Hierarchically Self-Assembled Amphiphilic Alternating Copolymer Brush Containing Side-Chain Cholesteryl Units

详细信息    查看全文

• 作者：Jing Ping ; Kehua Gu ; Sheng Zhou ; Hongbing Pan ; Zhihao Shen ; Xing-He Fan
• 刊名：Macromolecules
• 出版年：2016
• 出版时间：August 23, 2016
• 年：2016
• 卷：49
• 期：16
• 页码：5993-6000
• 全文大小：507K
• 年卷期：0
• ISSN：1520-5835

文摘

We synthesized a novel amphiphilic alternating copolymer brush (AACPB), poly{maleimide-g-poly[10-(cholesteryloxycarbonyl)decyl methacrylate]}-alt-(styrene-g-poly(ethylene oxide)) (P(MI-g-PCholMA)-alt-(St-g-PEO)), by copolymerization of maleimide-terminated poly[10-(cholesteryloxycarbonyl)decyl methacrylate] (MI-PCholMA) and styrene-terminated poly(ethylene oxide) (St-PEO). The thermal properties of the polymer brushes were investigated by thermogravimetric analysis and differential scanning calorimetry. After solvent and thermal annealing, the AACPB self-assembles into a hierarchically ordered nanostructure. One is the microphase-separated lamellar nanostructure with a 9.66 nm scale. The other is the cholesteryl double-layer smectic A phase (SmA_d) with a 5.46 nm scale. The order–disorder transition of the AACPB is associated with the SmA_d–isotropic transition. It is the first report on the microphase separation of AACPBs. We can construct ordered nanostructures with a sub-10 nm length scale with AACPBs. After the doping of 0.2 equiv of LiCF₃SO₃, the d-spacing of the lamellar structure formed by the PCholMA₈-alt-PEO₂₅/LiCF₃SO₃ complex increases because the interaction between Li⁺ and oxygen atom makes the PEO chains more stretched. Such a structure offers lithium salt-doped PEO nanochannels which can act as pathways for the transport of lithium ion.