41 results on '"Chandra Sekhar Tiwary"'
Search Results
2. Synthesis and Characterization of Biotene: A New 2D Natural Oxide From Biotite
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Preeti Lata Mahapatra, Raphael Tromer, Prafull Pandey, Gelu Costin, Basudev Lahiri, Kamanio Chattopadhyay, Ajayan P. M., Ajit K. Roy, Douglas S. Galvao, Partha Kumbhakar, and Chandra Sekhar Tiwary
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Biomaterials ,Drug Combinations ,Glucose Oxidase ,Aluminum Silicates ,Muramidase ,Oxides ,General Materials Science ,Ferrous Compounds ,Lactoperoxidase ,General Chemistry ,Biotechnology - Abstract
In this work, the synthesis and characterization of ultrathin metal oxide, called biotene, using liquid-phase exfoliation from naturally abundant biotite are demonstrated. The atomically thin biotene is used for energy harvesting using its flexoelectric response under multiple bending. The effective flexoelectric response increases due to the presence of surface charges, and the voltage increases up to ≈8 V, with a high mechano-sensitivity of 0.79 V N
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- 2022
3. 3D Printed Materials in Water Treatment Applications (Adv. Sustainable Syst. 3/2022)
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Pranjal Ghosal, Bramha Gupta, Rushikesh S. Ambekar, Muhammad M. Rahman, Pulickel M. Ajayan, Nirupam Aich, Ashok Kumar Gupta, and Chandra Sekhar Tiwary
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Renewable Energy, Sustainability and the Environment ,General Environmental Science - Published
- 2022
4. Atomic Scale Structure Inspired 3D‐Printed Porous Structures with Tunable Mechanical Response
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Rushikesh S. Ambekar, Sharan Kishore, Varinder Pal, Ipsita Mohanty, Chandra Sekhar Tiwary, Brijesh Kumar Kushwaha, Ajit K. Roy, Rakesh Das, and Sujoy Kumar Kar
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3d printed ,Materials science ,business.industry ,Structure (category theory) ,3D printing ,General Materials Science ,Nanotechnology ,Condensed Matter Physics ,business ,Porosity ,Atomic units - Published
- 2021
5. Mechanical and Acoustic Behavior of 3D‐Printed Hierarchical Mathematical Fractal Menger Sponge
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D.P. Jena, Kush Dwivedi, Chandra Sekhar Tiwary, Rushikesh S. Ambekar, Varinder Pal, Debiprosad Roy Mahapatra, and Brijesh Kumar Kushwaha
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3d printed ,Fractal ,Materials science ,Polymer science ,business.industry ,Acoustic property ,Three dimensional printing ,3D printing ,General Materials Science ,Menger sponge ,Condensed Matter Physics ,business - Published
- 2021
6. Confinement Aided Simultanous Water Cleaning and Energy Harvesting Using Atomically Thin Wurtzite (Wurtzene)
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Partha Kumbhakar, Chandra Sekhar Tiwary, Madhubanti Mukherjee, Srikanta Karmakar, Pathik Kumbhakar, Abhishek K. Singh, and Ashim Pramanik
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Materials science ,Renewable Energy, Sustainability and the Environment ,business.industry ,Optoelectronics ,Self-assembly ,business ,Energy harvesting ,General Environmental Science ,Wurtzite crystal structure - Published
- 2020
7. Bioinspired Aluminum Composite Reinforced with Soft Polymers with Enhanced Strength and Plasticity
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Douglas S. Galvao, Ravi Sastri Ayyagari, Chintan Bhatt, V. P. Mahesh, Praful Pandey, Pedro A. S. Autreto, Kiran Raphael, Femi Emmanuel Olu, Arpan Rout, Solomon Demiss, Mithun Palit, Eliezer Fernando Oliveira, Amit Arora, Chandra Sekhar Tiwary, and Anurag Gumaste
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chemistry.chemical_classification ,Molecular dynamics ,Materials science ,chemistry ,Aluminum composites ,General Materials Science ,Polymer ,Plasticity ,Composite material ,Condensed Matter Physics - Published
- 2020
8. 3D Printing: 3D Printed Tubulanes as Lightweight Hypervelocity Impact Resistant Structures (Small 52/2019)
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Prathyush Ramesh, Douglas S. Galvao, Peter J. Boul, Cristiano F. Woellner, Chandra Sekhar Tiwary, Muhammad M. Rahman, Qiushi Sun, Carl J. Thaemlitz, Seyed Mohammad Sajadi, Pulickel M. Ajayan, Ray H. Baughman, and Shannon L. Eichmann
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Biomaterials ,3d printed ,Materials science ,business.industry ,Hypervelocity ,3D printing ,Mechanical engineering ,General Materials Science ,General Chemistry ,business ,Biotechnology - Published
- 2019
9. Chromiteen: a new 2D oxide magnetic material from natural ore
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Sharmila N. Shirodkar, Farheen N. Sayed, Narumon Lertcumfu, Robert Vajtai, Kirtiman Deo Malviya, Thakur Prasad Yadav, Chandra Sekhar Tiwary, Gelu Costin, Sruthi Radhakrishnan, Pulickel M. Ajayan, and Boris I. Yakobson
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liquid exfoliation ,Materials science ,2D magnetic materials ,Mechanical Engineering ,Metallurgy ,chromiteen ,natural chromite ,Oxide ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,DFT ,Natural (archaeology) ,0104 chemical sciences ,chemistry.chemical_compound ,chemistry ,Mechanics of Materials ,Magnet ,Microscopy ,microscopy ,0210 nano-technology - Abstract
The absence of inherent magnetism in the family of 2D materials limits its application in magnetoelectric and magnetic storage media. Here, a simple scalable route for the synthesis of magnetic 2D material chromite (chromiteen) via sonication?assisted liquid?phase exfoliation is demonstrated. The (111) plane of the exfoliated chromite is found to be the most stable which is confirmed by its common occurrence in exfoliation. Further, the stability and dispersion are verified by ab initio density functional theoretical simulations. Magnetic measurements over a large temperature range of 4?K?????T?????300?K confirm ferromagnetic/superparamagnetic order with nearly 40 times higher magnetic moment saturation in chromiteen compared to chromite. The results reveal that 2D chromiteen causes a change in the magnetic behavior with respect to chromite which could be ascribed to the increase in the lattice strain as well as a magnetic strain due to high ferromagnetic fraction in 2D plane., by Chandra Sekhar Tiwary et al.
