Preparation and characterization of cross-linked starch nanocrystals and self-reinforced starch-based nanocomposite films

Effect of Molecular Weight and Degree of Substitution on the Physical-Chemical Properties of Methylcellulose-Starch Nanocrystal Nanocomposite Films

“…Starch nanocrystals (SNC) are crystalline platelets produced from the disruption of the semi-crystalline structure of starch granules by the acid hydrolysis of amorphous parts [ 9 ]. Researchers have studied the reinforcement effects of SNC in biopolymer films produced from incorporating SNC into carboxymethyl chitosan, pullulan, starch, pea starch, thermoplastic starch, amaranth protein, and soy protein isolate [ 10 , 11 , 12 , 13 , 14 , 15 ]. All these studies demonstrated that these biopolymer-SNC nanocomposite films exhibited improved mechanical, oxygen and water vapor barrier, surface hydrophobicity, and/or thermal properties in comparison with the pure biopolymer films.…”

Nanocomposite Starch Films: A New Approach for Biodegradable Packaging Materials

“…[ 56 ] The native starch‐based film had a WVP of around 8.9 × 10 −12 g m m −2 s −1 Pa −1 and the inclusion of 10% cross‐linked starch nanocrystals may drastically lower the WVP of the film up to 4.2 × 10 −12 g m m −2 s −1 Pa −1 . [ 58 ] The existence of cross‐linked starch nanocrystals can behave as a geometrical impedance for water molecules passing through the starch matrix, lowering the water permeability of nanocomposite films. [ 59 ]…”

“…But there were few clear concave areas on the surface of the native starch film. [ 58 ] The space among the three‐dimensional structures of starch films became the structural base for nanofiller to improve various physiochemical characteristics of the films. [ 60 ] Furthermore, nanocomposite films have rough surfaces on all sides, [ 58 ] specifying that a conglomeration of cross‐linked starch nanocrystals occurred.…”

“…[ 58 ] The space among the three‐dimensional structures of starch films became the structural base for nanofiller to improve various physiochemical characteristics of the films. [ 60 ] Furthermore, nanocomposite films have rough surfaces on all sides, [ 58 ] specifying that a conglomeration of cross‐linked starch nanocrystals occurred. [ 88 ] More precisely, the roughness of the corresponding nanocomposite film increased as the content of cross‐linked starch nanocrystals increased from 10% to 12%.…”

“…These phenomena can be ascribed to the cross-linked starch nanocrystals reinforcing impact. [58] Prior literature has shown that the rigorous three-dimensional network formed by the matrix and nanofiller can result in strong interactions such as hydrogen bonds. [70,71] The strong interactions with the reinforced matrix led to an efficient transfer of stress from the matrix to the cross-linked starch nanocrystals via the shearing mechanism, allowing the nanocomposite film to efficiently carry the load and enhance its strength.…”