Sustainable and industrially scalable ultrasonic liquid phase exfoliation technologies for manufacturing 2D advanced functional materials (EcoUltra2D)

超声波空化和流动广泛应用于化工、食品、石油、药物和油漆加工行业。超声空化气泡的产生是一种强有力的技术，它可以在液体介质中的多相系统中引起物理机械和物理化学效应。当内爆时，空化气泡产生高速液体射流（300-1000 m/s），伴随着高压（100-1000 MPa）和局部温度峰值（高达10000 K）。脉动的气泡施加几MPa量级的高频压力脉冲。这些基本现象涉及特定的且在许多情况下知之甚少的机制，其用作工作工具，例如，用于制造二维（2D）纳米材料，并用于工业中的各种其他应用。和其他层状材料被认为是独特的材料，可以帮助克服当前和未来的社会挑战，涉及能源生产，热管理和存储以及医疗保健领域。尽管进行了大量的研究，但在需要更快、更薄、更强设备的下一代技术中成功开发和集成2D材料仍然受到与当前制造技术的可扩展性、可再现性和可持续性相关的问题的阻碍，这些问题旨在生成均匀和高质量的2D材料。例如，2D材料的大多数当前生产工艺限于批量处理，并且需要大量有害溶剂和表面活性剂以进行剪切或超声处理，从而承担对环境造成很大危害的风险，同时所得结构通常在尺寸上受到限制，并且仅在剥离结构的边缘处具有单层的几层2D材料。在这里，我们建议推翻目前的剥离技术范式，使超声波诱导机制的层状材料的剥离中的主导作用。科学新奇在于通过先进的和定制的原位同步加速器X射线高速成像技术（每秒高达百万帧），小角度中子散射，精确的声学测量，先进的非原位表征和多尺度建模方法建立超声剥离的精确机制。技术的进步在于开发一种可扩展的环境友好型工艺，重点是使用水作为液体介质（最大限度地减少特殊、昂贵和有害的添加剂的用量），并将加工时间从几十小时缩短到几分钟，同时提高2D片材的产量和尺寸。该项目的加工部分将集中于开发创新反应器，控制超声波处理、优化工艺参数和选择合适的环保添加剂，以便在纳米片的横向尺寸、形状、质量、薄片厚度和产率方面实现最有效的剥离和分散。这些2D功能材料的性能将与市售2D材料进行测试和基准测试，并用于电池和热管理应用。

Ultrasonic cavitation and streaming are widely used in the chemical, food, oil, drag and paint processing industries. The generation of cavitation bubbles though ultrasound (US) is a powerful technique that induces physico-mechanical and physico-chemical effects in multiphase systems contained in liquid media. When imploding, cavitation bubbles produce high-speed liquid jets (300-1000 m/s) accompanied by high pressure (100-1000 MPa) and local temperature spikes (up to 10000 K). Pulsating bubbles impose high-frequency pressure pulses of several MPa in magnitude. These basic phenomena are involved in specific and in many cases poorly understood mechanisms that are used as a working tool, for instance, for manufacturing two-dimensional (2D) nanomaterials, and exploited for various other applications in industry.Two-dimensional (2D) nanomaterials, such as graphene, MoS2, WS2, h-BN, h-BCN, and other layered materials are being heralded as unique materials that may help overcome current and future societal challenges related to energy generation, thermal management, and storage and in the healthcare sectors. Despite intense research, the successful exploitation and integration of 2D materials in next generation technologies where faster, thinner, and stronger devices are needed is still hampered by the issues associated with the scalability, reproducibility, and sustainability of current manufacturing techniques, aimed at generating uniform and high-quality 2D materials. For example, most current production processes of 2D materials are limited to batch-processing and require large quantities of harmful solvents and surfactants for the shearing or ultrasonication to work, bearing the risk of causing much harm to the environment, whilst the resulting structures are often limited in size and to few layer 2D materials with monolayers only at the edges of the exfoliated structures. Here, we propose to overturn the current exfoliation technological paradigm by giving the ultrasound-induced mechanisms the leading role in the exfoliation of layered materials. The scientific novelty lies in establishing the precise mechanisms of ultrasonic exfoliation through advanced and bespoke in situ synchrotron X-ray ultrahigh speed imaging techniques (up to million frames per second), small-angle neutron scattering, precise acoustic measurements, advanced ex situ characterisation, and multi-scale modelling methods. The technological step-change advance lies in developing a scalable and environmentally friendly process with focus on using water as the liquid medium (minimising the amount of special, expensive, and harmful additives), and reducing the processing time from tens of hours to minutes whilst increasing yield and size of the 2D sheets.The processing part of the project will concentrate on the development of an innovative reactor, controlled ultrasonication, optimisation of processing parameters, and the selection of suitable eco-friendly additives in order to achieve the most efficient exfoliation and dispersion in terms of the lateral size, shape, quality, flake thickness, and yield of the nanosheets. The properties of these 2D functional materials will be tested and benchmarked against commercially available 2D materials and employed in batteries and thermal management applications.