Van der Waals force

简明释义

范德华引力

英英释义

例句

1.In biological systems, the stability of protein structures often relies on Van der Waals forces 范德华力 to maintain their shape.

在生物系统中，蛋白质结构的稳定性通常依赖于范德华力来维持其形状。

2.The Van der Waals force 范德华力 plays a critical role in the interaction between non-polar molecules.

在非极性分子之间的相互作用中，范德华力起着至关重要的作用。

3.The adhesion of the paint to the wall is largely due to the Van der Waals force 范德华力 acting between the molecules.

油漆与墙壁的附着力主要是由于分子之间作用的范德华力。

4.Nanotechnology often exploits Van der Waals forces 范德华力 for the assembly of nanoscale materials.

纳米技术常常利用范德华力来组装纳米尺度的材料。

5.When two surfaces come into contact, the Van der Waals forces 范德华力 can significantly affect friction.

当两个表面接触时，范德华力可以显著影响摩擦力。

作文

The fundamental forces that govern the interactions between molecules are crucial for understanding a wide array of physical phenomena. One such force is the Van der Waals force, which plays a significant role in molecular attraction and repulsion. This force is not as strong as ionic or covalent bonds but is essential for explaining how molecules behave in different environments.The Van der Waals force arises from the interactions between molecules, primarily due to temporary dipoles that occur when electron distributions around atoms become uneven. These temporary dipoles can induce similar dipoles in neighboring molecules, leading to an attraction between them. This phenomenon is particularly evident in nonpolar molecules, which do not have a permanent dipole moment. The Van der Waals force is generally classified into three categories: London dispersion forces, dipole-dipole interactions, and dipole-induced dipole interactions.London dispersion forces are the weakest of the three types of Van der Waals forces. They occur in all molecules, regardless of whether they are polar or nonpolar. These forces arise from the momentary fluctuations in electron density that create temporary dipoles. For example, even noble gases, which are typically nonreactive, experience these forces. As the size of the molecule increases, the strength of the London dispersion forces also increases, which explains why larger molecules tend to have higher boiling points.Dipole-dipole interactions occur between molecules that have permanent dipoles. In these cases, the positive end of one polar molecule is attracted to the negative end of another. This type of interaction is stronger than London dispersion forces but still weaker than ionic or covalent bonds. For instance, hydrogen chloride (HCl) exhibits dipole-dipole interactions due to the difference in electronegativity between hydrogen and chlorine, resulting in a polar molecule.Lastly, dipole-induced dipole interactions happen when a polar molecule induces a dipole in a nonpolar molecule. This can happen when a polar molecule approaches a nonpolar molecule and disturbs its electron cloud, creating a temporary dipole. The Van der Waals force is vital in many biological processes, including protein folding, enzyme-substrate interactions, and the formation of lipid bilayers in cell membranes.Understanding the Van der Waals force is essential for chemists and biologists alike, as it helps explain the stability and behavior of various compounds. For example, the structure of DNA relies on these forces to maintain its double-helix shape, as base pairs stack on top of each other through Van der Waals forces. Additionally, the properties of gases, liquids, and solids can often be explained by considering the influence of these forces on molecular interactions.In conclusion, while the Van der Waals force may be weaker than other types of chemical bonding, its significance cannot be overlooked. It is a fundamental aspect of molecular chemistry that contributes to the stability and behavior of substances in various states of matter. By appreciating the role of Van der Waals forces, scientists can gain deeper insights into molecular dynamics and the intricate relationships that govern the natural world.

支配分子之间相互作用的基本力对于理解各种物理现象至关重要。其中一种力是范德华力，它在分子的吸引和排斥中起着重要作用。这种力虽然不如离子键或共价键强，但对于解释分子在不同环境中的行为是必不可少的。范德华力源于分子之间的相互作用，主要是由于电子分布不均匀时产生的瞬时偶极子。这些瞬时偶极子可以在邻近分子中诱导出类似的偶极子，从而导致它们之间的吸引。这种现象在没有永久偶极子的非极性分子中尤为明显。范德华力通常分为三类：伦敦色散力、偶极-偶极相互作用和偶极-诱导偶极相互作用。伦敦色散力是三种范德华力中最弱的一种。它们发生在所有分子中，无论是极性还是非极性。这些力源于电子密度的瞬时波动，形成瞬时偶极子。例如，即使是通常不反应的惰性气体也会经历这些力。随着分子大小的增加，伦敦色散力的强度也增加，这就解释了为什么较大分子的沸点往往较高。偶极-偶极相互作用发生在具有永久偶极子的分子之间。在这种情况下，一个极性分子的正端吸引另一个分子的负端。这种类型的相互作用比伦敦色散力强，但仍然比离子键或共价键弱。例如，氯化氢（HCl）由于氢和氯之间的电负性差异而表现出偶极-偶极相互作用，形成极性分子。最后，偶极-诱导偶极相互作用发生在极性分子诱导非极性分子形成偶极子时。当一个极性分子接近一个非极性分子并扰动其电子云时，就会发生这种情况，形成一个瞬时偶极子。范德华力在许多生物过程中至关重要，包括蛋白质折叠、酶-底物相互作用以及细胞膜中脂质双层的形成。理解范德华力对化学家和生物学家来说都很重要，因为它有助于解释各种化合物的稳定性和行为。例如，DNA的结构依赖于这些力来维持其双螺旋形状，因为碱基对通过范德华力堆叠在一起。此外，气体、液体和固体的性质通常可以通过考虑这些力对分子相互作用的影响来解释。总之，尽管范德华力可能比其他类型的化学键弱，但其重要性不可忽视。它是分子化学的一个基本方面，有助于解释各种物质在不同物态下的稳定性和行为。通过欣赏范德华力的作用，科学家们可以更深入地了解分子动力学及支配自然界的复杂关系。