International Association of Advanced Materials
Advanced Materials Proceedings
2002-4428
2
4
2017
04
01
Evolution of the performance of SiNWs based electrochemical capacitor in ionic electrolyte
214
217
16233
10.5185/amp.2017/402
EN
Ankur
Soam
Semiconductor Thin Films and Plasma Processing Laboratory, Department of Metallurgical Engineering and Materials Science, Indian Institute of Technology Bombay, Mumbai, 400076, India
Nanomaterials and Device Fabrication Laboratory, Center for Nanoscience and Nanotechnology,
Siksha ‘O’ Anusandhan University, Bhubaneswar, Odisha, 751030, India
Rajiv
Dusane
Semiconductor Thin Films and Plasma Processing Laboratory, Department of Metallurgical Engineering and Materials Science, Indian Institute of Technology Bombay, Mumbai, 400076, India
Journal Article
2021
12
09
The development of micro-supercapacitor (µ-SC) based on silicon nanowires (SiNWs) has increased the demands of<br />cost-effective methods via low temperature processing routes for the fabrication of SiNWs which can enable the realization of µ-SC directly on a Si chip. In this work, SiNWs synthesized by hot-wire chemical vapor processing (HWCVP) at low substrate temperature of 350 <sup>o</sup>C have been explored as the electrodes for the use in µ-SC. Electrochemical behavior was tested by using cyclic voltammetry (CV) and galvanostatic charging/discharging in an ionic electrolyte. TEM characterization reveals as-grown SiNWs have inner crystalline core (c-core) sheeted with an amorphous layer of silicon (a-Si) which has poor electrical conductivity and reduces the capacitance of SiNWs. Copyright © 2017 VBRI Press.
https://amp.iaamonline.org/article_16233_cffa834c1c8ba2913de7c69854eeb433.pdf
International Association of Advanced Materials
Advanced Materials Proceedings
2002-4428
2
4
2017
04
01
Synthesis of highly dispersed FePO4 cathode material for rechargeable lithium battery
218
222
16234
10.5185/amp.2017/403
EN
Bikash
Mandal
Electrochemistry Laboratory, Department of Chemistry, Visva-Bharati (A Central University),
Santiniketan 731235, West Bengal, India
I.
Basumallick
Electrochemistry Laboratory, Department of Chemistry, Visva-Bharati (A Central University),
Santiniketan 731235, West Bengal, India
Susanta
Ghosh
Electrochemistry Laboratory, Integrated Science Education and Research Centre, Visva-Bharati (A Central University), Santiniketan 731235, West Bengal, India
Journal Article
2021
12
09
Highly dispersed, porous and nano-sized FePO<sub>4 </sub>have been synthesized by a facile aqueous and alcoholic medium for their application as cathode in rechargeable lithium batteries. Various dispersing templates in association with suitable solvents are used to introduce porosity and dispersive nature among the particles and to reduce the size of the particles. Characterization with FTIR, powder XRD and SEM suggests the formation of less crystalline, pure FePO<sub>4 </sub>with high surface area and high porosity. Cyclic voltametry has been employed to test the intercalation behaviour of lithium ions and confirms the reversible nature of the material. The role of the dispersing template for the material growth and the electrochemical performances of the synthesized FePO<sub>4</sub> as cathode in lithium battery have been discussed. It is found that poly(styrene-co-divinylbenzene) as the dispersing agent produces highly dispersed material with highest discharge capacity of 138 mAh.g<sup>-1</sup>. Copyright © 2017 VBRI Press.
