The Coil-to-Globule-to-Coil Transition of Linear Polymer Chains in Dilute Aqueous Solutions: Effect of Intrachain Hydrogen Bonding
The Coil-to-Globule-to-Coil Transition of Linear Polymer Chains in Dilute Aqueous Solutions: Effect of Intrachain Hydrogen Bonding
复制标题
稀水溶液中线性聚合物链的线圈到球体到线圈的转变：链内氢键的影响
DOI：
10.1021/ma8019128
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发表时间：
2008-11-25
期刊：
影响因子：
5.5
通讯作者：
Wu, Chi
中科院分区：
文献类型：
--
作者：
Zhou, Kejin;Lu, Yijie;Wu, Chi
我们以前对标题转变的研究表明，温度敏感的聚(N-异丙基丙烯酰胺)(PNIPAM)在水中可以形成稳定的单链微球，但在环己烷中不能形成聚苯乙烯(PS)。在本研究中，使用无给氢基的聚N，N-二乙基丙烯酰胺(PDEAM)(相对分子质量为1.7×107g/mol，分子量比为1.06)，我们试图发现链内氢键是否在稳定单个塌陷的PNIPAM单链小球中起作用。我们发现，PDEAM也可以在水中形成稳定的单链球体，尽管转变不那么尖锐。由此产生的单个PDEAM单链球不那么紧密，反映在较低的链密度和较高的旋转半径与流体动力学半径之比，可能是由于缺乏链内氢键。我们的结果还表明，与PNIPAM不同，PNIPAM在相变过程中没有磁滞，间接支持了我们先前的假设，即PNIPAM的磁滞是...
Our previous studies of the captioned transition have shown that thermally sensitive poly(N-isopropylacrylamide) (PNIPAM) in water can form stable individual single-chain globules, but not for polystyrene (PS) in cyclohexane. In the current study, using poly(N,N-diethylacrylamide) (PDEAM) (Mw = 1.7 × 107 g/mol and Mw/Mn = 1.06) with no hydrogen donator site, we intend to find whether the intrachain hydrogen bonding plays a role in stabilizing individual collapsed PNIPAM single-chain globules. We found that PDEAM can also form stable single-chain globules in water even though the transition is less sharp. The resultant individual PDEAM single-chain globules are less compact, reflecting in a lower chain density and a higher ratio of the radius of gyration to hydrodynamic radius, presumably due to the lack of intrachain hydrogen bonding. Our result also shows that, unlike PNIPAM, there is no hysteresis in the transition, indirectly supporting our previous assumption that the hysteresis observed for PNIPAM is...