在基板上的聚钢吸附层密度演变的机制
Lu Bai1, Zhenwei Jiang1, Liang Fan1
1School of Chemistry and Chemical Engineering, Key Laboratory of Surface & Interface Science of Polymer Materials of Zhejiang Province, Zhejiang Sci-Tech University, Hangzhou, 310018, P. R. China.
ACS macro letters
|October 29, 2024
概括
研究了在改性基板上的聚乙烯链密度. 增加的含量通过更强的π-π相互作用增强了吸附层厚度和密度,导致更紧密的结构.
科学领域:
- 材料科学 材料科学 材料科学
- 聚合物科学 聚合物科学
- 表面化学 表面化学
背景情况:
- 了解表面的聚合物吸附对于材料设计至关重要.
- 聚钢 (PS) 在基基板上的吸附行为具有显著的兴趣.
- 表面修饰可以改变聚合物-基板相互作用和薄膜特性.
研究的目的:
- 为了研究聚乙烯吸附层在基改性SiO2-Si基板上的密度演变.
- 为了阐明接口相互作用和化在吸附层结构上的作用.
- 为了确定不同含量下的PS层的平衡厚度和密度.
主要方法:
- 总频率生成振动光谱 (SFG) 用于探测界面相互作用.
- 在SiO2-Si基板上使用不同的含量来调整表面特性.
- 火时间被系统地改变,以观察密度的演变.
主要成果:
- 吸附的PS层厚度和密度随着化时间的增加而增加,在含含量>75%的基板上,达到4.7nm和1.37g/cm3.
- 基板上较高的含量增加了达到平衡所需的回火时间.
- SFG揭示了基质基和PS链之间的增强的界面π-π相互作用.
结论:
- 增加的界面 π-π 相互作用驱动链条拉伸和垂直方向.
- 这导致更密,更厚的吸附层,具有最接近的包装结构.
- 有利的热过程控制了吸附的平面化层的密集机制.
相关概念视频
Molecular Weight of Step-Growth Polymers
2.2K
Step growth polymerization involves bi or multifunctional monomers. Bifunctional monomers react to form linear step growth polymers, whereas multifunctional monomers react to form non-linear or branched polymers.
As the step-growth polymerization involves step-wise condensation of monomers, the molecular weight also builds up eventually. Consequently, high molecular weight polymers are obtained at the late stages of the polymerization, where 99% of monomers have been consumed.
The extent of the...
As the step-growth polymerization involves step-wise condensation of monomers, the molecular weight also builds up eventually. Consequently, high molecular weight polymers are obtained at the late stages of the polymerization, where 99% of monomers have been consumed.
The extent of the...
2.2K
Polymer Classification: Stereospecificity
2.4K
Polymerization generates chiral centers along the entire backbone of a polymer chain. Accordingly, the stereochemistry of the substituent group has a significant effect on polymer properties. Polymers formed from monosubstituted alkene monomers feature chiral carbons at every alternate position in the polymer backbone. Relative to the predominant orientation of substituents at the adjacent chiral carbons, the polymer can exist in three different configurations: isotactic, syndiotactic, and...
2.4K
Free-Radical Chain Reaction and Polymerization of Alkenes
7.7K
The conversion of alkenes to macromolecules called polymers is a reaction of high commercial importance. The structure of the polymer is defined by a repeating unit, while the terminal groups are considered insignificant. The average degree of polymerization represents the number of repeating units in the polymer molecule and is denoted by the subscript n.
7.7K
Polymer Classification: Architecture
2.6K
Polymers are classified as linear or branched on the basis of their chain architecture. The polymer chains in linear polymers have a long chain-like structure with minimal to no branching at all. Even if a polymer features large substituent groups on the monomer, which appear as branches to the skeleton, it is not considered a branched polymer. A branched polymer contains secondary polymer chains that arise from the main polymer chain. The branching occurs when the polymer growth shifts from...
2.6K
Polymers: Molecular Weight Distribution
3.3K
For any given polymer, the weight average molecular weight (Mw) is higher than, if not equal to, the number average molecular weight (Mn). The only situation in which the weight average molecular weight and the number average molecular weight are equal is when a polymer consists only of chains with equal molecular weight. However, this never happens in a synthetic polymer, since it is difficult to control the polymerization process up to a molecular level with accuracy to a hundred percent.
3.3K


