概括
界面切割应力测量显示,聚合物段的移动性显著影响摩擦. 接口两侧高度移动的材料导致压力较低,而薄的链可以增加摩擦.
科学领域:
- 聚合物科学 聚合物科学
- 部落学 (tribology) 是一个学科.
- 材料科学 材料科学 材料科学
背景情况:
- 了解聚合物界面行为对于滑剂和聚合物加工等应用至关重要.
- 界面切割应力控制了诸如聚合物中的墙壁滑动和融骨折等现象.
研究的目的:
- 测量移动的聚合物网络 (elastomer) 和不移动的 (玻璃) 聚合物表面之间的界面切割应力.
- 调查细分移动性和连接链层对界面摩擦的影响.
主要方法:
- 在一个光滑的玻璃状聚合物表面上滑动一个高度移动的聚合物网络,上面涂上了端附着的移动链.
- 确保在控制滑动实验的接口上没有自由链.
主要成果:
- 接口切削应力强烈依赖于聚合物在接口两侧的细分流动性.
- 当两种材料都具有高度移动性时,观察到较低的界面切割应力.
- 连接链的薄层可以增强界面摩擦.
结论:
- 聚合物段的移动性是确定界面剪切应力的关键因素.
- 连接链层可以用于修改界面摩擦特性.
- 这些发现对滑剂性能和聚合物加工挑战 (如墙壁滑动) 有影响.
相关概念视频
Characteristics of Dry Friction
Dry friction occurs when two solid surfaces slide against each other without any lubrication or fluid present. It causes resistance when pushing objects along a surface, like a gardener pushing a wheelbarrow. The force applied to move the cart causes dry friction between the wheel and the ground.
Before the wheelbarrow starts moving, the static frictional force acts tangentially to the contact surface, opposing the force that is about to induce the motion. This frictional force prevents the...
Before the wheelbarrow starts moving, the static frictional force acts tangentially to the contact surface, opposing the force that is about to induce the motion. This frictional force prevents the...
Types of Friction Problems
Friction is an essential concept in physics, engineering, and everyday life. It is the force that opposes the relative motion or tendency of such motion between two surfaces in contact. One of the most common types of friction encountered in various applications is dry friction. Dry friction problems can be broadly categorized into three types, each with unique characteristics and challenges.
The first type of dry friction problem involves situations where there is no apparent impending motion.
The first type of dry friction problem involves situations where there is no apparent impending motion.
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...
Rolling With Slipping
Rolling with slipping is a physical phenomenon that occurs when a rolling object experiences both rotational and linear motion but also experiences frictional forces that cause slipping. This phenomenon can occur in various situations, such as when a tire rolls on a wet road or a ball rolls on a rough surface.
An object's rolling motion is characterized by its rotation around its axis, while linear motion refers to the object's translational motion along a surface. Frictional forces can affect...
An object's rolling motion is characterized by its rotation around its axis, while linear motion refers to the object's translational motion along a surface. Frictional forces can affect...
Dry Friction
Dry friction occurs between two solid surfaces in contact as they attempt to move relative to one another. In daily life, dry friction is encountered in various forms, such as when walking on the ground, sliding an object across a table, or rubbing hands together. Despite its ubiquity, the underlying mechanisms behind dry friction are not readily visible.
To illustrate this concept, imagine a wooden crate resting on a rough, non-uniform horizontal surface. When an external force is applied to...
To illustrate this concept, imagine a wooden crate resting on a rough, non-uniform horizontal surface. When an external force is applied to...
Design Example: Deciding Thickness of Lubricating Fluid in a Shaft
Effective lubrication between a rotating shaft and its bearing housing is essential in rotating machinery to minimize friction, wear, and energy loss. With carefully controlled thickness and viscosity, the lubricant layer prevents metal-to-metal contact, ensuring smooth operation.
To calculate the required thickness of the lubricant layer, the tangential velocity at the shaft's surface must first be determined. This velocity is calculated by converting the rotational speed to angular velocity...
To calculate the required thickness of the lubricant layer, the tangential velocity at the shaft's surface must first be determined. This velocity is calculated by converting the rotational speed to angular velocity...


