Naval Materials Research Laboratory DRDO

Ambernath, India

Naval Materials Research Laboratory DRDO

Ambernath, India
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Jessy V.,Naval Materials Research Laboratory DRDO | Pradeep K.,Naval Materials Research Laboratory DRDO
Research Journal of Biotechnology | Year: 2017

Amphibalanus amphitrite, an acorn barnacle, found worldwide is a model organism for the study of biofouling and ecological research. This mini-review focuses on the recent transcriptome and proteome studies that have been carried out on this organism for better understanding of how marine organisms attach to a substrate causing biofouling. Still much is to be elucidated for the development of a good antifouling agent which will be cost efficient and eco-friendly.


Ghorpade T.K.,Naval Materials Research Laboratory DRDO | Palai A.K.,Laboratory for Advanced Research in Polymeric Materials | Rath S.K.,Naval Materials Research Laboratory DRDO | Sharma S.K.,Bhabha Atomic Research Center | And 4 more authors.
Sensors and Actuators, B: Chemical | Year: 2017

A series of poly(arylene-ethynylene)s (PAEs) containing pentiptycene and tbutylpyrene or pyrene in the main chain were synthesized. Introduction of pyrene moiety in the pentiptycene polymeric backbone made the polymers extremely sensitive and selective towards TNT in aqueous solution as well as vapour phase as compared to the other interfering nitroaromatic compounds (NACs) like DNT and PA. In solid state, one of the polymer P2 showed superior sensitivity towards TNT vapours with 60.4% and 90% fluorescence loss within respective 10 s and 30 s of exposure to TNT vapours, which is much higher than most of the reported NACs sensors. Even towards aqueous NACs, the performance of P2 is the best, with 69.8% fluorescence of P2 film getting quenched within 60 s of immersion in aqueous solution of TNT (50 μM). Fluorescence regain study showed that 94% fluorescence is re-gained after dipping the fluorescence-quenched polymer film in methanol for 20 s. The polymers were found to possess high thermal stability (282–585 °C) and appreciably high fluorescence quantum yield (0.39–0.65). We also report the sub-nanoscopic free volume and its distribution in the polymers, as quantified by positron annihilation life time spectroscopy (PALS). © 2017 Elsevier B.V.


Sivaraman P.,Naval Materials Research Laboratory DRDO | Kushwaha R.K.,Naval Materials Research Laboratory DRDO | Shashidhara K.,Naval Materials Research Laboratory DRDO | Hande V.R.,Naval Materials Research Laboratory DRDO | And 3 more authors.
Electrochimica Acta | Year: 2010

All solid supercapacitor based on polyaniline (PANI) and crosslinked sulfonated poly[ether ether ketone] (XSPEEK,) is reported in this paper. The crosslinker used for sulfonated poly[ether ether ketone] (SPEEK) is 1,4-bis(hydroxymethyl) benzene. The XSPEEK is used as both solid electrolyte and separator membrane. Supercapacitors are fabricated using various PANI/XSPEEK weight ratios. These are characterized by cyclic voltammetry and galvanostatic charge-discharge studies. The supercapacitor with PANI/XSPEEK weight ratio 1:0.5, exhibit a specific capacitance of 480 F g-1 of PANI. To the best of authors' knowledge, the value reported here is the highest for a supercapacitor based on a proton conducting solid polymer electrolyte and PANI. Detailed electrochemical impedance spectroscopy analysis is carried out. The analysis shows that the complex capacitance of the supercapacitor depends on the XSPEEK content. The time constant (t0), derived from the imaginary part of complex capacitance decreases with increase in the XSPEEK content in the supercapacitor. Cycle life characteristics of the supercapacitor show a decrease in specific capacitance during initial cycles and get stabilized during later cycles. © 2009 Elsevier Ltd. All rights reserved.


Khandpekar M.M.,Materials Research Laboratory | Kushwaha R.K.,Naval Materials Research Laboratory DRDO | Pati S.P.,Sambalpur University
Solid-State Electronics | Year: 2011

A 5 F-5 V prototype of solid state supercapacitor based on polymer electrolyte (PANI) and XSPEEK composing of six single cells stacked in series has been fabricated. The scale-up from a small single cell to a larger stack prototype of a solid-state electrochemical supercapacitor is discussed in this paper. The developed prototype showed a higher series resistance than estimated in our previous study on individual cell supercapacitor. The fabricated prototype achieved a specific capacitance of 480 F/g. The assembled capacitor has been characterized by cyclic voltammetry, impedance spectroscopy and galvanostatic charging/discharging. The performances of the electrodes have been compared with that of the single cell electrodes of area 4 cm 2. © 2011 Elsevier Ltd. All rights reserved.