https://amp.iaamonline.org/article_16234_8cf55f85578015ca09161d3354ac2fcf.pdf
International Association of Advanced Materials
Advanced Materials Proceedings
2002-4428
2
4
2017
04
01
Green synthesis, structural characterization and application of cadmium sulfide nanocrystals with fluorescent dyes for solar enhancement
223
227
16235
10.5185/amp.2017/404
EN
Yashvant
Rao
Centre for Nanosciences, Central university of Gujarat, Gandhinagar 382030, India
Gajendra Kumar
Inwati
Centre for Nanosciences, Central university of Gujarat, Gandhinagar 382030, India
Man
Singh
Centre for Nanosciences, Central university of Gujarat, Gandhinagar 382030, India
School of Chemical Sciences, Central university of Gujarat, Gandhinagar 382030, India
Journal Article
2021
12
09
Cadmium sulphide nanocrystals (CdS NCs) of ≈ 7.0 nm have been synthesized and structurally characterized with X-Ray Diffraction (XRD), High Resolution Transmission Electron Microscope (HR-TEM) and topographical 3D image by Atomic Force Microscopy (AFM). The binding and kinetic energies of 5<sup>th</sup> electron of 3d orbital (inner 3d<sub>5/2</sub>) and 3<sup>rd</sup> (outer 3d<sub>3/2</sub>) of Cd were 405.93 and 412.67 eV as well as 1074 and 1080.76 eV respectively determined with XPS. The CdS at 298.15 K, when dispersed in water, methanol and ethanol with 100 µM each of rhodamine B (RB), sulphorhodamine B (SRB) and carboxyfluorescein (CF) the fluorescent dyes (FD) separately has enhanced UV-Vis absorbance by 45, 30 and 25% respectively in order of (RB-CdS) > (SRB-CdS) > (CF-CdS) within 200 to 320 nm as compared to without CdS. Probably the CdS has functionalized the functional groups of the dyes that could have induced the p-conjugated bonds to detain higher UV-Vis abs. especially one -COOH, four -CH<sub>2</sub>CH<sub>3</sub>, two -SO<sub>3</sub>, four -CH<sub>2</sub>CH<sub>3 </sub>and two –COOH, one >C= with one hydroxyl group respectively. Thus, the CdS-Dye-UV-Vis model could be proposed as new finding of our studies. Copyright © 2017 VBRI Press.
https://amp.iaamonline.org/article_16235_534e32b51f098039399d0c244694bb76.pdf
International Association of Advanced Materials
Advanced Materials Proceedings
2002-4428
2
4
2017
04
01
Study of polyvinylalcohol/polyionic organic semiconductor as thermistor
228
230
16236
10.5185/amp.2017/405
EN
Anandraj
J
Polymer Nanocomposite Laboratory, Center for Crystal Growth, VIT University, Vellore 632014, Tamil Nadu, India
Girish M.
Joshi
Polymer Nanocomposite Laboratory, Center for Crystal Growth, VIT University, Vellore 632014, Tamil Nadu, India
Mayank
Pandey
Polymer Nanocomposite Laboratory, Center for Crystal Growth, VIT University, Vellore 632014, Tamil Nadu, India
Journal Article
2021
12
09
We have demonstrated the successful preparation of polyvinyl alcohol (PVA) composed CuBi<sub>2</sub>S<sub>3</sub> polyionic (PI) composites. Polymer composites were sensitive to the external stimuli, the modified PVA moiety exhibits excellent electrical property as a function of temperature. The volume resistance measured by impedance analyzer (40 to 150<sup>o</sup>C) under broadband frequency (50Hz -1MHz). The negative temperature coefficient (NTC) was observed in the temperature range of 40 to 150<sup>o</sup>C. It offers the nonlinear resistivity, ρ = 10<sup>5</sup> (Ω-m) across pure PVA moiety. The influence of polycationic-ions crucial to obtain the gradual decrease of resistivity (ρ) up to 10<sup>4</sup> (Ω<sup>-m</sup>). The thermistor characteristics were disclosed as function of polyionic loading (wt %). Copyright © 2017 VBRI Press
https://amp.iaamonline.org/article_16236_b09623250f6bc6d96cfd43f666f9b38b.pdf
International Association of Advanced Materials
Advanced Materials Proceedings
2002-4428
2
4
2017
04
01
Synthesis and characterization of flame retardant vermiculite polystyrene composites
231
234
16237
10.5185/amp.2017/406
EN
Panmei
Gaijon
Analytical Research Laboratory, Department of Chemistry, University of Delhi, Delhi 110007, India
