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1. Strain distribution in WS2 monolayers detected through Polarization-resolved Second Harmonic Generation

Author

Kourmoulakis, George, Psilodimitrakopoulos, Sotiris, Maragkakis, George Miltos, Mouchliadis, Leonidas, Michail, Antonios, Christodoulides, Joseph A, Tripathi, Manoj, Dalton, Alan B, Parthenios, John, Papagelis, Konstantinos, Stratakis, Emmanuel, and Kioseoglou, George

Subjects
Physics - Applied Physics, Condensed Matter - Materials Science
Abstract

Two-dimensional (2D) graphene and graphene-related materials (GRMs) show great promise for future electronic devices. Nevertheless, GRMs result distinct properties under the influence of the substrate that serves as support through uneven compression/ elongation of GRMs surface atoms. Strain in GRM monolayers is the most common feature that alters the interatomic distances, band structure, providing a new degree of freedom that allows regulation of their electronic properties and introducing the field of straintronics. Having an all-optical detection, a minimally invasive tool that rapidly probes strain in large areas of GRM monolayers, would be of great importance in the research and development of novel 2D devices. Here, we use Polarization-resolved Second Harmonic Generation (P-SHG) optical imaging to identify strain distribution, induced in a single layer of WS2 placed on a pre-patterned Si/SiO2 substrate with cylindrical wells. By fitting the P-SHG data pixel-by-pixel, we produce spatially resolved images of the crystal armchair direction. In regions where the WS2 monolayer conforms to the pattern topography, a distinct cross-shaped pattern is evident in the armchair image owing to strain. The presence of strain in these regions is independently confirmed using a combination of atomic force microscopy and Raman mapping.

Published
2024

2. Frictional Characteristics of Graphene on Textured Surfaces

Author

Tripathi, Manoj, Iyengar, Sathvik Ajay, Hasan-ur Rahman, Md., Gadhamshetty, Venkataramana, Ajayan, Pulickel Madhava, Dalton, Alan B., Avouris, Phaedon, Series Editor, Bhushan, Bharat, Series Editor, Bimberg, Dieter, Series Editor, Ning, Cun-Zheng, Series Editor, von Klitzing, Klaus, Series Editor, Wiesendanger, Roland, Series Editor, Gnecco, Enrico, editor, and Meyer, Ernst, editor

Published
2024
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4. Anisotropic Frictional Response of Texture Induced Strained Graphene

Author

Mescola, Andrea, Paolicelli, Guido, Guarino, Roberto, McHugh, James G., Ogilvie, Sean P., Rota, Alberto, Gnecco, Enrico, Iacob, Erica, Valeri, Sergio, Pugno, Nicola M., Gadhamshetty, Venkata, Rahman, Muhammad M., Ajayan, Pulickel M., Dalton, Alan B., and Tripathi, Manoj

Subjects
Condensed Matter - Materials Science
Abstract

Friction-induced energy dissipation impedes the performance of nanoscale devices during their relative motion. Nevertheless, an ingeniously designed structure which utilizes graphene topping can tune the friction force signal by inducing local strain. The present work reports capping of graphene over Si grooved surfaces of different pitch lengths from sub-nanoscale (P=40 nm) to a quarter of a micron (P= 250 nm). The variation in the pitch lengths induces different strains in graphene revealed by scanning probe techniques, Raman spectroscopy and molecular dynamics (MD) simulation. The asymmetric straining of C-C bonds over the groove architecture is exploited through friction force microscopy in different directions of orthogonal and parallel to groove axis. The presence of graphene lubricates the textured surface by a factor of 10 and periodically dissipated friction force, which was found to be stochastic over the bare surface. For the first time, we presented transformation of the lubrication into an ultra-low friction force by a factor of 20 over the crest scanning parallel to the groove axis. Such anisotropy is found to be insignificant at the bare textured system, clearly demonstrating the strain-dependent regulation of friction force. Our results are applicable for graphene, and other 2D materials covered corrugated structures with movable components such as NEMS, nanoscale gears and robotics., Comment: 32 pages, 4 figures

Published
2021

6. Nanosheet-stabilized emulsions: ultra-low loading segregated networks and surface energy determination of pristine few-layer 2D materials

Author

Ogilvie, Sean P., Large, Matthew J., Cass, Adam J., Graf, Aline Amorim, Sehnal, Anne C., O'Mara, Marcus A., Lynch, Peter J., Salvage, Jonathan P., Alfonso, Marco, Poulin, Philippe, King, Alice A. K., and Dalton, Alan B.

Subjects
Physics - Applied Physics, Condensed Matter - Mesoscale and Nanoscale Physics, Condensed Matter - Materials Science
Abstract

A framework is developed to allow emulsification to be used to fabricate functional structures from, and study the properties of, pristine layered nanosheets. Liquid-exfoliated few-layer graphene and MoS2 are demonstrated to stablize emulsions which exhibit system-scale electrical conductivity at ultra-low nanosheet volume fractions. When deposited on a substrate, the controlled drying dynamics of these emulsions facilitates their application as inks where the lack of any coffee ring effect allows manual deposition of high conductivity films. In order to broaden the range of compositions and subsequently applications, an understanding of emulsion stability and orientation in terms of surface energy of the three phases is developed. Importantly, this model facilitates determination of the surface energies of the nanosheets themselves and subsequently allows design of emulsions. Finally, emulsification by surfactant-exfoliated nanosheets and emulsion inversion using basic solution are demonstrated to allow water-based processing where composition and orientation can be tailored to enable applications.

Published
2020
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7. Processing dynamics of carbon nanotube-epoxy nanocomposites during 3D printing

Author

Khater, Ali Zein, Saadi, M.A.S.R., Bhattacharyya, Sohini, Kutana, Alex, Tripathi, Manoj, Kamble, Mithil, Song, Shaowei, Lou, Minghe, Barnes, Morgan, Meyer, Matthew D., Harikrishnan, Vijay Vedhan Jayanthi, Dalton, Alan B., Koratkar, Nikhil, Tiwary, Chandra Sekhar, Boul, Peter J., Yakobson, Boris, Zhu, Hanyu, Ajayan, Pulickel M., and Rahman, Muhammad M.

Published
2023
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8. Ethyl cellulose composite membranes containing a 2D material (MoS2) and helical carbon nanotubes for efficient solar steam generation and desalination

Author

Tunsound, Vasuphat, Krasian, Tharnthip, Daranarong, Donraporn, Jantanasakulwong, Kittisak, Punyodom, Winita, Sriyai, Montira, Somsunan, Runglawan, Manokruang, Kiattikhun, Rachtanapun, Pornchai, Tipduangta, Pratchaya, Srithep, Yottha, Amnuaypanich, Sittipong, Dalton, Alan B., and Worajittiphon, Patnarin

Published
2023
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9. Silver Nanowires on Carbon Nanotube Aerogel Sheets for Flexible, Transparent Electrodes

Author

Martinez, Patricia M., Ishteev, Arthur, Velten, Josef, Fahimi, Azin, Jurewicz, Izabela, Dalton, Alan B., Baughman, Ray H., and Zakhidov, Anvar A.

Subjects
Condensed Matter - Mesoscale and Nanoscale Physics
Abstract

Flexible, free-standing transparent conducting electrodes (TCEs) with simultaneously tunable transmittances up to 98% and sheet resistances down to 11 {\Omega}/sq were prepared by a facile spray-coating method of silver nanowires (AgNWs) onto dry-spun multiwall carbon nanotube (MWNT) aerogels. Counterintuitively, the transmittance of the hybrid electrodes can be increased as the mass density of AgNWs within the MWNT aerogels increase, however, the final achievable transmittance depends on the initial transparency of the MWNT aerogels. At the same time, a strong decrease in sheet resistance is obtained when AgNWs form a percolated network along the MWNT aerogel. Additionally, anisotropic reduction in sheet resistance and polarized transmittance of AgNWs/MWNTs aerogel is achieved with this method. The final AgNWs/MWNTs hybrid TCEs transmittance and sheet resistance can be fine-tuned by spray-coating mechanisms or by the choice of initial MWNT aerogel density. Thus, a wide range of AgNWs/MWNTs hybrid TCEs with optimized optoelectronic properties can be achieved depending of the requirements needed. Finally, the free-standing AgNWs/MWNTs hybrid TCEs can be laminated onto a wide range of substrates without the need of a bonding aid., Comment: 28 pages, 5 figures, supplemental information

Published
2019

11. Explosive percolation yields highly-conductive polymer nanocomposites

Author

Meloni, Manuela, Large, Matthew J., González Domínguez, José Miguel, Victor-Román, Sandra, Fratta, Giuseppe, Istif, Emin, Tomes, Oliver, Salvage, Jonathan P., Ewels, Christopher P., Pelaez-Fernandez, Mario, Arenal, Raul, Benito, Ana, Maser, Wolfgang K., King, Alice A. K., Ajayan, Pulickel M., Ogilvie, Sean P., and Dalton, Alan B.

