Effect of Graphene Nanoplatelets on Tribological Properties of Bacterial Cellulose/Polyolester Oil Bio-Lubricant

Abstract

The demand for bio-degradable lubricants is continuously increasing due to environmental concerns. One of the methods to achieve the bio-degradability property of lubricants is by using nanoparticles from bio-resources as additives in bio-degradable oils. Among the nanomaterials are nanofibers, cellulose, and graphene nanoplatelets. They can be mixed in Polyolester (POE) oil to produce lubricants for tribological applications. In a previous study, it has been confirmed that friction and wear of the tribo-pair reduced from 5 to 10% by mixing various volume percentages of bacterial cellulose (BC) into PEO as the base lubricant. The tribological performance BC containing POE base lubricant can further be enhanced by incorporating graphene nanoplatelets. This study shows that the specific wear rate of the material decreased by 20% by adding graphene nanoplatelets in BC containing POE oil. The friction and wear improvement can be related to the formation of tribofilm on the contact interface. EDS analysis indicates that oxygen played an important role in the friction and wear performance of the POE oil-based lubricant with BC and graphene additives. The tribofilm shows significant traces of oxygen elements. The presence of graphene nanoplatelets in POE oil removed the oxygen-rich layer but could not reduce the wear rate. However, incorporating both graphene and BC in POE oil significantly improved friction and wear, although the oxygen element was still traceable on the contact interface.

A Novel Highly Conductive, Transparent, and Strong Pure-Cellulose Film from TEMPO-Oxidized Bacterial Cellulose by Increasing Sonication Power

“…TEMPO treatment oxidizes BC nanofibers and weakens BC’s hydrogen bonds, presenting better dispersibility [ 26 , 27 , 28 , 29 , 30 ]. This treatment can promote individual nanofibers and a nanogap between BC nanofibers.…”

Effect of sonication to the stability properties of carboxymethyl cellulose/uncaria gambir extract water-based lubricant

“…In addition, there is a difference in the density of the nanoparticles with the base fluid. This will make the nanoparticles unstable, and sedimentation will occur [9]. On the other hand, besides its advantages, it requires a lot of processing in order to obtain the desired properties of vegetable oil-based lubricants.…”

Tribological Properties of Aqueous Carboxymethyl Cellulose/Uncaria Gambir Extract as Novel Anti-Corrosion Water-Based Lubricant

“…The tribological performances of the lubricant samples were measured with a pin-on-disk reciprocating tribometer which was also utilized in our previous work [15]. A gray cast iron (FC25) with 30 mm in diameter and 5 mm in thickness was utilized as the disk.…”

“…The qualitative sedimentation measurement via photo capturing was used to observe the lubricant's stability, as presented in Figure 1. This method has been employed in our previous works [15,16,30].…”

“…However, even though it can drastically improve properties, some nanoparticle mentioned above is not environmentally friendly and very expensive. One of the most abundant biopolymers is cellulose which is produced from algae, tunicates, certain bacteria, and plant-based materials [15,16]. This type of compound is also suitable as a lubricant additive.…”