Interfacial modification of starch at high concentration by sodium dodecylsulfate as revealed by experiments and molecular simulation

It is proposed that the interfacial compatibility of starch-based adhesives could be improved by sodium dodecylsulfate (SDS). The preparation of starch suspension with high concentration and molecular dynamics simulation were designed according to the adhesive preparation. The results showed that SDS without absorption competition expanded the molecular space and improved the starch dispersion. Additionally, the thickest interfacial layer was formed on starch containing 2% SDS due to the deeper immersion of SDS. Excessive SDS facilitated the supramolecular assembly, leading to the formation of starch colloid. SDS decreased the interfacial tension between the starch and different polarity matrix. Our simulated results accorded with the experimental results and presented the starch structure at the atomic level. Owing to the inhibition on molecular interaction of starch, SDS promoted the starch extensibility and flexibility. Moreover, three different contact forms (tail, head, and inclusion) between the starch and SDS were also presented in this work. This study is fundamental to establishing the relationship between macromolecular behaviors and product performance. (C) 2020 Published by Elsevier B.V.