Grafting electrosprayed silica microspheres on cellulosic textile via cyanuric chloride reactive groups

A novel method of covalently grafting solid or hollow microcapsules on cellulosic textiles was developed by surface functionalisation of capsules with reactive triazine moieties. Demonstrative silica microspheres, with 454 nm average particle size, were developed by electrospraying silica sol prepared via sol–gel process. The chemical–physical properties of submicron particles were characterised by Fourier transform infrared spectroscopy (FTIR), thermogravimetry (TGA) and scanning (SEM) and transmission electron microscopy (TEM). As a potential process towards functional textiles, the micro/nanosphere surface was modified with chlorotriazine ligands in a two-step procedure to react with the hydroxyl groups in cellulose under mild conditions. The first amine functionalisation was demonstrated by evaluation with FTIR and silicon-29 nuclear magnetic resonance (29Si-NMR), as well as using TGA. Subsequent chemical functionalisation of an amine–silica surface with triazine moieties was analysed by FTIR, proton solid-state NMR spectroscopy (1H-NMR) and TEM coupled to an X-ray detector. Finally, the covalent bonding of silica nanoparticles to cellulose was performed under simulated dying conditions and it was evaluated by SEM in combination to energy dispersive X-ray spectroscopy.