Pristine, Reduced, and Alkylated Graphene Oxide as Additives to Paraffin Grease for Enhancement of Tribological Properties

2020 ◽  
Vol 143 (2) ◽  
Author(s):  
Sooraj Singh Rawat ◽  
A. P. Harsha ◽  
O. P. Khatri ◽  
Rolf Wäsche
Keyword(s):  
Graphene Oxide ◽  
Coefficient Of Friction ◽  
Tribological Properties ◽  
Protective Film ◽  
Elemental Mapping ◽  
Graphene Oxides ◽  
Fiber Network ◽  
Maximum Reduction ◽  
Reduced Graphene ◽  
Minimum Resistance

Abstract Pristine, reduced, and alkylated graphene oxides are applied as lubricating additives in paraffin grease. It has revealed that their crystalline structure governs the tribological properties of grease for steel tribo-pair. The microstructural analyses of grease samples showed that a loose fiber network of soap in the presence of graphene-based additive allows their facile release for efficient lubrication. The surface analyses based on the microscopic and elemental mapping show the development of a graphene-derived protective film on the worn scars, which protected the tribo-surfaces and subsided the wear. The reduced graphene oxide (rGO) with the interlamellar distance of 0.35 nm in the (002) plane provided minimum resistance to shear and exhibited maximum reduction in coefficient of friction (COF) for the paraffin grease. The presence of oxygen functionalities in the basal of pristine and alkylated graphene oxide (GO) compromised the interlamellar shearing under tribo-stress; consequently, higher COF than that of rGO.

Optical Characteristics of Multilayer Reduced Graphene Oxides Films Fabricated Using UV Oven Spraying Technique with Various Interval Irradiation Time

2021 ◽  
Vol 1028 ◽  
pp. 279-284
Author(s):  
Nur Khanifah ◽  
Diyan Unmu Dzujah ◽  
Vika Marcelina ◽  
Rahmat Hidayat ◽  
Fitrilawati ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Irradiation Time ◽  
Active Material ◽  
Reduction Process ◽  
Optical Characteristics ◽  
Graphene Oxides ◽  
Super Capacitor ◽  
Reduced Graphene ◽  
Vis Spectroscopy ◽  
Coating Method

Reduced graphene oxide (RGO) is promising candidate to be used as an active material of super capacitor electrodes. Graphene oxide (GO) is mostly used as a precursor, therefore it is needed to remove its oxygen containing functional groups. Generally, the RGO films are obtained from Graphene Oxide (GO) films which are then treated using thermal reduction or photo reduction process. We developed a spraying coating method that called as UV oven spraying by combining spraying coating method and photo reduction process. By this deposition method, we can obtain RGO films directly from the GO precursor since deposition and photo reduction steps are taken place at the same time. Level of oxygen removal of the obtained RGO film depends on irradiation intensity and length of irradiation. In this work, we report the effect of varied length of irradiation time on the RGO optical characteristics. We prepared multilayer of RGO films using UV oven spraying technique on quartz substrates from 0.5 mg/ml commercial GO dispersion (Graphenea) with varied the UV irradiation time. We used 125-Watt mercury lamp that was set at distance of 30 cm from substrates. We examined the effect of varied of length of irradiation time on its optical characteristics using UV-Vis Spectroscopy. Level of reduction by provided irradiation time was examined using SEM/EDS measurement.

Tribological properties of alkylated reduced graphene oxide as lubricant additive

2022 ◽  
Vol 165 ◽  
pp. 107273
Author(s):  
Bo Yu ◽  
Kai Wang ◽  
Xianjuan Pang ◽  
Gensheng Wu ◽  
Jibin Pu ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Tribological Properties ◽  
Lubricant Additive ◽  
Reduced Graphene

scholarly journals Effects of Reduced Graphene Oxide (rGO) at Different Concentrations on Tribological Properties of Liquid Base Lubricants

Lubricants ◽  
2019 ◽  
Vol 7 (2) ◽  
pp. 11 ◽  
Author(s):  
Jankhan Patel ◽  
Amirkianoosh Kiani
Keyword(s):  
Graphene Oxide ◽  
Physical Properties ◽  
Reduced Graphene Oxide ◽  
Tribological Properties ◽  
High Speed ◽  
Friction And Wear ◽  
Control Sample ◽  
Wear Properties ◽  
Reduced Graphene ◽  
Friction And Wear Properties

In this study, reduced graphene oxide (rGO) nano platelets were used as an additive to enhance friction and wear properties of oil-based lubricants by preparing three samples at 0.01% w/w, 0.05% w/w, and 0.1% w/w concentrations. To analyze the direct effect of rGO nano platelets on tribological properties, 99.9% pure oil was used as a liquid lubricant. A comparative tribological study was done by performing a ball-on-disk wear test in situ under harsh conditions, which was further analyzed using a non-contact 3D optical profilometer. Morphological evaluation of the scar was done using transmission and scanning electron microscopy (TEM, SEM) at micro and nano levels. The lubricants’ physical properties, such as viscosity and oxidation number, were evaluated and compared for all samples including pure oil (control sample) as per ASTM standards. Findings of all these tests show that adding rGO nano platelets at 0.05% w/w showed significant reduction in friction at high speed and in wear up to 51.85%, which is very promising for increasing the life span of moving surfaces in machinery. Oxidation and viscosity tests also proved that adding rGO nano platelets to all samples does not sacrifice the physical properties of the lubricant, while it improves friction and wear properties.

Synthesis of reduced graphene oxide/Cu nanoparticle composites and their tribological properties

RSC Advances ◽  
2013 ◽  
Vol 3 (48) ◽  
pp. 26086 ◽  
Author(s):  
Yi Zhang ◽  
Hua Tang ◽  
Xiaorui Ji ◽  
Changsheng Li ◽  
Lin Chen ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Tribological Properties ◽  
Reduced Graphene ◽  
Cu Nanoparticle ◽  
Nanoparticle Composites

scholarly journals A Green Approach for Highly Reduction of Graphene Oxide by Supercritical Fluid

2014 ◽  
Vol 1004-1005 ◽  
pp. 1013-1016 ◽  
Author(s):  
Chang Yi Kong ◽  
Yuuki Shiratori ◽  
Takeshi Sako ◽  
Futoshi Iwata
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Supercritical Fluid ◽  
Large Scale ◽  
Scale Production ◽  
Graphene Oxides ◽  
Practical Applications ◽  
Green Approach ◽  
Large Scale Production ◽  
Reduced Graphene

A green method to synthesize the reduced graphene oxide using supercritical fluid has been developed, which is an environmentally friendly and efficient route. The reduced graphene oxide has been examined by X-ray diffraction, Raman spectroscopy. We have also studied the effects of reduction temperatures and supercritical fluids on the electrical properties of reduced graphene oxide. It was found that ethanol has higher reducing capability than CO2at all temperatures (200 - 400°C) examined in this study for graphene oxide reduction. As a result, reduced graphene oxide (6300 S/m) from supercritical ethanol treatment has 5 times as high conductivity as that from supercritical CO2treatment at the reduction temperature of 400°C. This green process is applicable for large scale production of reduced graphene oxides for various practical applications.

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