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- 2018
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10. Liquid exfoliation of icosahedral quasicrystals
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Chandra Sekhar Tiwary, O.N. Srivastava, Amey Apte, Tiva Sharifi, Douglas S. Galvao, Thakur Prasad Yadav, Pulickel M. Ajayan, Nilay Krishna Mukhopadhyay, Robert Vajtai, Shyam Kanta Sinha, and Cristiano F. Woellner
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Materials science ,Polymer science ,Icosahedral symmetry ,Materials Engineering (formerly Metallurgy) ,Quasicrystal ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,Exfoliation joint ,0104 chemical sciences ,Electronic, Optical and Magnetic Materials ,Biomaterials ,Electrochemistry ,0210 nano-technology - Abstract
The realization of quasicrystals has attracted a considerable attention due to their unusual structures and properties. The concept of quasicrystals in the atomically thin materials is even more appealing due to the in‐plane covalent bonds and weak interlayer interactions. Here, it is demonstrated that 2D quasicrystals can be created/isolated from bulk phases because of long‐range interlayer ordered aperiodic arrangements. An ultrasonication‐assisted exfoliation of polygrained icosahedral Al–Pd–Mn quasicrystals at room temperature shows the formation of a large area of mono‐ and few layers in threefold quasicrystalline plane. The formation of these layers from random grain orientation consistently indicates that the threefold plane is most stable in comparison to the twofold and fivefold planes in icosahedral clusters. The above experimental observations are further supported with help of theoretical simulations. The mono‐ and few‐layered aperiodic planes render plentiful active sites for the catalysis of hydrogen evolution reaction. The threefold 2D quasicrystalline plane exhibits a hydrogen evolution reaction overpotential of ≈100 mV (160 times less than bulk counterpart) and long‐term durability. These systems constitute the first demonstration of quasicrystalline monolayer ordering in a free‐standing thin layer without requiring the support of periodic or aperiodic substrate., by Thakur Prasad Yadav, Cristiano F. Woellner, Shyam K. Sinha, Tiva Sharifi, Amey Apte, Nilay Krishna Mukhopadhyay, Onkar Nath Srivastava, Robert Vajtai, Douglas S. Galvao, Chandra Sekhar Tiwary and Pulickel M. Ajayan
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- 2018
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11. Origami-inspired 3D interconnected molybdenum carbide nanoflakes
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Sehmus Ozden, Glaura G. Silva, Robert Vajtai, Chandra Sekhar Tiwary, Pulickel M. Ajayan, Ryota Koizumi, Abhishek K. Singh, Atanu Samanta, Ana Paula Alves, Gonglan Ye, and Avanish Mishra
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Materials science ,supercapacitors ,Polymer science ,3D architecture ,Mechanical Engineering ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Molybdenum carbide ,hydrogen evolution reactions ,0104 chemical sciences ,Mechanics of Materials ,molybdenum carbide ,0210 nano-technology ,density functional theory - Abstract
High-temperature stable transition metal carbides are one of the promising classes of materials for next-generation energy applications such as water splitting catalysis and electrodes for energy storage devices. Herein, origami-like molybdenum carbide flakes with interfacially connected structures in various orientations using an easily scalable chemical vapor deposition method are synthesized. Interestingly, each individual flake of similar orientation is interconnected across different planes. The interconnected architectures are found to be highly elastic and behave in a sponge-like manner. In addition, the surface energy of each plane is calculated using the first-principle density functional theory. The molybdenum carbide shows excellent activity for the hydrogen evolution reaction, with the onset over potential occurring around ?16 to ?25 mV with high stability. The material is used as an electrode for supercapacitors as a second demonstration. The supercapacitor constructed with polypyrrole reaches the specific capacitance of ?279 F g?1 at a current density of 0.5 A g?1., by Ryota Koizumi, Sehmus Ozden, Atanu Samanta, Ana Paula P. Alves, Avanish Mishra, Gonglan Ye, Glaura G. Silva, Robert Vajtai, Abhishek K. Singh, Chandra S. Tiwary and Pulickel M. Ajayan
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- 2018
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12. 2D Materials: Re Doping in 2D Transition Metal Dichalcogenides as a New Route to Tailor Structural Phases and Induced Magnetism (Adv. Mater. 43/2017)
