The origin of the coil-globule transition for water-soluble thermoresponsive polymers frequently used in nanomaterials remains elusive. Using polypropylene oxide as an example we demonstrate by means of atomistic molecular dynamics simulations that temperature-induced increase in the sequence length of monomers that are not hydrogen bonded to water drives the coil-globule transition. Longer chains statistically exhibit longer sequences which serve as nucleation sites for hydrophobic cluster formation, facilitating chain collapse at lower temperature in agreement with experimental data.

中文翻译：

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水溶性热敏聚合物中氢键序列引导的线圈-球状转变

纳米材料中常用的水溶性热敏聚合物的线圈-球状转变的起源仍然难以捉摸。以聚环氧丙烷为例，我们通过原子分子动力学模拟证明，温度引起的不与水键合的单体序列长度的增加驱动了线圈-球体转变。更长的链在统计上表现出更长的序列，作为疏水簇形成的成核位点，促进链在较低温度下坍塌，与实验数据一致。