论文标题
电荷调节的热力学在表面中性附近
Thermodynamics of Charge Regulation Near Surface Neutrality
论文作者
论文摘要
已知浸入水溶液中的两个相邻带电表面之间的相互作用受电荷调节的影响 - 当两个带电表面彼此接近时，表面电荷的调节。这种现象尤为重要，近地表面中立性，诸如胶体或生物分子等物体的稳定性受到危害。为了关注这种普遍存在的情况，我们阐明了潜在的热力学，并表明在这种情况下，电荷调节受到表面熵的控制。我们为电荷调节提供了明确的表达，并为离子吸附到表面的自由能制定了新的通用限制定律。事实证明，后者与$ k_ {b} t $成正比，并且独立于离子与表面组的关联能量。这些新结果应用于对单极和两性表面的分析，例如在其零电荷点附近的氧化物或蛋白附近的蛋白质。
The interaction between two adjacent charged surfaces immersed in aqueous solution is known to be affected by charge regulation - the modulation of surface charge as two charged surfaces approach each other. This phenomenon is particularly important near surface neutrality where the stability of objects such as colloids or biomolecules is jeopardized. Focusing on this ubiquitous case, we elucidate the underlying thermodynamics and show that charge regulation is governed in this case by surface entropy. We derive explicit expressions for charge regulation and formulate a new universal limiting law for the free energy of ion adsorption to the surfaces. The latter turns out to be proportional to $k_{B}T$, and independent of the association energy of ions to surface groups. These new results are applied to the analysis of unipolar as well as amphoteric surfaces such as oxides near their point of zero charge or proteins near their isoelectric point.