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Jordan A. Hachtel, Priya Vashishta, Vidya Kochat, Pulickel M. Ajayan, Fuyuki Shimojo, Juan Carlos Idrobo, Chandra Sekhar Tiwary, Hiroyuki Kumazoe, Rajiv K. Kalia, Aiichiro Nakano, Sandhya Susarla, Amey Apte, and Aravind Krishnamoorthy
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Phase transition ,Materials science ,Transition metal ,Mechanics of Materials ,Magnetism ,Mechanical Engineering ,Inorganic chemistry ,Doping ,General Materials Science ,Nanotechnology - Published
- 2017
13. Nitrogen-Doped Carbon Nanotube Arrays for High-Efficiency Electrochemical Reduction of CO2: On the Understanding of Defects, Defect Density, and Selectivity
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Jun Lou, Ram Manohar Yadav, Chandra Sekhar Tiwary, Pulickel M. Ajayan, Xiao-Dong Zhou, Christopher J. Wright, Mingjie Liu, Jingjie Wu, Boris I. Yakobson, and Pranav P. Sharma
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Chemistry ,Nanotechnology ,General Medicine ,General Chemistry ,Carbon nanotube ,Overpotential ,Photochemistry ,Antibonding molecular orbital ,Electrocatalyst ,Electrochemistry ,Catalysis ,law.invention ,law ,Selectivity ,Lone pair - Abstract
Nitrogen-doped carbon nanotubes (NCNTs) have been considered as a promising electrocatalyst for carbon-dioxide-reduction reactions, but two fundamental chemistry questions remain obscure: 1) What are the active centers with respect to various defect species and 2) what is the role of defect density on the selectivity of NCNTs? The aim of this work is to address these questions. The catalytic activity of NCNTs depends on the structural nature of nitrogen in CNTs and defect density. Comparing with pristine CNTs, the presence of graphitic and pyridinic nitrogen significantly decreases the overpotential (ca. −0.18 V) and increases the selectivity (ca. 80 %) towards the formation of CO. The experimental results are in congruent with DFT calculations, which show that pyridinic defects retain a lone pair of electrons that are capable of binding CO2. However, for graphitic-like nitrogen, electrons are located in the π* antibonding orbital, making them less accessible for CO2 binding.
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- 2015
14. Zirconia-Nanoparticle-Reinforced Morphology-Engineered Graphene-Based Foams
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Shrikant V. Joshi, Dibyendu Chakravarty, Leonardo D. Machado, Douglas S. Galvao, Ram Manohar Yadav, Chandra Sekhar Tiwary, G. Sundararajan, Soumya Vinod, Pulickel M. Ajayan, and Gustavo Brunetto
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Yield (engineering) ,Materials science ,Morphology (linguistics) ,Graphene ,Mechanical Engineering ,Nanoparticle ,Microstructure ,Nanocrystalline material ,law.invention ,Mechanics of Materials ,law ,General Materials Science ,Cubic zirconia ,Composite material - Abstract
The morphology of graphene-based foams can be engineered by reinforcing them with nanocrystalline zirconia, thus improving their oil-adsorption capacity; This can be observed experimentally and explained theoretically. Low zirconia fractions yield flaky microstructures where zirconia nanoparticles arrest propagating cracks. Higher zirconia concentrations possess a mesh-like interconnected structure where the degree of coiling is dependant on the local zirconia content.
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- 2015
15. Chemical Vapor Deposition of Monolayer Rhenium Disulfide (ReS2)
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Chandra Sekhar Tiwary, Bo Li, Yongji Gong, Douglas S. Galvao, Antony George, Amelia H. C. Hart, Kunttal Keyshar, Robert Vajtai, Gustavo Brunetto, Gonglan Ye, Pulickel M. Ajayan, Yongmin He, Ken Hackenberg, Daniel P. Cole, Leonardo D. Machado, Mohamad Kabbani, and Wu Zhou
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Materials science ,business.industry ,Mechanical Engineering ,Transistor ,Inorganic chemistry ,technology, industry, and agriculture ,chemistry.chemical_element ,Chemical vapor deposition ,Rhenium ,equipment and supplies ,law.invention ,Characterization (materials science) ,Semiconductor ,chemistry ,Mechanics of Materials ,law ,Microscopy ,Monolayer ,General Materials Science ,Spectroscopy ,business - Abstract
The direct synthesis of monolayer and multilayer ReS2 by chemical vapor deposition at a low temperature of 450 °C is reported. Detailed characterization of this material is performed using various spectroscopy and microscopy methods. Furthermore initial field-effect transistor characteristics are evaluated, which highlight the potential in being used as an n-type semiconductor.
