2020 journal article
Effect of Poly(vinyl butyral) Comonomer Sequence on Adhesion to Amorphous Silica: A Coarse-Grained Molecular Dynamics Study
ACS APPLIED MATERIALS & INTERFACES, 12(42), 47879–47890.
author keywords: polymer adsorption; silica; copolymer sequences; coarse-graining; molecular dynamics
TL;DR:
An unexpectedly complex relationship between blockiness parameter and adhesion energy is discovered for intermediate vinyl alcohol (VA) content; adhesion strength to the silica slab was found to be maximal not for diblockCopolymers, but rather random-blocky copolymers with a moderately high degree of blockiness.
(via Semantic Scholar)
UN Sustainable Development Goal Categories
3. Good Health and Well-being
(Web of Science)
6. Clean Water and Sanitation
(Web of Science)
Source: Web Of Science
Added: December 21, 2020
Modulating a comonomer sequence, in addition to overall chemical composition, is the key to unlocking the true potential of many existing commercial copolymers. We employ coarse-grained molecular dynamics (MD) simulations to study the behavior of random-blocky poly(vinyl butyral-co-vinyl alcohol) (PVB) melts in contact with an amorphous silica surface, representing the interface found in laminated safety glass. Our two-pronged coarse-graining approach utilizes both macroscopic thermophysical data and all-atom molecular dynamics simulation data. Polymer-polymer nonbonded interactions are described by the fused-sphere SAFT-γ Mie equation of state, while bonded interactions are derived using Boltzmann inversion to match bond and angle distributions from all-atom PVB chains. Spatially-dependent polymer-surface interactions are mapped from a hydroxylated all-atom amorphous silica slab model and all-atom monomers to an external potential acting on the coarse-grained sites. We ran a series of interfacial coarse-grained MD simulations for PVB melts, systematically varying overall chemical composition and block length distribution. We discovered an unexpectedly complex relationship between blockiness parameter and adhesion energy. For intermediate vinyl alcohol (VA) content, adhesion strength to the silica slab was found to be maximal not for diblock copolymers, but rather random-blocky copolymers with a moderately high degree of blockiness. We attribute this to two main factors: (1) changes in morphology, which dramatically alter the number of VA beads interacting with the surface, and (2) a non-negligible contribution of vinyl butyral (VB) monomers to adhesion energy, due to their preference to adsorb to zones with low hydroxyl density on the silica surface.