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11. Influence of Various Physiochemical Parameters of AFeO3 (A = Bi, Er, Ga, La, Sm, Y) Fillers on the Dielectric, Ferroelectric, Energy Storage, and Mechanical Energy Harvesting Performance of PVDF.

Author

Sasmal, Abhishek, Devi, Parukuttyamma Sujatha, and Sen, Shrabanee

Subjects
*ENERGY storage, *MECHANICAL energy, *DIELECTRICS, *ENERGY harvesting, *DIFLUOROETHYLENE, *DENSITY currents, *POWER density, *SAMARIUM
Abstract

Different filler particles are very often used by researchers all over the world to tune the dielectric, ferroelectric, piezoelectric, energy storage, and energy harvesting properties of poly(vinylidene fluoride) (PVDF). In the present work, different perovskite ferrites, AFeO3 (A = Bi, Er, Ga, La, Sm, and Y), are included into PVDF matrix separately. The roles of different parameters like, particle size, dielectric permittivity, ferroelectric polarization, crystal structure, etc. of the fillers in tuning the performance of respective PVDF‐based composites are comprehensively and simultaneously studied here. Non‐centrosymmetric fillers are found to improve the output performances of PVDF more effectively compared to that of centrosymmetric fillers. 5 wt% BiFeO3‐loaded PVDF film (5BF) shows the best performance in all aspects. Upon repeated human finger tapping, the maximum instantaneous output power density and instantaneous current across a 10 MΩ resistor connected across the 5BF film are found to be ≈3 µW cm−2 and 1.25 µA, respectively. The rectified voltage from 5BF nanogenerator is used to charge a 10 µF commercial capacitor up to ≈2.8 V and lights up some LEDs as a part of its real life applicability. The fabricated nanogenerator also shows good vibration and pressure sensing ability. [ABSTRACT FROM AUTHOR]

Published
2022
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39. Design and application of Au decorated ZnO/TiO2 as a stable photocatalyst for wide spectral coverage.

Author

Mukhopadhyay, Soumita, Maiti, Debabrata, Chatterjee, Sabyasachi, Devi, Parukuttyamma Sujatha, and Suresh Kumar, Gopinatha

Abstract

A ternary nanostructured photocatalyst consisting of ZnO/TiO2/Au was designed to achieve an enhanced solar absorption due to the coupling of surface enhanced plasmonic absorption of metal and semiconductor excitons. TiO2 coated ZnO rods with an aspect ratio of 8–12 were decorated with citrate capped gold nanoparticles for photocatalytic degradation of organic pollutants in simulated waste water under solar irradiation. Simulated waste water was prepared so as to get a mixture exhibiting a wide range of spectral distribution in the UV-visible region by deliberately mixing congo red, methylene blue and malachite green. Photo-oxidation of few phenolic compounds such as phenol, 4-chlorophenol and polycyclic aromatic hydrocarbons viz. anthracene and phenanthrene were also investigated in order to rule out the visible light sensitization of the dye molecules and confirm the photocatalytic efficacy of the ternary composite for a wide range of water pollutants under simulated solar irradiation. The composite exhibited enhanced photocatalytic activity and photoelectrochemical stability upon UV and visible light exposure. This enhanced efficiency was also corroborated with the photocarrier lifetime and chronoamperometric studies. Under simulated solar irradiation, UV light induced well separated charge carriers coupled with the visible light induced local surface plasmon resonance of AuNPs to exert significantly enhanced photocatalytic activity in a broad spectral region. This type of material may evolve as a novel photocatalyst for the efficient removal of organic contaminants in waste water and photoelectrochemical water splitting under the solar spectrum. [ABSTRACT FROM AUTHOR]

Published
2016
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44. Surface-Engineered Multifunctional Eu:Gd2O3Nanoplates for Targeted and pH-Responsive Drug Delivery and Imaging Applications

Author

Saha, Arindam, Mohanta, Subas Chandra, Deka, Kashmiri, Deb, Pritam, and Devi, Parukuttyamma Sujatha

