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Investigation of Surface Free Energy for PTFE Polymer by Bipolar Argon Plasma Treatment

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Journal of Surface Engineered Materials and Advanced Technology 2012年第2期2卷 132-136页

作者： S. M. Pelagade N. L. Singh R. S. Rane S. Mukherjee U. P. Deshpande V. Ganesan T. Shripathi Department of Physics The Maharaja Sayajirao University of Baroda Vadodara India FCIPT Institute for Plasma Research Gandhinagar India FCIPT Institute for Plasma Research Gandhinagar India 3ugc-dae-csr Indore India. ugc-dae-csr Indore India ugc-dae-csr Indore India.

The low ion energy argon plasma was used for surface modification of Poly tetra fluoroethylene (PTFE) polymer. The plasma was generated between two plane metal electrode by using 50 kHz bipolar power supply. The plasma treated surface was characterized by atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS). The surface free energy (SFE) of plasma treated surface was calculated from contact angle measurement. SFE increases from 33.39 mJ/m2 to 41.40 mJ/m2 with the increase in plasma treatment time and the corresponding contact angle changed from 76? to 60?. XPS study shows that F/C ratio change from 1.8 (untreated) to 1.3 (treated) and O/C ratio changes from 0.094 (untreated) to 0.148 (treated). The XPS analysis shows that both F1s and the C1s spectra for PTFE are marginally modified by plasma treatment. AFM study shows that the average surface roughness (Ra) increased from 8.5 nm to 22.8 nm after plasma treatment. Vicker’s micro hardness of the film increases upon plasma treatment. The increase in SFE after plasma treatment is attributed to the functionalization of the polymer surface with hydrophilic groups as supported from the above observations.

关键词： PTFE Surface Energy XPS AFM Microhardness

A catalyst-free new polyol method synthesized hot-pressed Cu-doped Bi2S3 nanorods and their thermoelectric properties

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Nano Research 2016年第11期9卷 3291-3304页

作者： Tarachand Vikash Sharma Ranu Bhatt Vedachalaiyer Ganesan Gunadhor Singh Okram ugc-dae Consortium for Scientific Research Indore 452001 India Technical Physics Division Bhabha Atomic Research Centre Mumbai 400085 India

This is the first report on the thermoelectric properties of a catalyst-free polyol method used to prepare stoichiometric Bi2-xCuxS3 samples, x = 0.1, 0.2, 0.3, 0.4, via hot pressing. Various systematic approaches to arrive at in their stoichiometric compositions are explored precisely with introduction of excess precursor of S. X-ray diffraction data analysis using Rietveld refinement confirms a polyhedral orthorhombic crystal structure with a space group Pnma, in contrast to Pbnm reported earlier. Raman data further substantiates this. X-ray photoelectron spectroscopy confirms the valence states of the constituent elements （Bi^3＋, Cu^2＋, and S^2-） and energy dispersive X-ray analysis corroborates their compositions. The particle sizes of the pure Bi2S3 nanoparticles were 20, 35, and 82 nm as determined from the Scherrer formula, atomic force microscopy, and dynamic light scattering, respectively. Their transmission electron microscopy image shows rod-like nanostructures elongated in the 〈010〉 direction with an average diameter of 23 nm and a length of several hundreds of nanometers. A 34% improvement in the thermoelectric figure of merit is observed for Bi.6Cu0.4S3 as compared to pure Bi2S3 at 300 K.