Published
2022
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13. Tunable 2D Conjugated Porous Organic Polymer Films for Precise Molecular Nanofiltration and Optoelectronics.

Author

Miller, Kristen, Gayle, Jessica M., Roy, Soumyabrata, Abdellah, Mohamed H., Hardian, Rifan, Cseri, Levente, Demingos, Pedro G., Nadella, Hema Rajesh, Lee, Frank, Tripathi, Manoj, Gupta, Sashikant, Guo, Galio, Bhattacharyya, Sohini, Wang, Xu, Dalton, Alan B., Garg, Ashish, Singh, Chandra Veer, Vajtai, Robert, Szekely, Gyorgy, and Ajayan, Pulickel

Published
2024
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14. Strain distribution in WS2 monolayers detected through polarization-resolved second harmonic generation.

Author

Kourmoulakis, George, Psilodimitrakopoulos, Sotiris, Maragkakis, George Miltos, Mouchliadis, Leonidas, Michail, Antonios, Christodoulides, Joseph A., Tripathi, Manoj, Dalton, Alan B., Parthenios, John, Papagelis, Konstantinos, Stratakis, Emmanuel, and Kioseoglou, George

Subjects
SECOND harmonic generation, ATOMIC force microscopy, SUBSTRATES (Materials science), RAMAN microscopy, DEGREES of freedom
Abstract

Two-dimensional (2D) graphene and graphene-related materials (GRMs) show great promise for future electronic devices. GRMs exhibit distinct properties under the influence of the substrate that serves as support through uneven compression/ elongation of GRMs surface atoms. Strain in GRM monolayers is the most common feature that alters the interatomic distances and band structure, providing a new degree of freedom that allows regulation of their electronic properties and introducing the field of straintronics. Having an all-optical and minimally invasive detection tool that rapidly probes strain in large areas of GRM monolayers, would be of great importance in the research and development of novel 2D devices. Here, we use Polarization-resolved Second Harmonic Generation (P-SHG) optical imaging to identify strain distribution, induced in a single layer of WS2 placed on a pre-patterned Si/SiO2 substrate with cylindrical wells. By fitting the P-SHG data pixel-by-pixel, we produce spatially resolved images of the crystal armchair direction. In regions where the WS2 monolayer conforms to the pattern topography, a distinct cross-shaped pattern is evident in the armchair image owing to strain. The presence of strain in these regions is independently confirmed using a combination of atomic force microscopy and Raman mapping. [ABSTRACT FROM AUTHOR]

Published
2024
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15. Machine Learning-Assisted Raman Spectroscopy and SERS for Bacterial Pathogen Detection: Clinical, Food Safety, and Environmental Applications.

Author

Rahman, Md Hasan-Ur, Sikder, Rabbi, Tripathi, Manoj, Zahan, Mahzuzah, Ye, Tao, Gnimpieba Z., Etienne, Jasthi, Bharat K., Dalton, Alan B., and Gadhamshetty, Venkataramana

Subjects
SERS spectroscopy, CONVOLUTIONAL neural networks, MACHINE learning, RAMAN spectroscopy, RAPID diagnostic tests, DEEP learning
Abstract

Detecting pathogenic bacteria and their phenotypes including microbial resistance is crucial for preventing infection, ensuring food safety, and promoting environmental protection. Raman spectroscopy offers rapid, seamless, and label-free identification, rendering it superior to gold-standard detection techniques such as culture-based assays and polymerase chain reactions. However, its practical adoption is hindered by issues related to weak signals, complex spectra, limited datasets, and a lack of adaptability for detection and characterization of bacterial pathogens. This review focuses on addressing these issues with recent Raman spectroscopy breakthroughs enabled by machine learning (ML), particularly deep learning methods. Given the regulatory requirements, consumer demand for safe food products, and growing awareness of risks with environmental pathogens, this study emphasizes addressing pathogen detection in clinical, food safety, and environmental settings. Here, we highlight the use of convolutional neural networks for analyzing complex clinical data and surface enhanced Raman spectroscopy for sensitizing early and rapid detection of pathogens and analyzing food safety and potential environmental risks. Deep learning methods can tackle issues with the lack of adequate Raman datasets and adaptability across diverse bacterial samples. We highlight pending issues and future research directions needed for accelerating real-world impacts of ML-enabled Raman diagnostics for rapid and accurate diagnosis and surveillance of pathogens across critical fields. [ABSTRACT FROM AUTHOR]

Published
2024
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18. Quantum Gas-Enabled Direct Mapping of Active Current Density in Percolating Networks of Nanowires

Author

Fekete, Julia, primary, Joshi, Poppy, additional, Barrett, Thomas J., additional, James, Timothy Martin, additional, Shah, Robert, additional, Gadge, Amruta, additional, Bhumbra, Shobita, additional, Evans, William, additional, Tripathi, Manoj, additional, Large, Matthew, additional, Dalton, Alan B., additional, Oručević, Fedja, additional, and Krüger, Peter, additional

Published
2024
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19. Vertical heterostructure of graphite-MoS2 for gas sensing

Author

Tripathi, Manoj, primary, Deokar, Geetanjali, additional, Casanova-Chafer, Juan, additional, Jin, Jinjie, additional, Sierra-Castillo, Ayrton, additional, Ogilvie, Sean Paul, additional, Lee, Frank, additional, Iyengar, Sathvik Ajay, additional, Biswas, Abhijit, additional, Haye, Emile, additional, Genovese, Alessandro, additional, Llobet, Eduard, additional, Colomer, Jean François, additional, Jurewicz, Izabela, additional, Gadhamshetty, Venkataramana, additional, Ajayan, Pulickel M., additional, Schwingenschlogl, Udo, additional, Costa, Pedro M. F. J., additional, and Dalton, Alan B, additional

Published
2024
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20. Probing the interaction between 2D materials and oligoglycine tectomers

Author

University of Sussex, Gobierno de Aragón, UK Research and Innovation, Tripathi, Manoj [0000-0002-8052-428X], Garriga, Rosa [0000-0003-2607-7834], Ogilvie, Sean P. [0000-0002-0433-8186], Amorim Graf, Aline [0000-0003-3071-2255], Large, Matthew J. [0000-0001-7295-7619], Lynch, Peter J. [0000-0001-8805-0632], Papagelis, Konstantinos [0000-0001-5094-9837], Parthenios, Jhon [0000-0001-6066-7120], Cebolla, Vicente L. [0000-0002-9786-9217], Jurewicz, Izabela [0000-0003-0237-8384], Dalton, Alan B. [0000-0001-8043-1377], Muñoz, Guillermo [0000-0001-8567-4327], Tripathi, Manoj, Garriga, Rosa, Lee, Frank, Ogilvie, Sean P., Amorine Graf, Aline, Large, Matthew J., Lynch, Peter J., Papagelis, Konstantinos, Parthenios, John, Cebolla, Vicente L., Jurewicz, Izabela, Dalton, Alan B., Muñoz, Edgar, University of Sussex, Gobierno de Aragón, UK Research and Innovation, Tripathi, Manoj [0000-0002-8052-428X], Garriga, Rosa [0000-0003-2607-7834], Ogilvie, Sean P. [0000-0002-0433-8186], Amorim Graf, Aline [0000-0003-3071-2255], Large, Matthew J. [0000-0001-7295-7619], Lynch, Peter J. [0000-0001-8805-0632], Papagelis, Konstantinos [0000-0001-5094-9837], Parthenios, Jhon [0000-0001-6066-7120], Cebolla, Vicente L. [0000-0002-9786-9217], Jurewicz, Izabela [0000-0003-0237-8384], Dalton, Alan B. [0000-0001-8043-1377], Muñoz, Guillermo [0000-0001-8567-4327], Tripathi, Manoj, Garriga, Rosa, Lee, Frank, Ogilvie, Sean P., Amorine Graf, Aline, Large, Matthew J., Lynch, Peter J., Papagelis, Konstantinos, Parthenios, John, Cebolla, Vicente L., Jurewicz, Izabela, Dalton, Alan B., and Muñoz, Edgar

