纳米级分子接触的接触力学:粘附,摩擦和键热力学之间的相关性
Katerina Busuttil1, Mark Geoghegan, Christopher A Hunter
1Department of Chemistry, University of Sheffield, Brook Hill, Sheffield S3 7HF, UK.
Journal of the American Chemical Society
|May 13, 2011
概括
溶剂中碳酸盐表面之间的粘附力取决于极性溶剂度,随着极性降低而增加. 摩擦行为从Amontons转移到Amontons.
科学领域:
- 表面科学是一门学科.
- 部落学 (tribology) 是一个学科.
- 物理化学 物理化学
背景情况:
- 了解界面力对于设计材料和工艺至关重要.
- 溶剂对表面相互作用的影响,特别是粘附和摩擦,是复杂的.
- 碳酸终结自组装单层 (SAM) 是研究表面化学的模型系统.
研究的目的:
- 为了研究溶剂极性对碳酸SAMS之间的粘附力的影响.
- 分析各种溶剂环境中的摩擦负荷关系.
- 为了将溶解模型与测量的粘附和摩擦行为相关联.
主要方法:
- 使用扫描力显微镜 (SFM) 测量粘附力.
- 摩擦力显微镜 (FFM) 用于确定摩擦-负载关系.
- 极性溶剂 (乙,乙酸乙烯) 度在非极性溶剂 (赫普坦) 中的系统变化.
主要成果:
- 附着力随着极性溶剂度的下降,以对数方式增加,在纯非极性溶剂中达到最大值.
- 摩擦负载关系从极性溶剂中的线性 (阿蒙顿定律) 转变为非极性溶剂中的非线性 (DMT模型).
- 一个简单的溶解模型准确地预测了粘附力的观察到的溶剂依赖性.
结论:
- 用极性溶剂溶解碳酸组显著影响着粘附和摩擦.
- 摩擦力学中的过渡与负载依赖和剪切贡献之间的相互作用有关.
- 这些发现为预测和控制液体环境中的界面行为提供了一个框架.
相关概念视频
Noncovalent Attractions in Biomolecules
Noncovalent attractions are associations within and between molecules that influence the shape and structural stability of complexes. These interactions differ from covalent bonding in that they do not involve sharing of electrons.
Four types of noncovalent interactions are hydrogen bonds, van der Waals forces, ionic bonds, and hydrophobic interactions.
Hydrogen bonding results from the electrostatic attraction of a hydrogen atom covalently bonded to a strong-electronegative atom like oxygen,...
Four types of noncovalent interactions are hydrogen bonds, van der Waals forces, ionic bonds, and hydrophobic interactions.
Hydrogen bonding results from the electrostatic attraction of a hydrogen atom covalently bonded to a strong-electronegative atom like oxygen,...
Noncovalent Attractions in Biomolecules
Noncovalent attractions are associations within and between molecules that influence the shape and structural stability of complexes. These interactions differ from covalent bonding in that they do not involve sharing of electrons.
Four types of noncovalent interactions are hydrogen bonds, van der Waals forces, ionic bonds, and hydrophobic interactions.
Hydrogen bonding results from the electrostatic attraction of a hydrogen atom covalently bonded to a strong-electronegative atom like oxygen,...
Four types of noncovalent interactions are hydrogen bonds, van der Waals forces, ionic bonds, and hydrophobic interactions.
Hydrogen bonding results from the electrostatic attraction of a hydrogen atom covalently bonded to a strong-electronegative atom like oxygen,...
Frictional Force
When a body is in motion, it encounters resistance because the body interacts with its surroundings. This resistance is known as friction, a common yet complex force whose behavior is still not completely understood. Friction opposes relative motion between systems in contact, but also allows us to move. Friction arises in part due to the roughness of surfaces in contact. For one object to move along a surface, it must rise to where the peaks of the surface can skip along the bottom of the...
Hydrogen Bonds
A hydrogen bond is formed when a weakly positive hydrogen atom already bonded to one electronegative atom (for example, the oxygen in the water molecule) is attracted to another electronegative atom from another polar molecule, such as water (H2O), hydrogen fluoride (HF), or ammonia (NH3). The huge electronegativity difference between the H atom (2.1) and the atom to which it is bonded (4.0 for an F atom, 3.5 for an O atom, or 3.0 for an N atom), combined with the very small size of an H atom...
Hydrogen Bonds
Hydrogen BondsHydrogen bonds are weak attractions between atoms that have formed other chemical bonds. One of these atoms is electronegative, like oxygen, and has a partial negative charge. The other is a hydrogen atom that has bonded with another electronegative atom and has a partial positive charge.Hydrogen Bonds Control the World!Because hydrogen has very weak electronegativity when it binds with a strongly electronegative atom, such as oxygen or nitrogen, electrons in the bond are...
Surface Tension
Surface tension is defined as the force per unit length (γ) acting along the surface of a liquid. It arises due to strong intermolecular forces of attraction. A molecule located inside the bulk of the liquid is surrounded by other molecules and experiences equal forces in all directions. However, a molecule at the surface experiences unbalanced forces because there are more neighboring molecules below than above. This creates a net inward force that pulls surface molecules toward the interior,...