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- 2015
16. 2D Materials: Quaternary 2D Transition Metal Dichalcogenides (TMDs) with Tunable Bandgap (Adv. Mater. 35/2017)
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Vidya Kochat, Boris I. Yakobson, Amey Apte, Alex Kutana, Jordan A. Hachtel, Sandhya Susarla, Chandra Sekhar Tiwary, Robert Vajtai, Pulickel M. Ajayan, and Juan Carlos Idrobo
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Materials science ,Band gap ,Mechanical Engineering ,Inorganic chemistry ,Nanotechnology ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,Transition metal ,Mechanics of Materials ,General Materials Science ,0210 nano-technology - Published
- 2017
17. Boxception : Impact Resistance Structure Using 3D Printing
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Peter Samora Owuor, Chandra Sekhar Tiwary, Ravi Sastri Ayyagari, Seyed Mohammad Sajadi, Robert Vajtai, Pulickel M. Ajayan, and Jun Lou
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Impact resistance ,Materials science ,business.industry ,Mechanical engineering ,3D printing ,General Materials Science ,Condensed Matter Physics ,business ,Finite element method - Published
- 2019
18. Structure‐Dependent Electrical and Magnetic Properties of Iron Oxide Composites
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Narumon Lertcumfu, Chandra Sekhar Tiwary, Sharmila N. Shirodkar, Farheen N. Sayed, Gobwute Rujijanagul, Abhishek K. Singh, Sruthi Radhakrishnana, Pulickel M. Ajayan, Boris I. Yakobson, and Avanish Mishra
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Materials science ,Magnetism ,Iron oxide ,Surfaces and Interfaces ,Dielectric ,Conductivity ,Condensed Matter Physics ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,chemistry.chemical_compound ,chemistry ,Materials Chemistry ,Interphase ,Electrical and Electronic Engineering ,Composite material - Published
- 2019
19. Two‐Dimensional Amorphous Cr 2 O 3 Modified Metallic Electrodes for Hydrogen Evolution Reaction
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Tharangattu N. Narayanan, Aravind Puthirath Balan, Femi Mathew, Thoufeeq Subair, Soorya P. Narayanan, Asha Ann Abraham, Pulickel M. Ajayan, Senoy Thomas, Pallavi Thakur, Chandra Sekhar Tiwary, Munaiah Yeddala, and M. R. Anantharaman
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Materials science ,Chemical engineering ,Metallic electrode ,General Materials Science ,Hydrogen evolution ,Condensed Matter Physics ,Amorphous solid - Published
- 2019
20. Direct Ink Writing of Cement Structures Modified with Nanoscale Additive
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Ashok Kumar Meiyazhagan, Chandra Sekhar Tiwary, Peter J. Boul, Carl J. Thaemlitz, Muhammad M. Rahman, Anand B. Puthirath, Pulickel M. Ajayan, and Seyed Mohammad Sajadi
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Cement ,Materials science ,Inkwell ,Rheology ,business.industry ,3D printing ,General Materials Science ,Nanotechnology ,Condensed Matter Physics ,business ,Nanoscopic scale - Published
- 2019
21. Strain-Induced Structural Deformation Study of 2D Mo x W(1- x ) S2
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Ygor M. Jaques, Praveena Manimunda, Douglas S. Galvao, Juan C. Idrobo, S. A. Syed Asif, Sandhya Susarla, Jordan A. Hachtel, Chandra Sekhar Tiwary, and Pulickel M. Ajayan
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symbols.namesake ,Materials science ,Strain (chemistry) ,Mechanics of Materials ,Mechanical Engineering ,Fracture (geology) ,symbols ,Structural deformation ,Composite material ,Raman spectroscopy - Published
- 2019
22. Fluorinated Boron Nitride Quantum Dots: A New 0D Material for Energy Conversion and Detection of Cellular Metabolism
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Ram Neupane, Carlos A. de los Reyes, Sruthi Radhakrishnan, Maggie Paulose, Angel A. Martí, Valery N. Khabashesku, Jun Hyoung Park, Chandra Sekhar Tiwary, Parambath M. Sudeep, Oomman K. Varghese, Benny Abraham Kaipparettu, and Pulickel M. Ajayan
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Cellular metabolism ,Materials science ,Nanotechnology ,02 engineering and technology ,General Chemistry ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,0104 chemical sciences ,chemistry.chemical_compound ,chemistry ,Quantum dot ,Boron nitride ,Photocatalysis ,Energy transformation ,General Materials Science ,0210 nano-technology - Published
- 2018
23. Quaternary Alloys: Thermally Induced 2D Alloy-Heterostructure Transformation in Quaternary Alloys (Adv. Mater. 45/2018)
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Sandhya Susarla, Zehua Jin, Jordan A. Hachtel, Chandra Sekhar Tiwary, Robert Vajtai, Pulickel M. Ajayan, Juan Carlos Idrobo, Boris I. Yakobson, Alex Kutana, Jun Lou, Xiting Yang, and Amey Apte
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Materials science ,Condensed matter physics ,Phase stability ,Mechanical Engineering ,Alloy ,Heterojunction ,engineering.material ,Transformation (function) ,Mechanics of Materials ,Scanning transmission electron microscopy ,engineering ,General Materials Science ,Density functional theory ,Quaternary ,Phase diagram - Published
- 2018
24. An Insight into the Phase Transformation of WS 2 upon Fluorination
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Guillaume Colas, Sruthi Radhakrishnan, Abhishek K. Singh, Angel A. Martí, Parambath M. Sudeep, Sadegh Yazdi, Deya Das, Pulickel M. Ajayan, Tobin Filleter, Carlos A. de los Reyes, Liangzi Deng, Ching-Wu Chu, and Chandra Sekhar Tiwary
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Phase transition ,Materials science ,Band gap ,Mechanical Engineering ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,Metal ,Transformation (function) ,Transition metal ,Mechanics of Materials ,Chemical physics ,visual_art ,Phase (matter) ,Microscopy ,visual_art.visual_art_medium ,Surface modification ,General Materials Science ,0210 nano-technology - Abstract
The transformation from semiconducting to metallic phase, accompanied by a structural transition in 2D transition metal dichalcogenides has attracted the attention of the researchers worldwide. The unconventional structural transformation of fluorinated WS2 (FWS2 ) into the 1T phase is described. The energy difference between the two phases debugs this transition, as fluorination enhances the stability of 1T FWS2 and makes it energetically favorable at higher F concentration. Investigation of the electronic and optical nature of FWS2 is supplemented by possible band structures and bandgap calculations. Magnetic centers in the 1T phase appear in FWS2 possibly due to the introduction of defect sites. A direct consequence of the phase transition and associated increase in interlayer spacing is a change in friction behavior. Friction force microscopy is used to determine this effect of functionalization accompanied phase transformation.