Abstract

In this paper, we report the synthesis of surface-engineered multifunctional Eu:Gd2O3triangular nanoplates with small size and uniform shape via a high-temperature solvothermal technique. Surface engineering has been performed by a one-step polyacrylate coating, followed by controlled conjugation chemistry. This creates the desired number of surface functional groups that can be used to attach folic acid as a targeting ligand on the nanoparticle surface. To specifically deliver the drug molecules in the nucleus, the folate density on the nanoparticle surface has been kept low. We have also modified the drug molecules with terminal double bond and ester linkage for the easy conjugation of nanoparticles. The nanoparticle surface was further modified with free thiols to specifically attach the modified drug molecules with a pH-responsive feature. High drug loading has been encountered for both hydrophilic drug daunorubicin (∼69% loading) and hydrophobic drug curcumin (∼75% loading) with excellent pH-responsive drug release. These nanoparticles have also been used as imaging probes in fluorescence imaging. Some preliminary experiments to evaluate their application in magnetic resonance imaging have also been explored. A detailed fluorescence imaging study has confirmed the efficient delivery of drugs to the nuclei of cancer cells with a high cytotoxic effect. Synthesized surface-engineered nanomaterials having small hydrodynamic size, excellent colloidal stability, and high drug-loading capacity, along with targeted and pH-responsive delivery of dual drugs to the cancer cells, will be potential nanobiomaterials for various biomedical applications.

Published
2017
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45. Selective Binding of Genomic Escherichia coliDNA with ZnO Leads to White Light Emission: A New Aspect of Nano–Bio Interaction and Interface

Author

Das, Sumita, Pramanik, Srikrishna, Chatterjee, Sabyasachi, Das, Partha Pratim, Devi, Parukuttyamma Sujatha, and Suresh Kumar, Gopinatha

Abstract

Here, we report for the first time, a novel and intriguing application of deoxyribonucleic acid (DNA) in the area of optics by demonstrating white light emission by tuning the emission of a nanomaterial, ZnO rods, exhibiting surface defects, in the presence of genomic Escherichia coliDNA with a comparatively high quantum efficiency. In order to understand the DNA specificity, we have also studied the interaction of ZnO with CT, and ML DNA, ss EC DNA, synthetic polynucleotides and different mononucleosides and bases. Further, in order to understand the effect of particle shape and defects present in ZnO, we have also extended our study with ZnO rods prepared at higher temperature exhibiting red emission and ZnO particles exhibiting yellow emission. Interestingly, none of the above studies resulted in white light emission from ZnO–DNA complex. Our studies unequivocally confirmed that the concentration and the nature of DNA and ZnO together plays a crucial role in obtaining CIE coordinates (0.33, 0.33) close to white light. The much enhanced melting temperature (Tm) of EC DNA and the energetics factors confirm enhanced hydrogen bonding of ZnO with EC DNA leading to a new emission band. Our experimental observations not only confirm the selective binding of ZnO to EC DNA but also open a new perspective for developing energy saving light emitting materials through nano-bio interactions.

Published
2017
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49. Formation of Self-Assembled Defect-Free Zn2SnO4 Nanostructures from Binary Oxides without the Kirkendall Effect.

Author

Das, Partha Pratim and Devi, Parukuttyamma Sujatha

Subjects
*ZINC oxide, *ANTIMONY, *OXIDES, *KIRKENDALL effect, *NANOPARTICLES, *PHOTOCATALYSIS
Abstract

In this Communication, we report a facile approach to synthesize a technologically important oxide Zn2SnO4 (ZTO) by a temperature-dependent solid-state reaction without the Kirkendall effect. Single-phase defect-free ZTO was formed upon calcination of a homogeneous 2:1 mixture of reactive ZnO rods and SnO2 nanoparticles at 1000 °C. We also observed interesting photocatalytic and photovoltaic properties from the synthesized ZTO material. [ABSTRACT FROM AUTHOR]

Published
2014
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50. Enhanced performance of CNT/SnO2 thick film gas sensors towards hydrogen.

Author

Majumdar, Sanhita, Nag, Pratanu, and Devi, Parukuttyamma Sujatha

Subjects
*TIN oxides, *THICK films, *GAS detectors, *CARBON nanotubes, *HYDROGEN detectors, *NANOPARTICLES
Abstract

Abstract: Nanosized SnO2/carbon nanotube composite gas sensing material has been synthesized by a wet chemical method. The gas sensing studies were performed against a wide range of concentration of hydrogen gas. The sensing performance of the composite was compared with the bulk tin oxide nanoparticles and pure CNT. At 200 °C, 0.1% CNT/SnO2 composite sensor exhibited 84% sensitivity against 4% hydrogen gas with a relatively low recovery time of 120 s. It has been demonstrated that SnO2/CNT composite sensor is highly suitable for sensing hydrogen gas at comparatively lower operating temperatures and has the ability to arrest the effect of moisture, by which the stability of the sensors are enhanced markedly, in spite of the lower operating temperatures. [Copyright &y& Elsevier]

Published
2014
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