Nonuniformity of starch/nanosilica composites and interfacial behaviour of water and organic compounds

Hydrated starch alone and in composition with nanosilica A-300 and quercetin (natural antioxidant) was studied in the form of powders (mechanical mixture) and gels using 1H NMR (at 200–280 K), FTIR (293 K), TG (293–573 K), TSDC (90–265 K) and quantum chemistry methods. Influence of weakly polar (chloroform-d, CDCl3) and polar ((CD3)2SO, DMSO) deuterated solvents on bound water structure in these systems was also analysed at 200–280 K. The energetic and structural boundaries between weakly (unfrozen at 250–260 < T < 273 K) and strongly (unfrozen at 200 < T < 250–260 K) bound waters become nonabrupt after the addition of these solvents to quercetin/starch/nanosilica composites because of the differences in water interaction with these substances differently affecting its freezing point depression.