Piezoelectric nanogenerator using conductive polymer and silver nanowires as an electrodes

( Shubhangi Khadtare ),고의진,문두경 한국공업화학회 2018 한국공업화학회 연구논문 초록집 Vol.2018 No.1

PVDF based flexible piezoelectric energy harvester using silver nanowires and PEDOT derivatives

( Shubhangi Khadtare ),고의진,문두경 한국공업화학회 2019 한국공업화학회 연구논문 초록집 Vol.2019 No.0

A piezoelectric nanogenerator (PNG) device consisting of conducting polymer and AgNWs as an electrode using poly(vinylidene fluoride) (PVDF) as an active layer is demonstrated. Here, a poly(3,4-ethylenedioxythiophene) (PEDOT) derivative, poly(2-hexyl-2,3-dihydrothieno [3,4-b][1,4]dioxine:dodecyl sulfate (PEDOT-C₆:DS) was synthesized. This PNG exhibit superior energy harvesting performance with maximum piezoelectric output voltage and current 7.02 V and 1.11 μA, at 8 Hz operating frequency, respectively. The fabricated hybrid electrode PNG (1.5 cmx2.5 cm) generates a maximum output power of 1.18 μW. The fabricated PNG device is capable to lit up white LEDs and charged a commercial capacitor of 1 μF with charged voltage 2.68 V in 80 s. Further, with the results obtained it is confirmed that the PEDOTC6:DS is a promising material for hybrid electrodes in electronic applications.

Metal-oxide based flexible piezoelectric energy harvester

( Shubhangi Khadtare ),고의진,문두경 한국공업화학회 2019 한국공업화학회 연구논문 초록집 Vol.2019 No.0

Piezoelectric nanogenerators (PNG) plays an important role in energy sources in modern electronics hub. Among the various materials available for high-performance piezoelectric energy harvesters, the metal oxide such as ZnO, TiO₂, SnO₂, NiO, etc., has attracted a great deal of attention due to the coupling of its good piezoelectric and semiconducting properties. These oxide materials have relatively low toxicity and cost-effectiveness in comparison to other piezoelectric materials. Further, PNG device made up of metal oxides deposited by using solution processed method and their output characteristics of piezoelectric response are in process.

Experimental Study in Micro-drilling Mechanism on Heterogeneous Structure of Thermal Barrier Coated Inconel 718 Superalloy

Avinash N. Khadtare,Raju Pawade,Suhas S. Joshi 한국정밀공학회 2024 International Journal of Precision Engineering and Vol.25 No.3

Thermal barrier coated (TBC) superalloys are extensively used for manufacturing turbine blades to sustain high temperature zone while in operation. The production of cooling holes on these blades surface at various inclinations to the surface is essential to minimize the severe heat load experienced during working to achieve higher service life. Manufacturing of these holes is a main challenge in TBC superalloys due to combined metal and ceramic layers along the hole depth which effect on the thrust force generation, tool life and hole quality. Therefore, in this study mechanical micro-drilling is proposed to analyze the above highlighted difficulty. The experiments were performed on TBC Inconel 718 sheet having 3.3 mm thickness using 600 μm TiAlN coated carbide drill under dry environment. Three input parameters with their two levels are chosen for experimentations and each experiment is performed two times. Micro-drilling performance is assessed in terms of drilling thrust at different material layer with hole depth, taper of hole and distribution of thrust along the cutting edge of drill. Results show that magnitude of dynamic drilling thrust variation is observed at interface drilling irrespective of hole orientation. Whereas, maximum drilling thrust is observed before retraction of the drill. Magnitude of thrust force and fluctuation of thrust signal increases with depth of hole due to chip clogging in flute space. Minimum taper of a hole is observed in case of straight hole drilling than inclined hole whereas circular shape of hole is produced in straight hole drilling whereas elliptical hole is produced in case of inclined hole. Equal amount of thrust distribution along the cutting edge is observed in case of straight hole drilling but unequal amount of thrust distribution is seen in of case inclined hole due to drill-workpiece interaction.