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- 2018
25. Thermally Induced 2D Alloy‐Heterostructure Transformation in Quaternary Alloys
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Jordan A. Hachtel, Sandhya Susarla, Chandra Sekhar Tiwary, Alex Kutana, Robert Vajtai, Boris I. Yakobson, Amey Apte, Jun Lou, Xiting Yang, Pulickel M. Ajayan, Juan Carlos Idrobo, and Zehua Jin
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Materials science ,Photoluminescence ,Condensed matter physics ,Spinodal decomposition ,Band gap ,Mechanical Engineering ,Heterojunction ,02 engineering and technology ,Condensed Matter::Mesoscopic Systems and Quantum Hall Effect ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,Condensed Matter::Materials Science ,symbols.namesake ,Mechanics of Materials ,Phase (matter) ,Scanning transmission electron microscopy ,symbols ,General Materials Science ,0210 nano-technology ,Raman spectroscopy ,Phase diagram - Abstract
Composition and phase specific 2D transition metal dichalogenides (2D TMDs) with a controlled electronic and chemical structure are essential for future electronics. While alloying allows bandgap tunability, heterostructure formation creates atomically sharp electronic junctions. Herein, the formation of lateral heterostructures from quaternary 2D TMD alloys, by thermal annealing, is demonstrated. Phase separation is observed through photoluminescence and Raman spectroscopy, and the sharp interface of the lateral heterostructure is examined via scanning transmission electron microscopy. The composition-dependent transformation is caused by existence of miscibility gap in the quaternary alloys. The phase diagram displaying the miscibility gap is obtained from the reciprocal solution model based on density functional theory and verified experimentally. The experiments show direct evidence of composition-driven heterostructure formation in 2D atomic layer systems.
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- 2018
26. Achieving Self‐Stiffening and Laser Healing by Interconnecting Graphene Oxide Sheets with Amine‐Functionalized Ovalbumin
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Sandhya Susarla, Bingqing Wei, HyeYoon Hwang, Peter Samora Owuor, Jun Lou, Thierry Tsafack, Pulickel M. Ajayan, Seohui Jung, Steven Schara, Robert Vajtai, James M. Tour, Chandra Sekhar Tiwary, Rodrigo V. Salvatierra, Muqing Ren, and Tong Li
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Materials science ,Oxide ,Mechanical properties ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,law.invention ,Molecular dynamics ,chemistry.chemical_compound ,law ,Molecular dynamics simulation ,Graphene oxide ,biology ,Graphene ,Mechanical Engineering ,Self?healing ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,Stiffening ,Ovalbumin ,Chemical engineering ,chemistry ,Mechanics of Materials ,Self-healing ,biology.protein ,Amine gas treating ,Egg white ,0210 nano-technology - Abstract
Mimicking the remarkable properties of natural materials such as toughness, self?stiffening, self?healing, etc., is useful for several structural, functional, and biomedical applications. The judicious combination of natural and synthetic building blocks to design hybrid materials could offer an alternative route to achieving the aforementioned properties of natural materials. This study reports easily scalable process to synthesize graphene oxide (GO)/egg white hybrid material (polyalbumene) by cross?linking GO nanosheet with the amine?based cross?linker diethylenetriamine (DETA) and egg white. The result is a layered material like nacre, exhibiting high strength and toughness. Abundant functional groups on the GO allow covalent interactions between DETA and egg white protein amino acids. The atomistic simulations reveal that the insertion of GO into the composite has a sizeable impact on the composite's stiffness. As shown by experiments, the hybrid material has an elastic modulus of ?41 MPa and a ductility of more than 25%. The hybrid material also exhibits a fracture repair property under laser exposure as well as CO2 absorption and stiffening over time, suggesting an adaptable behavior. This work explores the possibility that the combination of synthetic and natural approaches offers a better route to designing advanced, tough, strong, adaptable, and fracture recovering materials., by Chandra Sekhar Tiwary et al.
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- 2018
27. One Step Process for Infiltration of Magnetic Nanoparticles into CNT Arrays for Enhanced Field Emission
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Srividya Sridhar, Krisztian Kordas, Kaushik Kalaga, Pulickel M. Ajayan, Wongbong Choi, Benjamin Sirota, Sehmus Ozden, Chandra Sekhar Tiwary, and Robert Vajtai
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Materials science ,Mechanical Engineering ,One-Step ,02 engineering and technology ,Carbon nanotube ,Magnetic particle inspection ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Infiltration (HVAC) ,01 natural sciences ,0104 chemical sciences ,law.invention ,Field electron emission ,Chemical engineering ,Mechanics of Materials ,law ,Magnetic nanoparticles ,0210 nano-technology - Published
- 2018
28. Synthesis and enhanced green photoluminescence emission from BCT ZnS nanocrystals
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Pathik Kumbhakar, Chandra Sekhar Tiwary, A. K. Mitra, and Amit Kumar Mondal
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Diffraction ,Materials science ,Photoluminescence ,Coprecipitation ,Analytical chemistry ,Nanotechnology ,Surfaces and Interfaces ,Condensed Matter Physics ,Nanocrystalline material ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Nanocrystal ,Transmission electron microscopy ,Phase (matter) ,Materials Chemistry ,Electrical and Electronic Engineering ,Absorption (chemistry) - Abstract
