Wettability of soft PLGA surfaces predicted by experimentally augmented atomistic models

A challenging topic in surface engineering is predicting the wetting properties of soft interfaces with different liquids. However, a robust computational protocol suitable for predicting wettability with molecular precision is still lacking. In this article, we propose a workflow based on molecular dynamics simulations to predict the wettability of polymer surfaces and test it against the experimental contact angle of several polar and nonpolar liquids, namely water, formamide, toluene, and hexane. The specific case study addressed here focuses on a poly(lactic-co-glycolic acid) (PLGA) flat surface, but the proposed experimental-modeling protocol may have broader fields of application. The structural properties of PLGA slabs have been modeled on the surface roughness determined with microscopy measurements, while the computed surface tensions and contact angles were validated against standardized characterization tests, reaching a discrepancy of less than 3% in the case of water. Overall, this work represents the initial step toward an integrated multiscale framework for predicting the wettability of more complex soft interfaces, which will eventually take into account the effect of surface topology at higher scales and synergically be employed with experimental characterization techniques.