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Kumar N, Siroha P, Shankar H, Singh D, Sharma Y, Kumar R, Ramovatar, Yadav N, Dey KK, Borkar H, Gangwar J. Probing into crystallography and morphology properties of MoS 2 nanoflowers synthesized via temperature dependent hydrothermal method. Nano Ex 2022. [DOI: 10.1088/2632-959x/ac7cfe] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Abstract
This paper reports the formation of flower-like hierarchical molybdenum disulfide (MoS2) nanoparticles following a simple one-step hydrothermal process with varying temperatures (200 °C and 220 °C). The as-synthesized particles were examined crystallographically by X-ray diffraction (XRD) method which revealed the formation of hexagonal MoS2 (2H-MoS2) and that the crystallite size of the particles increased with increasing hydrothermal temperature. Surface morphological characteristics of the particles were investigated by a field emission scanning electron microscope (FESEM) and interesting details were revealed such as the rounded 3D flower-like microstructure of the MoS2 particles and the petals of the flowers were composed of platelets built up by stacked-up MoS2 nanosheets. With the increase in hydrothermal temperature, the interlayer spacing of stacked layers of intense (002) plane is slightly decreased although the crystallinity of the material is improved. Both diameter and thickness of the nanoflowers and the nanoplatelets increased twice with increasing the temperatures. A visual crystallographic perspective was presented through simulation of 3D wireframe unit cell associated with the individual lattice planes as observed in the XRD pattern of the samples. In addition, a plausible growth mechanism is proposed for the formation of the obtained MoS2 nanoflowers on the basis of experimental observations and analysis.
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Verma R, Pathak S, Dey KK, Sikarwar S, Yadav BC, Srivastava AK. Facile synthesized zinc oxide nanorod film humidity sensor based on variation in optical transmissivity. Nanoscale Adv 2022; 4:2902-2912. [PMID: 36131997 PMCID: PMC9418808 DOI: 10.1039/d1na00893e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/27/2021] [Accepted: 05/23/2022] [Indexed: 05/14/2023]
Abstract
Variation in the transmitted light intensity from metal oxide thin films with moisture content provides a great opportunity to use them for humidity sensing. Herein, we have developed a novel and simple humidity sensor based on ZnO nanorod (ZNR) thin films which work as transmission-based sensing elements in an in-house fabricated sensing setup. The ZNR sensing element shows excellent linear sensing performance in the relative humidity (RH) range 10-90% and does not show any hysteresis. A maximum change in optical power of ∼95 μW is observed with the change in RH in the range 10-90%, for the sample with the smallest crystallite size (ZNR1) and highest pore diameter of the ZNR film. Also, a maximum sensitivity of 1.104 μW/% RH is observed for the ZNR1 sample which drops to 0.604 μW/% RH for the highest crystallite size sample (ZNR4). The presence of oxygen vacancies and the micro-porous nature of the film allow the absorption of water vapour on the film which deflects light at different angles that vary with the moisture content. The experimental results suggest that the ZNR film with a smaller crystallite size and larger pore diameter is more sensitive for humidity measurements. Further, an improved sensing performance is perceived in ZNRs because of the larger surface area of the nanorods. The ZNR based sensing elements do not suffer from ageing effects and exhibit high repeatability (88.74%). Further, the humidity sensor has a response time of 62 seconds and recovery time of 100 seconds which can be considered as a fairly quick response.