Abstract

Heterostructures of two-dimensional (2D) materials using graphene and MoS2 have enabled both pivotal fundamental studies and unprecedented sensing properties. These heterosystems are intriguing when graphene and MoS2 are interfaced with 2D sheets that emulate biomolecules, such as amino-terminated oligoglycine self-assemblies (known as tectomers). The adsorption of tectomer sheets over graphene and MoS2 modulates the physicochemical properties through electronic charge migration and mechanical stress transfer. Here, we present a systematic study by Raman spectroscopy and tectomer-functionalised scanning probe microscopy to understand mechanical strain, charge transfer and binding affinity in tectomer/graphene and tectomer/MoS2 hybrid structures. Raman mapping reveals distinctive thickness dependence of tectomer-induced charge transfer to MoS2, showing p-doping on monolayer MoS2 and n-doping on multilayer MoS2. By contrast, graphene is n-doped by tectomer independently of layer number, as confirmed by x-ray photoelectron spectroscopy. The interfacial adhesion between the amino groups and 2D materials are further explored using tectomer-functionalised probe microscopy. It is demonstrated here that these probes have potential for chemically sensitive imaging of 2D materials, which will be useful for mapping chemically distinct domains of surfaces and the number of layers. The facile tectomer-coating approach described here is an attractive soft-chemistry strategy for high-density amine-functionalisation of atomic force microscopy probes, therefore opening promising avenues for sensor applications.

Published
2022

21. Explosive percolation yields highly-conductive polymer nanocomposites

Author

European Commission, Engineering and Physical Sciences Research Council (UK), Agencia Estatal de Investigación (España), Ministerio de Ciencia e Innovación (España), Gobierno de Aragón, Meloni, Manuela [0000-0001-7009-3140], Large, Matthew J. [0000-0001-7295-7619], González Domínguez, José Miguel [0000-0002-0701-7695], Víctor-Román, Sandra [0000-0003-0924-5840], Fratta, Giuseppe [0000-0001-7903-1659], Istif, Emin [0000-0003-4700-7050], Savage, Jonathan P. [0000-0002-0627-6249], Peláez-Fernández, Mario [0000-0001-5079-621X], Arenal, Raúl [0000-0002-2071-9093], Benito, Ana M. [0000-0002-8654-7386], Maser, Wolfgang K. [0000-0003-4253-0758], King, Alice A. K. [0000-0002-1637-757X], Ogilvie, Sean P. [0000-0002-0433-8186], Dalton, Alan B. [0000-0001-8043-1377], Meloni, Manuela, Large, Matthew J., González Domínguez, José Miguel, Víctor-Román, Sandra, Fratta, Giuseppe, Istif, Emin, Tomes, Oliver, Savage, Jonathan P., Ewels, Christopher P., Peláez-Fernández, Mario, Arenal, Raúl, Benito, Ana M., Maser, Wolfgang K., King, Alice A. K., Ogilvie, Sean P., Dalton, Alan B., European Commission, Engineering and Physical Sciences Research Council (UK), Agencia Estatal de Investigación (España), Ministerio de Ciencia e Innovación (España), Gobierno de Aragón, Meloni, Manuela [0000-0001-7009-3140], Large, Matthew J. [0000-0001-7295-7619], González Domínguez, José Miguel [0000-0002-0701-7695], Víctor-Román, Sandra [0000-0003-0924-5840], Fratta, Giuseppe [0000-0001-7903-1659], Istif, Emin [0000-0003-4700-7050], Savage, Jonathan P. [0000-0002-0627-6249], Peláez-Fernández, Mario [0000-0001-5079-621X], Arenal, Raúl [0000-0002-2071-9093], Benito, Ana M. [0000-0002-8654-7386], Maser, Wolfgang K. [0000-0003-4253-0758], King, Alice A. K. [0000-0002-1637-757X], Ogilvie, Sean P. [0000-0002-0433-8186], Dalton, Alan B. [0000-0001-8043-1377], Meloni, Manuela, Large, Matthew J., González Domínguez, José Miguel, Víctor-Román, Sandra, Fratta, Giuseppe, Istif, Emin, Tomes, Oliver, Savage, Jonathan P., Ewels, Christopher P., Peláez-Fernández, Mario, Arenal, Raúl, Benito, Ana M., Maser, Wolfgang K., King, Alice A. K., Ogilvie, Sean P., and Dalton, Alan B.

Abstract

Explosive percolation is an experimentally-elusive phenomenon where network connectivity coincides with onset of an additional modification of the system; materials with correlated localisation of percolating particles and emergent conductive paths can realise sharp transitions and high conductivities characteristic of the explosively-grown network. Nanocomposites present a structurally- and chemically-varied playground to realise explosive percolation in practically-applicable systems but this is yet to be exploited by design. Herein, we demonstrate composites of graphene oxide and synthetic polymer latex which form segregated networks, leading to low percolation threshold and localisation of conductive pathways. In situ reduction of the graphene oxide at temperatures of <150 °C drives chemical modification of the polymer matrix to produce species with phenolic groups, which are known crosslinking agents. This leads to conductivities exceeding those of dense-packed networks of reduced graphene oxide, illustrating the potential of explosive percolation by design to realise low-loading composites with dramatically-enhanced electrical transport properties.

Published
2022

22. Graphene as thinnest coating on copper electrodes in microbial methanol fuel cells

Author

Islam, Jamil, Obulisamy, Parthiba Karthikeyan, Upadhyayula, Venkata K.K., Dalton, Alan B., Ajayan, Pulickel M., Rahman, Muhammad M., Tripathi, Manoj, Sani, Rajesh Kumar, Gadhamshetty, Venkataramana, Islam, Jamil, Obulisamy, Parthiba Karthikeyan, Upadhyayula, Venkata K.K., Dalton, Alan B., Ajayan, Pulickel M., Rahman, Muhammad M., Tripathi, Manoj, Sani, Rajesh Kumar, and Gadhamshetty, Venkataramana

Abstract

Dehydrogenation of methanol (CH3OH) into direct current (DC) in fuel cells can be a potential energy conversion technology. However, their development is currently hampered by the high cost of electrocatalysts based on platinum and palladium, slow kinetics, the formation of carbon monoxide intermediates, and the requirement for high temperatures. Here, we report the use of graphene layers (GL) for generating DC electricity from microbially driven methanol dehydrogenation on underlying copper (Cu) surfaces. Genetically tractable Rhodobacter sphaeroides 2.4.1 (Rsp), a nonarchetypical methylotroph, was used for dehydrogenating methanol at the GL-Cu surfaces. We use electrochemical methods, microscopy, and spectroscopy methods to assess the effects of GL on methanol dehydrogenation by Rsp cells. The GL-Cu offers a 5-fold higher power density and 4-fold higher current density compared to bare Cu. The GL lowers charge transfer resistance to methanol dehydrogenation by 4 orders of magnitude by mitigating issues related to pitting corrosion of underlying Cu surfaces. The presented approach for catalyst-free methanol dehydrogenation on copper electrodes can improve the overall sustainability of fuel cell technologies.

