Arun Kumar Sarma | VIT University (original) (raw)

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Papers by Arun Kumar Sarma

Proceedings of the Indian National Science Academy

Materials Technology

ABSTRACT Water hyacinth [Eichhornia crassipes] is a widely available natural fiber and used in ma... more ABSTRACT Water hyacinth [Eichhornia crassipes] is a widely available natural fiber and used in many applications in recent years. Eco friendly plasma sputtering technique has been employed to get Copper (Cu) coat on Water hyacinth fibers. The effects of working pressure, power and working time have been considered to optimize the best possible output on Cu coated fibers. Functional group of the coated and uncoated fibers has been analyzed by XRD and ATR-FTIR. The Surface morphology is analyzed by Scanning Electron Microscope and the hydrophobic nature of the fiber is measured by Water Contact Angle measurement. The antibacterial properties and behavioral change of the material has been discussed. It shows that the Cu coated fiber acquires greater antibacterial activity against Escherichia Coli (E.coli) and Staphylococcus aureus (S.aureus) than the raw fiber. The Changes in the moisture content of Cu deposited fibers are characterized quantitatively using Thermo Graphic Analyzer.

Materials Research Express

Disposable and highly efficient device that can separate oil from water is in high demand. This w... more Disposable and highly efficient device that can separate oil from water is in high demand. This work reveals the concept of oil/water separation using plasma technology. Copper coated, oxygen plasma-treated mesh has been used to separate oil and water from its mixture. At some critical conditions, the prepared coated mesh showed hydrophobic and oleophilic behavior. The coated mesh was used to separate the oil-water mixture, which allowed the oil to pass through, while it repelled water completely. The designed coated mesh maintained separation efficiency as high as 99 percent. Properties of coated and uncoated mesh were examined using various techniques and analyzed to understand the physical changes.

Contributions to Plasma Physics

Journal of Materials Science: Materials in Electronics

A facile and efficient one-pot solvothermal synthesis of reduced graphene oxide-CuSbS2 (rGO-CAS) ... more A facile and efficient one-pot solvothermal synthesis of reduced graphene oxide-CuSbS2 (rGO-CAS) nanobrick composite has been processed using ethylenediamine as reaction medium. In this case reduction of GO and the formation of CAS nanobricks on the surface of GO occurs simultaneously. The structural and morphological confirmation of the GO reduction and composite formation have been characterized using X-ray diffractometry, Raman spectroscopy, Fourier transform infrared spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy and X-ray photoelectron spectroscopy (XPS) analysis. Highly crystalline CAS material with orthorhombic structure in the composite has been observed through structural analysis. SEM micrographs reveal the brick-like structure of the CAS nanocrystals, which are well attached onto the individual layers of the graphene sheets. Improved optical absorption of the composite has been studied by absorption spectroscopy and the band gap tailoring of CAS nanobricks has also been achieved with GO matrix. XPS analysis verify the valence state of the composite material to be Cu+Sb3+(S2−)2. The composite also exhibits a remarkable photoelectric response due to increased surface to volume ratio. The good electron trapping, shuttling ability of GO resulted in an efficient separation of the photo-excited charge carriers from rGO-CAS nanobrick composites. The photocurrent demonstrated by the composite is 46% higher than that of the bare CAS nanobricks.

Tribology - Materials, Surfaces & Interfaces

ABSTRACT Increasing environmental awareness and demanding low energy consumption are of the top p... more ABSTRACT Increasing environmental awareness and demanding low energy consumption are of the top priorities for future vehicles manufacturing companies. This can be achieved by reducing wear and friction of engine components, so that its efficiency and lifetime can be increased. Surface treatments and coatings contribute to a better lubrication with oils and can participate significantly in achieving these goals. In this paper, diamond-like carbon (DLC) coating has been incorporated to the vehicle piston rings with different RF powers using magnetron sputtering method. The tribological properties like wear and coefficient of friction have been analysed using Pin-on-Disk tribometer. Micro-hardness and nano-hardness of the coated piston rings were characterized by micro-indentor and nano-indentation processes. Surface microstructure and elemental compositions were observed using Scanning Electron Microscopy. Experimental results demonstrated that the DLC coating shows lower wear and friction under similar operating conditions as compared to uncoated piston rings. Thus, usage of DLC coating has enhanced the engine life time. Silicon interlayer has also been applied between nitrided piston rings and DLC layer in order to have better coating adhesion. The properties of the interlayer are not studied but usage of it is found to protect DLC coating from delamination.

