Improved micro oil droplet coalescence for oil/water separation by spider silk-like structures

为了保护环境和为全世界提供清洁的自来水，从工业和自然水域中分离分散的石油已经成为一个日益严峻的世界性挑战。现有的去除油滴的方法要么条件苛刻，设备昂贵，设备复杂，加工步骤复杂，加工成本高，要么加工时间长。这项研究将揭示纤维表面的微观和宏观几何结构对流动的水介质中油的吸附和分离的结构影响。我们将分析水中油滴在化学和地形结构表面上局部定向传输的基本原理。这种提高石油聚结效率的创新仿生研究方法源于液滴在结构自然表面(如蜘蛛网纤维)上的黏附和聚结机制。其基于纺锤结的串珠式结构促进了露珠在纤维上的结合。在一种独特的方法中，已知的纤维-空气-水三相体系中液滴聚结的结构-性质-关系将转移到纤维-水-油体系中，并通过理论建模、特殊纤维纺丝、表面和聚结分析进行研究。水滴在水下的传输(颗粒运动)、油滴附着在水浸泡的梯度纤维结构上的动力学和热力学以及随后的聚结以及叠加的压差提供了非常复杂的条件，这些条件在它们的详细相互作用中尚不清楚。为此，将进一步研究相关的生物模型--优先考虑蜘蛛纤维--建立模型，并开发结构的吸油机理。这些发现将通过将发现和计算的纤维表面形态和化学成分转移到新的纺织和金属过滤结构中来实现，以提高聚结和过滤效率。

Separation of dispersed oil from industrial and natural waters has become an increasing worldwide challenge in order to protect the environment and to provide worldwide clean tap water. The established methods for oil droplet elimination involve either harsh conditions, expensive equipment, complex devices, complicated processing steps, high processing cost or long processing time. This study will reveal the structural influence of micro and macro geometry of fiber surfaces on oil sorption und separation from flowing aqueous media. We will analyze the fundamental principles of a local directed transport of oil droplets in water on chemically and topographically structured surfaces. This innovative biomimetic research approach for improved oil coalescence efficiency is derived from the mechanisms of droplet adhesion and coalescence on structured natural surfaces like spider web fibers. Their spindle-knots based beads-on-a-string structure promotes the coalescence of dew water droplets on the fibers. In a unique methodology, the known structure-property-relationships of droplet coalescence in the three-phase-system fiber-air-water will be transferred into the fiber-water-oil system and investigated by theoretical modelling, special fiber spinning, surface and coalescence analysis.Droplet transport (particle movement) under water, the kinetics and thermodynamics of oil droplet attachment to a water-immersed graded fiber structure and subsequent coalescence as well as superimposed pressure differences provide very complex conditions which have not yet been understood in their detailed interaction. For this purpose, the relevant biological models - priority on spider fibers - will be further investigated, models established and the oil absorption mechanism of the structures will be developed. The findings will be technically implemented by transferring the found and calculated fiber surface morphology and chemical compositions in new textile and metallic filter structures for improved coalescence and filter efficiency.