Morphology Control of Selenophene-Thiophene Block Copolymers through Side Chain Engineering
Morphology Control of Selenophene-Thiophene Block Copolymers through Side Chain Engineering
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DOI：
10.1021/ma501231d
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发表时间：
2014-08-12
期刊：
影响因子：
5.5
通讯作者：
Seferos, Dwight S.
中科院分区：
文献类型：
--
作者：
Hollinger, Jon;Seferos, Dwight S.
我们报道了三个完全π共轭的二嵌段共聚物的合成，含有硒和噻吩为基础的重复单元。所有这些二嵌段共聚物都经历相分离，并且通过侧链改性系统地改变两个嵌段的相容性，我们能够获得不同的薄膜形态。引入大体积的2-乙基己基侧链增加溶解度，同时保持硒代嵌段的结晶度。聚（3-己基硒代苯）-b-聚（3-己基噻吩）和聚（3-（2-乙基己基）硒代苯-b-聚（3-（2-乙基己基）噻吩）形成更无序的纤维状结构，而聚（3-己基噻吩）-b-聚（3-（2-乙基己基）硒代苯）形成长的（1-2 μ m）固态纤维状结构，这使人联想到由非共轭嵌段共聚物形成的层状结构。我们进一步使用电子能量损失光谱可视化噻吩和硒吩丰富的领域在纳米尺度在这些例子中的每一个。通过研究新的聚合物组成并将其与固态结构联系起来，我们进一步理解了杂环诱导的相分离和一般的相分离。
We report the synthesis of three fully pi-conjugated diblock copolymers containing selenophene- and thiophene-based repeating units. All of these diblock copolymers undergo phase separation, and by systematically changing the compatibility of the two blocks through side chain modification, we are able to access different thin film morphologies. Introducing a bulky 2-ethylhexyl side chain increases solubility while retaining crystallinity of the selenophene block. While poly(3-hexylselenophene)-b-poly(3-hexylthiophene) and poly(3-(2-ethylhexyl)selenophene-b-poly(3-(2-ethylhexyl)thiophene) form more disordered fibrillar structures, poly(3-hexylthiophene)-b-poly(3-(2-ethylhexyl)selenophene) forms long (1-2 mu m) solid state fibrillar structures that are reminiscent of the lamellae that are formed by nonconjugated block copolymers. We further use electron energy loss spectroscopy to visualize thiophene- and selenophene-rich domains at the nanometer scale in each of these examples. By studying new polymer compositions and relating them to solid state structure, we further our understanding of heterocycle induced phase separation and phase separation in general.