Fabrication and physicomechanical enhancement of APTES Cross-linked gelatin biopolymer films

The exceptional film-forming ability, biodegradability, biocompatibility, and wide availability of cross-linked gelatin have sparked considerable interest in its utilization for packaging purposes. APTES (3-Aminopropyltriethoxysilane) cross-linker is preferred due to its ability to bind with gelatin involving its silanol groups and for its non-hazardous nature. This study aims to fabricate cross-linked gelatin films specifically tailored for packaging applications. The FTIR spectra of the gelatin films provided evidence of successful cross-linking, as indicated by the presence of Si–O-Si and Si–OH bonds. SEM analysis exhibited structural uniformity with increasing concentrations of the cross-linker, indicating favorable interactions between APTES and gelatin molecules. Furthermore, enhanced thermal stability was observed, as evidenced by TGA results, suggesting the formation of stable cross-links. The introduction of APTES to the gelatin films preserved their transparency, reduced solubility (from 84 to 58%), lowered water permeability, and increased tensile strength up to 7.3 MPa with the increase in film thickness from 0.129 mm to 0.150 mm. Moreover, the films exhibited decreased transmission of UV light (reduced from 4.8 to 1.4% by adding APTES in the 280 nm wavelength), indicating potential applications in UV protection. Finally, the cross-linked gelatin films modified with APTES demonstrated favorable characteristics for packaging applications.