关键词： Bi2S3 polyol nanorods thermoelectrics

Multiferroic Consequence of Porous (BiFeO_3)_x–(BiCrO_3)_(1-x) Composite Thin Films by Novel Sol–Gel Method

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Acta Metallurgica Sinica(English Letters) 2018年第3期31卷 299-307页

作者： William Raja Victor Marikani Arumugam Thiruramanathan Pandirengan Madhavan Durairaj Raghavendra Reddy Varimalla Department of Physics Mepco Schlenk Engineering College Department of Chemistry Mepco Schlenk Engineering College ugc-dae Consortium for Scientific Research University Campus

In this work,we have presented a spin-coating method to produce thin films started with pure BiCrO3（BCO）and ended up with BiFeO3（BFO）by increasing x values in the（BiFeO3）x-（BiCrO3）1-x *** the produced thin films have been crystallized at the annealing temperatures of 400 ℃ for 0.5 *** XRD and EDAX spectrums give insight that the two crystal phases related to BCO and BFO stayed together within the thin film *** analysis showed that the prepared composite had macroporous morphology with interconnected pores and its width（size）decreased with increasing x *** strong correlations are observed among the microstructure,dielectric,ferroelectric,ferromagnetic properties and Fe *** all composites,the composition of 0.75 shows an attractive magnetization,polarization,switching and improved dielectric behaviors at room *** increase in the multiferroic characteristics of 0.75 composition is due to arise of lower leakage current by causing reduction in oxygen vacancy density,and enhancement of super-exchange magnetic interaction between Fe3＋ and Cr3＋ at BFO/BCO interface *** result shows that the thin layer on Pt（111）/Ti/SiO2/Si substrate possesses simultaneously improved ferroelectric and ferromagnetic properties which make an inaccessible potential application for nonvolatile ferroelectric memories.

关键词： Multiferroic Dual-phase composites Spin-coating method NV-Fe-RAM PUND

Dielectric relaxation and conduction mechanism in Aurivillius ceramic Bi_(5)Ti_(3)FeO_(15)

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International Journal of Minerals,Metallurgy and Materials 2021年第6期28卷 1063-1071页

作者： Rasmita Jena K.Chandrakanta P.Pal Md.F.Abdullah S.D.Kaushik A.K.Singh Department of Physics and Astronomy National Institute of Technology RourkelaRourkela-769008OdishaIndia ugc-dae Consortium for Scientific Research Mumbai Centre BARCMumbai-400085India

For this study,we synthesized Aurivillius Bi_(5)Ti_(3)FeO_(15) ceramic using the generic solid-state reaction route and then performed roomtemperature X-ray diffraction to confirm that the compound had a single phase with no *** surface morphology of the prepared sample was observed to contain microstructural grains approximately 0.2–2μm in *** dielectric properties of the sample were determined as a function of frequency in a range of approximately 100 Hz to 1 MHz at various temperatures(303 K≤T≤773 K).Nyquist plots of the impedance data were found to exhibit a semi-circular arc in the high-temperature region,which is explained by the equivalent electrical circuit(R_(1)C_(1))(R_(2)QC_(2)),where R_(1) and R_(2) represent the resistances associated with the grains and grain boundaries,respectively,C_(1) and C_(2) are the respective capacitances,and Q is the constant phase element(CPE),which accounts for non-Debye type of *** results indicate that both the resistance and capacitance of the grain boundaries are more prominent than those of the *** alternating current(ac)conductivity data were analyzed based on the Jonscher universal power law,which indicated that the conduction process is dominated by the hopping *** calculated activation energies of the relaxation and conduction processes were very similar(0.32 to 0.53 eV),from which we conclude that the same type of charge carriers are involved in both processes.

关键词： Nyquist plot impedance spectroscopy activation energy ac conductivity hopping

Wastewater treatment using Fe-doped perovskite manganites by photocatalytic degradation of methyl orange,crystal violet and indigo carmine dyes in tungsten bulb/sunlight

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稀土学报:英文版 2023年第9期41卷 1311-1322,I0002页

作者： Brajendra Singh Priyanka Singh Saiqua Siddiqui Divyanshu Singh Mukul Gupta Materials Chemistry Lab Centre of Material SciencesUniversity of AllahabadPrayagraj21002India ugc-dae Consortium for Scientific Research University CampusKhandwa Road Indore452001India

