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Papers by Suprakash Samanta

Materials Science in Semiconductor Processing

Soft Matter

Tribological behavior of graphene-based polymer brushes (Gr-PB) in lube oil is investigated. Gr-P... more Tribological behavior of graphene-based polymer brushes (Gr-PB) in lube oil is investigated. Gr-PB reduce COF and the wear of steel–steel tribocontact in variable pressure conditions aided by the formation of robust tribofilm in sliding interface.

New Journal of Chemistry, 2019

Modulating physico-chemical and structural evolution of thermally treated functionalized graphiti... more Modulating physico-chemical and structural evolution of thermally treated functionalized graphitic nanolubricants for effective control of metallic sliding contact friction.

Surface Topography: Metrology and Properties, 2021

The Ni–P-B ternary coating was prepared on steel specimens through electroless deposition and the... more The Ni–P-B ternary coating was prepared on steel specimens through electroless deposition and their microstructural and tribo-mechanical properties were investigated. Heat treatment of the as plated coating was carried out at 390 °C to realize its effect on microstructural, mechanical, tribological properties of the coating. Microstructural analysis was carried out to study phase structure, morphology, topography, and coating compositions by using XRD, FESEM, AFM, and EDS. Contact angle measurement was also performed to evaluate the wetting behavior of the coatings. The as-plated coating exhibited hydrophobic character with a contact angle of ∼ 96.7°, whereas the heat-treated coating resulted in hydrophilic character with a contact angle of ∼ 79.5°. Mechanical and tribological properties were evaluated by using Vickers microhardness, nanoindentation, and dry sliding friction test. It is observed that the heat treatment process has an excellent impact on mechanical and tribological p...

Thin Solid Films, 2019

Graphene-based polymer brush containing multilayer film has been fabricated on silicon wafer (SW)... more Graphene-based polymer brush containing multilayer film has been fabricated on silicon wafer (SW) via self-assembled multistep approach based on covalent insertion of 3-aminopropyltrimethoxysilane as a chemical linker on graphene oxide (GO) followed by covalently anchored with polyethyleneimine (PEI). A multilayer polymer brush film was then constructed by electrostatic layer-by-layer (LBL) self-assembly technique between positively charged outer layer PEI grafted GO and anionic polyelectrolyte, poly (sodium 4-styrenesulfonate) (PSS). The LBL formation and microstructure of as prepared films were characterized by Raman spectroscopy, atomic force microscopy, field emission scanning electron microscopy and elemental electron dispersive spectroscopy analysis. The changes in wettability of films during grafting of chemical components on silicon substrate were determined by water contact angle measurement. Microtribological performances of the films were investigated using ball-on-disc c...

Understanding the mechanism of precision sliding contacts with thin, adherent solid nano lubricat... more Understanding the mechanism of precision sliding contacts with thin, adherent solid nano lubricating particle films is important to improve friction and wear behavior and ensure mechanical devices have long service lifetimes. Herein, a facile and multistep approach for the preparation of graphene oxide (GO) is presented. Subsequently, surface modification of as-synthesized GO with octadecyl amine (ODA) is performed to prepare hydrophobic GO-ODA and with 6-amino-4-hydroxy-2-naphthalenesulfonic acid (ANS) to prepare amphoteric GO-ANS through a nucleophilic addition reaction. X-ray diffraction and ultraviolet-visible, Fourier transform infrared, and Raman spectroscopy provide significant information about the reduction of oxygen functionalities on GO and the introduction of new functionalities in GO-ODA and GO-ANS. The effects of particle functionalization for the improved control of particle adhesion to the tribocontact have been studied. Wettability and thermal stability were determi...

Electrodeposited nickel-graphene oxide (GO) composite coating was produced by pulse electrodeposi... more Electrodeposited nickel-graphene oxide (GO) composite coating was produced by pulse electrodeposition method followed by a functionalization with octadecyl amine (ODA) molecules to convert the embedded hydrophilic GO to hydrophobic reduced GO-ODA. Morphology, compositional, and tribological properties were investigated for the functionalized Ni-GO-ODA composite coating. FE-SEM and AFM microscopic studies show the homogeneous presence of embedded GO-ODA particles in the Ni matrix. XRD, EDS, and Raman spectra confirmed the successful functionalization of GO to GO-ODA. Post-functionalization, the water contact angle of the coating shows 111.8°, thereby confirming its hydrophobic nature. Tribological experiments were conducted by using a linear reciprocating ball on flat sliding microtribometer with varying load and sliding speed at ambient dry sliding condition. Experimental results showed that the wear and friction resistance properties were significantly enhanced after functionalizat...