The Journal of The Textile Institute

Abstract It is necessary to study the suitable effect of plasma parameters, such as exposure time... more Abstract It is necessary to study the suitable effect of plasma parameters, such as exposure time and applied voltage on the wicking properties of silk fabrics. Wicking property of silk fabric has been improved by using air dielectric barrier discharge plasma treatment. The plasma treatment has been utilized to modify the surface properties of silk fabrics. Untreated and plasma-treated fabrics have been characterized by contact angle Goniometer, wicking test, Wet-out time, scanning electron microscope, Attenuated Total Reflection Fourier Transforms Infrared spectrometer (ATR-FTIR) and dye uptake test. The ATR-FTIR characterization shows that the hydroxyl functional group has been increased after plasma treatment of silk fabric. The experimental results of wicking rate and Wet-out time of the plasma-treated silk fabrics have shown significant improvement in hydrophilic properties that could be confirmed by contact angle measurement which is close to 0°. The tensile strength of untreated and plasma-treated fabrics has been measured to confirm the enhanced surface property.

Surface Review and Letters

In this work, we study the hydrophobic properties of silk fabrics by deposition of plasma-polymer... more In this work, we study the hydrophobic properties of silk fabrics by deposition of plasma-polymerized (pp) hexamethyldisiloxane (HMDSO) using low-pressure plasma-enhanced chemical vapor deposition. Recently, hydrophobic properties are under active research in textile industry. The effects of coating time and power on the HMDSO-coated silk fabrics are investigated. Water contact angle of pp-HMDSO-coated silk fabric surface is measured as a function of power and coating time. Fabric surface shows an enhancement in hydrophobicity after coating. Attenuated total reflectance-Fourier transform infrared spectroscopy reveals the surface chemistry, and scanning electron microscopy shows the surface morphology of the uncoated and HMDSO-coated fabrics, respectively. In the case of uncoated fabric, water droplet absorbs swiftly, whereas in the case of HMDSO-coated fabric, water droplet remains on the fabric surface with a maximum contact angle of 140[Formula: see text]. The HMDSO-deposited silk...

Plasma Physics and Controlled Fusion

American Journal of Materials Science and Engineering

Water hyacinth [Eichhornia crassipes] fiber has been treated using DC glow discharge plasma to ma... more Water hyacinth [Eichhornia crassipes] fiber has been treated using DC glow discharge plasma to make its surface more hydrophobic in nature for various applications. The plasma treated fibers have been coated with synthesized phase pure ZnO nano-particle at room temperature to enhance both hydrophobicity and Ultra Violet [UV] light protection rate. The behavioral changes of fibers and its characteristics have been studied using XRD, SEM, EDS, a ATR-FTIR and TGA. Surface chemistry of the treated fiber has been altered as depicted by ATR-FTIR studies, while the improve degree of crystallinity analysed by XRD shows the effects of molecular structure of the fibers. The hydrophobic nature of the fibers has been recognized by contact angle measurement using Goniometer and by water absorption processes. Moreover, moisture content of treated fiber has been measured quantitatively using TGA. Finally wavelet analysis has been applied to understand the surface characteristics of water hyacinth fiber and compare its surface roughness value was measured by SEM. Furthermore, entropy of the treated and untreated fibers has also been calculated.