S. K.
Shukla
Department of Polymer Science, Bhaskaracharya College of Applied Sciences,
University of Delhi, Delhi 110075, India
Monika
Datta
Analytical Research Laboratory, Department of Chemistry, University of Delhi, Delhi 110007, India
Journal Article
2021
12
09
Presently, polymer-clay composites (PCC) have shown promising advancements in different properties of polymers due to presence of layered silicate structure and also extend its multi fold advanced applications. In the present work, vermiculite (VT) was organically modified by cetylpyridinium chloride (CPC). Thus obtained organo vermiculite (OVT) was used to prepare its composite film with polystyrene (PS-OVMT) with varying amounts of OVT by the solution blending and casting method on a glass substrate. The prepared films were characterized by scanning electron microscope (SEM), x-ray diffraction (XRD), infrared (FT-IR) spectroscopy and thermal analytical (TG-DTA) techniques. X-ray diffraction pattern of the composite shows peaks of VT and PS along with decrease in the intensity of the PS peaks present between 2Ө = 12.5˚ to 24.5˚. Decreases in the intensity of peaks suggest dispersion of clay within the polymer matrix and lowering of crystallinity. The dispersion of clay and interaction with PS is also evident from the FTIR and microscopic data. Further, hardness test (shore-D), TG-DTA and flammability(UL-94) results of the composite indicate the improvement in hardness, thermal stability and inhibition in burning behaviour of the PS due to the presence of OVT in the PS matrix. Copyright © 2017 VBRI Press.
https://amp.iaamonline.org/article_16237_661747f89fcf4c5d674f8f8a1745e88b.pdf
International Association of Advanced Materials
Advanced Materials Proceedings
2002-4428
2
4
2017
04
01
Nanoscale zero-valent iron for aqueous lead removal
235
241
16238
10.5185/amp.2017/407
EN
Yana
Bagbi
Special Centre for Nanosciences, Jawaharlal Nehru University, New Delhi, 110067, India
Department of Physics, North Eastern Regional Institute of Science and Technology,
Nirjuli Arunachal Pradesh, 791109, India
Ankur
Sarswat
School of Environmental Sciences, Jawaharlal Nehru University, New Delhi, 110067, India
Sachchidanand
Tiwari
Special Centre for Nanosciences, Jawaharlal Nehru University, New Delhi, 110067, India
Dinesh
Mohan
School of Environmental Sciences, Jawaharlal Nehru University, New Delhi, 110067, India
Arvind
Pandey
Department of Physics, North Eastern Regional Institute of Science and Technology,
Nirjuli Arunachal Pradesh, 791109, India
Pratima
R. Solanki
Special Centre for Nanosciences, Jawaharlal Nehru University, New Delhi, 110067, India
Journal Article
2021
12
09
Zero-valent iron nanoparticles (NZVI) were synthesized using chemical reduction method. These were applied for lead removal from water. The structural, morphological, compositional and optical studies were studied out using X-ray diffraction (XRD), transmission electron microscopy (TEM), dynamic light scattering, scanning electron microscopy (SEM) and Fourier transforms infrared spectroscopy (FTIR). The NZVI optical energy band gap as calculated by UV absorption spectrum was 1.7 eV. The zeta potential was obtained as -32.0 mV. The biocompatibility test of NZVI was performed using MTT assay on MDCK-2 as model cell lines. Lead adsorption on NZVI was examined at different pHs, equilibrium time, temperature, and NZVI/Pb<sup>2+</sup> concentrations. Almost 100% Pb<sup>2+</sup> removal was achieved at NZVI dose: 0.4 g/L;<br />Pb<sup>2+</sup> concentration: 50 mg/L; equilibrium time: 15 min; pH 5-6; and temperature: 25°C. Pb<sup>2+</sup> sorption kinetic data were fitted to pseudo-first and second-order kinetic equations. Pseudo-second-order kinetic equation best fitted the data. These studies clearly demonstrate NZVI as an efficient nano-adsorbent for Pb<sup>2+</sup> removal from water. Copyright © 2017 VBRI Press
https://amp.iaamonline.org/article_16238_420d0e32f85aec7486f354578027fec5.pdf
International Association of Advanced Materials
Advanced Materials Proceedings
2002-4428
2
4
2017
04
01
Synthesis and characterization of (Ba,Ca)TiO<sub>3</sub> - (Ni,Co,Zn)Fe<sub>2</sub>O<sub>4</sub> multiferroic particulate composite
