Photonic Block Copolymer Films Swollen with an Ionic Liquid
Photonic Block Copolymer Films Swollen with an Ionic Liquid
复制标题
DOI：
10.1021/ma500517e
复制
发表时间：
2014-06-24
期刊：
影响因子：
5.5
通讯作者：
Thomas, Edwin L.
中科院分区：
文献类型：
--
作者：
Noro, Atsushi;Tomita, Yusuke;Thomas, Edwin L.
通过离子液体的渗透，从具有中等分子量的片层形成嵌段共聚物制备了非挥发性溶剂溶胀的一维周期性膜。在旋涂具有大约50/50组成的聚苯乙烯-b-聚（2-乙烯基吡啶）（PS-P2 VP）嵌段共聚物的薄膜之后，加入咪唑和咪唑鎓双（三氟甲磺酰基）酰亚胺的混合物作为室温离子液体，以产生在可见光范围内反射的光子膜。在正常的温度和湿度条件下，薄膜保持其光子特性超过100天，没有明显的变化，这是由于离子液体的不挥发性。透射电子显微镜显示的P2 VP nanodomains的IL和超小角X-射线散射测量的选择性溶胀提供定量的纳米结构的信息的周期性的膜。通过使用不同分子量的嵌段共聚物以及通过使用两种嵌段共聚物的共混物，光子薄膜的反射光的波长是可调的。由光纤分光光度计检测到的反射光的实验波长与从布拉格条件估计的值一致，并且能够从约380至620 nm控制。
Nonvolatile solvent swollen 1D periodic films were fabricated from lamellae-forming block copolymers with medium molecular weight by infiltrating an ionic liquid. A mixture of imidazole and imidazolium bis(trifluoromethanesulfonyl)imide as a room temperature ionic liquid was added after spin-coating of thin films of polystyrene-b-poly(2-vinylpyridine) (PS-P2VP) block copolymers having an approximately 50/50 composition to create photonic films reflecting in the visible regime. Under normal conditions of temperature and humidity, the films maintained their photonic properties for more than 100 days without perceptible change, stemming from the nonvolatility of the ionic liquid. Transmission electron microscopy revealed the selective swelling of the P2VP nanodomains by the IL and ultrasmall angle X-ray scattering measurements provided quantitative nanostructure information on the periodicities of the films. The wavelength of reflected light from photonic films was tunable by using different molecular weight block copolymers as well as by employing blends of two block copolymers. The experimental wavelength of the reflected light, detected by a fiber-optic spectrophotometer, agreed with values estimated from the Bragg condition and was able to be controlled from about 380 to 620 nm.