Published
2023
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23. MoS2 nanosheet networks as resistive gas sensors for NO2 detection

Author

Sayago, Isabel, Sánchez-Vicente, Carlos, Sanjurjo, José Luis, Santos Blanco, José Pedro, Ogilvie, Sean P., Dalton, Alan B., Muñoz, Edgar, Sayago, Isabel, Sánchez-Vicente, Carlos, Sanjurjo, José Luis, Santos Blanco, José Pedro, Ogilvie, Sean P., Dalton, Alan B., and Muñoz, Edgar

Published
2023

26. Localised strain and doping of 2D materials

Author

Lee, Frank, primary, Tripathi, Manoj, additional, Sanchez Salas, Roque, additional, Ogilvie, Sean Paul, additional, Amorim Graf, Aline, additional, Jurewicz, Izabela, additional, and Dalton, Alan B, additional

Published
2023
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28. Laser patterning of transparent silver nanowire electrodes biofunctionalized with oligopeptide tectomer coatings

Author

Seral-Ascaso, Andrés, Garriga, Rosa, Jurewicz, Izabela, Cebolla, Vicente L., Lahoz, Ruth, Fuente, Jesús M. de la, Mitchell, Scott G., Dalton, Alan B., Muñoz, Edgar, Seral-Ascaso, Andrés, Garriga, Rosa, Jurewicz, Izabela, Cebolla, Vicente L., Lahoz, Ruth, Mitchell, Scott G., Dalton, Alan B., Muñoz, Edgar, Seral-Ascaso, Andrés [0000-0002-0616-1644], Garriga, Rosa [0000-0003-2607-7834], Jurewicz, Izabela [0000-0003-0237-8384], Cebolla, Vicente L. [0000-0002-9786-9217], Lahoz, Ruth [0000-0003-4708-5577], Mitchell, Scott G. [0000-0003-4848-414X], Dalton, Alan B. [0000-0001-8043-1377], and Muñoz, Edgar [0000-0001-9309-2394]

Subjects
Silver nanowire, Transparent electrodes, Nanotechnology, Optoelectronics, Peptides
Abstract

1 figure.-- Abstract of the talk delivered at the 2021 Spring Meeting of the European Materials Research Society (E-MRS), Virtual Conference, from May 31st to June 3rd, 2021., The performance of transparent silver nanowire (AgNW) electrodes can be improved by using thin coatings of two-dimensional assemblies of amino-terminal oligoglycines (denoted as tectomers), which causes a ~50% sheet resistance decrease for AgNW electrodes with initial resistivities of 100 Ω/sq, while largely retaining the electrodes’ high transparency. Tectomer coatings also remarkably impart enhanced hydrophobicity and protection against AgNW degradation under ambient conditions. Additionally, these coatings are pH-sensitive, and their rich surface chemistry enables opening new perspectives on the fabrication of AgNW electrodes with (bio)sensor functionalities. In this work, we report on the laser patterning of AgNW electrodes biofunctionalized with tectomer coatings. A pulsed, green laser (532nm) was utilized to create non-conductive paths, 12 to 50 μm in width, and the conditions were tuned to avoid the damage of the substrate materials: glass and polyethylene terephthalate (PET) for rigid and flexible electrodes, respectively. The electron transport properties, transparency, and durability of the resulting interdigitated electrodes were characterized, and their potential applications in optoelectronics will be discussed.

Published
2021

29. Probing the interaction between 2D materials and oligoglycine tectomers

Author

Tripathi, Manoj, primary, Garriga, Rosa, additional, Lee, Frank, additional, Ogilvie, Sean P, additional, Graf, Aline Amorim, additional, Large, Matthew J, additional, Lynch, Peter J, additional, Papagelis, Konstantinos, additional, Parthenios, John, additional, Cebolla, Vicente L, additional, Jurewicz, Izabela, additional, Dalton, Alan B, additional, and Muñoz, Edgar, additional

Published
2022
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30. Carbon Nanotube- and Graphene Oxide / 2D Oligoglycine Tectomer Composites and Coatings

Author

Garriga, Rosa [0000-0003-2607-7834], Jurewicz, Izabela [0000-0003-0237-8384], Seyedin, Shayan [0000-0001-7322-0387], Tripathi, Manoj [0000-0002-8052-428X], Pearson, J. R. [0000-0002-2267-0844], Cebolla, Vicente L. [0000-0002-9786-9217], Razal, Joselito M. [0000-0002-9758-3702], Dalton, Alan B. [0000-0001-8043-1377], Muñoz, Edgar [0000-0001-9309-2394], Garriga, Rosa, Jurewicz, Izabela, Seyedin, Shayan, Tripathi, Manoj, Pearson, J. R., Cebolla, Vicente L., Razal, Joselito M., Dalton, Alan B., Muñoz, Edgar, Garriga, Rosa [0000-0003-2607-7834], Jurewicz, Izabela [0000-0003-0237-8384], Seyedin, Shayan [0000-0001-7322-0387], Tripathi, Manoj [0000-0002-8052-428X], Pearson, J. R. [0000-0002-2267-0844], Cebolla, Vicente L. [0000-0002-9786-9217], Razal, Joselito M. [0000-0002-9758-3702], Dalton, Alan B. [0000-0001-8043-1377], Muñoz, Edgar [0000-0001-9309-2394], Garriga, Rosa, Jurewicz, Izabela, Seyedin, Shayan, Tripathi, Manoj, Pearson, J. R., Cebolla, Vicente L., Razal, Joselito M., Dalton, Alan B., and Muñoz, Edgar

Abstract

Amino-terminated oligoglycines non-covalently self-assemble, through cooperative hydrogen bonding formation, into biocompatible rigid 2D nanostructures called tectomers, either in solution or in surfacepromoted processes. Tectomers effectively coat carboxylated multi-walled carbon nanotubes (MWCNT-COOH) and strongly interact with graphene oxide (GO). Electrostatic interactions and hydrogen bonding formation accounts for the strong interfacial interaction of tectomers with MWCNTCOOH and GO, respectively. The resulting composites were characterized by electron- and atomic force microscopies, UV-vis and X-ray photoelectron (XPS) spectroscopies and contact angle measurements. Because of this high affinity of tectomers to GO, tectomers efficiently coat wet-spun GO fibers (Fig. 1). We also show that, due to their versatile surface chemistry, tectomers act as supramolecular peptidic adhesives for the immobilization of a variety of carbon nanomaterials, nanoparticles, molecules and drugs on the GO fiber surface therefore allowing GO fiber functionalization. The resulting ultrathin coatings exhibit remarkable water-resistant properties. This tectomer-based “double-sided sticky tape” fiber functionalization strategy can be extended to other fibers, fabrics and substrates, making it very attractive for technological and smart textile applications

Published
2021

31. Future of 2D materials in biosensing applications

Author

Tripathi, Manoj [0000-0002-8052-428X], Garriga, Rosa [0000-0003-2607-7834], Jurewicz, Izabela [0000-0003-0237-8384], Papagelis, Konstantinos [0000-0001-5094-9837], Muñoz, Edgar [0000-0001-9309-2394], Rahman, M. M. [0000-0003-1374-0561], Dalton, Alan B. [0000-0001-8043-1377], Tripathi, Manoj, Garriga, Rosa, Jurewicz, Izabela, Parthenios, John, Papagelis, Konstantinos, Muñoz, Edgar, Rahman, M. M., Gadhamshetty, V., Ajayan, Pulickel M., Dalton, Alan B., Tripathi, Manoj [0000-0002-8052-428X], Garriga, Rosa [0000-0003-2607-7834], Jurewicz, Izabela [0000-0003-0237-8384], Papagelis, Konstantinos [0000-0001-5094-9837], Muñoz, Edgar [0000-0001-9309-2394], Rahman, M. M. [0000-0003-1374-0561], Dalton, Alan B. [0000-0001-8043-1377], Tripathi, Manoj, Garriga, Rosa, Jurewicz, Izabela, Parthenios, John, Papagelis, Konstantinos, Muñoz, Edgar, Rahman, M. M., Gadhamshetty, V., Ajayan, Pulickel M., and Dalton, Alan B.