242
246
16239
10.5185/amp.2017/408
EN
Richa
Sharma
Department of Physics and Astrophysics, University of Delhi, Delhi 110007, India
N. C.
Mehra
Department of Geology, University of Delhi, Delhi 110007, India
R. P.
Tandon
Department of Physics and Astrophysics, University of Delhi, Delhi 110007, India
Journal Article
2021
12
09
In the present work, the composite series (1-x) Ba<sub>0.94</sub>Ca<sub>0.06</sub>TiO<sub>3</sub> - (x) Ni<sub>0.7</sub>Co<sub>0.1</sub>Zn<sub>0.2</sub>Fe<sub>2</sub>O<sub>4</sub> (where x = 0.1, 0.2, 0.3 and 0.4 wt. fraction) was synthesized by solid state reaction method followed by conventional sintering. The structure and morphology of prepared samples were examined using X-ray diffractometer (XRD) and scanning electron microscopy (SEM), respectively. In addition, dielectric constant (<em>ε΄</em>) and loss tangent (tan <em>δ</em>) of prepared samples were measured as a function of frequency and temperature. The room temperature values of dielectric constant (<em>ε΄</em>) of composite samples are found to decrease from 529.29 to 159.52 as ferrite content increased from x = 0.1 to x = 0.4 at 1 kHz frequency. Moreover, in the dielectric constant vs. temperature plots of the composite samples, ferroelectric to paraelectric phase transition of pure Ba<sub>0.94</sub>Ca<sub>0.06</sub>TiO<sub>3</sub> is observed. Furthermore, ferroelectric and magnetic properties of the composite samples were studied at room temperature. With increasing addition of the ferrite content in the composites, the ferroelectric properties get weakened and the magnetic behavior of the composite samples improved. The maximum values of saturation magnetization ( ) and remanant magnetization ( ) are 22.52 emu/gm and 3.39 emu/gm, respectively, for composite sample containing 0.4 wt. fraction Ni<sub>0.7</sub>Co<sub>0.1</sub>Zn<sub>0.2</sub>Fe<sub>2</sub>O<sub>4</sub>. Copyright © 2017 VBRI Press.
https://amp.iaamonline.org/article_16239_3b1393f13ef4994ab4212231649d6163.pdf
International Association of Advanced Materials
Advanced Materials Proceedings
2002-4428
2
4
2017
04
01
Quaternary ammonium poly(amidoamine) dendrimer stabilized gold and other metal nanoparticles for biosensor applications
247
253
16240
10.5185/amp.2017/409
EN
Eagambaram
Murugan
Department of Physical Chemistry, School of Chemical Sciences, University of Madras,
Maraimalai Campus, Guindy, Chennai, 600025, Tamil Nadu, India
Venkatesan
Yogaraj
Department of Physical Chemistry, School of Chemical Sciences, University of Madras,
Maraimalai Campus, Guindy, Chennai, 600025, Tamil Nadu, India
Journal Article
2021
12
09
Quaternary ammonium poly(amidoamine) (PAMAM) dendrimer stabilized gold nanoparticles (QPAMAM-AuNPs) were prepared and used for fabrication of new GC-QPAMAM-AuNPs electrode and this in turn was investigated for sensing of trace quantity of H<sub>2</sub>O<sub>2. </sub>Further, the QPAMAM-AuNPs were inspected for catalysis of nitrobenzene. Initially, amine-terminated PAMAM dendrimer was neutralised by acetylation followed by quaternization reactions. This quaternized product was used as a template for stabilization of gold nanoparticles by conducting the reactions at room temperature and thus produced quaternized dendrimer stabilised gold nanoparticles labelled as QPAMAM-AuNPs. The synthesized QPAMAM-AuNPs were characterized by UV-Vis, FTIR, <sup>1</sup>H NMR, MALDI-TOF and TEM analyses. This QPAMAM-AuNPs was coated on newly produced glassy carbon modified electrode without any binding agent, particularly any enzyme to produced GC-QPAMAM-AuNPs electrode. This newly fabricated electrode in turn were employed for detection and sensing of trace quantity of H<sub>2</sub>O<sub>2</sub> and it is observed that the electrode has an ability to detect the H<sub>2</sub>O<sub>2 </sub>ranging from [100 µM] to [5 mM] in neutral pH. Similarly, it is also proved that QPAMAM-AuNPs has effectively reduced the nitrobenzene and the observed pseudo-first order rate constant was 25.25 ×10-3s-1. It is established that the stabilized nanoparticles are water-soluble and stable for three months. Copyright © 2017 VBRI Press.
https://amp.iaamonline.org/article_16240_815b8387d0d75f4ed59aaf79f4fe2528.pdf
International Association of Advanced Materials
Advanced Materials Proceedings
2002-4428
2
4
2017
04
01
Microwave synthesized zinc-boro-vanadate glasses: Structural elucidation by employing ultrasonic and MAS NMR studies
254
258
16241
10.5185/amp.2017/410
EN
N.
