Shimokita Keisuke, Yamamoto Katsuhiro, Miyata Noboru, Shibata Motoki, Nakanishi Yohei, Arakawa Masato, Takenaka Mikihito, Kida Takumitsu, Tokumitsu Katsuhisa, Tanaka Ryo, Shiono Takeshi, Yamada Masako, Seto Hideki, Yamada Norifumi L, Aoki Hiroyuki, Miyazaki Tsukasa
Department of Life Science and Applied Chemistry, Gradual School of Engineering, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya 466-8555, Japan.
Neutron Science and Technology Center, Comprehensive Research Organization for Science and Society, 162-1 Shirakata, Tokai, Ibaraki 319-1106, Japan.
Langmuir. 2024 Jul 16. doi: 10.1021/acs.langmuir.4c01584.
To investigate the structure of the interface between polyethylene films and substrates, the neutron reflectivity (NR) of deuterated polyethylene (dPE) thin films deposited on Si substrates was measured, demonstrating water accumulation at the interface, even under ambient conditions. After leaching the thermally annealed dPE films in hot -xylene, NR measurements were conducted on the layers remaining on the substrate, clearly revealing that the adsorption layer of dPE grew during annealing and consisted of two layers, an inner adsorption layer and an outer adsorption layer, as previously proposed for amorphous polymers. The inner adsorption layer was approximately 3.7 nm thick with a density comparable to that of the bulk. The outer adsorption layer was several nanometers thick and appeared to grow insufficiently on top of the inner adsorption layer under the annealing conditions examined in this study. This study clarifying the growth of the adsorption layer of polyethylene at the interface with an inorganic substrate is useful for improving the performance of polymer/inorganic filler nanocomposites due to the wide utility of crystalline polyolefins as polymer matrix materials in nanocomposites.
为了研究聚乙烯薄膜与基底之间界面的结构，测量了沉积在硅基底上的氘代聚乙烯（dPE）薄膜的中子反射率（NR），结果表明即使在环境条件下，界面处也存在水的积累。在将热退火后的dPE薄膜在热二甲苯中浸提后，对基底上剩余的层进行了NR测量，结果清楚地表明，dPE的吸附层在退火过程中生长，并且由两层组成，即内层吸附层和外层吸附层，正如之前针对无定形聚合物所提出的那样。内层吸附层厚度约为3.7 nm，密度与本体相当。外层吸附层厚度为几纳米，在本研究考察的退火条件下，似乎在内层吸附层之上生长不足。由于结晶聚烯烃作为纳米复合材料中聚合物基体材料具有广泛的用途，本研究阐明了聚乙烯在与无机基底界面处吸附层的生长情况，这对于提高聚合物/无机填料纳米复合材料的性能是有用的。
