Coarse-Grained Simulations to Understand the Effect of Grafting on Methylcellulose

Methylcellulose is a biopolymer derived from sugar, and it has a wide range of industrial applications. Recent experiments on methylcellulose solutions showed that they undergo fibril formation above the lower critical solution temperature. However, on grafting the methylcellulose polymer with polyethylene oxide (PEG), experiments show that the fibril structure is destroyed. We use coarse-grained molecular dynamics simulations to provide molecular insights into the effect of grafting on fibril formation. Our results showed that the radius of gyration of the polymer increases with increasing grafting density, in qualitative agreement with the experimental results. We also show that the loss in fibrillar structure arises from a steric repulsion between the grafted PEG monomers and the methylcellulose backbone.