Structure and properties of cationic starches synthesized by using 3-chloro-2-hydroxypropyltrimethylammonium chloride

Facile construction of cationic lignin modified bentonite–alginate nanocomposite gel for sustained release of alachlor

“…To further explore the structure of the nanocomposite gels, the FTIR spectra of the gel films were obtained and summarized in Figure 3a. The characteristic adsorption bands of alginate at 3438, 1625, 1412, 949, and 883 cm −1 were corresponded to O–H vibration, symmetric and asymmetric stretching vibration of the carboxylate, C–O–C stretching vibration and C–O stretching vibration, respectively 49,50 . The main infrared characteristic bands of CL modified bentonite were similar to alginate gels.…”

“…The characteristic adsorption bands of alginate at 3438, 1625, 1412, 949, and 883 cm À1 were corresponded to O-H vibration, symmetric and asymmetric stretching vibration of the carboxylate, C-O-C stretching vibration and C-O stretching vibration, respectively. 49,50 The main infrared characteristic bands of CL modified bentonite were similar to alginate gels. Besides the decrease of carboxyl absorption intensity, the addition of modified bentonite had no obvious effect on the characteristic absorption wavelength of alginate gels.…”

Peculiarities of Cross‐Linking Degree Determination for the Starches of Different Botanical Origin

“…It can be speculated that cross‐linking of the granules is taken mainly in the outer layers of the granules, which was confirmed previously in other modification reactions. [ 16 ] Therefore, the smaller granules possess larger surface and at the same amount of the granules, higher amount of the cross‐linking agent is needed to achieve similar cross‐linking and solubility characteristics. Another possible explanation concerning the inconsistencies of the results achieved by employing different methods is related with the differences in the solvation power of the solvents used.…”

“…Meanwhile, by adding 0.01 mol of cross‐linking agent per mole of starch potato, wheat and corn starches granules were cross‐linked to 92.5%, 67.5%, and 46.2%, respectively. The observed trend could be due to the fact that smaller starch granules of the same mass have larger surface area and if the reaction takes place on the surface of the granules, [ 16 ] the larger particles will need less cross‐linking agent to be cross‐linked to the extent. This finding has been also confirmed by the results of solubility in KOH solution, where potato starch, which consists of the largest granules, dissolves worse with increasing EPI content.…”

“…These factors can strongly influence both the cross‐linking reaction, pasting characteristics, and consequent viscosity parameters. As it is known that when modifying the starch, reaction does not take place evenly over the entire volume of the granule but mainly on its surface, [ 16 ] the taking into the account of the size and density of the granules is of high importance.…”