Kitabı oku: «First virtual Bilateral Conference on Functional Materials (BiC-FM)», sayfa 2

The electric resistivity and piezoresistive response of functional carbon nanocomposites

Hassaan A. Butt, Stepan V. Lomov, Iskander S. Akhatov, Sergey G. Abaimov

Centre for Design, Manufacturing and Materials

Skolkovo Institute of Science and Technology, Moscow, Russia

hassaan.butt@skoltech.ru

Functional nanocomposites are allowing fundamental changes to the way system and material monitoring and testing takes place, both during manufacturing as well as during composite usage lifecycle [1, 2]. One such application of these materials is the replacing of traditional sensors for deformation sensing, allowing the reduction in cost and weight of systems and potential usage has already been highlighted in fields such as the automotive, aerospace, renewable energy and sensor manufacturing sectors [3, 4].

In recent years, nano-carbon particles, in particular, carbon nanotubes and graphene/derivatives, have been under intense scientific scrutiny as additives for composite manufacturing, not only increasing the mechanical properties of composites but allowing the final composites to be electrically conductive and piezoresistive in nature [5, 6].

In this work, industrial masterbatches have been used to manufacture functional nanocomposites and evaluate their feasibility for large scale production of strain sensing thermoplastic nanocomposites. Masterbatches are high weight/volume fraction compounds premixed with nanoadditives in a selected matrix and provide a safe medium for implementing nanomaterials on an industrial scale. From a safety, production line modification and financial standpoint, masterbatches are the most feasible implementation medium for large scale production. However, very few publications deal masterbatch-based nanocomposites and of those available, even fewer deal with piezoresistivity or self-diagnostics.

Six types of carbon nanoparticle masterbatches were employed during this study, each type containing either single-wall carbon nanotubes (SWCNT), multi-wall carbon nanotubes (02 types, MWCNT), graphene (G), reduced graphene oxide (RGO) or nitrogen doped graphene (NDG). These particles were added to an epoxy matrix at three weight percentages of interest, 0.5 %, 1.0 % and 2 %. The electrical and piezoresistive properties of the formulated nanocomposites were studied, with higher weight fractions yielding higher electrical conductivities whereas the same yielded lower piezoresistive response. Carbon nanotube (CNT) based nanocomposites outperformed graphene/derivative nanocomposites in terms of electrical conductance, showing resistivities between 2 – 10⁶ Ohm∙cm as compared to G/RGO/NDG samples, with values between 10¹¹-10¹² Ohm∙cm. CNT based nanocomposites showed strain based gauge factors between ~2–7, while graphene/derivative nanocomposites showed extremely high resistivities infeasible for piezoresistive monitoring at the studied weight percentages. A clear relationship between the attained electrical conductance of CNT nanocomposites and their strain sensing ability (gauge factor) has also been established, with the dependency following a semi-logarithmic system; GF=A*log(R0)+B.

References

1. Lee, J. and B.L. Wardle. Nanoengineered In Situ Cure Status Monitoring Technique Based on Carbon Nanotube Network. in AIAA Scitech 2019 Forum. 2019. San Diego, California.

2. Cao X., et al., Strain sensing behaviors of epoxy nanocomposites with carbon nanotubes under cyclic deformation. Polymer, 2017. 112: p. 1–9.

3. Kumar A., K. Sharma, and A.R. Dixit, Carbon nanotube- and graphene-reinforced multiphase polymeric composites: review on their properties and applications. Journal of Materials Science, 2019. 55(7): p. 2682–2724.

4. Camilli L. and Passacantando M., Advances on sensors based on carbon nanotubes. Chemosensors, 2018. 6(4): p. 62–80.

5. Atif R., I. Shyha, and F. Inam, Mechanical, thermal, and electrical properties of graphene-epoxy nanocomposites-A Review. Polymers, 2016. 8(8): p. 281–317.

6. Caradonna A., et al., Electrical and thermal conductivity of epoxy-carbon filler composites processed by calendaring. Materials (Basel), 2019. 12(9): p. 1–17.