Abstract

The atomically thin 2D materials have unique physicochemical properties useful for sensing applications in chemical, biological and corrosion science.1, 2 The high surface-to-volume ratio of these layered materials facilitates efficient response due to the ultrafast carrier mobility of surface atoms. These surface atoms form physiosorbed bonds with adsorbed analyte through electrostatic interactions that can be envisioned in terms of locally induced strain (%) and charge redistribution (n) compared to its pristine state.3 The non-covalent interaction between the analyte and 2D materials shift the Fermi energy level of the host, useful for the selectivity as it offers unique ‘figureprints’ in the optical spectrum. Here, I will present an overview of a systematic study of surface analysis techniques, in particular, using scanning probe microscopy and Raman spectroscopy to uncover physical strain and doping in different 2D materials of graphene and MoS2 for physio-adsorption of analytes. The present study strengthens the possibility of sensing the interaction between several organic and biomolecules toward different 2D materials which is essential in biological and polymeric systems.

Published
2021

32. Resistive gas sensors based on MoS2 nanosheets with high response to low NO2 concentrations

Author

Ministerio de Ciencia e Innovación (España), European Commission, Sayago, I. [0000-0002-5917-9469], Sánchez-Vicente, Carlos [0000-0002-7665-1075], Santos, José Pedro [0000-0002-4181-5148], Ogilvie, Sean P. [0000-0002-0433-8186], Large, Matthew J. [0000-0001-7295-7619], Dalton, Alan B. [0000-0001-8043-1377], Garriga, Rosa [0000-0003-2607-7834], Muñoz, Edgar [0000-0001-9309-2394], Sayago, Isabel, Sánchez-Vicente, Carlos, Sanjurjo, José Luis, Santos, José Pedro, Ogilvie, Sean P., Wood, Hannah J., Graf, Aline A., Large, Matthew J., Dalton, Alan B., Garriga, Rosa, Muñoz, Edgar, Ministerio de Ciencia e Innovación (España), European Commission, Sayago, I. [0000-0002-5917-9469], Sánchez-Vicente, Carlos [0000-0002-7665-1075], Santos, José Pedro [0000-0002-4181-5148], Ogilvie, Sean P. [0000-0002-0433-8186], Large, Matthew J. [0000-0001-7295-7619], Dalton, Alan B. [0000-0001-8043-1377], Garriga, Rosa [0000-0003-2607-7834], Muñoz, Edgar [0000-0001-9309-2394], Sayago, Isabel, Sánchez-Vicente, Carlos, Sanjurjo, José Luis, Santos, José Pedro, Ogilvie, Sean P., Wood, Hannah J., Graf, Aline A., Large, Matthew J., Dalton, Alan B., Garriga, Rosa, and Muñoz, Edgar

Abstract

This work reports on two-dimensional MoS 2 nanomaterial-based resistive gas sensors and their response to sub-ppm NO 2 concentrations. The sensitive material was prepared by drop-casting MoS 2 nanosheet dispersions on silicon nitride suspended membranes. The sensor response was studied at operating temperatures up to 300 °C. The fabricated sensors provided good responses to NO 2 concentrations as low as 20 ppb at room temperature. The n-type MoS 2 sensing mechanism is here discussed.

Published
2021

33. Carbon Nanotube- and Graphene Oxide / 2D Oligoglycine Tectomer Composites and Coatings

Author

Garriga, Rosa, Jurewicz, Izabela, Seyedin, Shayan, Tripathi, Manoj, Pearson, J. R., Cebolla, Vicente L., Razal, Joselito M., Dalton, Alan B., Muñoz, Edgar, Garriga, Rosa [0000-0003-2607-7834], Jurewicz, Izabela [0000-0003-0237-8384], Seyedin, Shayan [0000-0001-7322-0387], Tripathi, Manoj [0000-0002-8052-428X], Pearson, J. R. [0000-0002-2267-0844], Cebolla, Vicente L. [0000-0002-9786-9217], Razal, Joselito M. [0000-0002-9758-3702], Dalton, Alan B. [0000-0001-8043-1377], Muñoz, Edgar [0000-0001-9309-2394], Garriga, Rosa, Jurewicz, Izabela, Seyedin, Shayan, Tripathi, Manoj, Pearson, J. R., Cebolla, Vicente L., Razal, Joselito M., Dalton, Alan B., and Muñoz, Edgar

Subjects
Coatings, Tectomers, Adhesives, Surface functionalization, Carbon nanotubes, Oligoglycine, Smart textile, Carbon nanotube, Graphene oxide, Composites
Abstract

1 figure.-- Talk delivered at the SmallChem 2021 International online conference (17th-18th february 2021)., Amino-terminated oligoglycines non-covalently self-assemble, through cooperative hydrogen bonding formation, into biocompatible rigid 2D nanostructures called tectomers, either in solution or in surfacepromoted processes. Tectomers effectively coat carboxylated multi-walled carbon nanotubes (MWCNT-COOH) and strongly interact with graphene oxide (GO). Electrostatic interactions and hydrogen bonding formation accounts for the strong interfacial interaction of tectomers with MWCNTCOOH and GO, respectively. The resulting composites were characterized by electron- and atomic force microscopies, UV-vis and X-ray photoelectron (XPS) spectroscopies and contact angle measurements. Because of this high affinity of tectomers to GO, tectomers efficiently coat wet-spun GO fibers (Fig. 1). We also show that, due to their versatile surface chemistry, tectomers act as supramolecular peptidic adhesives for the immobilization of a variety of carbon nanomaterials, nanoparticles, molecules and drugs on the GO fiber surface therefore allowing GO fiber functionalization. The resulting ultrathin coatings exhibit remarkable water-resistant properties. This tectomer-based “double-sided sticky tape” fiber functionalization strategy can be extended to other fibers, fabrics and substrates, making it very attractive for technological and smart textile applications

Published
2021

34. Future of 2D materials in biosensing applications

Author

Tripathi, Manoj, Garriga, Rosa, Jurewicz, Izabela, Parthenios, John, Papagelis, Konstantinos, Muñoz, Edgar, Rahman, M. M., Gadhamshetty, V., Ajayan, Pulickel M., Dalton, Alan B., Tripathi, Manoj [0000-0002-8052-428X], Garriga, Rosa [0000-0003-2607-7834], Jurewicz, Izabela [0000-0003-0237-8384], Papagelis, Konstantinos [0000-0001-5094-9837], Muñoz, Edgar [0000-0001-9309-2394], Rahman, M. M. [0000-0003-1374-0561], Dalton, Alan B. [0000-0001-8043-1377], Tripathi, Manoj, Garriga, Rosa, Jurewicz, Izabela, Papagelis, Konstantinos, Muñoz, Edgar, Rahman, M. M., and Dalton, Alan B.

Subjects
Thin film, Graphene, MoS2
Abstract

Work presented at the International Biodeterioration & Biodegradation Symposium (IBBS18), 6-9 September 2021 | Online conference, The atomically thin 2D materials have unique physicochemical properties useful for sensing applications in chemical, biological and corrosion science.1, 2 The high surface-to-volume ratio of these layered materials facilitates efficient response due to the ultrafast carrier mobility of surface atoms. These surface atoms form physiosorbed bonds with adsorbed analyte through electrostatic interactions that can be envisioned in terms of locally induced strain (%) and charge redistribution (n) compared to its pristine state.3 The non-covalent interaction between the analyte and 2D materials shift the Fermi energy level of the host, useful for the selectivity as it offers unique ‘figureprints’ in the optical spectrum. Here, I will present an overview of a systematic study of surface analysis techniques, in particular, using scanning probe microscopy and Raman spectroscopy to uncover physical strain and doping in different 2D materials of graphene and MoS2 for physio-adsorption of analytes. The present study strengthens the possibility of sensing the interaction between several organic and biomolecules toward different 2D materials which is essential in biological and polymeric systems.

