Interaction potential between polymer grafted nanosheets in an architecturally dissimilar polymer matrix

• Published in: Chemical engineering science 2019-12, Vol.209, p.115184, Article 115184
• Main Authors: Gupta, Supriya, Chokshi, Paresh
• Format: Article
• Language: English
• Subjects: Clay nanosheets; Dispersion; Exfoliation; Polymer nanocomposites; Self-consistent field theory
• ISSN: 0009-2509; 1873-4405
• DOI: 10.1016/j.ces.2019.115184

•Polymer mediated interaction between two functionalized nanosheets is estimated.•Effect of polymer chain architecture on the interaction potential curve is examined.•Nanosheets are better dispersed in a star polymer matrix compared to linear polymer. We examine the polymer mediated interaction between two brush coated nanosheets to address the quality of dispersion of clay sheets in a polymer matrix. The distance dependent potential curve for a pair of interacting nanosheets is constructed using self-consistent field theory. We study the role of polymer chain architecture, in addition to the size and chemical dissimilarities between free and grafted chains, in controlling the nature of interaction between finite sized nanosheets. By replacing linear polymeric chains of the matrix polymer with multi-armed star polymer of same degree of polymerization, the strength of attraction is found to be weakened and is completely eliminated for high degree of branching. The compactness of star molecule overcomes entropy driven depletion between nanosheets leading to wetting of brush with purely repulsive potential, indicative of exfoliated dispersion. Thus, the quality of dispersion can be improved by altering the architecture of free and grafted polymeric chains.