Sivasankarareddy
Department of Physics, Center for Post Graduate Studies, Jain University, Bangalore, 560011, India
R.
Viswanatha
Solid State and Structural Chemistry Unit, IISc, Bangalore, 560012, India
B.
Sujatha
Department of Electronics and Communication, MSRIT, Bangalore, 560054, India
C.
Narayanareddy
Department of Physics, Sree Kongadiappa College, Bangalore, 561203, India
Journal Article
2021
12
09
Correlation between mechanical properties and MAS NMR spectroscopic revelations have been carried out on the glass system, xZnO – 50 B<sub>2</sub>O<sub>3</sub> – (50 – x) V<sub>2</sub>O<sub>5</sub> where 15 ≤ x ≤ 40 is prepared by a novel microwave heating method. Elastic moduli were computed from ultrasound velocities measured by a pulse echo superposition method. Both ultrasound velocities and elastic properties increase monotonically as a function of ZnO content. The variations observed in the mechanical properties were explained in view of modifications occur in the network structure consisting of borovanadate units. The bulk and shear moduli increase due to the presence of four coordinated borons along with diborovanadate units, which increases the dimensionality and connectivity of the glass network. Surprisingly, the process of the reconversion of four coordinated borons into three coordinated borons beyond 33.3mol% of modifier concentration is not initiated in these glasses, which is essentially due to the formation of [B<sub>2</sub>V<sub>2</sub>O<sub>9</sub>]<sup>2-</sup> units similar to the [B<sub>4</sub>O<sub>7</sub>]<sup>2-</sup>units. This is well supported by the monotonic increase in N<sub>4</sub> - values even above the 33.3 mol%of modifier content. Materials with enhanced elastic properties find application in cathode materials. Copyright © 2017 VBRI Press.
https://amp.iaamonline.org/article_16241_96f092638d116375be4d29726541f565.pdf
International Association of Advanced Materials
Advanced Materials Proceedings
2002-4428
2
4
2017
04
01
The study of microhardness of powder metallurgy fabricated Fe-Cu alloy using vickers indenter
259
263
16242
10.5185/amp.2017/411
EN
Shuhaib
Mushtaq
High temperature tribology laboratory, National Institute of Technology, Hazratbal, Srinagar190006, India
M.F
Wani
High temperature tribology laboratory, National Institute of Technology, Hazratbal, Srinagar190006, India
Journal Article
2021
12
09
In the present study, micro hardness values of Iron-Copper based alloys with different compositions have been obtained by using Vickers indenter. The samples Fe-5Cu-1Sn-7.5BN (wt. %), Fe-5Cu-1.5Sn-5BN (wt. %) and Fe-5Cu-2.5Sn-2.5BN<br />(wt. %) were prepared using Powder metallurgy technique. The elemental powder mixture was mixed for 2 hours, and compacted at a pressure of 500Mpa, and then was sintered in dry hydrogen atmosphere at a temperature of 900<sup>0</sup>C for 50 minutes time. Vickers hardness values were obtained under the loads of 0.01 kg to 0.3 kg. The material with 2.5 wt. % of Sn exhibited the highest value of the hardness. The material with higher hardness shows better mechanical and tribological properties and can be used for various applications such as gears, bearings, connecting rods cams etc. Copyright © 2017 VBRI Press.<br />
https://amp.iaamonline.org/article_16242_aef1b5385a482302ead5d0aa3ae2457d.pdf
International Association of Advanced Materials
Advanced Materials Proceedings
2002-4428
2
4
2017
04
01
Dependence of the size of copper nanoparticles on laser energy synthesized by pulsed laser ablation in liquid
264
268
16243
10.5185/amp.2017/412
EN
Prahlad
K. Baruah
Department of Physics, Indian Institute of Technology Guwahati, Guwahati 781039, India
Ashwini K.