Published
2021

36. Supramolecular two-dimensional peptidic adhesives for graphene oxide fiber functionalization

Author

Muñoz, Edgar [0000-0001-9309-2394], Jurewicz, Izabela [0000-0003-0237-8384], Seyedin, Shayan [0000-0001-7322-0387], Tripathi, Manoj [0000-0002-8052-428X], Pearson, J. R. [0000-0002-2267-0844], Cebolla, Vicente L. [0000-0002-9786-9217], Razal, Joselito M. [0000-0002-9758-3702], Dalton, Alan B. [0000-0001-8043-1377], Garriga, Rosa [0000-0003-2607-7834], Muñoz, Edgar, Jurewicz, Izabela, Seyedin, Shayan, Tripathi, Manoj, Pearson, J. R., Cebolla, Vicente L., Razal, Joselito M., Dalton, Alan B., Garriga, Rosa, Muñoz, Edgar [0000-0001-9309-2394], Jurewicz, Izabela [0000-0003-0237-8384], Seyedin, Shayan [0000-0001-7322-0387], Tripathi, Manoj [0000-0002-8052-428X], Pearson, J. R. [0000-0002-2267-0844], Cebolla, Vicente L. [0000-0002-9786-9217], Razal, Joselito M. [0000-0002-9758-3702], Dalton, Alan B. [0000-0001-8043-1377], Garriga, Rosa [0000-0003-2607-7834], Muñoz, Edgar, Jurewicz, Izabela, Seyedin, Shayan, Tripathi, Manoj, Pearson, J. R., Cebolla, Vicente L., Razal, Joselito M., Dalton, Alan B., and Garriga, Rosa

Abstract

Amino-terminated oligoglycines non-covalently self-assemble, through cooperative hydrogen bonding formation, into biocompatible rigid 2D nanostructures called tectomers. Tectomers effectively coat carboxylated multi-walled carbon nanotubes (MWCNT-COOH) and strongly interact with graphene oxide (GO). Electrostatic interactions and hydrogen bonding formation accounts for the strong interfacial interaction of tectomers with MWCNT-COOH and GO, respectively. Because of the high affinity of tectomers to GO, tectomers have been used to coat wet-spun GO fibers. We here show that, due to their versatile surface chemistry, tectomers act as supramolecular adhesives for nanomaterial and molecule immobilization on the GO fiber surface. Tectomer-coated GO fibers can then be subsequently decorated with a variety of carbon nanomaterials (carbon nanotubes, carbon nanohorns, carbon nanocones, and highly fluorescent nanodiamonds), metal (gold, platinum, iron) nanoparticles, acrylate-based polymer nanoparticles, fluorophores and drugs. The resulting ultrathin coatings exhibit remarkable water resistant properties. We show that this tectomer-based “double-sided sticky tape” fiber functionalization strategy can be extended to other fibers and fabrics, such as polyurethane/PEDOT:PSS, poly(methyl methacrylate) and polyester, making it very attractive for a variety of technological and smart textile applications.

Published
2020

37. Supramolecular two-dimensional peptidic adhesives for graphene oxide fiber functionalization

Author

Muñoz, Edgar, Jurewicz, Izabela, Seyedin, Shayan, Tripathi, Manoj, Pearson, J. R., Cebolla, Vicente L., Razal, Joselito M., Dalton, Alan B., Garriga, Rosa, Muñoz, Edgar, Jurewicz, Izabela, Seyedin, Shayan, Tripathi, Manoj, Pearson, J. R., Cebolla, Vicente L., Razal, Joselito M., Dalton, Alan B., Garriga, Rosa, Muñoz, Edgar [0000-0001-9309-2394], Jurewicz, Izabela [0000-0003-0237-8384], Seyedin, Shayan [0000-0001-7322-0387], Tripathi, Manoj [0000-0002-8052-428X], Pearson, J. R. [0000-0002-2267-0844], Cebolla, Vicente L. [0000-0002-9786-9217], Razal, Joselito M. [0000-0002-9758-3702], Dalton, Alan B. [0000-0001-8043-1377], and Garriga, Rosa [0000-0003-2607-7834]

Subjects
Tectomers, Adhesives, Smart textile, Graphene oxide
Abstract

Work presented at the nano Portugal 2020 Online Conference (nanoPT2020), Nanoscience and Nanotechnology International Conference, 23th - 24th september 2020., Amino-terminated oligoglycines non-covalently self-assemble, through cooperative hydrogen bonding formation, into biocompatible rigid 2D nanostructures called tectomers. Tectomers effectively coat carboxylated multi-walled carbon nanotubes (MWCNT-COOH) and strongly interact with graphene oxide (GO). Electrostatic interactions and hydrogen bonding formation accounts for the strong interfacial interaction of tectomers with MWCNT-COOH and GO, respectively. Because of the high affinity of tectomers to GO, tectomers have been used to coat wet-spun GO fibers. We here show that, due to their versatile surface chemistry, tectomers act as supramolecular adhesives for nanomaterial and molecule immobilization on the GO fiber surface. Tectomer-coated GO fibers can then be subsequently decorated with a variety of carbon nanomaterials (carbon nanotubes, carbon nanohorns, carbon nanocones, and highly fluorescent nanodiamonds), metal (gold, platinum, iron) nanoparticles, acrylate-based polymer nanoparticles, fluorophores and drugs. The resulting ultrathin coatings exhibit remarkable water resistant properties. We show that this tectomer-based “double-sided sticky tape” fiber functionalization strategy can be extended to other fibers and fabrics, such as polyurethane/PEDOT:PSS, poly(methyl methacrylate) and polyester, making it very attractive for a variety of technological and smart textile applications.

Published
2020

39. Nanosheet-Stabilized Emulsions: Near-Minimum Loading and Surface Energy Design of Conductive Networks

Author

Ogilvie, Sean P., primary, Large, Matthew J., additional, O’Mara, Marcus A., additional, Sehnal, Anne C., additional, Amorim Graf, Aline, additional, Lynch, Peter J., additional, Cass, Adam J., additional, Salvage, Jonathan P., additional, Alfonso, Marco, additional, Poulin, Philippe, additional, King, Alice A. K., additional, and Dalton, Alan B., additional

Published
2022
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40. Tuneable synthetic reduced graphene oxide scaffolds elicit high levels of three-dimensional glioblastoma interconnectivity in vitro

Author

Brown, Christopher J., primary, Simon, Thomas, additional, Cilibrasi, Chiara, additional, Lynch, Peter J., additional, Harries, Rhiannon W., additional, Graf, Aline Amorim, additional, Large, Matthew J., additional, Ogilvie, Sean P., additional, Salvage, Jonathan P., additional, Dalton, Alan B., additional, Giamas, Georgios, additional, and King, Alice A. K., additional

Published
2022
Full Text
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42. Controlled assembly and reduction of graphene oxide networks for conductive composites

Author

Meloni, Manuela [0000-0001-7009-3140], Víctor-Román, Sandra [0000-0003-0924-5840], King, Alice A. K. [0000-0002-1637-757X], Fratta, Giuseppe [0000-0001-7903-1659], Istif, Emin [0000-0003-4700-7050], Large, Matthew J. [0000-0001-7295-7619], Peláez-Fernández, Mario [0000-0001-5079-621X], Ogilvie, Sean P. [0000-0002-0433-8186], Arenal, Raúl [0000-0002-2071-9093], Benito, Ana M. [0000-0002-8654-7386], Maser, Wolfgang K. [0000-0003-4253-0758], Dalton, Alan B. [0000-0001-8043-1377], Meloni, Manuela, Víctor-Román, Sandra, King, Alice A. K., Fratta, Giuseppe, Istif, Emin, Large, Matthew J., Peláez-Fernández, Mario, Ogilvie, Sean P., Arenal, Raúl, Benito, Ana M., Maser, Wolfgang K., Dalton, Alan B., Meloni, Manuela [0000-0001-7009-3140], Víctor-Román, Sandra [0000-0003-0924-5840], King, Alice A. K. [0000-0002-1637-757X], Fratta, Giuseppe [0000-0001-7903-1659], Istif, Emin [0000-0003-4700-7050], Large, Matthew J. [0000-0001-7295-7619], Peláez-Fernández, Mario [0000-0001-5079-621X], Ogilvie, Sean P. [0000-0002-0433-8186], Arenal, Raúl [0000-0002-2071-9093], Benito, Ana M. [0000-0002-8654-7386], Maser, Wolfgang K. [0000-0003-4253-0758], Dalton, Alan B. [0000-0001-8043-1377], Meloni, Manuela, Víctor-Román, Sandra, King, Alice A. K., Fratta, Giuseppe, Istif, Emin, Large, Matthew J., Peláez-Fernández, Mario, Ogilvie, Sean P., Arenal, Raúl, Benito, Ana M., Maser, Wolfgang K., and Dalton, Alan B.