We documented(ⅰ) the decolorization of wastewater in visible light,which contains methyl orange,crystal violet and indigo carmine dyes,using La_(0.7)Sr_(0.3)Mn_(1-x)Fe_(x)O_(3)(x=0.0,0.05,0.1 and 0.5) manganites and(ⅱ) efficient separation of photocatalysts from water using magnetic *** ceramic photocatalysts were sintered at 1050℃ for 12 *** were characterized by X-ray diffraction(XRD),soft X-ray absorption spectroscopy(SXAS),Fourier transform infrared spectroscopy(FTIR) and UV-visible diffuse reflectance spectroscopy(DRS).SXAS studies show the presence of Mn(Mn^(3+)/Mn^(4+)) and Fe(Fe^(3+)/Fe^(4+)) mixes valences in Fe-doped *** band gap is found in visible light range for La_(0.7)Sr_(0.3)Mn_(1-x)Fe_(x)O_(3)(x=0.0,0.05,0.1) ***_(0.7)Sr_(0.3)MnO_(3) degrades 94.6% methyl orange in7 min,81.9% crystal violet in 10 min and 99.1% indigo carmine in 5 ***_(0.7)Sr_(0.3)Mn_(0.9)Fe_(0.1)O_(3) degrades the 92.6% methyl orange dye solution in 9 min,94.8% crystal violet in 25 min and 97.1% indigo carmine in3 *** and Fe doped manganites can be separated in 60 s from wastewater.

关键词： Synchrotron X-ray absorption Dye degradation Magnetic separation Mixed valences Rare earths Wastewater treatment

Magnetic Phase Separation in Diluted Magnetic System:Zn1-xFexO

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Acta Metallurgica Sinica(English Letters) 2017年第6期30卷 521-527页

作者： Archita Mondal Sanchari Sarkar Neepamala Giri Souvik Chatterjee Ruma Ray Department of Physics Jadavpur UniversityKolkata 700 032India ugc-dae Consortium for Scientific Research Kolkata CentreSector IIILB-8Salt LakeKolkata 700098India

Single-phase diluted magnetic systems Zn1-xFexO have been prepared by chemical route. Structural and spectroscopic （UV-Vis and Mossbauer） studies indicate the incorporation of Fe^3＋ ions in the lattice sites. The UV-Vis results point to a systematic increase in the band gap with increasing Fe doping. The room temperature magnetization of Zni-xFexO indicates a paramagnetic behavior which is in accordance with the Mossbauer results, illustrating quadrupolar doublet. At low temperature, the zero-field-cooled （ZFC） magnetization shows a cusp and this temperature increases systematically with decreasing particle size. The weak exchange bias effect manifested by a M-H loop shift is observed for x = 0.03. This shift is accompanied by the enhancement of coercivity. The dc magnetization results suggest the coexis tence of ferromagnetic and antiferromagnetic exchange interactions for low doping of Fe, i.e., for x = 0.03.

关键词： Diluted magnetic system Optical band gap Moissbauer Exchange bias effect

Effect of Co substitution on the structural,dielectric and optical properties of KBiFe_(2)O_(5)

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International Journal of Minerals,Metallurgy and Materials 2021年第11期28卷 1861-1867页

作者： K.Chandrakanta R.Jena P.Pal Md.F.Abdullah S.D.Kaushik A.K.Singh Department of Physics and Astronomy National Institute of TechnologyRourkela-769008OdishaIndia ugc-dae Consortium for Scientific Research Mumbai Centre R-5 ShedBARCMumbai-400085India