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Affiliation(s)
- Rajni Verma
- School of Physics, The University of Melbourne Parkville VIC 3010 Australia
| | - Saurabh Pathak
- Department of Mechanical Engineering, The University of Melbourne Parkville Victoria 3010 Australia
| | - Kajal Kumar Dey
- Centre for Nanoscience & Technology, Prof. Rajendra Singh Institute of Physical Sciences for Study and Research, VBS Purvanchal University Jaunpur Uttar Pradesh 2220003 India
| | - Samiksha Sikarwar
- Department of Physics, School of Physical and Decision Sciences, Babasaheb Bhimrao Ambedkar University Lucknow 226025 India
| | - B C Yadav
- Department of Physics, School of Physical and Decision Sciences, Babasaheb Bhimrao Ambedkar University Lucknow 226025 India
| | - A K Srivastava
- CSIR-Advanced Materials and Processes Research Institute Bhopal Madhya Pradesh 462026 India
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Verma AK, Yadav N, Singh SP, Dey KK, Singh D, Yadav RR. Study of Ultrasonic Attenuation and Thermal Conduction in Bimetallic Gold/Platinum Nanofluids : Effect of thermal conductivity on ultrasonic attenuation of gold and gold/platinum nanofluids. Johnson Matthey Technology Review 2021. [DOI: 10.1595/205651321x16038755164270] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Here, we report the frequency dependent ultrasonic attenuation of monometallic gold and bimetallic gold/platinum based aqueous nanofluids (NFs). The as-synthesised bimetallic NFs (BMNFs) revealed less resistance to ultrasonic waves compared to the monometallic NFs. Thermal conductivity
of both NFs taken at different concentrations revealed substantial conductivity improvement when compared to the base fluid, although gold/platinum showed lesser improvement compared to gold. Characterisation of the as-synthesised nanoparticles (NPs) and fluids was carried out with X-ray diffraction
(XRD), ultraviolet-visible (UV-vis) spectroscopy, transmission electron microscopy (TEM) and energy-dispersive X-ray spectroscopy (EDS). The distinct two-phase bimetallic nature of gold/platinum, its two plasmonic band optical absorption features and the spherical morphology of the particles
were shown. The findings were correlated with the observed thermal and ultrasonic behaviour and proper rationalisation is provided. It was revealed that the comparatively lesser thermal conductivity of gold/platinum had direct implication on its attenuation property. The findings could have
important repercussions in both industrial applications and in the mechanistic approach towards the field of ultrasonic attenuation in NFs.
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Affiliation(s)
- Alok Kumar Verma
- Department of Physics, Prof. Rajendra Singh (Rajju Bhaiya) Institute of Physical Sciences for Study and Research, Veer Bahadur Singh Purvanchal University Jaunpur-222003, Uttar Pradesh India
| | - Navneet Yadav
- Department of Physics, University of Allahabad Allahabad-211002 India
| | - Shakti Pratap Singh
- Department of Physics, Prof. Rajendra Singh (Rajju Bhaiya) Institute of Physical Sciences for Study and Research, Veer Bahadur Singh Purvanchal University Jaunpur-222003, Uttar Pradesh India
| | - Kajal Kumar Dey
- Centre for Nanoscience and Technology, Prof. Rajendra Singh (Rajju Bhaiya) Institute of Physical Sciences for Study and Research, Veer Bahadur Singh Purvanchal University Jaunpur-222003, Uttar Pradesh India
| | - Devraj Singh
- Department of Physics, Prof. Rajendra Singh (Rajju Bhaiya) Institute of Physical Sciences for Study and Research, Veer Bahadur Singh Purvanchal University Jaunpur-222003, Uttar Pradesh India
| | - Raja Ram Yadav
- Department of Physics, Prof. Rajendra Singh (Rajju Bhaiya) Institute of Physical Sciences for Study and Research, Veer Bahadur Singh Purvanchal University Jaunpur-222003, Uttar Pradesh India
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Dey KK, Bhatnagar D, Srivastava AK, Wan M, Singh S, Yadav RR, Yadav BC, Deepa M. VO₂ nanorods for efficient performance in thermal fluids and sensors. Nanoscale 2015; 7:6159-6172. [PMID: 25773921 DOI: 10.1039/c4nr06032f] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
VO2 (B) nanorods with average width ranging between 50-100 nm are synthesized via a hydrothermal method and the post hydrothermal treatment drying temperature is found to be influential in their overall phase and growth morphology evolution. The nanorods with unusually high optical bandgap for a VO2 material are effective in enhancing the thermal performance of ethylene glycol nanofluids over a wide temperature range as is indicated by the temperature dependent thermal conductivity measurements. Humidity and LPG sensors fabricated using the VO2 (B) nanorods bear testament to their efficient sensing performance, which can be partially attributed to the mesoporous nature of the nanorods.
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Affiliation(s)
- Kajal Kumar Dey
- National Physical Laboratory, Dr K. S. Krishnan Road, New Delhi-110012, India.
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Dey KK, Kumar P, Yadav RR, Dhar A, Srivastava AK. CuO nanoellipsoids for superior physicochemical response of biodegradable PVA. RSC Adv 2014. [DOI: 10.1039/c3ra46898d] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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Gangwar J, Dey KK, Tripathi SK, Wan M, Yadav RR, Singh RK, Srivastava AK. NiO-based nanostructures with efficient optical and electrochemical properties for high-performance nanofluids. Nanotechnology 2013; 24:415705. [PMID: 24060744 DOI: 10.1088/0957-4484/24/41/415705] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
NiO nanostructures were synthesized via a simple wet chemical solution method with varying calcination temperatures. The synthesized nanostructures were characterized by XRD, TG/DSC, FT-IR and high-resolution electron microscopy techniques. The nanostructures revealed dependence of particle size, stoichiometry, optical band gap and luminescence intensity on calcination temperatures. The materials exhibited efficient electrochemical properties with decent capacitance values. Ethylene-glycol-based nanofluids of these nanoparticles registered excellent thermal conductivity enhancement of 59-69% in the room temperature region and 125% enhancement at higher temperatures (80 ° C), establishing NiO to be a top-draw contender for high-performance heat transfer fluids.
