The generation and controlled or uncontrolled release of hydrocarbon-contaminated industrial wastewater effluents to water matrices are a major environmental concern. The contaminated water comes to surface in the form of stable emulsions, which sometimes require different techniques to mitigate or separate effectively. Both the crude emulsions and hydrocarbon-contaminated wastewater effluents contain suspended solids, oil/grease, organic matter, toxic elements, salts, and recalcitrant chemicals. Suitable treatment of crude oil emulsions has been one of the most important challenges due to the complex nature and the substantial amount of generated waste. Moreover, the recovery of oil from waste will help meet the increasing demand for oil and its derivatives. In this context, functional nanostructured materials with smart surfaces and switchable wettability properties have gained increasing attention because of their excellent performance in the separation of oil–water emulsions. Recent improvements in the design, composition, morphology, and fine-tuning of polymeric nanostructured materials have resulted in enhanced demulsification functionalities. Herein, we reviewed the environmental impacts of crude oil emulsions and hydrocarbon-contaminated wastewater effluents. Their effective treatments by smart polymeric nanostructured materials with wettability properties have been stated with suitable examples. The fundamental mechanisms underpinning the efficient separation of oil–water emulsions are discussed with suitable examples along with the future perspectives of smart materials.

受碳氢化合物污染的工业废水的产生和受控或不受控制的释放到水基质中是一个主要的环境问题。受污染的水以稳定的乳液形式浮出水面，有时需要不同的技术来有效缓解或分离。原油乳液和碳氢化合物污染的废水都含有悬浮固体、油/油脂、有机物、有毒元素、盐和顽固的化学物质。由于原油乳液的复杂性和产生的大量废物，适当处理原油乳液一直是最重要的挑战之一。此外，从废物中回收石油将有助于满足对石油及其衍生物日益增长的需求。在这种情况下，具有智能表面和可切换润湿性的功能性纳米结构材料因其在油水乳液分离方面的优异性能而受到越来越多的关注。最近在聚合物纳米结构材料的设计、组成、形态和微调方面的改进导致破乳功能增强。在此，我们回顾了原油乳液和碳氢化合物污染的废水流出物的环境影响。它们通过具有润湿性的智能聚合物纳米结构材料进行的有效处理已经用合适的例子进行了说明。通过合适的例子以及智能材料的未来前景讨论了支持有效分离油水乳液的基本机制。