Instituto de Física de São Carlos, USP, C.P. 369, 13560-250 São Carlos/SP, Brazil.
J Colloid Interface Sci. 2010 Jun 1;346(1):87-95. doi: 10.1016/j.jcis.2010.02.061. Epub 2010 Mar 3.
The applicability of azopolymers in optical storage can be extended through the use of nanostructured films produced with the Langmuir-Blodgett (LB) technique, but the film properties need to be optimized since these polymers generally do not form stable Langmuir films to be transferred onto solid substrates. Here, photoinduced birefringence was investigated for mixed Langmuir-Blodgett films from the homopolymers 4-[N-ethyl-N-(2-methacryloxyethyl)]-4'-nitroazobenzene (HPDR1-MA) and poly(dodecylmethacrylate) (HPDod-MA). The interactions between these polymers were studied in Langmuir and LB films. Surface pressure-area isotherms pointed to molecular-level interactions for proportions of 51 mf%, 41 mf% and 31 mf% of HPDR1-MA. Phase segregation was not apparent in the BAM images, in which the morphology of the blend film was clearly different from that of the Langmuir films of neat homopolymers. Through PM-IRRAS, we noted that the interaction between the azopolymer and HPDod-MA affected the orientation of carbonyl groups. Strong interactions for the mixture with 41 mf% of poly(dodecylmethacrylate) led to stable Langmuir films that were transferred onto solid supports as LB films. The photoinduced birefringence of 101-layer mixed LB films show features that make these films useful for optical storage, with the advantage of short writing times in comparison to other azopolymer films.
通过使用 Langmuir-Blodgett (LB) 技术制备的纳米结构薄膜，可以扩展偶氮聚合物在光存储中的适用性，但需要优化薄膜性能，因为这些聚合物通常不能形成稳定的 Langmuir 薄膜以转移到固体基底上。在这里，研究了均聚物 4-[N-乙基-N-(2-甲基丙烯酰氧基乙基)]-4'-硝基偶氮苯 (HPDR1-MA) 和聚(十二烷基甲基丙烯酸酯) (HPDod-MA) 的混合 Langmuir-Blodgett 薄膜的光致双折射。在 Langmuir 和 LB 薄膜中研究了这些聚合物之间的相互作用。表面压-面积等温线表明，HPDR1-MA 的比例为 51 mf%、41 mf%和 31 mf%时存在分子水平的相互作用。BAM 图像中没有明显的相分离，混合薄膜的形态明显不同于纯均聚物的 Langmuir 薄膜。通过 PM-IRRAS，我们注意到偶氮聚合物与 HPDod-MA 之间的相互作用影响了羰基的取向。与聚(十二烷基甲基丙烯酸酯)的混合物具有 41 mf%的强相互作用，导致稳定的 Langmuir 薄膜可以作为 LB 薄膜转移到固体载体上。101 层混合 LB 薄膜的光致双折射具有使这些薄膜可用于光存储的特征，与其他偶氮聚合物薄膜相比，具有较短的写入时间的优点。