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Affiliation(s)
- Jitendra Gangwar
- National Physical Laboratory, Council of Scientific and Industrial Research, Dr K S Krishnan Road, New Delhi, 110012, India. Department of Physics, Panjab University, Chandigarh, 160014, India
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Melzer MJ, Sugano JS, Cabanas D, Dey KK, Kandouh B, Mauro D, Rushanaedy I, Srivastava S, Watanabe S, Borth WB, Tripathi S, Matsumoto T, Keith L, Gonsalves D, Hu JS. First Report of Pepper mottle virus Infecting Tomato in Hawaii. Plant Dis 2012; 96:917. [PMID: 30727375 DOI: 10.1094/pdis-02-12-0147-pdn] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
In August 2011, tomato (Solanum lycopersicum L.) fruit from a University of Hawaii field trial displayed mottling symptoms similar to that caused by Tomato spotted wilt virus (TSWV) or other tospoviruses. The foliage from affected plants, however, appeared symptomless. Fruit and leaf tissue from affected plants were negative for TSWV analyzed by double antibody sandwich (DAS)-ELISA and/or TSWV ImmunoStrips (Agdia, Elkhart, IN) when performed following the manufacturer's instructions. Total RNA from a symptomatic and an asymptomatic plant was isolated using an RNeasy Plant Mini Kit (Qiagen, Valencia, CA) and reverse transcribed using Invitrogen SuperScript III reverse transcriptase (Life Technologies, Grand Island, NY) and primer 900 (5'- CACTCCCTATTATCCAGG(T)16-3') following the enzyme manufacturer's instructions. The cDNA was then used as template in a universal potyvirus PCR assay using primers 900 and Sprimer, which amplify sequences encoding the partial inclusion body protein (NIb), coat protein, and 3' untranslated region of potyviruses (1). A ~1,700-bp product was amplified from the cDNA of the symptomatic plant but not the asymptomatic plant. This product was cloned using pGEM-T Easy (Promega, Madison, WI) and three clones were sequenced at the University of Hawaii's Advanced Studies in Genomics, Proteomics, and Bioinformatics laboratory. The 1,747-bp consensus sequence of the three clones was deposited in GenBank (Accession No. JQ429788) and, following primer sequence trimming, found to be 97% identical to positions 7,934 through 9,640 of Pepper mottle virus (PepMoV; family Potyviridae, genus Potyvirus) accessions from Korea (isolate '217' from tomato; EU586126) and California (isolate 'C' from pepper; M96425). To determine the incidence of PepMoV in the field trial, all 292 plants representing 14 tomato cultivars were assayed for the virus 17 weeks after planting using a PepMoV-specific DAS-ELISA (Agdia) following the manufacturer's directions. Plants were considered positive if their mean absorbance at 405 nm was greater than the mean absorbance + 3 standard deviations + 10% of the negative control samples. The virus incidence ranged from 4.8 to 47.6% for the different varieties, with an overall incidence of 19.9%. Although plant growth was not noticeably impaired by PepMoV infection, the majority of fruit from infected plants was unsaleable, making PepMoV a considerable threat to tomato production in Hawaii. PepMoV has been reported to naturally infect tomato in Guatemala (3) and South Korea (2). To our knowledge, this is the first report of this virus in Hawaii and the first report of this virus naturally infecting tomato in the United States. References: (1) J. Chen et al. Arch. Virol. 146:757, 2001. (2) M.-K. Kim et al. Plant Pathol. J. 24:152, 2008. (3) J. Th. J. Verhoeven et al. Plant Dis. 86:186, 2002.
