A novel strategy for preparing pullulan electrospun short nanofiber aerogel-templated oleogels with regulatability, compressibility and multi-functionality via rapid oil adsorption

In this work, electrospun short nanofiber aerogel-templated oleogels (ESNF-ATO) were fabricated by electrospun pullulan nanofibers. Spinning solutions with different concentrations were utilized to maintain fiber diameter, and short nanofibers were homogenized to prepare aerogel templates for oil adsorption. The shape of the templates could be easily controlled, and the fabrication process unchanged the properties of pullulan and the diameter of short nanofibers. Increasing the fiber diameter resulted in more flexible aerogel templates, which exhibited lower compressive strengths but higher recovery rates in 100-cycle fatigue tests. Simple linear fitting further confirmed the above results. Oleogels could be formed by rapid oil adsorption (normally within 100 s), and capillarity mainly induced this procedure. The thinner nanofibers provided the templates a high oil adsorption capacity (up to 69.05 g/g) but a relatively weakened oil holding capacity. ESNF-ATO exhibited good rheological properties, and could effectively realize the sustained-release of free fatty acids or lipo-soluble compounds. The significance of this work lied in the innovativeness of the combination of electrospun short nanofibers and aerogel templates, and the characteristics of fiber-based templates and oleogels were adjustable by modulating the fiber diameter.