Evaluation of effective parameters to describe wetting, adhesion and, sorption phenomena on biogeochemical interfaces

评估描述生物地球化学界面润湿、粘附和吸附现象的有效参数

• 批准号: 40997208
• 负责人: Professor Dr. Jörg Bachmann
• 金额: --
• 依托单位: Institut für Bodenkunde (IFBK)
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2007
• 资助国家: 德国
• 起止时间: 2006-12-31 至 2014-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/40997208?language=en
• 关键词: Evaluation; effective; parameters; describe; wetting

Nearly all processes in soils take place at biogeochemical interfaces. Until now, specific interfacial parameters which are able to link the chemical surface structure with physical interactions in the liquid phase (wettability, sorption) are still missing. Our hypothesis is that thermodynamically defined surface parameters like the contact angle and surface free energy components (dispersive and acid-base components) may be appropriate as effective parameters, complementary to soil properties like pH, texture or cation exchange capacity. To relate effective parameters to chemical structure, the contact angle relevant interphase will be analyzed by X-ray photoelectron spectroscopy. Knowledge of effective parameters should allow to detect relevant modifications of the interfaces or to explain interactions between surfaces and pore water (liquid penetration dynamics), solutes (pesticides) or dispersed particles (colloids). We will apply a thermodynamically-based concept to quantify the transition from hydrophilic to hydrophobic wetting systems. The significance of this transition i.e. on pore liquid distribution and geometry (film thickness and fragmentation), will be analyzed with confocal laser scanning microscopy. Modification of natural and model soils by chemical treatment and cation exchange will ensure a wide range of parameter variation.

土壤中几乎所有过程都在生物地球化学界面进行。到目前为止，能够将化学表面结构与液相（润湿性，吸附）中的物理相互作用联系起来的特定界面参数仍缺失。我们的假设是，热力学定义的表面参数，例如接触角和表面自由能成分（分散和酸碱成分）可能是有效参数，是对pH，质地或阳离子交换能力等土壤特性的互补参数。为了将有效参数与化学结构相关联，将通过X射线光电子光谱法分析接触角相关的相间。有效参数的知识应允许检测界面的相关修改或解释表面和孔隙水之间的相互作用（液体穿透动力学），溶质（农药）或分散的颗粒（胶体）。我们将采用基于热力学的概念来量化从亲水性到疏水性润湿系统的过渡。这种过渡的意义，即对孔隙液分布和几何形状（膜厚度和碎片化）的意义，将通过共聚焦激光扫描显微镜进行分析。通过化学处理和阳离子交换对天然和模型土壤的修饰将确保广泛的参数变化。