Sharma
Department of Physics, Indian Institute of Technology Guwahati, Guwahati 781039, India
Alika
Khare
Department of Physics, Indian Institute of Technology Guwahati, Guwahati 781039, India
Journal Article
2021
12
09
In this paper, the effect of incident laser energy on the localized surface plasmon resonance (LSPR) and size of copper (Cu) nanoparticles (NPs) synthesized via pulsed laser ablation of copper in distilled water (DW) is reported. The absorption spectra show plasmon peak in the visible spectral region. The increase in the laser energy from 30 mJ to 70 mJ of the second harmonic of a Q-switched Nd:YAG laser induces a blue shift in the plasmon peak from 627 nm to 617 nm along with its broadening from 180 nm to 242 nm, respectively. These observations have been explained on the basis of the effect of the small size of the NPs formed. The Transmission electron microscope (TEM) substantiates these results as it shows the decrease in the average particle size of the NPs from ~20 nm to ~7 nm with the increase in the incident laser energy from<br />30 mJ to 70 mJ, respectively. By merely increasing the laser energy, a size-dependent LSPR has been achieved and this can be used as an effective way to control the size of Cu NPs and hence LSPR. Copyright © 2017 VBRI Press.
https://amp.iaamonline.org/article_16243_1e290803604f60d51b979815befd2250.pdf
International Association of Advanced Materials
Advanced Materials Proceedings
2002-4428
2
4
2017
04
01
Electrical characterization of perovskite nanocubes of Na0.5K0.5NbO3 at low temperature
269
274
16244
10.5185/amp.2017/413
EN
Deepak M.
Kapse
National Center for Nanosciences and Nanotechnology, University of Mumbai, Santacruz (E), Mumbai 400 098, India
Pradnya
Parab
National Center for Nanosciences and Nanotechnology, University of Mumbai,Santacruz (E), Mumbai 400 098, India
UM-DAE Center for Excellence in Basic Sciences (CBS), University of Mumbai,Santacruz (E), Mumbai 400 098, India
Sangita
Bose
UM-DAE Center for Excellence in Basic Sciences (CBS), University of Mumbai,Santacruz (E), Mumbai 400 098, India
H.
Muthurajan
National Center for Nanosciences and Nanotechnology, University of Mumbai,Santacruz (E), Mumbai 400 098, India
Journal Article
2021
12
09
Due to the toxicity of lead, there is an urgent necessity to develop lead-free alternatives to replace the currently dominant lead-based piezoelectric such as Pb(Zr,Ti)O<sub>3</sub> (PZT). Na<sub>0.5</sub>K<sub>0.5</sub>NbO<sub>3</sub> based piezoelectric nanomaterial are promising because of their relatively high Curie temperatures as well as good piezoelectric coefficients among the non-lead piezoelectrics. We have successfully synthesized 3-dimensional perovskite nanocubes of functional ternary transition-metal oxide of sodium potassium niobate Na<sub>0.5</sub>K<sub>0.5</sub>NbO<sub>3</sub> by using novel synthesis method. We have carried out resistance and impedance spectroscopy studies at low temperature using two probe technique. For this electrical measurement, we have used CCR system. There has been much interest in the texturing of electro ceramics, due to the possibility of achieving enhanced electrical properties. A major purpose for this electrical characterization study is to examine how Na<sub>0.5</sub>K<sub>0.5</sub>NbO<sub>3</sub> (NKN) pellet behaves under low temperature. Copyright © 2017 VBRI Press.
