Nanofilled dielectrics for high voltage electrical insulation

使用微米尺寸填料对用于高压应用的复合材料进行进一步改进是不可能的，因为粘性组合物的混合已经达到了当前材料加工技术的限制。 然而，纳米尺寸颗粒（纳米颗粒）填充的电介质材料的初步发现显示出在显著减少的填料添加量下对材料的类似改进;因此，对电介质材料的进一步改进的前景可能与现有的加工技术。 大多数研究人员认为，有机材料（纳米复合材料）中纳米颗粒的问题是颗粒的分散，均匀混合在纳米复合材料的开发中至关重要。 问题之一是由于颗粒的高表面能，纳米颗粒容易团聚，并且常规的混合技术不能使纳米颗粒团聚体破裂。 另一个问题是疏水性聚合物与亲水性纳米颗粒的不相容性，导致界面相互作用差。 因此，非常需要发现替代方法来获得纳米颗粒的更好分散。本研究主要是利用表面活性剂对纳米粒子进行物理和化学的表面改性。 虽然表面活性剂通常应用于液体，但它们在形成固体介电材料的组合物中分散纳米颗粒的应用尚未报道。 使用表面活性剂的主要优点是它降低了纳米颗粒的表面和界面张力，从而减少了团聚，并使颗粒更容易分散。 初步研究结果表明，triton是一种常见的表面活性剂，有助于纳米二氧化硅和纳米氧化铝在硅橡胶中的分散。 该研究将集中在了解表面活性剂如何改善纳米电介质的性能，以及哪些复合系统适合优化这些复合材料的介电性能，以实现高压电绝缘。

Further improvements to composite materials for use in high voltage applications using micron size fillers are not likely, as mixing of the viscous compositions has reached the limitation of current material processing technology. However, initial findings of nano-size particle (nanoparticle) filled dielectrics show similar improvements to materials at considerably reduced filler additions; thereby, the promise of further improvements to dielectric materials are likely with the existing processing technology. Most researchers agree that the problem with nanoparticles in organic materials (nanocomposites) is the dispersion of particles and uniform mixing is critical in the development of nanocomposites. One of the problems is that the nanoparticles agglomerate easily because of the high surface energy of the particles and conventional mixing techniques do not break apart the nanoparticle agglomerates. Another problem is the incompatibility of the hydrophobic polymer with hydrophilic nanoparticles, resulting in poor interfacial interactions. Thus, there is a great need to discover alternative ways to obtain a better dispersion of the nanoparticles. The reseach focuses on the surface modification of the nanoparticles by physical and chemical methods using surfactants. Although surfactants are commonly applied to liquids, their application to disperse nanoparticles in compositions forming solid dielectric materials has not yet been reported. The main advantage of using a surfactant is that it lowers the surface and interfacial tensions of the nanoparticles resulting in reduced agglomeration and makes it easier to disperse the particles. Preliminary findings have shown that triton, a common surfactant, aids in the dispersion of nanosilica and nanoalumina in silicone rubber. The research will concentrate on the understanding of how surfactants can improve the properties of nanodielectrics and which composite systems are appropriate to optimize the dielectric properties of these composites for high voltage electrical insulation.