Nanobubble-induced centrifugal flotation of nanoparticles

经典的泡沫浮选用于产品颗粒的选择性分离，在10µm以下的产率损失很大，因此必须实现细颗粒范围的新概念。在本课题中，提出了一种新的方法，该方法是基于悬浮液减压过程中纳米颗粒在纳米颗粒上形成纳米气泡的影响。这些纳米气泡应该选择性地在纳米颗粒表面诱导并稳定，以便在管式离心机中简单、选择性地分离纳米颗粒-纳米气泡团簇。虽然气泡的形成取决于颗粒表面的结构和化学性质，但对于分离而言，气泡体积与颗粒体积的比例也起着关键作用。作为第一阶段的科学目标，研究了结构和化学性质明确的纳米颗粒上纳米气泡的形成及其在离心场中的行为。第二个阶段的目标是研究技术颗粒系统，通过添加表面活性剂使其疏水，并在离心机中分离。最后，根据材料和尺寸设计一个连续的二维分离过程。

The classical froth flotation, which is used for the selective separation of product particles, losses drastically on yield below 10 µm so that new concepts have to be realized for the fine particle range. In the proposed project, a new approach is presented, which is based on the effect that during depressurizing of suspensions nanobubbles are formed on nanoparticles. These nanobubbles should be induced selectively on the surface of nanoparticles and stabilized so that the nanoparticle-nanobubble clusters can be separated simply and slectively in a tubular centrifuge. While the formation of the bubbles depends on structure and chemistry of the particle surface, for the separation also the ratio of bubble volume to particle volume plays a key role. As scientific objective of the first period, the formation of the nanobubbles on structurally and chemically well defined nanoparticles and their behavior in a centrifugal field were investigated. For the second period, the objective is on technical particle systems, which are hydrophobized by the addition of surfactants and which are separated in a centrifuge. Finally, a continuous 2-dimensional separation process according to material and size is intended.