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Affiliation(s)
- M J Melzer
- Plant and Environmental Protection Sciences, University of Hawaii, Honolulu96822
| | - J S Sugano
- Plant and Environmental Protection Sciences, University of Hawaii, Honolulu96822
| | - D Cabanas
- Plant and Environmental Protection Sciences, University of Hawaii, Honolulu96822
| | - K K Dey
- Plant and Environmental Protection Sciences, University of Hawaii, Honolulu96822
| | - B Kandouh
- Plant and Environmental Protection Sciences, University of Hawaii, Honolulu96822
| | - D Mauro
- Plant and Environmental Protection Sciences, University of Hawaii, Honolulu96822
| | - I Rushanaedy
- Plant and Environmental Protection Sciences, University of Hawaii, Honolulu96822
| | - S Srivastava
- Plant and Environmental Protection Sciences, University of Hawaii, Honolulu96822
| | - S Watanabe
- Plant and Environmental Protection Sciences, University of Hawaii, Honolulu96822
| | - W B Borth
- Plant and Environmental Protection Sciences, University of Hawaii, Honolulu96822
| | - S Tripathi
- USDA-ARS Pacific Basin Agricultural Research Center, Hilo, HI 96720
| | - T Matsumoto
- USDA-ARS Pacific Basin Agricultural Research Center, Hilo, HI 96720
| | - L Keith
- USDA-ARS Pacific Basin Agricultural Research Center, Hilo, HI 96720
| | - D Gonsalves
- USDA-ARS Pacific Basin Agricultural Research Center, Hilo, HI 96720
| | - J S Hu
- Plant and Environmental Protection Sciences, University of Hawaii, Honolulu, HI 96822
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Dey KK, Lin H, Borth WB, Melzer MJ, Hu JS. A highly sensitive single-tube nested PCR assay for the detection of Pineapple mealybug wilt associated virus-2 (PMWaV-2). J Virol Methods 2012; 183:215-8. [PMID: 22484612 DOI: 10.1016/j.jviromet.2012.03.025] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2011] [Revised: 03/15/2012] [Accepted: 03/21/2012] [Indexed: 11/18/2022]
Abstract
An assay was developed for the detection of Pineapple mealybug wilt associated virus-2 (PMWaV-2), an important factor in the etiology of mealybug wilt of pineapple. The assay combines reverse transcription of RNA isolated from pineapple with a specific and very sensitive, single, closed-tube nested polymerase chain reaction (PCR) to amplify a segment of the coat protein gene of the PMWaV-2. The outer primers were designed to anneal at higher temperatures than the nested primers to prevent primer competition in consecutive amplification reactions. To reduce potential competition further, the outer primers were used at one-thousandth the concentration of the nested primers. The specificity and sensitivity of this assay are much greater than PCR using only a single primer-pair. A TaqMan(®) probe was also designed for use in quantitative PCR to detect and quantify the PCR amplification products directly in a single-tube assay. The advantages of the single-tube assays using both conventional and quantitative PCR are reduced handling time and prevention of cross contamination compared to regular nested PCR in which the reactions are carried out in two separate tubes.
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Affiliation(s)
- K K Dey
- Department of Plant and Environmental Protection Sciences, University of Hawaii at Manoa, 3190 Maile Way, Honolulu, HI 96822, USA
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Dey KK, Kumar A, Shanker R, Dhawan A, Wan M, Yadav RR, Srivastava AK. Growth morphologies, phase formation, optical & biological responses of nanostructures of CuO and their application as cooling fluid in high energy density devices. RSC Adv 2012. [DOI: 10.1039/c1ra00710f] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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Boyle-Roden E, Hoefer N, Dey KK, Grandinetti PJ, Caffrey M. High resolution 1H NMR of a lipid cubic phase using a solution NMR probe. J Magn Reson 2007; 189:13-9. [PMID: 17855136 DOI: 10.1016/j.jmr.2007.08.010] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2007] [Revised: 08/08/2007] [Accepted: 08/11/2007] [Indexed: 05/17/2023]
Abstract
The cubic mesophase formed by monoacylglycerols and water is an important medium for the in meso crystallogenesis of membrane proteins. To investigate molecular level lipid and additive interactions within the cubic phase, a method was developed for improving the resolution of (1)H NMR spectra when using a conventional solution state NMR probe. Using this approach we obtained well-resolved J-coupling multiplets in the one-dimensional NMR spectrum of the cubic-Ia3d phase prepared with hydrated monoolein. A high resolution t-ROESY two-dimensional (1)H NMR spectrum of the cubic-Ia3d phase is also reported. Using this new methodology, we have investigated the interaction of two additive molecules, L-tryptophan and ruthenium-tris(2,2-bipyridyl) dichloride (rubipy), with the cubic mesophase. Based on the measured chemical shift differences when changing from an aqueous solution to the cubic phase, we conclude that L-tryptophan experiences specific interactions with the bilayer interface, whereas rubipy remains in the aqueous channels and does not associate with the lipid bilayer.
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Affiliation(s)
- E Boyle-Roden
- Department of Chemistry, The Ohio State University, 120 W. 18th Avenue, Columbus, OH 43210-1173, USA
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