Limited studies have been done on silk fibroins of wild silkworm species owing to their relative insolubility in many solvents. In this study, the solubility of Argema mimosae wild silk fibroin in different salts (LiBr, LiCl, Ca(NO3)2, and CaCl2) dissolved in formic acid under varying temperatures was investigated. The dissolution conditions under which the solubility was optimum were optimized using a central composite design approach. The optimum range for solvation of the fibroin were visualized using contour plots. The influence of temperature and salt concentration were found to significantly influence the solvation of the fibroin. Following the successful dissolution of the fibroin, the regenerated silk fibroin solutions were cast to obtain water insoluble films which were used in investigating optimum electrospinning conditions. Average nanofiber diameters in the 110–141 nm range were obtained under optimum electrospinning conditions. The silk forms were characterized using the FTIR, TGA, XRD, and SEM to understand their properties. The investigations revealed that formic acid—salt solvents were effective in the solvation of the wild silk fibroin. Some of the dissolution conditions induced mild effects on the silk fibroin while others were harsh. Furthermore, processing to nanofibers resulted in the degradation of the β-sheets producing nanofibers rich in α-helices. However, post-treatment using methanol and water vapor were effective in restoring β-sheet crystallinity.

Pollutants mainly exist as multicomponent mixtures in the environment. Therefore, it is necessary to synthesize low-cost adsorbents that can simultaneously adsorb multiple compounds. This work presents the prospect of the adsorption of multiclass pharmaceuticals from the aqueous environment using an adsorbent derived from silk fibroin of the wild silkworm Argema mimosae. The adsorbent was prepared by dissolving degummed silk fibroin and the resultant solution was cast to obtain films that were ball-milled to powder. FTIR results revealed bands corresponding to N-H and C=O stretching vibrations. Particle size distribution data generally showed two size groups in the range of 50–90 nm and 250–625 nm. The study focused on the adsorptive removal of multiple compounds consisting of eight pharmaceuticals representing various classes including a β-blocker (pindolol), anesthetic (lidocaine), stimulant (caffeine), antiviral (nevirapine), steroid (estriol), anti-epileptic (carbamazepine), and a non-steroidal anti-inflammatory drug (naproxen). The adsorption process was best fitted to the pseudo-second-order isotherm and an overall match to the Freundlich model. Thermodynamic parameters suggested that the process was mainly exothermic and more spontaneous at lower temperatures. The performance of the adsorbent was further evaluated using environmental waters and the adsorbent demonstrated good potential for simultaneous adsorption of multicomponent pharmaceuticals.