Manufacturable Novel Nanogrease with Superb Physical Properties

High-performance nanogrease manufactured from carbon nanomaterials is observed to be stable and homogeneous and have superb physical properties, such as thermal and electrical conductivities, compared with current commercial greases made of lithium, calcium, and aluminum. For the first time, carbon nanomaterials have been observed to disperse well as the sole thickeners in oil systems, e.g., polyalphaolefin and polyester (ROYCO), without the aid of any chemical surfactants. Three-dimensional percolation network structures that exist among carbon nanomaterials are easily scalable, which can be attributed to the intermolecular van der Waals forces. Moreover, the introduction of hydrogen bonding in any form to grease significantly increases its thermal and electrical conductivities and substantially reduces the weight percentage of carbon nanomaterials needed to fabricate stable grease. For example, loading of only 1.4 wt% hydroxyl-functionalized multiwalled carbon nanotube (MWNT-OH) with Krytox XHT750 oil leads to a 37.8% increase in thermal conductivity. Moreover, 75% glycerol, 25% water, and 4.5 wt% MWNT-OH yielded the lowest electrical resistivity of 10.0 Ω cm. This finding can be extended to hydrogen bonding materials with functional groups, such as OH, COOH, F, and NH. The nanogrease reported in this study has been manufactured using the three-roll mill method, which is an easy and cost-effective method, as the loading weight percentage of carbon nanomaterials to fabricate stable grease decreases from 12 wt% to 3–4 wt%. Furthermore, the process is easily scalable, reproduced, and optimized. This novel high-performance nanogrease has a high commercial value and numerous applications and could replace current commercial greases.