Building on our recent work that mapped the profile in local glass transition temperature T_g(z) across a single polystyrene (PS)/poly(n-butyl methacrylate) (PnBMA) interface, we explore the impact of limiting domain size and increasing cooling rate. This study is motivated by traditional computational approaches employed to overcome computer-power limitations, extrapolating short time scales and using periodic boundary conditions that introduce repeating interfaces. Using a localized fluorescence method, we find addition of a second PS/PnBMA interface perturbs the local PS T_g(z) at a distance of z = 100 nm from the first interface when the second interface approaches a distance closer than 300 nm. The local T_g(z) profile across a finite PS domain size of 300 nm for a range of cooling rates shows that limiting domain size and increasing cooling rate (faster time scales) diminishes and truncates the broad asymmetric T_g(z) profile, weakening the confinement effect for dissimilar polymer–polymer interfaces, consistent with previous studies on single-layer polymer films.

中文翻译：

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周期性边界条件影响的实验研究：有限尺寸和更快的冷却速率对异种聚合物-聚合物界面的影响

基于我们最近的工作，该工作在单个聚苯乙烯（PS）/聚甲基丙烯酸正丁酯（PnBMA）界面上绘制了局部玻璃化转变温度T _g（z）中的分布图，我们探索了限制晶畴尺寸和增加冷却的影响速度。这项研究的动机是采用传统的计算方法来克服计算机能力的局限性，外推短时标并使用引入重复接口的周期性边界条件。使用的本地化的荧光的方法，我们发现加入第二PS / PnBMA接口扰乱本地PS的Ť_克（ž在距离）Ž当第二界面接近小于300 nm的距离时，距第一界面= 100 nm。在一定冷却速率范围内，在300 nm的有限PS域尺寸上的局部T _g（z）分布图表明，限制域尺寸和增大的冷却速率（较快的时间尺度）会减小并截断宽的不对称T _g（z）分布图，削弱了对异种聚合物-聚合物界面的约束作用，这与先前对单层聚合物膜的研究一致。