Chitosan-poly(ethylene glycol) diacrylate beads prepared by radiation-induced crosslinking and their promising applications derived from encapsulation of essential oils

Abstract

The extraction of essential oils (EOs) from plants has been receiving great attention. EOs are well known for their capacity to ease tension and reduce stress. However, EOs are volatile, making them unstable due to rapid evaporation and oxidization in air or under ultraviolet light. Encapsulation of EOs in polymeric substrate can help overcome this limitation as well as make their applications more practical. The aim of this study is to fabricate chitosan-poly(ethylene glycol) diacrylate (CS-PEGDA) beads by radiation-induced crosslinking. CS-PEGDA beads were prepared by gamma irradiation. The successful synthesis of CS-PEGDA beads was confirmed by FTIR, TGA and SEM. Effects of radiation dose and PEGDA concentration on diameter, porosity and swelling degree of the obtained beads were analyzed. At 0.25 and 0.5% (w/v) of PEGDA concentration, the porosity and swelling degree of CS-PEGDA beads increased with radiation dose. Gamma irradiation at 25 kGy resulted in maximum values of porosity (97.50 ± 0.73%) and swelling degree (48.32 ± 4.90%) of CS-PEGDA beads. The solubility tests of CS-PEGDA beads in acidic, neutral and basic media were also investigated to prove the formation of CS-PEGDA beads. The CS-PEGDA beads can serve as a polymeric substrate for encapsulation of essential oils.