Nickel-graphene oxide (GO) nanocomposite coatings with a uniform grain distribution were prepared... more Nickel-graphene oxide (GO) nanocomposite coatings with a uniform grain distribution were prepared on the SS440 samples and SS ball surface by pulsed electrodeposition (PED) method. The morphology, compositional, and tribological properties were investigated. FE-SEM and AFM microscopic studies shows a homogenous presence of GO particles intercalated in the Ni matrix in the composite coating. The incorporation of GO into the Ni matrix reduced the water contact angle of the coating showing its hydrophilic nature. XRD, EDS, and Raman spectra also confirmed the presence of GO on the coating surface as well as inside the matrix. The tribological studies show that the trapped GO particles positively affect the friction and wear resistance of the coating through formation of a tribo film in the contact interface. The effect of sliding speed on COF and wear rate of the pristine Ni coating was compared with Ni-GO composite coating and the insertion of GO into Ni matrix is found to reduce the ...

RSC Advances, 2015

An improved method for the preparation of graphene oxide (GO) and further exfoliation of GO to gr... more An improved method for the preparation of graphene oxide (GO) and further exfoliation of GO to graphene is described. Simultaneous surface functionalization and reduction of GO with octadecylamine (ODA) was also achieved without any further reducing agents. The structural aspects of GO, GO-ODA and graphene were analyzed by UV-Vis spectrometry, infra red spectroscopy, Raman spectroscopy and transmission electron microscopy. The wetting behavior of the functionalized particles were accessed by water contact angle measurements. The particle sizes in the oil suspensions which is actually fed to contact for lubrication were estimated using dynamic light scattering technique. Tribological performances and load bearing capacity of the particle suspensions were tested under two different pressure regime on a rotational tribometer with pin/ball-on-disc set up. The increase in hydrophobicity in GO-ODA helped the particles to work much better in low load condition due to the presence of long h...

ACS Applied Nano Materials

The present study demonstrates an improved and facile method for the exfoliation and chemical oxi... more The present study demonstrates an improved and facile method for the exfoliation and chemical oxidation of bulk hexagonal boron nitride (h-BN) powder. Further, chemical functionalization of oxidize...

BioEnergy Research

Here, a cost-effective route for the preparation of biodiesel (BD) from waste cooking oil (WCO) a... more Here, a cost-effective route for the preparation of biodiesel (BD) from waste cooking oil (WCO) as an alternative eco-friendly fuel and lubricant via catalytic transesterification process using simple base catalyst was demonstrated. Physical and chemical characterization based on FT-IR, 1 H-NMR, and 13 C-NMR spectroscopy reveals that free carboxylic acid functionality successfully alters to methyl ester of same hydrocarbon chain during the reaction. The BD was characterized by its physical, fuel characteristics including density, viscosity, acid value, flash point, pour point, and foaming tendency, and compared with existing diesel fuel in accordance with ASTM test standard. Prepared BD showed excellent fuel efficiency with higher flash (142 °C) and fire point (147 °C) than the existing diesel fuel. In order to use these synthetic biodiesel esters as advanced green lubricants, their lubrication behavior was tested and compared with hydrocarbon base oil hexadecane (HD). The macrotribological results showed the biodiesel significantly reduced the coefficient of friction by a maximum ~ 43% and specific wear rate ~ 71% in comparison with that of HD at variable applied load. The lubricating efficiency of prepared BD was found to be a similar trend in microtribometric experiments with reciprocating sliding motion under variable loads with similar contact pressure ( P m ~ 1.36–1.95 GPa) as demonstrated in macrotribological rotating motion. Due to polar nature of biodiesel, it deposits on the contact interface and provides a thick molecular film, which may be responsible for enhanced tribological behavior compared with pristine hydrocarbon oil.

Materials Research Express

Surface Topography: Metrology and Properties