https://amp.iaamonline.org/article_16244_cfc8eaab02c08112d5cf0ec4fab84f8b.pdf
International Association of Advanced Materials
Advanced Materials Proceedings
2002-4428
2
4
2017
04
01
Synthesis and characterization of a nano Cu2 cluster
275
279
16245
10.5185/amp.2017/414
EN
Sayantan
Pathak
Department of Chemistry, University of GourBanga, Malda-732103, West Bengal, India
Niladri
Biswas
Department of Chemistry, West Bengal State University, Barasat, Kolkata-700126, West Bengal, India
Barun
Jana
Department of Inorganic Chemistry, Indian Association for The Cultivation of Science, Jadavpur, Kolkata 700032, India
Tanmay K
Ghorai
Department of Chemistry, University of GourBanga, Malda-732103, West Bengal, India
Department of Chemistry, Indira
Gandhi National Tribal University, Amarkantak-484887, M.P., India
Journal Article
2021
12
09
The synthesis and crystal structure of Cu<sub>2</sub>(C<sub>6</sub>H<sub>5</sub>COO)<sub>4</sub>(C<sub>6</sub>H<sub>5</sub>COOH)<sub>2 </sub>(<strong>1</strong>) is herein reported. However, our intention was to incorporate Pb into the present system and make a new high nuclearity heteronuclear Cu-Pb cluster with magnetic or antibacterial properties. For its synthesis, first Cu (NO<sub>3</sub>)<sub>2</sub>.3H<sub>2</sub>O (2mmol) and PhCOOH (10mmol) was dissolved in a mixed solvent MeCN/EtOH (10/10, v/v); separately Pb(NO<sub>3</sub>)<sub>2</sub> (1mmol) was dissolved in EtOH/H<sub>2</sub>O (20/5, v/v) and added drop-wise to the previous mixture. The mixture was stirred vigorously for half an hour with step-wise addition of NaN<sub>3</sub> (2mmol). The heterogenous reaction mixture was filtered and the deep greenish filtrate was stored at ambient condition. In four weeks, green single crystals were generated at the bottom of the flask. Single crystal X-ray measurement shows the formation of the title compound, where Cu atoms are in +2 oxidation state that is further confirmed by BVS calculation. The Cu-Cu distance in the molecular structure is found to be 2.608 (2) Å, which indicates a Cu-Cu bond in the molecule. Each Cu atom is bonded to four oxygen atoms of two benzoate ligands and one oxygen atom of a benzoic acid molecule. The octahedral geometry of the copper(II) atoms are fulfilled by an additional copper-copper bond. The most interesting in complex 1 is both intra and intermolecular hydrogen and C-H-C bonding present in the system. The length of nano molecular size of the Cu<sub>2</sub> cluster is found to be 1.55nm. The antibacterial study of complex 1 has been checked and it has no such high antibacterial activity. Copyright © 2017 VBRI Press.
https://amp.iaamonline.org/article_16245_4a5e0915768df0a0a55c98a3e7d55843.pdf
International Association of Advanced Materials
Advanced Materials Proceedings
2002-4428
2
4
2017
04
01
Nonlinear enhancement of the dielectric properties of PVA-Al<sub>2</sub>O<sub>3</sub> nanocomposites
280
287
16246
10.5185/amp.2017/415
EN
Ram J.
Sengwa
Dielectric Research Laboratory, Department of Physics, Jai Narain Vyas University, Jodhpur 342 005, India
Shobhna
Choudhary
Dielectric Research Laboratory, Department of Physics, Jai Narain Vyas University, Jodhpur 342 005, India
Journal Article
2021
12
09
Dielectric dispersion and relaxation behaviour of aqueous solution grown polymeric nanocomposite films consisting of poly(vinyl alcohol) (PVA) and alumina (Al<sub>2</sub>O<sub>3</sub>) (PVA–<em>x</em> wt% Al<sub>2</sub>O<sub>3</sub> (<em>x</em> = 0, 1, 3 and 5)) have been studied in the frequency range from 20 Hz to 1 MHz by employing dielectric relaxation spectroscopy (DRS). It is found that at constant frequency, the real part of complex permittivity increases nonlinearly with the increase of Al<sub>2</sub>O<sub>3</sub> nanoparticles concentrations in the PVA matrix, whereas it decreases with increase of frequency at constant concentration of Al<sub>2</sub>O<sub>3</sub>. The temperature dependent investigation on PVA–3 wt% Al<sub>2</sub>O<sub>3</sub> film reveals that the dielectric properties increase with the increase of temperature confirming its thermally activated dielectric behaviour. The ac electrical conductivity of the nanocomposites increases and the impedance values decreases with the increase of frequency which are moderately affected by Al<sub>2</sub>O<sub>3</sub> concentrations<br />(<em>x</em> = 0 to 5 wt%) and temperatures (30 to 60 °C). The dc conductivity and relaxation time of PVA chain segmental motion of the nanocomposites obey the Arrhenius behaviour. The X-ray diffraction (XRD) study reveals that the crystallite size and amorphous phase of PVA increase with the increase of Al<sub>2</sub>O<sub>3</sub> concentration in the PVA–Al<sub>2</sub>O<sub>3</sub> nanocomposites. Results of this study confirm the suitability of PVA–Al<sub>2</sub>O<sub>3</sub> nanocomposite materials as tunable nanodielectric for their use as insulator and substrate in the fabrication of microelectronic devices operated at audio and radio frequencies. Copyright © 2017 VBRI Press.<br />
https://amp.iaamonline.org/article_16246_ec6371018abb125e2839ded975ec37f6.pdf