Hole transport layer based on conjugated polyelectrolytes for polymer solar cells

Moon, Sanghun,Khadtare, Shubhangi,Wong, Matthew,Han, Sung-Hwan,Bazan, Guillermo C.,Choi, Hyosung Elsevier 2018 JOURNAL OF COLLOID AND INTERFACE SCIENCE - Vol.518 No.-

<P><B>Abstract</B></P> <P>We demonstrate the conjugated polyelectrolytes (CPEs) as efficient hole transport layer (HTL) of polymer solar cells. Replacing poly(3,4-ethylenedioxy-thiophene):poly(styrenesulfonate) (PEDOT:PSS) with a CPEs with narrow bandgap results in both improvements in device efficiency and stability. In spite of their narrow bandgap, thin CPE films (thickness of ∼30 nm) enable sufficient light absorption within the active layer. Enhancement of device efficiency is attributed to low surface roughness, high transmittance in visible region, and reduced charge transfer resistance. Compared to the device with PEDOT:PSS, pH neutral nature of CPEs may enhance device stability under ambient condition.</P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Anodically Grown Binder-Free Nickel Hexacyanoferrate Film: Toward Efficient Water Reduction and Hexacyanoferrate Film Based Full Device for Overall Water Splitting

Bui, Hoa Thi,Shrestha, Nabeen K.,Khadtare, Shubhangi,Bathula, Chinna D.,Giebeler, Lars,Noh, Yong-Young,Han, Sung-Hwan American Chemical Society 2017 ACS APPLIED MATERIALS & INTERFACES Vol.9 No.21

<P>One of the challenges in obtaining hydrogen economically by electrochemical water splitting is to identify and substitute cost-effective earth-abundant materials for the traditionally used precious-metal-based water-splitting electrocatalysts. Herein, we report the electrochemical formation of a thin film of nickel-based Prussian blue analogue hexacyanoferrate (Ni-HCF) through the anodization of a nickel substrate in ferricyanide electrolyte. As compared to the traditionally used Nafion-binder-based bulk film, the anodically obtained binder-free Ni-HCF film demonstrates superior performance in the electrochemical hydrogen evolution reaction (HER), which is highly competitive with that shown by a Pt-plate electrode. The HER onset and the benchmark cathodic current density of 10 mA cm(-2) were achieved at small overpotentials of 15 mV and 0.2 V (not iR-corrected), respectively, in 1 M KOH electrolyte, together with the long-term electrochemical durability of the film. Further, a metal-HCF-electrode-based full water-splitting device consisting of the binder-free Ni-HCF film on a Ni plate and a one-dimensional Co-HCF film on carbon paper as the electrodes for the HER and the oxygen evolution reaction (OER), respectively, was designed and was found to demonstrate very promising performance for overall water splitting.</P>

Synthesis and photophysical investigations of pyromellitic diimide based small molecules

Bathula, Chinna,Mallikarjuna, K.,Kadam, Abhijit,Shrestha, Nabeen K.,Khadtare, Shubhangi,Mane, Suresh D.,Kim, Haekyoung Elsevier 2019 Inorganic chemistry communications Vol.102 No.-

<P><B>Abstract</B></P> <P>The present work reports on the highly efficient microwave assisted Suzuki coupling reaction for obtaining pyromellitic diimide based symmetrical small molecules with donor-acceptor-donor (<I>D</I>-<I>A</I>-<I>D</I>) configuration. Electron rich bithiophene is employed as a donor and alkyl substituted pyromellitic diimide units are explored as acceptors to get the desired small molecules. In order to study the relation between chemical structures and material properties, the prepared compounds were characterized in detail using absorption spectroscopy, cyclic voltammetry and thermograviometric analysis. The compounds exhibited good thermal stabilities with high decomposition temperature. Photophysical investigations of the newly synthesized pyromellitic diimide based small molecules, suggests these materials as potential candidates for organic electronic applications.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Two novel symmetrical π conjugated oligomers are synthesized. </LI> <LI> Microwave assisted PdCl<SUB>2</SUB>(dppf) catalyzed Suzuki coupling reaction. </LI> <LI> The shorter reaction time, high yields and simple isolation is the novelty of this method. </LI> <LI> Determination of photophysical studies and HOMO-LUMO levels. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>