The removal of ultrathin amorphous polymer films in contact with nonsolvent/solvent binary mixtures is addressed by means of neutron reflectometry and atomic force microscopy. The high resolution of neutron scattering makes it possible to resolve the distribution profiles of heavy water and benzyl alcohol inside Laropal®A81, often employed as a protective varnish layer for Culture Heritage in restoration of easel paintings. The swelling kinetics and distribution profiles were recorded as a function of time and increasing benzyl alcohol concentration in water. The varnish film swells by penetration of the good solvent. At higher concentrations water-filled cavities appear inside the varnish and grow with time. Contrary to homogeneous dissolution dewetting is observed at late stages of exposure to the liquid which leads to the Breakup of the film. The high resolution measurements are compared to bulk behaviour characterized by the ternary phase diagram and the Flory-Huggins interaction parameters are calculated and used to predict the swelling and solvent partition in the films. Distinct differences of the thin film to bulk behaviour are found. The expectations made previously for the behaviour of solvent/non-solvent mixtures on the removal of thin layers in the restoration of easel paintings should be revised in view of surface interactions.

中文翻译：

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用于文化遗产的聚合物薄膜的膨胀，去湿和破裂。

通过中子反射法和原子力显微镜研究了与非溶剂/溶剂二元混合物接触的超薄无定形聚合物薄膜的去除。中子散射的高分辨率使得解析Laropal®A81内重水和苯甲醇的分布状况成为可能，该物质通常用作文化遗产的保护性清漆层，用于修复画架画。溶胀动力学和分布曲线记录为时间和水中苄醇浓度增加的函数。清漆膜通过良溶剂的渗透而溶胀。在较高浓度下，充满水的空腔会出现在清漆内部，并随时间而增长。与均匀溶解反润湿相反，在暴露于液体的后期可观察到这导致薄膜破裂。将高分辨率测量值与以三元相图表征的整体性能进行比较，并计算出Flory-Huggins相互作用参数，并将其用于预测薄膜中的溶胀和溶剂分配。发现薄膜与本体行为的明显差异。先前对溶剂/非溶剂混合物在修复画架油画中去除薄层的行为的预期应根据表面相互作用进行修改。