MACROMOLECULAR STRUCTURES OF HUMIC SUBSTANCES
MACROMOLECULAR STRUCTURES OF HUMIC SUBSTANCES
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DOI：
10.1097/00010694-198005000-00002
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发表时间：
1980-01-01
期刊：
影响因子：
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通讯作者：
SCHNITZER, M
中科院分区：
文献类型：
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作者：
GHOSH, K;SCHNITZER, M
腐殖物质的表面压力和粘度的测量在不同的pH值和中性盐浓度，以阐明其大分子结构进行了研究。这样的配置不是唯一的;它们随着介质的变化而变化。控制参数为样品浓度、体系pH值和介质离子强度。模型大分子结构的基础上提出的调查和发表在文献中的数据。借助这些模型，可以解决所谓刚性球胶体和柔性线性分子概念之间的矛盾。腐殖酸和富里酸在高样品浓度、低pH值或存在足够量的中性电解质时表现得像刚性球状胶体，但在低样品浓度时它们是柔性线性胶体，条件是pH值不太低或离子强度相对较低，通常在土壤中占主导地位。
Humic substances were investigated by surface pressure and viscosity measurements at different pH and neutral salt concentrations to elucidate their macromolecular configurations. Such configurations were not unique; they varied with the changes in the medium. The controlling parameters were sample concentration, pH of the system, and the ionic strength of the medium. Model macromolecular structures are proposed on the basis of the investigation and of data published in the literature. With the aid of these models, the contradictions between the so-called rigid spherocolloid and flexible linear molecule concepts could be resolved. Humic and fulvic acids behave like rigid spherocolloids at high sample concentrations, low pH, or in the presence of sufficient amounts of neutral electrolytes, but they are flexible linear colloids at low sample concentrations, provided that the pH is not too low or that the ionic strength is relatively low, conditions that normally prevail in soils.