Simultaneously improved chitin gel formation and thermal stability promoted by TiO2

Abstract A severe challenge hindering preparation of chitin-based composites is their insolubility in normal solvents. Different composites gels were successfully fabricated through alkali and freezing treatment in chitin‑titanium dioxide (TiO2) suspensions. TiO2 particles played a key role in chitin gel performance, in which improved thermal stability and a unique cell-structure-like morphological result were simultaneously achieved. The thermal stabilizing effect was attributed to the high thermal stability of TiO2 particles. With respect to the mechanism of gel formation, the TiO2 particles reduce the effect of the alkali treatment and induce specific interactions with chitin to lead to a stronger and denser gel network. The former was supported by the increase in crystallinity, while the latter was substantiated by FT-IR results. Our current study provides a green and simple approach to prepare chitin-TiO2 composites with improved performance.