用Brillouin光谱学观察到的聚烯胺水凝中对自由水的聚合效应
1Department of Physics and Astronomy, University of North Carolina, Chapel Hill, North Carolina 27599, USA. mcneil@physics.unc.edu.
Soft matter
|June 19, 2024
概括
聚合物度显著影响聚烯胺凝模块. 在 GHz 频率下,聚合烯胺减少了自由水的含量.
科学领域:
- 材料科学 材料科学 材料科学
- 聚合物物理 聚合物物理
- 声学 声学 在声学方面
背景情况:
- 聚烯胺水凝是广泛使用的材料,其机械性能取决于其组成.
- 了解聚合物结构和水凝力学之间的关系对于材料设计至关重要.
- 之前在kHz频率的研究表明交叉连接会影响水凝模块,但GHz频率的影响不太清楚.
研究的目的:
- 为了研究聚合物度,交叉连接密度和聚合物对GHz频率的聚烯胺水凝模块的影响.
- 确定聚合烯胺对水凝内自由水的声速和机械性能的影响.
- 阐明水凝性质观察到的变化背后的分子机制.
主要方法:
- 采用布里卢因光谱法测量了聚烯胺水凝的纵向储存和损失模块.
- 一个模型由 Chiarelli等人. 用于计算自由水中的声音速度.
- 在不同的聚合物度,交叉连接密度和聚合状态上进行了实验.
主要成果:
- 发现聚合物度是影响聚合物矩阵模块的主导因素.
- 交叉连接密度对 GHz 频率的纵向模块没有可测量的影响,与 kHz 频率研究相反.
- 聚合物显著影响了自由水的机械特性,降低了声音的速度并增加了纵向储存模块.
结论:
- 在GHz频率下,聚烯胺凝模块主要由聚合物度来决定,而不是交叉连接密度.
- 纳入聚合烯胺链改变了水凝中的自由水的结构和键.
- 观察到的自由水特性变化有助于增加水凝的纵向储存模量.
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