Plasma synthesis of reactive species and nanoparticles with controlled surface chemistry

纳米粒子是具有至少一个维度小于100纳米的物理化学实体。由于其极高的表面积，这种颗粒是化学反应的理想宿主，通过在其表面吸附来储存气体。它们可以由多种材料制成，包括金属、半导体和绝缘体，并用于催化、光伏电池和火箭发动机的燃料添加剂等各种应用。当适当地稳定和分散在宿主流体中时，它们可能形成胶体悬浮液。由此产生的纳米流体相对于基础流体表现出增强的或新的特性。纳米颗粒可以使原本绝缘的流体导电。它们的组成可以调整以获得不寻常的特性，如高效的直接太阳能吸收，增强的热容量（存储容量），激光放大和与特定分子的化学亲和力。本研究计划的主要目标之一是进一步发展各种等离子体辅助合成工艺，以获得所需的纳米颗粒和纳米流体。将考虑在传质、储气和太阳能收集和转换方面的具体应用。

Nanoparticles are physicochemical entities having at least one dimension inferior to 100 nm. Due to their extremely high surface areas, such particles are ideal hosts for chemical reactions and gas storage through adsorption on their surface. They can be fabricated of numerous materials including metals, semiconductors and insulators and used in a variety of applications ranging from catalysis, photovoltaic cells, and fuel additives in rocket engines. When properly stabilized and dispersed in a host fluid, they may form colloidal suspensions. The nanofluids thus produced exhibit enhanced or new properties with respect to the base fluids. Nanoparticles may render electrically conductive an otherwise insulating fluid. Their composition can be tuned to acquire uncommon properties like efficient direct solar energy absorbance, enhanced heat capacity (storage capacity), laser light amplification and chemical affinity with specific molecules. One of the main objectives of this research programme is to further develop various plasma-assisted synthesis processes to obtain the desired nanoparticles and nanofluids. Specific applications in mass transfer, gas storage and solar energy harvesting and conversion will be considered. Miniature high-pressure cold plasma jets are the subject of intense research and development. Plasma jets of size in the 1-20 mm range and capable of efficiently produce and transport reactive species at atmospheric pressure and above are sought for applications in a vast and rapidly growing range of fields, including plasma medicine and plasma-assisted combustion. We will investigate two particularly important aspects of cold plasma jet generation at high pressures: 1) How to design a plasma jet device which more efficiently produces and transports the species of interest to the remote surface; 2) How to design a plasma jet device to operate at pressures exceeding atmospheric. We will target applications in the synthesis and transport of NO to biological surfaces, and the OH radicals in plasma-assisted combustion.