在线块共聚物化中出现六角密集球体
Cheng Zhang1, Daniel L Vigil, Dan Sun
1Australian Institute for Bioengineering and Nanotechnology and ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, University of Queensland, Brisbane, Queensland 4072, Australia.
Journal of the American Chemical Society
|August 27, 2021
概括
研究人员在特定的线性块共聚物中发现了纯六角密集球体 (HCP). 这一发现挑战了此前关于在此类材料中进入HCP阶段的假设.
科学领域:
- 聚合物科学
- 材料科学
- 软物质物理学
背景情况:
- 六角密封 (HCP) 球相在线性块共聚物中理论上是稳定的,但由于很小的自由能量差异,它经常与其他相共存.
- 为了获得纯净的HCP,通常需要复杂的加工或混合技术.
研究的目的:
- 报告在新的线性块共聚物化中发现纯净的HCP球体.
- 研究HCP阶段形成和稳定的条件和机制.
主要方法:
- 线性块共聚物与特定聚合物块 (聚二三乙烯酸) 和聚二二乙烯酸或聚四二乙烯酸) 的合成
- 跨越A块体积分数范围的相位行为.
- 阶段形成动力学和可逆性的分析.
- 自己一致的场理论计算以了解相位稳定性.
主要成果:
- 在4DF双块和F4DF三块共聚物中成功合成纯HCP球体.
- 在一个显著的A块体积分数范围内观察到HCP阶段 (大约0. 25- 0. 30).
- 在F4DF三重块中,HCP阶段形成可逆,表明平衡状态.
- 在超冷液体或软固体中直接形成HCP,绕过中间准晶体阶段.
- 发现摩尔质分散度 (Đ) 对HCP稳定性至关重要,低分散度 (例如, Đ = 1.04) 有利于HCP阶段.
结论:
- 这项研究证明了在不需要复杂处理的情况下在线性块共聚物中获得纯的HCP球的新途径.
- 这些发现强调了低摩尔质分散在稳定HCP阶段的关键作用.
- 这项工作挑战了传统的理解,并为复杂的聚合物架构的控制合成开辟了可能性.
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