Effects of temperature and carbon nanocapsules (CNCs) on the production of poly(D,L-lactic acid) (PLA) nonwoven nanofibre mat

Solution viscosity can be regarded as the most important factor in determining the morphology of the product obtained in electro spinning. Viscosity can be adjusted for a given solution by tuning the solution temperature or by adding fillers to the solution prepared. The electro spinning of PLA solution was performed at a temperature ranging from 25 to 100 °C to determine the effects of temperature on fiber morphology. For the solution of sufficiently high entanglement density (i.e., 20 wt%), the as-spun fiber diameter was in the range of 330 ± 20 nm because the electro spinning was conducted at elevated temperatures. In contrast, for the solution without sufficient entanglement density (i.e., 13 wt%), the solution entanglement density was enhanced by the addition of fillers, which caused the as-spun fibers to become smooth. The fiber diameter obtained was in the range of 90 ± 10 nm. By varying the solution temperature, the chain entanglement status existing in the solution remained intact. In contrast, the chain entanglement density could be enhanced by the addition of fillers. However, both temperature and fillers significantly altered the solution viscosity. Therefore a complete understanding of the temperature and filler effect on the solution and electro spinning gave rise to a feasible route for manipulating the as-spun fiber diameter.