Binders for paints or adhesives are frequently polymerized as melt or in solution. To use these apolar polymers in water-based formulations, they should first be emulsified in water with the help of an incorporated ionic emulsifier (surfactant). Here, we aim for a deeper understanding of this emulsification process. On mixing oil, water and surfactant, the mixture is expected to evolve into its thermodynamic equilibrium state, denoted by the phrase ‘microemulsion.’ For unclear reasons, however, the mixture frequently becomes entrapped into an arrested structure, before reaching equilibrium. Then, a so-called metastable emulsion is attained that might remain stable over many years. This study focuses on the underlying reason for oil/water/surfactant mixtures to become entrapped into such a metastable state. From an engineering perspective, this is essential to know since the tools available to control the size of the emulsion droplets are entirely different for microemulsions, on the one hand, and metastable emulsions, on the other hand. First, a generic classification scheme is proposed to distinguish between emulsification processes and resulting emulsion structures from a thermodynamic perspective. Second, emulsions are studied by mixing an acetone solution of apolar ionic polymer with varying amounts of water. First, we examined the rate at which microemulsion structures were assembled by ‘thermodynamics.’ This was done by measuring the response of the emulsion turbidity, on a stepwise change of the water/acetone (w/a) ratio. Upon a stepwise reduction of the w/a ratio down to 0.7, spontaneous assembly of the equilibrium structure appeared to be already finished in less than 6 min. At increasing w/a ratio, however, the time required to reach equilibrium strongly increased. At a w/a ratio of 2.2, spontaneous assembly even appeared to be practically blocked, indicating that a metastable emulsion was attained. We suggest that the assembly rate declines with increasing w/a ratio due to decreasing solubility of polymer in the water-enriched phase of the emulsions. Next, we determined the equilibrium phase diagram and the composition line where inversion occurs from ‘water-in-oil’ (w/o) into ‘oil-in-water’ (o/w) microemulsions. In practice, the polymer solution in acetone is emulsified by gradually dosing water to the stirred solution, up to a w/a ratio in the range of 2.0–2.5. The results of our study clarify that the success of this process is likely related to the very moment the thermodynamically driven assembly comes to a halt: either before or after inversion. If spontaneous assembly only comes to a halt after inversion, an arrested o/w microemulsion will be obtained, with a polymer particle size being independent on both stirring speed and water dosing rate. However, if spontaneous assembly already stops before effectuation of inversion, then ‘hydrodynamics’ will take the lead at inverting the w/o emulsion into an o/w emulsion. Consequently, inversion will then be effectuated by the less effective mechanism of mechanical rupture, resulting in particles that might be large and rapidly sediment. Consequently, the emulsion might be judged as being unstable.

油漆或粘合剂的粘合剂通常以熔融或溶液形式聚合。要将这些非极性聚合物用于水基制剂中，首先应在掺入的离子乳化剂（表面活性剂）的帮助下将其在水中乳化。在此，我们旨在更深入地了解这种乳化过程。在将油，水和表面活性剂混合后，预期混合物会演变成其热力学平衡状态，用短语“微乳液”表示。然而，由于不清楚的原因，混合物在达到平衡之前经常被截留为被阻止的结构。然后，获得了可以在多年内保持稳定的所谓的亚稳乳液。这项研究集中于油/水/表面活性剂混合物陷入这种亚稳态的根本原因。从工程角度来看，这一点是必须知道的，因为可用于控制乳液液滴大小的工具一方面对于微乳液而言完全不同，另一方面对于亚稳乳液而言则完全不同。首先，提出了一种通用的分类方案，从热力学的角度来区分乳化过程和所得的乳液结构。其次，通过将非极性离子聚合物的丙酮溶液与不同量的水混合来研究乳液。首先，我们研究了通过“热力学”组装微乳液结构的速率。这是通过在水/丙酮逐步变化时测量乳液浊度的响应来完成的（另一方面，还有亚稳乳液。首先，提出了一种通用的分类方案，从热力学的角度来区分乳化过程和所得的乳液结构。其次，通过将非极性离子聚合物的丙酮溶液与不同量的水混合来研究乳液。首先，我们研究了通过“热力学”组装微乳液结构的速率。这是通过在水/丙酮逐步变化时测量乳液浊度的响应来完成的（另一方面，还有亚稳乳液。首先，提出了一种通用的分类方案，从热力学的角度来区分乳化过程和所得的乳液结构。其次，通过将非极性离子聚合物的丙酮溶液与不同量的水混合来研究乳液。首先，我们研究了通过“热力学”组装微乳液结构的速率。这是通过在水/丙酮逐步变化时测量乳液浊度的响应来完成的（我们研究了通过“热力学”组装微乳液结构的速率。这是通过在水/丙酮逐步变化时测量乳液浊度的响应来完成的（我们研究了通过“热力学”组装微乳液结构的速率。这是通过在水/丙酮逐步变化时测量乳液浊度的响应来完成的（w / a）比率。将w / a的比例逐步降低至0.7后，平衡结构的自发组装似乎已在不到6分钟的时间内完成。然而，随着w / a比率的增加，达到平衡所需的时间大大增加。在一个瓦特/一个的2.2比，自发装配甚至出现而不能实际阻断，这表明亚乳液获得。我们建议装配率随w / a的增加而下降由于聚合物在乳液的水富集相中的溶解度降低而导致该比值降低。接下来，我们确定了从“油包水”（w / o）转变为“水包油”（o / w）微乳液的平衡相图和组成线。在实践中，通过将水逐渐加到搅拌溶液中，使聚合物在丙酮中的溶液乳化，w / a的比值在2.0-2.5范围内。我们的研究结果表明，此过程的成功可能与热力学驱动的组件停止运行的时刻有关：在反转之前或之后。如果自发组装仅在反转后停止，则将其逮捕将获得o / w微乳液，其聚合物粒度与搅拌速度和加水速率均无关。但是，如果在进行反转之前已经自发停止组装，那么“流体力学”将率先将w / o乳液转化为o / w乳液。因此，倒转将通过机械破裂效率较低的机制来实现，从而导致颗粒变大并迅速沉降。因此，可以判断乳液不稳定。