Anisotropic electrical conductivity in graphene films with vertically aligned single-walled carbon nanotubes: new advances in mechanisms and applications

Glukhova O.E.^1,2, Slepchenkov M.M. ¹

1 – Saratov State University, Saratov, Russia

2 – I.M. Sechenov First Moscow State Medical University, Moscow, Russia

glukhovaoe@info.sgu.ru

In this paper, we suggest an idea of a new approach to control the electrical conductivity and its anisotropy in graphene-nanotube films with vertically oriented single-walled carbon nanotubes (SWCNTs) seamlessly connected to graphene. The basis of this approach is the phenomenon of aromaticity occurred in the hexagons of armchair-type SWCNTs at a certain nanotube length, which induces the oscillations of electronic characteristics with increasing the SWCNT length [1]. The proposed idea was tested on the example of two graphene nanomesh (GNM) atomistic models with nanoholes for SWCNTs with the chirality (6,6) and (9,9) in the case of sequentially increasing the SWCNT length. These types of SWCNTs were revealed using original approach called “virtual growing”, which shown that among the armchair SWCNTs with a diameter of 0.6–1.2 nm, the energetically favorable SWCNT- graphene junction will be formed with the SWCNTs (6,6) and (9,9). The calculations of geometric parameters of graphene-nanotube atomistic models were obtained using the self-consistent charge density functional tight-binding (SCC-DFTB) method [2]. The calculations of the electron transmission function T(E) and electrical conductivity G were carried out at 300 K using the Landauer-Buttiker formalism [3]. It was found that the nanoholes in monolayer graphene form conducting pathways in one direction, inducing anisotropy of the conducting properties. The anisotropy of the G value reaches 5 times. The formation of SWCNTs in the nanoholes does not remove anisotropy, amplifying it up to 7 times. The value of electrical conductivity G is strongly influenced by the length of the formed nanotube. It was found that a sharp increase in the value of G occurs at a certain length of 0.615 nm, 0.984 nm, 1.353 nm, and so on with in steps of 0.369 nm. These values of the SWCNT length were determined by the number of atomic layers in the SWCNT framework that is a multiple of three. Especially noticeable jumps in electrical conductivity occur for the armchair direction of electron transport. Thus, by adjusting the SWCNT length, it is possible to enhance or weaken the anisotropy of the conductive properties of graphene-nanotube films.

Acknowledgement. This work was supported by the Ministry of Science and Higher Education of the Russian Federation, grant FSRR-2020-0004.

References:

[1] F. Buonocore, F. Trani, D. Ninno, A. Di Matteo, G. Cantele, G. Iadonisi, Nanotechnology, 19, 025711 (2008).

[2] M. Elstner, D. Porezag, G. Jungnickel, J. Elsner, M. Haugk, Th. Frauenheim, S. Suhai, G. Seifert, Phys. Rev. B 58, 7260 (1998).

[3] S. Datta, Quantum Transport: Atom to Transistor. 2nd ed. Cambridge: Cambridge University Press; 2005

O.E. Glukhova received Ph.D. in Vacuum and Plasma Electronics (1997) and Dr. Sc. in Solid State Electronics and Nanoelectronics (2009) from the Saratov State University, Russia. She is a head of Department of Radiotechnique and electrodynamics at Saratov State University and leads the Division of Mathematical modeling in Educational and scientific institution of nanostructures and biosystems at Saratov State University. Her main fields of investigation are: nanoelectronics, molecular modeling of biomaterials and nanostructures, molecular electronics, mechanics of nanostructures, quantum chemistry and molecular dynamics, carbon nanostructures (fullerenes, nanotubes, graphene, graphane). She has published more 200 peer-reviewed journal papers and five monographs.

Oxygen evolution reaction on pristine and defective nitrogen-doped carbon nanotubes and graphene

Murdachaew G.¹, and Laasonen K.¹

1) Aalto University, Department of Chemistry and Materials Science, Finland

kari.laasonen@aalto.fi

Hydrogen obtained by electrochemical water splitting on a suitable catalyst has raised a lot of interest. The ideal catalyst should be efficient, stable under operating conditions, and composed of earth-abundant elements. Density functional theory simulations within a simple thermodynamic model of the more difficult half-reaction, the anodic oxygen evolution reaction (OER), with a single-walled carbon nanotube as a catalyst, showed that the presence of < 1 % nitrogen reduces the required OER overpotential significantly. We performed an extensive exploration of systems and active sites with various nitrogen functionalities [1] (graphitic, pyridinic, or pyrrolic) obtained by introducing nitrogen and simple lattice defects (atomic substitutions, vacancies, or Stone-Wales rotations). The lowest predicted overpotentials were about 0.4 V, close to what has been measured experimentally for the best-performing nitrogen-doped nanocarbon catalysts. The lowest predicted overpotential of 0.39 V was obtained for a model system with a Stone-Wales defect in combination with pyrrolic nitrogen doping. The most OER-active sites/systems were carbon atoms in the vicinity of Stone-Wales pyrrolic nitrogen, followed by graphitic nitrogen. For the majority of the nanotube-based systems, the third step of the four-step OER mechanism, the formation of attached OOH, is the potential-determining step of the reaction. The nanotube radius and chirality effects were examined by considering OER in the limit of large radius by studying graphene as a model system. They exhibited trends similar to those of the nanotube-based systems but often with reduced reactivity due to weaker attachment of the OER intermediate molecules.

