Preparation and Characterization of Electrospun Pullulan Webs

Abstract

Electrospinning is a versatile process used to prepare micro or nano sized fibers from various materials dissolved in volatile solvents. This study reports electrospun pullulan fibrous webs fabricated through electrospinning using water as a solvent. The electrospinning conditions such as pullulan (PUL) concentration and applied voltage were optimized in order to obtain smooth electrospun fibers. The concentration of PUL greatly influenced the viscosity and surface tension of PUL solution. PUL beaded electrospun fibers were obtained from PUL solutions with concentrations lower than 5 wt%, while homogenous electrospun fibers were prepared from solutions with high concentration and high viscosity. The average diameters of PUL fibers were decreased to 200 nm when the polymer concentration was kept at 10 wt% and the applied voltage was fixed at 15 kV during electrospinning. PUL electrospun fiber exhibited higher solubility, flexibility, softness and adhesive strength.

Graphene Derivatives in Biopolymer-Based Composites for Food Packaging Applications

“…This microbial extracellular polysaccharide is a biodegradable, biocompatible, non-mutagenic, nontoxic, hygroscopic (meaning that depending on the relative humidity at which it stored it can absorb water), non-carcinogenic, and edible polymer [ 88 , 89 ]. To create pullulan films or coatings, numerous techniques such as solvent casting [ 90 , 91 ], extrusion [ 92 , 93 ], coating by dipping or spraying [ 94 , 95 ], layer-by-layer assembly [ 96 , 97 ] or electrospinning [ 98 , 99 , 100 ] can be used. The resulting films are devoid of color, opacity, taste, and odor, and are also heat-stable and impermeable to both oil and oxygen [ 88 , 89 ].…”