Nayak N.,Proof and Experimental Establishment DRDO | Sivaraman P.,Naval Materials Research Laboratory DRDO | Banerjee A.,Proof and Experimental Establishment DRDO | Madhu V.,Indian Defence Research And Development Laboratory | And 3 more authors.
Polymer Composites | Year: 2012

Ballistic impact performance of aramid fiber fabric-epoxy and aramid fiber fabric-polypropylene (PP)-based composite laminates has been studied against 7.62 mm armor piercing projectiles. Twaron® was used as aramid fiber fabric in the composites. Role of matrix on the damage pattern has been investigated by impacting the composites of different thickness with projectiles having different strike velocity (SV). Ballistic limit (BL) for each composite has been estimated through correlation of SV and residual velocity (RV) of the projectile by usual V 50 method. Ballistic limit was found to vary linearly with composite laminate thickness. Twaron®-PP composites exhibited higher ballistic limit compared toequivalent thickness of Twaron®-epoxy composites. Epoxy-based composites exhibited localized damage mode compared to a global mode of failure in PP-based composites. Scanning electron microscopy revealed that fibers in Twaron®-epoxy composites failed largely by shear while tensile mode of failure was observed for Twaron®-PP composites. © 2012 Society of Plastics Engineers.


Hastak R.S.,Naval Materials Research Laboratory DRDO | Sivaraman P.,Naval Materials Research Laboratory DRDO | Potphode D.D.,Naval Materials Research Laboratory DRDO | Shashidhara K.,Naval Materials Research Laboratory DRDO | Samui A.B.,Naval Materials Research Laboratory DRDO
Electrochimica Acta | Year: 2012

In the present work, we report high temperature performance of solid electrolyte supercapacitor based on activated carbon (AC) and phosphoric acid doped poly [2,5 benzimidazole] (ABPBI). Supercapacitors with varying concentrations of solid electrolyte in the electrode were fabricated and unit cells were analyzed over a wide temperature range of 27-120°C. Supercapacitor with AC/ABPBI wt ratio 1.0:0.25 exhibited a specific capacitance of 197 F g -1 at room temperature. To the best of our knowledge, the value reported here is one of the highest for electric double layer supercapacitor with a solid electrolyte. The specific capacitance of supercapacitors having various compositions increased with temperature. The specific capacitance for AC/ABPBI wt ratio 1.0:0.25, capacitance increased to 248 F g -1 at 120°C. The performance of supercapacitors was also analyzed by electrochemical impedance spectroscopy. The Nyquist plots at room temperature and 100°C were studied by fitting them using Randles equivalent circuit. Supercapacitor with AC/ABPBI wt ratio 1.0:0.25 showed phase angle of 86.8°at low frequency which indicated excellent capacitive behavior at room temperature. The supercapacitor was found to have good stability during galvanostatic charge-discharge cycling even after repeated heating and cooling. © 2011 Elsevier Ltd. All Rights Reserved.


Hastak R.S.,Naval Materials Research Laboratory DRDO | Sivaraman P.,Naval Materials Research Laboratory DRDO | Potphode D.D.,Naval Materials Research Laboratory DRDO | Shashidhara K.,Naval Materials Research Laboratory DRDO | Samui A.B.,Naval Materials Research Laboratory DRDO
Journal of Solid State Electrochemistry | Year: 2012

Supercapacitor containing multi-walled carbon nanotubes (MWCNT) as the electrode material and phosphoric acid-doped poly[2,5 benzimidazole] (ABPBI) as the solid electrolyte and separator membrane has been investigated in a wide temperature range. Supercapacitors with different solid electrolyte concentrations have been fabricated and evaluated for their electrochemical performance. Specific capacitance of supercapacitors at room temperature was found to increase after the first heating cycle. Supercapacitor containing 10 wt.% of solid electrolyte in the electrode shows higher specific capacitance than the supercapacitor with liquid electrolyte. Cyclic voltammetry analysis of supercapacitors indicates high rate capability. The linear increase in the specific capacitance with temperature implies that capacitance is predominantly due to electric double layer. Electrochemical impedance analysis indicates that the mass capacitance and Warburg parameter increase with temperature, while solution resistance and leakage resistance decrease with temperature. The complex capacitance of the supercapacitors shows that both real and loss capacitances increase with temperature. The phase angle of supercapacitors is found to be around 85.2±1° at room temperature and it decreases with temperature. Galvanostatic charge-discharge cycling exhibits almost constant specific capacitance of 28 Fg -1 at room temperature. However, it increases sharply and then attains stable value of 52 Fg -1 during cycling at 100 °C. The increase in specific capacitance has been attributed to increase in surface area of the carbon nanotube (CNT), due to activation by phosphoric acid and diffusion of free phosphoric acid into the central canal of MWCNT. © Springer-Verlag 2012.

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