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发生在生物地球化学界面。到目前为止，仍然缺乏能够将化学表面结构与液相中的物理相互作用（润湿性、吸附性）联系起来的特定界面参数。我们的假设是，热力学定义的表面参数，如接触角和表面自由能分量（色散和酸碱分量）可能适合作为有效参数，与 pH、质地或阳离子交换能力等土壤特性互补。为了将有效参数与化学结构联系起来，将通过 X 射线光电子能谱分析接触角相关的界面。了解有效参数应能够检测界面的相关修改或解释表面与孔隙水（液体渗透动力学）、溶质（农药）或分散颗粒（胶体）之间的相互作用。我们将应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转变。这种转变的重要性，即孔隙液体分布和几何形状（薄膜厚度和破碎），将用共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土壤和模型土壤进行改性将确保参数变化范围广泛。