Abstract

Graphene has attracted enormous interest in the scientific community as the first 2D material with exceptional mechanical, electronic and thermal properties. Pristine Graphene is notoriously difficult to process for macroscale applications, to overcome this many people use graphene oxide (GO) instead. GO is water soluble and easily functionalised and so can be simply processed into various systems. GO lacks the exceptional electronic properties of graphene due to structural disorder, therefore an important area of research is on the reduction of GO, which partly restores the structure and properties of graphene. Various techniques have been developed to perform the reduction step. We report a simple approach for preparing conductive Polymer Latex-rGO composites by using a latex-assembly method. After a treatment in the oven at low T, we can reduce the GO in situ. We make use of the inherent GO properties to optimise the aqueous composite fabrication, which is scalable and adaptable, and then restore conductivity with a simple, low temperature, heating step; opening up pathways to tunable electronic composite materials on a large scale.

Published
2019

43. Sonochemical edge functionalisation of molybdenum disulfide

Author

European Commission, Ministerio de Economía y Competitividad (España), Gobierno de Aragón, Science Foundation Ireland, European Research Council, Universidad de Zaragoza, Amorim Graf, Aline [0000-0003-3071-2255], Large, Matthew J. [0000-0001-7295-7619], Ray, Santanu [0000-0002-2414-2930], Arenal, Raul [0000-0002-2071-9093], Dalton, Alan B. [0000-0001-8043-1377], Amorim Graf, Aline, Large, Matthew J., Ogilvie, Sean P., Rong, Yuanyang, Lynch, Peter J., Fratta, Giuseppe, Ray, Santanu, Shmeliov, Aleksey, Nicolosi, Valeria, Arenal, Raúl, King, Alice A. K., Dalton, Alan B., European Commission, Ministerio de Economía y Competitividad (España), Gobierno de Aragón, Science Foundation Ireland, European Research Council, Universidad de Zaragoza, Amorim Graf, Aline [0000-0003-3071-2255], Large, Matthew J. [0000-0001-7295-7619], Ray, Santanu [0000-0002-2414-2930], Arenal, Raul [0000-0002-2071-9093], Dalton, Alan B. [0000-0001-8043-1377], Amorim Graf, Aline, Large, Matthew J., Ogilvie, Sean P., Rong, Yuanyang, Lynch, Peter J., Fratta, Giuseppe, Ray, Santanu, Shmeliov, Aleksey, Nicolosi, Valeria, Arenal, Raúl, King, Alice A. K., and Dalton, Alan B.

Abstract

Liquid-phase exfoliation (LPE) has been shown to be capable of producing large quantities of high-quality dispersions suitable for processing into subsequent applications. LPE typically requires surfactants for aqueous dispersions or organic solvents with high boiling point. However, they have major drawbacks such as toxicity, aggregation during solvent evaporation or the presence of residues. Here, dispersions of molybdenum disulfide in acetone are prepared and show much higher concentration and stability than predicted by Hansen parameter analysis. Aiming to understand these enhanced properties, the nanosheets were characterised using UV-visible spectroscopy, zeta potential measurements, atomic force microscopy, Raman spectroscopy, transmission electron microscopy, X-ray photoelectron spectroscopy and scanning transmission microscopy combined with spatially-resolved electron energy loss spectroscopy. Also, the performance of the MoS2 nanosheets exfoliated in acetone was compared to that of those exfoliated in isopropanol as a catalyst for the hydrogen evolution reaction. The conclusion from the chemical characterisation was that MoS2 nanosheets exfoliated in acetone have an oxygen edge functionalisation, in the form of molybdenum oxides, changing its interaction with solvents and explaining the observed high-quality and stability of the resulting dispersion in a low boiling point solvent. Exfoliation in acetone could potentially be applied as a pretreatment to modify the solubility of MoS2 by edge functionalisation.

Published
2019

44. Two-dimensional oligoglycine tectomer adhesives for graphene oxide fiber functionalization

Author

Fundación Domingo Martínez, Gobierno de Aragón, University of Sussex, Australian Research Council, Garriga, Rosa [0000-0003-2607-7834], Jurewicz, Izabela [0000-0003-0237-8384], Seyedin, Shayan [0000-0001-7322-0387], Tripathi, Manoj [0000-0002-8052-428X], Cebolla, Vicente L. [ 0000-0002-9786-9217 ], Dalton, Alan B. [0000-0001-8043-1377], Razal, Joselito M. [0000-0002-9758-3702], Muñoz, Edgar [0000-0001-9309-2394], Garriga, Rosa, Jurewicz, Izabela, Seyedin, Shayan, Tripathi, Manoj, Pearson, J. R., Cebolla, Vicente L., Dalton, Alan B., Razal, Joselito M., Muñoz, Edgar, Fundación Domingo Martínez, Gobierno de Aragón, University of Sussex, Australian Research Council, Garriga, Rosa [0000-0003-2607-7834], Jurewicz, Izabela [0000-0003-0237-8384], Seyedin, Shayan [0000-0001-7322-0387], Tripathi, Manoj [0000-0002-8052-428X], Cebolla, Vicente L. [ 0000-0002-9786-9217 ], Dalton, Alan B. [0000-0001-8043-1377], Razal, Joselito M. [0000-0002-9758-3702], Muñoz, Edgar [0000-0001-9309-2394], Garriga, Rosa, Jurewicz, Izabela, Seyedin, Shayan, Tripathi, Manoj, Pearson, J. R., Cebolla, Vicente L., Dalton, Alan B., Razal, Joselito M., and Muñoz, Edgar

Abstract

Amino-terminated oligoglycine two-dimensional (2D) peptide self-assemblies (known as tectomers) have a versatile surface chemistry that allows them to interact with a variety of nanomaterials and to actas supramolecular adhesives for surface functionalization. Here, we have exploited the strong hydrogen-bond based interaction between tectomers and graphene oxide (GO) to functionalize GO fiber surfaces with different carbon nanomaterials (carbon nanotubes, carbon nanohorns, carbon nanocones, and highly fluorescent nanodiamonds), metal (gold, platinum, iron) nanoparticles, acrylate-based polymernanoparticles, fluorophores and drugs. The resulting ultrathin coatings exhibit remarkable water resis-tant properties. This tectomer-mediated fiber decoration strategy allows coating functionalities to be tailored by choosing the appropriate nanomaterials or other molecules. We show that this strategy can be extended to other fibers and fabrics, such as polyurethane/PEDOT:PSS, poly(methyl methacrylate) and polyester, making it very attractive for a variety of technological and smart textile applications.

Published
2019

45. Graphene Confers Ultralow Friction on Nanogear Cogs

Author

Mescola, Andrea, primary, Paolicelli, Guido, additional, Ogilvie, Sean P., additional, Guarino, Roberto, additional, McHugh, James G., additional, Rota, Alberto, additional, Iacob, Erica, additional, Gnecco, Enrico, additional, Valeri, Sergio, additional, Pugno, Nicola M., additional, Gadhamshetty, Venkataramana, additional, Rahman, Muhammad M., additional, Ajayan, Pulickel, additional, Dalton, Alan B., additional, and Tripathi, Manoj, additional

Published
2021
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46. Cell–substrate interactions lead to internalization and localization of layered MoS₂ nanosheets

Author

Harries, Rhiannon W, Brown, Christopher J, Woodbine, Lisa, Amorim Graf, Aline, Large, Matthew J, Clifford, Keiran, Lynch, Peter J, Ogilvie, Sean P, Dalton, Alan B, and King, Alice A K

Abstract

Using an ultrathin film substrate, the first internalization of MoS2 nanosheets through mechanotransduction is demonstrated. The usual method of dispersing nanomaterials in the media limits interactions to random, serendipitous surface contact, and the nanoparticles must be dispersible in media. A substrate approach means that cells directly engage with the nanomaterial, sensing and adhering through sustained interaction and actively internalizing the nanomaterial. This activates previously unobserved cell–substrate mechanotransduction mechanisms and receptor-mediated uptake pathways. Moreover, a wide variety of nonsoluble nanomaterials can be used, improving control over the amount of material exposed to a cell through tunable deposition density. Volumetric Raman mapping demonstrates localization of material to the endoplasmic reticulum, a historically hard-to-target region. The nanosheets do not cause cytotoxicity, are transferred to daughter cells, and have applicability across multiple cell lines. The innate fluorescence or Raman signal of the nanosheet can be utilized for live cell imaging, and targeted accumulation within specific cellular organelles offers potential for photothermal treatments or drug delivery vectors. This substrate-mediated approach provides a step change to studying nanomaterial–cellular interactions, taking advantage of the broad palette of available two-dimensional (2D) materials and making use of mechanosensing to stimulate tunable responses, with potential for therapies and diagnostics.