Body-centered-tetragonal (BCT) ZnS nanocrystals have been synthesized, for the first time to the best of our knowledge, by using the chemical coprecipitation method at higher synthesis temperatures of 65 and 95 degrees C. It is confirmed from X-ray diffraction (XRD) studies that in the high-temperature-synthesized samples, cubic and BCT phases coexist, in contrast to the room-temperature-synthesized sample, which consists of only cubic phase with sizes of the particles lying between 2 and 3 nm. The sizes of BCT phase nanocrystals are bigger than those of cubic phase of ZnS. The presence of BCT phase of ZnS in the samples is increased from 40 to 90% when the temperature of synthesis is increased from 65 to 95 degrees C. The nanocrystalline nature and UV-Vis absorption characteristics of the prepared samples have been studied with a transmission electron microscope (TEM) and a UV-Visible pectrophotometer, respectively. The room-temperature-synthesized ZnS sample shows photoluminescence (PL) emission in the blue region with multiple peaks, whereas the high-temperature-synthesized samples show PL emissions in the visible region. The Gaussian fittings of the measured PL spectra shows that three PL peaks at 429, 477, and 525 nm are appeared in the 65 degrees C sample and two peaks at 491 and 540 nm appear in the 95 degrees C sample with the enhanced PL intensity of the green peak at 540 nm. (C) 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
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- 2010
29. Graphene Oxide Epoxy (GO‐xy): GO as Epoxy Adhesive by Interfacial Reaction of Functionalities
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Atanu Samanta, Tharangattu N. Narayanan, Vipin Agarwal, Soumya Vinod, Pulickel M. Ajayan, Sehmus Ozden, Abhishek K. Singh, Chandra Sekhar Tiwary, George John, and Robert Vajtai
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Interfacial reaction ,Epoxy adhesive ,Materials science ,Graphene ,Mechanical Engineering ,Oxide ,02 engineering and technology ,Epoxy ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,law.invention ,chemistry.chemical_compound ,chemistry ,Mechanics of Materials ,law ,visual_art ,visual_art.visual_art_medium ,Composite material ,0210 nano-technology ,Graphene oxide paper - Published
- 2017
30. Multiscale Geometric Design Principles Applied to 3D Printed Schwarzites
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Peter Samora Owuor, Cristiano F. Woellner, Varlei Rodrigues, Robert Vajtai, Seyed Mohammad Sajadi, Douglas S. Galvao, Chandra Sekhar Tiwary, Steven Schara, Jun Lou, and Pulickel M. Ajayan
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Materials science ,Gaussian ,Mechanical engineering ,3D printing ,Nanotechnology ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,law.invention ,symbols.namesake ,Molecular dynamics ,law ,General Materials Science ,Minimal surface ,Bearing (mechanical) ,business.industry ,Mechanical Engineering ,021001 nanoscience & nanotechnology ,Finite element method ,0104 chemical sciences ,Deformation mechanism ,Mechanics of Materials ,symbols ,0210 nano-technology ,business ,Gyroid - Abstract
Schwartzites are 3D porous solids with periodic minimal surfaces having negative Gaussian curvatures and can possess unusual mechanical and electronic properties. The mechanical behavior of primitive and gyroid schwartzite structures across different length scales is investigated after these geometries are 3D printed at centimeter length scales based on molecular models. Molecular dynamics and finite elements simulations are used to gain further understanding on responses of these complex solids under compressive loads and kinetic impact experiments. The results show that these structures hold great promise as high load bearing and impact-resistant materials due to a unique layered deformation mechanism that emerges in these architectures during loading. Easily scalable techniques such as 3D printing can be used for exploring mechanical behavior of various predicted complex geometrical shapes to build innovative engineered materials with tunable properties.
- Published
- 2017
31. ChemInform Abstract: Chemical Vapor Deposition of Monolayer Rhenium Disulfide (ReS2)
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Chandra Sekhar Tiwary and null et al.
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Chemistry ,Inorganic chemistry ,Monolayer ,Disulfide bond ,chemistry.chemical_element ,General Medicine ,Chemical vapor deposition ,Rhenium - Published
- 2015
32. Multifunctional Hybrids Based on 2D Fluorinated Graphene Oxide and Superparamagnetic Iron Oxide Nanoparticles
- Author
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Douglas S. Galvao, Parambath M. Sudeep, Kierstein Maladonado, Benny Abraham Kaipparettu, Jun Hyoung Park, Sruthi Radhakrishnan, Pulickel M. Ajayan, Chandra Sekhar Tiwary, and Cristiano F. Woellner
- Subjects
Materials science ,Graphene ,Composite number ,Iron oxide ,Oxide ,Nanotechnology ,02 engineering and technology ,General Chemistry ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,0104 chemical sciences ,law.invention ,Nanomaterials ,Paramagnetism ,chemistry.chemical_compound ,chemistry ,law ,General Materials Science ,0210 nano-technology ,Iron oxide nanoparticles ,Superparamagnetism - Abstract
Carbon-based nanomaterials have garnered a lot of attention in the research of yesteryear. Here this study reports a composite based on fluorinated graphene oxide—a multifunctional subsidiary of graphene; and iron oxide nanoparticles as a contrast agent for magnetic resonance imaging (MRI). Extensive structural and functional characterization is carried out to understand composite behavior toward biotoxicity and its performance as a contrast agent. The electron withdrawing fluorine group decreases the charge transfer to iron oxide increasing the magnetic saturation of the composite thus enhancing the contrast. The interaction of paramagnetic and superparamagnetic systems yields a superior contrast agent for MRI and fluorescent imaging.
