Abstract
Protective clothing for health workers requires heat transfer in hot and humid environments. To study the thermal conduction of phase-change materials and protect them from leakage, we selected skin-friendly shea-butter due to its suitable melting temperature, and the electrospinning processibility of biocompatible cellulose acetate. The shea-butter as a phase-change material was encapsulated in electrospun cellulose acetate fibres within a core/sheath structure, which was stabilised by two concentric Taylor cones during coaxial electrospinning. Transmission and scanning electron microscopy revealed a blood-in-tube vessel-like morphology. Next, differential scanning calorimetry and thermogravimetric analyses confirmed the heat capacity of shea-butter (latent heat of fusion: 42.73 J/g; thermal conductivity: 1.407 W/m∙K). The flow rate of the core was proportional to the heat capacity of the shea-butter/cellulose acetate fibres. This was consistent with the finding that the electrospun fibres of the highest-ratio shea-butter (16.19%) had the highest thermal conductivity (0.421 J/g∙K). The shea-butter:cellulose acetate ratio was approximately 15:80. The efficacy of heat transfer for the core/sheath fibres in human clothing was assessed by measuring skin temperatures at 13 sites in six males aged 25 to 35 under two conditions: wearing a mask and hood with attached cellulose acetate fibres in the presence and absence of shea-butter. The mean difference in skin temperatures (0.5 ℃) between the two conditions was significant. Coaxial electrospinning of shea-butter/cellulose acetate fibres is therefore promising for protective clothing with efficient heat-transfer in the use of a large area.
Core-sheath Electrospinning of Shea Butter and Cellulose Acetate to Enhance Heat Transfer in Protective Clothing