Published
2021

47. Functionalization of silver nanowire transparent electrodes with two-dimensional oligoglycine tectomers

Author

Muñoz, Edgar, Jurewicz, Izabela, Seral-Ascaso, Andrés, Cebolla, Vicente L., Lahoz, Ruth, Dalton, Alan B., and Garriga, Rosa

Subjects
Silver nanowires, Transparent electrodes, MathematicsofComputing_GENERAL, ComputingMilieux_MISCELLANEOUS
Abstract

of the talk delivered at the SmallChem2021, International Online Conference, 17th-18th february, 2021., Silver nanowire (AgNWs) networks combine high optical transmission with low sheet resistance that, together with their decreasing cost and large-scale manufacturing methods, make them perfect candidates as replacement materials of Indium Tin Oxide (ITO) for transparent electrode applications, as well as for platforms with potential applications in bio-sensors and bio-engineering. On the other hand, amine-terminated oligoglycines self-assemble into unique two-dimensional nanostructures called tectomers. The exceptional structural features and surface chemistry of tectomers have already been successfully used to coat negatively-charged surfaces, and biological membranes, and have promising potential in the field of antiviral application. Previously we reported that tectomers efficiently act as pH-responsive nanocarriers, and showed, for the first time, that tectomers strongly interact with graphene oxide and carboxylated carbon nanotubes, and with a variety of other carbon nanomaterials and functionalized nanoparticles, offering promise for a range of technological applications and in electronic- and smart textiles. We here report on the fabrication of AgNW/tectomer peptidic nanohybrids by coating transparent AgNW electrodes with thin tectomer films.

Published
2021

48. Functionalization of silver nanowire transparent electrodes with self-assembled 2-Dimensional tectomer nanosheets

Author

Engineering and Physical Sciences Research Council (UK), Ministerio de Economía y Competitividad (España), European Commission, Jurewicz, Izabela [0000-0003-0237-8384], Garriga, Rosa [0000-0003-2607-7834], Large, Matthew J. [0000-0001-7295-7619], Bardi, Niki [0000-0002-2679-5150], King, Alice A. K. [0000-0002-1637-757X], Velliou, Eirini G. [0000-0003-3313-4446], Watts, John F. [0000-0003-2109-0335], Muñoz, Edgar [0000-0001-9309-2394], Dalton, Alan B. [0000-0001-8043-1377], Jurewicz, Izabela, Garriga, Rosa, Large, Matthew J., Burn, Jake, Bardi, Niki, King, Alice A. K., Velliou, Eirini G., Watts, John F., Hinder, Steven J., Muñoz, Edgar, Dalton, Alan B., Engineering and Physical Sciences Research Council (UK), Ministerio de Economía y Competitividad (España), European Commission, Jurewicz, Izabela [0000-0003-0237-8384], Garriga, Rosa [0000-0003-2607-7834], Large, Matthew J. [0000-0001-7295-7619], Bardi, Niki [0000-0002-2679-5150], King, Alice A. K. [0000-0002-1637-757X], Velliou, Eirini G. [0000-0003-3313-4446], Watts, John F. [0000-0003-2109-0335], Muñoz, Edgar [0000-0001-9309-2394], Dalton, Alan B. [0000-0001-8043-1377], Jurewicz, Izabela, Garriga, Rosa, Large, Matthew J., Burn, Jake, Bardi, Niki, King, Alice A. K., Velliou, Eirini G., Watts, John F., Hinder, Steven J., Muñoz, Edgar, and Dalton, Alan B.

Abstract

Here, we describe the unusual self-assembly of amine-terminated oligoglycine peptides into extended two-dimensional sheets in the presence of silver nanowires. The resulting tectomer sheets are shown to have a strong affinity for the nanowires through a charge-transfer interaction as evidenced by X-ray photoelectron spectroscopy. We show that extended assemblies of metal–peptide hybrids offer additional augmentative functionalities; for instance, the tectomer sheets are hydrophobic in nature and act as a protective layer preventing oxidation and degradation of the nanowires when exposed to atmospheric conditions. Moreover, for silver nanowire percolating networks the presence of the peptide markedly increases the overall electrical conductivity through mechanical squeezing of wire–wire junctions in the network. The peptide–metal interface can be controlled by pH stimulus thus potentially offering new directions where silver nanowire assemblies are used for transparent electrodes ranging from antimicrobial coatings to biosensors.

Published
2018

49. Ultrasensitive strain gauges enabled by graphene-stabilized silicone emulsions

Author

O'Mara, Marcus A, Ogilvie, Sean P, Large, Matthew J, Salvage, Jonathan P, Graf, Aline Amorim, Sehnal, Anne C, Lynch, Peter J, Jurewicz, Izabela, King, Alice A K, and Dalton, Alan B

Subjects
Coalescence (physics), Materials science, Graphene, 02 engineering and technology, 010402 general chemistry, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Silicone rubber, Elastomer, Microstructure, 01 natural sciences, 0104 chemical sciences, Electronic, Optical and Magnetic Materials, law.invention, Biomaterials, chemistry.chemical_compound, Silicone, chemistry, Gauge factor, law, Electrochemistry, Composite material, 0210 nano-technology, Strain gauge
Abstract

Here, we present an approach to incorporate graphene nanosheets into a silicone rubber matrix via solid stabilization of oil-in-water emulsions. These emulsions can be cured into discrete, graphenecoated silicone balls or continuous, elastomeric films by controlling the degree of coalescence. We characterize the electromechanical properties of the resulting composites as a function of interdiffusion time and graphene loading level. With conductivities approaching 1 S m-1, elongation to break up to 160% and a gauge factor of ~20 in the low-strain linear regime, we can accurately measure small strains such as pulse. At higher strains, the electromechanical response exhibits a robust exponential dependence, allowing accurate readout for higher strain movements such as chest motion and joint bending. The exponential gauge factor is found to be ~20, independent of loading level and valid up to 80% strain; this consistent performance is due to the emulsiontemplated microstructure of the composites. The robust behavior may facilitate high-strain sensing in the non-linear regime using nanocomposites, where relative resistance change values in excess of 107 enable highly accurate bodily motion monitoring.

Published
2020

50. Ultra-Sensitive Strain Gauges Enabled by Graphene-Stabilized Silicone Emulsions

Author

O'Mara, Marcus A., Ogilvie, Sean P., Large, Matthew J., Salvage, Jonathan P., Graf, Aline Amorim, Sehnal, Anne C., Lynch, Peter J., Jurewicz, Izabela, King, Alice A.K, and Dalton, Alan B.

Abstract

Here, we present an approach to incorporate graphene nanosheets into a silicone rubber matrix via solid stabilization of oil-in-water emulsions. These emulsions can be cured into discrete, graphenecoated silicone balls or continuous, elastomeric films by controlling the degree of coalescence. We characterize the electromechanical properties of the resulting composites as a function of interdiffusion time and graphene loading level. With conductivities approaching 1 S m-1, elongation to break up to 160% and a gauge factor of ~20 in the low-strain linear regime, we can accurately measure small strains such as pulse. At higher strains, the electromechanical response exhibits a robust exponential dependence, allowing accurate readout for higher strain movements such as chest motion and joint bending. The exponential gauge factor is found to be ~20, independent of loading level and valid up to 80% strain; this consistent performance is due to the emulsiontemplated microstructure of the composites. The robust behavior may facilitate high-strain sensing in the non-linear regime using nanocomposites, where relative resistance change values in excess of 107 enable highly accurate bodily motion monitoring.

Published
2020

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