Department of Polymer Science, The University of Akron, Akron, Ohio 44325, USA.
Soft Matter. 2017 Nov 22;13(45):8556-8564. doi: 10.1039/c7sm01959a.
The complexity of induced ordering for tactic poly(methyl methacrylate) (PMMA) thin films in contact with water is examined through all-atom molecular dynamics with validated potentials. We observe that for the water molecules that are hydrogen bonded to the PMMA surface, the isotactic and atactic PMMA show a 33% longer relaxation time compared to syndiotactic PMMA. Almost 94% of hydrogen bonds are with the carbonyl groups of PMMA, irrespective of temperature and tacticity. The stability in re-orientation and nature of hydrogen bond participation for the carbonyl groups as well as about 20% higher interaction energies of carbonyl group hydrogen bonded with water for atactic form indicates existence of cooperative effects. Quantifying the dynamics of hydrogen bond at the tactic interface is important in understanding the role tacticity plays in controlling adhesion and biocompatibility, a design choice that has been gaining ground in the soft material science community.
通过具有验证势能的全原子分子动力学，研究了与水接触的战术聚甲基丙烯酸甲酯（PMMA）薄膜的诱导有序复杂性。我们观察到，对于与 PMMA 表面形成氢键的水分子，与 syndiotactic PMMA 相比，isotactic 和 atactic PMMA 的弛豫时间长 33%。几乎 94%的氢键与 PMMA 的羰基有关，与温度和立构规整度无关。羰基的再取向稳定性和氢键参与性质以及与水形成氢键的羰基的相互作用能高出约 20%，表明存在协同效应。在战术界面量化氢键动力学对于理解立构规整度在控制粘附和生物相容性中的作用非常重要，这是软物质科学界越来越关注的设计选择。