- Published
- 2017
33. Quaternary 2D Transition Metal Dichalcogenides (TMDs) with Tunable Bandgap
- Author
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Chandra Sekhar Tiwary, Sandhya Susarla, Robert Vajtai, Amey Apte, Pulickel M. Ajayan, Juan Carlos Idrobo, Boris I. Yakobson, Jordan A. Hachtel, Alex Kutana, and Vidya Kochat
- Subjects
Imagination ,Range (particle radiation) ,Materials science ,Chemical substance ,Band gap ,business.industry ,Mechanical Engineering ,media_common.quotation_subject ,Doping ,Nanotechnology ,02 engineering and technology ,Chemical vapor deposition ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,Transition metal ,Mechanics of Materials ,Optoelectronics ,General Materials Science ,0210 nano-technology ,business ,Science, technology and society ,media_common - Abstract
Alloying/doping in 2D material is important due to wide range bandgap tunability. Increasing the number of components would increase the degree of freedom which can provide more flexibility in tuning the bandgap and also reduces the growth temperature. Here, synthesis of quaternary alloys Mox W1-x S2y Se2(1-y) is reported using chemical vapor deposition. The composition of alloys is tuned by changing the growth temperatures. As a result, the bandgap can be tuned which varies from 1.61 to 1.85 eV. The detailed theoretical calculation supports the experimental observation and shows a possibility of wide tunability of bandgap.
- Published
- 2017
34. Nature Inspired Strategy to Enhance Mechanical Properties via Liquid Reinforcement
- Author
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Alin Cristian Chipara, Pulickel M. Ajayan, S. R. Hiremath, Chandra Sekhar Tiwary, Jun Lou, Peter Samora Owuor, D. Roy Mahapatra, and Robert Vajtai
- Subjects
Bulk modulus ,Materials science ,Mechanical Engineering ,Composite number ,chemistry.chemical_element ,02 engineering and technology ,Strain hardening exponent ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Viscoelasticity ,Finite element method ,0104 chemical sciences ,chemistry ,Deformation mechanism ,Mechanics of Materials ,Hydrostatic stress ,Gallium ,Composite material ,0210 nano-technology - Abstract
Solid-solid interface mechanism understanding of composite inclusions, when extended to solid-liquid interface design of composite using Eshelby theory, indicates a possibility of decreasing effective stiffness with increasing liquid inclusion in a solid matrix. In contrast, experimental evidence in the current paper suggests high stiffness and enhanced dynamic energy absorption in a soft polymer (polydimethylsiloxane) with high bulk modulus liquid inclusions (gallium). The basic deformation mechanism is governed by hydrostatic stress causing shape change of the liquid inclusion in large deformation regime and strain hardening of a soft polymer matrix. In addition, dynamic viscoelasticity and fluid motion also play a significant role. These understandings are developed here based on analytical modeling and a detailed finite element with smooth particle hydrodynamic simulations. The large deformation with viscoelasticity of gallium composite shows higher energy absorption and dissipation. Similar strategies of liquid reinforcement to compliant solid matrices are abundant in nature, for example, the intervertebral discs in the spinal cord and deep sea animal skin and lungs.
- Published
- 2017
35. Metal Immiscibility Route to Synthesis of Ultrathin Carbides, Borides, and Nitrides
- Author
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Xiang Zhang, Suman Sarkar, Vidya Kochat, Kamanio Chattopadhyay, Soham Chattopadhyay, Sanjay Kashyap, Zixing Wang, S. A. Syed Asif, Abhisek K. Singh, Chandra Sekhar Tiwary, Praveena Manimunda, Atanu Samanta, Prafull Pandey, and Pulickel M. Ajayan
- Subjects
Materials science ,chemistry.chemical_element ,02 engineering and technology ,Chemical vapor deposition ,Nitride ,010402 general chemistry ,01 natural sciences ,Carbide ,Metal ,chemistry.chemical_compound ,Boride ,General Materials Science ,Ceramic ,Materials Research Centre ,Mechanical Engineering ,Metallurgy ,Materials Engineering (formerly Metallurgy) ,021001 nanoscience & nanotechnology ,Copper ,0104 chemical sciences ,chemistry ,Chemical engineering ,Mechanics of Materials ,visual_art ,visual_art.visual_art_medium ,0210 nano-technology ,Tantalum carbide - Abstract
Ultrathin ceramic coatings are of high interest as protective coatings from aviation to biomedical applications. Here, a generic approach of making scalable ultrathin transition metal-carbide/boride/nitride using immiscibility of two metals is demonstrated. Ultrathin tantalum carbide, nitride, and boride are grown using chemical vapor deposition by heating a tantalum-copper bilayer with corresponding precursor (C2 H2 , B powder, and NH3 ). The ultrathin crystals are found on the copper surface (opposite of the metal-metal junction). A detailed microscopy analysis followed by density functional theory based calculation demonstrates the migration mechanism, where Ta atoms prefer to stay in clusters in the Cu matrix. These ultrathin materials have good interface attachment with Cu, improving the scratch resistance and oxidation resistance of Cu. This metal-metal immiscibility system can be extended to other metals to synthesize metal carbide, boride, and nitride coatings.
- Published
- 2017
36. Self-Stiffening Behavior of Reinforced Carbon Nanotubes Spheres
- Author
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Enrique V. Barrera, Chandra Sekhar Tiwary, Amelia H. C. Hart, Ryota Koizumi, Robert Vajtai, Pulickel M. Ajayan, Matias Soto, Peter Samora Owuor, and Jun Lou
- Subjects
Materials science ,Nanocomposite ,Stiffness ,Mechanical properties of carbon nanotubes ,02 engineering and technology ,Carbon nanotube ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Elastomer ,01 natural sciences ,0104 chemical sciences ,Stiffening ,law.invention ,symbols.namesake ,law ,medicine ,symbols ,Surface modification ,General Materials Science ,Composite material ,medicine.symptom ,van der Waals force ,0210 nano-technology - Abstract
Strong van der Waals forces between individual carbon nanotubes pose a major hurdle for effective use of nanotubes as reinforcement in nanocomposite due to agglomeration. In this paper, the authors show that van der Waals forces in combination with functionalization of carbon nanotubes, can be utilized to design nanocomposites mimicking stiffening behavior normally observed in biological materials such as fibrin gels, health bones, actin filaments in cytoskeletons etc. Carbon nanotube spheres are used as reinforcement in an elastomer matrix and when subjected to dynamic loads exhibit significant self-stiffening. Increased stiffness is also observed in dynamic loading after every relaxation cycle. The authors further show high energy absorption of the nanocomposite in impact tests. Authors study shows that the rational design of macroscale materials from nano-scale constituents can be achieved utilizing simple methodology to produce multifunctional materials with broad applications.
