Amine and carboxylate functionalisation of silicate compounds and their effects when incorporated into alginate films

• Silicate compounds succesfuly functionalised with carboxylate group through two step functionalisation procedure. • Alginate films generated with functionalised silicates at 5–20% w/w of alginate. • Carboxylate functionalisation of silicate had shown reduced agglomeration within alginate film when compared to all other developed silicates. This study investigates the incorporation of amine- and carboxylate-functionalised silicates into alginate films to assess structural and functional performance. Silicates were derived from tetraethyl orthosilicate (TEOS) and sugarcane fly ash via the sol–gel process and added to alginate matrices at 5%, 10%, and 20% w/w. While the sugarcane fly ash-derived silicates had been successfully functionalised with carboxylate groups, the carboxylate functionalisation of TEOS-derived silicates was unsuccessful due to insufficient mesoporous structure. When incorporated into the alginate film matrix, the carboxylate-functionalised silicates exhibited reduced agglomeration, enabling more uniform dispersion within the alginate films. However, only TEOS-derived silicates preserved the films’ original tensile strength and elongation. These findings suggest that carboxylate functionalisation of silicates has been shown to enhance compatibility between silicate particles and alginate matrices, improving dispersion and reducing agglomeration. This approach offers potential for applications in alginate-based gels and wound dressings, particularly where controlled release and particle stability are critical.