Results in Physics, 2016

It has been shown that a non-contact force acts between two macroscopic physical objects held clo... more It has been shown that a non-contact force acts between two macroscopic physical objects held close together, which is not associated with the gravitational and electrostatic force. An experiment was conducted with objects of different mass, material and geometry to find the magnitude and properties of this apparent or pseudo force. The order of magnitude was found to be 10 À5 and it remained constant for all types of objects while only the coefficient increased as the distance between the objects reduced. It only started acting at small distances and failed to make a body move if it experienced static friction from any contact surface. The nature of the force was found to be attractive as well as repulsive. Due to gravitation being a solely attractive force, it was eliminated as a possible reason for the pseudo force. The experiment was performed twice, once by grounding the apparatus and then again without grounding. The order of the force remained the same for both cases. As the test objects were held by hand, they were grounded through the human body. Also, none of the objects used were in contact with each other for the duration of this work, preventing any contact electrification. Due to these factors, the force was not considered electrostatic in nature.

Fibers and Polymers, 2016

Experimental investigations have been carried out to modify the surface properties of natural Kan... more Experimental investigations have been carried out to modify the surface properties of natural Kanchipuram silk (pattu) fibers using a low temperature DC glow discharge air Plasma. Silk is an externally spun fibrous protein secretion formed into fibers. Plasma treatment is an eco-friendly, dry, and clean process over wet chemical method and does not suffer from any environmental and health concerns. Experiments have been performed considering three parameters such as discharge current, treatment time, and working pressure. The structural, thermal, morphological, optical, and mechanical studies of raw and plasma treated silk fibers have been obtained out using attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR) spectroscopy, X-ray diffraction (XRD), thermo gravimetric analyzer (TGA), scanning electron microscope (SEM) with energy dispersive spectroscopy (EDS), diffuse absorbance spectroscopy, and tensile test. A comparative study has been done for the untreated and different treated fibers. Various characterization analyses reveal that surface roughness of the plasma treated silk fiber is increased and also crystallite size of treated samples is enhanced, plasma treated silk fibers maintain the whiteness effect and it is observed that UV transmittance region (A & B) is more for the treated fiber which signifies enhanced UV protection.

The dissipation of the dust ion-acoustic soliton is studied experimentally in a homogeneous unmag... more The dissipation of the dust ion-acoustic soliton is studied experimentally in a homogeneous unmagnetized dusty double plasma device. The experiment is carried out in the device having 50 cm in diameter and 90 cm in length. The dust density inside the chamber is controlled by the input power applied to the ultrasonic vibrator. A Langmuir probe which detects solitons from its electron saturation current is placed few mm away from the dust region in the target plasma. A sinusoidal pulse is applied to the source anode to launch a wave. When there is no dust in the system, the leading part of the pulse steepens to form some solitons. As the dust density introduced in the system increases the amplitude of the solitons decreases and at a high dust density the structure of the soliton completely disappears and the pulse becomes broaden. This broadening of the pulse leads to the formation of a tail. The K-dV Bergers equation is also numerically integrated by considering the experimental para...

Instrumentation Science & Technology, 2015

ABSTRACT A D.C. glow discharge plasma source was employed to characterize changes in water absorb... more ABSTRACT A D.C. glow discharge plasma source was employed to characterize changes in water absorbance and surface morphology of natural jute fibers. The low temperature plasma removed moisture from the fibers and significantly modified surface properties. Scanning electron microscopy and energy dispersive X-ray spectroscopy were used for characterization. Open source software was used for the processing of the scanning electron micrographs. The changes in the macromolecular structure and the crystallinity were characterized by X-ray diffraction. Thermogravimetric analysis demonstrated moisture removal from the fibers following plasma treatment.

Bi-layered Zn rich ZnO film has been developed on uniformly etched soda-lime glass substrate usin... more Bi-layered Zn rich ZnO film has been developed on uniformly etched soda-lime glass substrate using vacuum thermal evaporation system. The experiment has been performed by analyzing samples with different concentrations of etched soda-lime. At the same time, the tray containing the ZnO powder has been covered with mesh grids of different sizes each time. It has been shown this provides relatively lower resistivity and exhibits an excellent light scattering property [1] and relatively good electrical properties of the film. The produced film is characterized with SEM-EDAX, FTIR and DRS setup. This has shown improvement in its performance and quantum efficiency (QE). Thus, the developed glass/bi-layered ZnO film with a Zn-rich layer is a new promising upcoming material since its resistivity is low while its light-scattering property is still high.

Chinese Physics Letters, 2014

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