- Published
- 2017
37. High Toughness in Ultralow Density Graphene Oxide Foam
- Author
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Bingqing Wei, Peter Samora Owuor, Douglas S. Galvao, Jun Lou, Suppanat Kosolwattana, James M. Tour, Sehmus Ozden, S. A. Syed Asif, Robert Vajtai, Luong Xuan Duy, Chandra Sekhar Tiwary, Tong Li, Sanjit Bhowmick, Cristiano F. Woellner, Rodrigo V. Salvatierra, Soumya Vinod, and Pulickel M. Ajayan
- Subjects
Toughness ,Materials science ,Polydimethylsiloxane ,Graphene ,Mechanical Engineering ,Graphene foam ,technology, industry, and agriculture ,Oxide ,macromolecular substances ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,law.invention ,chemistry.chemical_compound ,chemistry ,Mechanics of Materials ,law ,Ultimate tensile strength ,Composite material ,0210 nano-technology ,Separator (electricity) ,Graphene oxide paper - Abstract
Here, the scalable synthesis of low-density 3D macroscopic structure of graphene oxide (GO) interconnected with polydimethylsiloxane (PDMS) is reported. A controlled amount of PDMS is infused into the freeze-dried foam to result into a very rigid structure with improved mechanical properties, such as tensile plasticity and toughness. The PDMS wets the graphene oxide sheets and acts like glue between the 2D sheets. Molecular dynamics simulations are used to further elucidate the mechanisms of the interactions of graphene oxide layers with PDMS. The ability of using the interconnecting graphene oxide foam as an effective oil–water separator and stable insulating behavior to elevated temperatures are further demonstrated. The structural rigidity of the sample is also tested using laser impact and compared with GO foam.
- Published
- 2017
38. Growth of Molybdenum Carbide–Graphene Hybrids from Molybdenum Disulfide Atomic Layer Template
- Author
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Mingjie Liu, Atanu Samanta, Jun Lou, Abhishek K. Singh, Jiangtan Yuan, Bo Li, Lulu Ma, Jing Zhang, Boris I. Yakobson, Yingchao Yang, Pulickel M. Ajayan, Jingjie Wu, Yongji Gong, Chandra Sekhar Tiwary, and Robert Vajtai
- Subjects
Materials science ,Graphene ,Mechanical Engineering ,Inorganic chemistry ,02 engineering and technology ,Chemical vapor deposition ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Molybdenum carbide ,0104 chemical sciences ,law.invention ,Catalysis ,chemistry.chemical_compound ,Molybdenum sulfide ,chemistry ,Mechanics of Materials ,law ,0210 nano-technology ,Layer (electronics) ,Molybdenum disulfide - Published
- 2017
39. Enhancing Mechanical Properties of Nanocomposites Using Interconnected Carbon Nanotubes (iCNT) as Reinforcement
- Author
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Sehmus Ozden, Takami Kaji, Ryota Koizumi, Yang Yang, Chandra Sekhar Tiwary, Evgeni S. Penev, Robert Vajtai, Boris I. Yakobson, Pulickel M. Ajayan, Peter Samora Owuor, and Jun Lou
- Subjects
Nanocomposite ,Materials science ,02 engineering and technology ,Carbon nanotube ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,0104 chemical sciences ,law.invention ,law ,General Materials Science ,Composite material ,0210 nano-technology ,Reinforcement - Published
- 2016
40. Metal‐Free Dual Modal Contrast Agents Based on Fluorographene Quantum Dots
- Author
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Chandra Sekhar Tiwary, Kiersten L. Maldonado, Atanu Samanta, Ghanashyam Acharya, Abhishek K. Singh, Parambath M. Sudeep, Sendurai A. Mani, Pulickel M. Ajayan, and Sruthi Radhakrishnan
- Subjects
Physics ,business.industry ,Nanotechnology ,02 engineering and technology ,General Chemistry ,DUAL (cognitive architecture) ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,0104 chemical sciences ,Modal ,Metal free ,Quantum dot ,Optoelectronics ,General Materials Science ,0210 nano-technology ,business ,Fluorographene - Abstract
NEWS COVERAGE: A news release based on this journal publication is available online: http://news.rice.edu/2016/11/10/rice-expands-graphene-repertoire-with-mri-contrast-agent/
- Published
- 2016
41. Controlled 3D Carbon Nanotube Structures by Plasma Welding
- Author
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Srinivasa R. Bakshi, Sehmus Ozden, Ajit K. Roy, Gustavo Brunetto, Chandra Sekhar Tiwary, Douglas S. Galvao, N.S. Karthiselva, and Pulickel M. Ajayan
- Subjects
Materials science ,Mechanical Engineering ,Spark plasma sintering ,Nanotechnology ,02 engineering and technology ,Carbon nanotube ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,law.invention ,Plasma arc welding ,Mechanics of Materials ,law ,Microscopy ,0210 nano-technology - Published
- 2016
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