The connection between block copolymer architecture and adsorption at fluid/fluid interfaces is poorly understood. We characterize the interfacial properties of a well-defined series of polyethylene oxide/polydimethyl siloxane (PDMS) diblock and BAB triblock copolymers at the dodecane/water interface. They are oil-soluble and quite flexible because of their hydrophobic PDMS block. Rather than relying on equilibrium interfacial measurements for which it is difficult to mitigate experimental uncertainty during adsorption, we combine measurements of steady-state adsorption, dilatational rheology, and adsorption/desorption dynamics. Steady-state interfacial pressure is insensitive to interfacial curvature and mostly agrees with theory. Adsorption does not occur in the diffusive limit as is the case for many aqueous, small-molecule surfactants. Dilatational rheology reveals differences in behavior between the diblocks and triblocks, and all interfaces possess elasticities below the thermodynamic limit. Desorption dynamics show that material exchange between the interface and the neighboring fluid occurs too slowly to relax dilatational stresses. The mechanism of relaxation occurs at the interface, likely from the reorientation of adsorbed chains.

中文翻译：

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将柔性，油溶性二嵌段和BAB三嵌段共聚物运输到油/水界面。

嵌段共聚物结构与流体/流体界面处的吸附之间的联系了解甚少。我们表征了十二烷/水界面上一系列定义明确的聚环氧乙烷/聚二甲基硅氧烷（PDMS）二嵌段和BAB三嵌段共聚物的界面性能。它们具有油溶性，并且由于其疏水性PDMS嵌段而具有很高的柔韧性。而不是依靠平衡界面测量来缓解吸附过程中的实验不确定性，我们将稳态吸附，膨胀流变学和吸附/解吸动力学的测量结合起来。稳态界面压力对界面曲率不敏感，并且与理论基本一致。不会像许多水性小分子表面活性剂那样在扩散极限内发生吸附。膨胀流变学揭示了二嵌段和三嵌段之间的行为差​​异，并且所有界面都具有低于热力学极限的弹性。解吸动力学表明，界面和邻近流体之间的物质交换发生得太慢，以致于无法消除膨胀应力。松弛的机理发生在界面，可能是由于吸附链的重新取向。