers with hydrophobic structure are also slightly soluble in water when they contain hydrophobic EO [17].
The electrospinning method used by Formhals in 1934 to spin synthetic fibers using electric charges was used to spin small diameter fibers and cellulose acetate fibers were spun using acetone/alcohol solution [18]. On the other hand, when PLA-based nanomaterials form composites with antibiotic compounds by electrospinning method, they can produce controlled release [19]. The oscillation of nanofibers when loaded with essential oil has been observed in Cupressus sempervirens L. loaded nanofiber study and it is thought that it can make an important contribution to drug designs [20].
Short-term thermal protection ways are known generally as vasodilation, vasoconstriction and shivering in humans and is associated with change body temperature of 36.5°C (average 33.0°C for the skin), which is ideal temperature, and in this case, people lose their comfort of life [21]. Provide thermal comfort may be of vital importance, during a regional body temperature decrease or increase even for a certain period of time.
Although production of PCM-containing materials has become focus of attention in recent years, the target temperature range should be specific according to usage area. In this study, PEG/PLA/EO composite nanofibers containing PEG (Mw:1000) and clove essential oil at certain ratios (100/100/25, 150/100/25, 200/100/25), respectively, were produced by electrospinning method and nanofiber morphology, chemical composition, thermal reliability and heat storage/release performances of composite fibers were investigated.