Cobalt(Co)-modified brownmillerite KBiFe_(2)O_(5)(KBFO;[KBiFe_(2(1−x))Co_(2x)O_(5)(x=0,0.05)])polycrystalline is synthesized following the solid-state reaction *** refinement of X-ray diffraction data confirmed the phase purity of KBFO and KBiFe_(1.9)Co_(0.1)O_(5)(KBFCO).The optical bandgap energy(Eg)of KBFO decreased from 1.59 to 1.51 eV because of Co *** decrease in bandgap can be attributed to the tilting of the Fe–O tetrahedral structure of *** observed room-temperature Raman peaks of KBFCO shifted by 3 cm^(−1) toward a lower wavenumber than that of *** shift in Raman active modes can be attributed to the change in the bond angles and bond lengths of the Fe–O tetrahedral structure and modification in response to oxygen deficiency in KBFO because of Co *** with that of KBFO,the frequency-dependent dielectric constant and dielectric loss of KBFCO decrease at room temperature,which is a consequence of the reduction in oxygen migration and modification in response to vibrational modes present in the sample.

关键词： brownmillerite rietveld refinement Raman spectroscopy bandgap

A Novel Synthesis of Malic Acid Capped Silver Nanoparticles using Solanum lycopersicums Fruit Extract

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Journal of Materials Science & Technology 2013年第4期29卷 317-322页

作者： M.Umadevi M.R.Bindhu V.Sathe Department of Physics Mother Teresa Women's UniversityKodaikanal 624 102Tamil NaduIndia ugc-dae Consortium for Scientific Research University CampusKhandwa RoadIndore 452 017India

Integration of green chemistry principles to nanotechnology is one of the key issues in nanoscience research. The development of the concept of green nanoparticle preparation has been growingly needed for environmentally benign metal nanoparticle synthesis protocols to avoid adverse effects in medical applications. Keep this in mind, in the present study, silver nanoparticles were synthesized using Solanum lycopersicums fruit extract. The prepared silver nanoparticles were characterized by UV-visible spectroscopy, Fourier transform infrared spectroscopy, Raman spectroscopy, scanning electron microscopy and transmission electron microscopy techniques. The surface plasmon resonance peak was found at 445 nm. The synthesized silver nanoparticles were spherical in shape with the average size of 10 nm. The citric acid present in S. lycopersicums fruit extract acted as reducing agent and malic acid was responsible for capping of the bioreduced silver nanoparticles.

关键词： Silver nanoparticles Solanum lycopersicums UV--visible spectroscopy Fourier transform infrared spectroscopy Ramanspectroscopy

Diallyl disulfide and diallyl trisulfide in garlic as novel therapeutic agents to overcome drug resistance in breast cancer

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Journal of Pharmaceutical Analysis 2022年第2期12卷 221-231页

作者： RamaRao Malla Rakshmitha Marni Anindita Chakraborty Mohammad Amjad Kamal Cancer Biology Lab Department of Biochemistry and BioinformaticsInstitute of ScienceGandhi Institute of Technology and ManagementVisakhapatnam530045India Radiation Biology UGC-DAE-CSRKolkata CentreKolkata700098India King Fahd Medical Research Center King Abdulaziz UniversityJeddah21589Saudi Arabia Enzymoics HebershamNovel Global Community Educational FoundationNew South Wales2770Australia

Breast cancer is one of the leading causes of cancer-related deaths in women *** is a cancer that originates from the mammary ducts and involves mutations in multiple ***,the treatment of breast cancer has become increasingly challenging owing to the increase in tumor heterogeneity and aggressiveness,which gives rise to therapeutic ***,populationbased,and hospital-based case-control studies have demonstrated an association between high intake of certain Allium vegetables and a reduced risk in the development of breast *** disulfide(DADS)and diallyl trisulfide(DATS)are the main allyl sulfur compounds present in garlic,and are known to exhibit anticancer activity as they interfere with breast cancer cell proliferation,tumor metastasis,and *** present review highlights multidrug resistance mechanisms and their signaling pathways in breast *** review discusses the potential anticancer activities of DADS and DATS,with emphasis on drug resistance in triple-negative breast cancer(TNBC).Understanding the anticancer activities of DADS and DATS provides insights into their potential in targeting drug resistance mechanisms of TNBC,especially in clinical studies.

关键词： Breast cancer Diallyl disulfide Diallyl trisulfide Drug resistance Metastasis