Fabrication of Polysaccharide-Based Halochromic Nanofibers via Needle-Less Electrospinning and Their Characterization: A Study of the Leaching Effect

Abstract

Responsive materials, i.e., smart materials, have the ability to change their physical or chemical properties upon certain external signals. The development of nanofibrous halochromic materials, specifically combining the pH-sensitive functionality and unique nanofiber properties, could yield interesting new applications, especially when the common problem of dye leaching is successfully tackled. Therefore, in this article, we studied the fabrication process of polysaccharide-based halochromic nanofibrous materials by using a combination of various halochromic dyes (bromothymol blue, bromocresol green, and thymol blue) and cellulose acetate in a spinning solution using a one-pot strategy. The inhibition of leaching was addressed by using a complexing agent: poly-diallyl-dimethylammonium chloride (PDADMAC). The preparation of hybrid spinning solutions, their characterization, and ability to form continuous nanofibers were studied using a high production needle-less electrospinning system. The produced hybrid solutions and nanofibers were characterized, in terms of their rheological properties, chemical structure, morphology, and functionality. Fabricated nanofibrous halochromic structures show a clear color change upon exposure to different pH values, as well as the reduced leaching of dyes, upon the addition of a complexing agent. The leaching decreased by 61% in the case of bromocresol green, while, in the case of bromothymol blue and thymol blue, the leaching was reduced by 95 and 99%, respectively.

The Applications of Ferulic-Acid-Loaded Fibrous Films for Fruit Preservation

“…The antioxidant properties of the preparations were analyzed using the DPPH radical scavenging method [67][68][69][70][71][72]. We prepared a DPPH standard solution at a concentration of 60 mg/L and placed 10 mg of the functional nanofiber membrane in 10 mL of anhydrous ethanol.…”

Cell Electrospinning: A Mini‐Review of the Critical Processing Parameters and Its Use in Biomedical Applications

“…Taking these factors into account, it is difficult to define a standard for electrode spacing. As was found by the authors of this review, a change in the presence of one component in the ES formulation affected the optimal distance by 20 mm (the distance had to be lowered from 160 [ 32 ] to 140 mm [ 33 ] to achieve desired resulting nanofiber properties).…”

Optical Properties of Electrospun Nanofiber Mats

“…In addition to the aforementioned bathochromic shift, based on chemical reactions, nanofiber mats can also change their color when they are dyed. An often-applied process is adding a dye directly to the spinning solution, which should result in a colored nanofiber mat [168][169][170][171].…”