Thermal degradation and stability of cationic starches and their complexes with iodine.

Thermal degradation processes of cationic starch (CS) and CS-iodine complex were investigated by thermogravimetry (TG) in air and under nitrogen atmosphere at 10 °C min(-1) heating rate and compared. Moreover, the thermal stability of CS with different degree of substitution (DS) and their complexes with iodine was studied by TG under nitrogen atmosphere at different heating rates. The average E(a) values for CS were found to be slightly lower as compared to native starch, suggesting lower thermal stability of modified starches due to cationisation.

Preparation, stability and antimicrobial activity of cationic cross-linked starch-iodine complexes.

Cationic cross-linked starch (CCS)-iodine complexes containing different amounts of quaternary ammonium groups (different degrees of substitution (DS)) and iodine have been obtained by iodine adsorption on CCS from aqueous iodine potassium iodide solution. Equilibrium adsorption studies showed that with an increase of DS the amount of iodine adsorbed on CCS and the affinity of iodine to CCS increased linearly. The influences of the DS of CCS and the amount of adsorbed iodine on the stability of CCS-iodine complexes in a solution of 0.

Cationic starch nanoparticles based on polyelectrolyte complexes.

Cationic starch nanoparticles were obtained by aqueous polyelectrolyte complex formation between cationic quaternary ammonium substituted starches and anionic sodium tripolyphosphate. The formation of nanosized starch particles of spherical shape was verified by dynamic light scattering and scanning electron microscopy measurements. The cationic starch nanoparticles of different constitution and containing various contents of free quaternary ammonium groups were produced and their zeta potential was modulated between +4 mV and +34 mV by varying polycation/polyanion ratio.

Adsorption of hexavalent chromium on cationic cross-linked starches of different botanic origins.

The influence of origin of native starch used to obtain cationic cross-linked starch (CCS) on the adsorption of Cr(VI) onto CCS has been investigated. CCS granule size is influenced by the botanic source of native starch. The equilibrium adsorption of Cr(VI) onto CCS was described by the Langmuir, Freundlich, Dubinin-Radushkevich and Temkin models.