References:

[1] G. Murdachaew and K. Laasonen J. Phys. Chem. C, 2018, 122, 25882, https://doi.org/10.1021/acs.jpcc.8b08519

Kari Laasonen is a professor of physical chemistry in Aalto University (from 2010). He did his M.Sc. in University of Helsinki 1988, PhD. in 1991 in TKK (physics). Before Aalto he worked in EPFL (Lausanne), IBM Research Laboratory (Zurich), University of Pennsylvania (Philadelphia) and University of Oulu. He has specialized to computational chemistry and especially on modelling surfaces and electrochemical reactions. He has also long expertise of modelling reaction in solutions. He has published more 150 papers and these papers have been cited more than 10.000 times.

Starfish-like phosphorus carbide nanotubes

Kistanov A. A.¹, Shcherbinin S. A.², Huttula M.¹, Cao W.¹

1 – Nano and Molecular Systems Research Unit, University of Oulu, Oulu, Finland

2 – Southern Federal University, Rostov-on-Don, Russia

stefanshcherbinin@gmail.com

Recently several allotropes of a novel two-dimensional material, phosphorus carbide (PC), have been predicted theoretically and some of them have already been successfully fabricated [1]. For one of these PC allotropes, α-PC, the possibility of its rolling to a PC nanotube (PCNT) at room temperature under compressive strain has been found [2]. These PCNTs of different sizes exhibit high thermal stability and possess well tunable band gap. In this work, PCNT obtained by the rippling of β₀-PC and β₁-PC monolayers along their armchair (APCNT) and zigzag (ZPCNT) directions are investigated in the framework of density functional theory.

It has been found that most of created β-PCNTs possess starfish-like structure (see Figure 1a). The dynamical stability of these β-PCNTs has been verified using ab initio molecular dynamics calculations conducted at 300 K. It is also found that β-PCNTs of the smallest/biggest size consist of 12/44 atoms. According to electronic band structure calculations, β-PCNTs can be semiconductors, semimetals or metals depending on their size and form (see Figure 1b). Therefore, due to their extraordinary form and highly tunable band structure, β-PCNTs may find the application in straintronic, optical and photovoltaic devices.

Figure 1. (a) Atomic structure and (b) band gap size as a function of size of β₀– and β₁-APCNT and β₀– and β₁-ZPCNT.

Acknowledgement.A.A.K. M.H. and W.C. acknowledges the financial support by the Academy of Finland (grant No. 311934). S.A.Sh. acknowledges the financial support by the Ministry of Education and Science of the Russian Federation (state task in the field of scientific activity, Southern Federal University), theme N BAS0110/20-3-08IF.

References:

[1] X. Huang, Y. Cai, X. Feng, W. C. Tan, D. Md. N. Hasan, L. Chen, N. Chen, L. Wang, L. Huang, T. J. Duffin, C. A. Nijhuis, Y. W. Zhang, C. Lee and K. W. Ang, ACS Photonics, 5(8), 3116–3123 (2018)

[2] S. A. Shcherbinin, K. Zhou, S. V. Dmitriev, E. A. Korznikova, A. R. Davletshin and A. A. Kistanov, J. Phys. Chem. C, 124(18), 10235-10243 (2020)

Computational search for new high-T_C superconductors with subsequent synthesis

A.G. Kvashnin¹, I.A. Kruglov^2,3, D.V. Semenok¹, A.R. Oganov¹,

1 – Skolkovo Institute of Science and Technology, Moscow, Russia

2 – Moscow Institute of Physics and Technology, Dolgoprudny, Russia

3 – Dukhov Research Institute of Automatics (VNIIA), Moscow, Russia

A.Kvashnin@skoltech.ru

Hydrogen-rich hydrides attract great attention due to recent theoretical [1] and then experimental discovery of record high-temperature superconductivity in H₃S (T_C = 203 K at 155 GPa [2]).

Here we perform a systematic evolutionary search for new phases in the Fe-H [3], Th-H [4], U-H [5] and other numerous systems under pressure [6] in order to predict new materials which are unique high-temperature superconductors.

We predict new hydride phases at various pressures using the variable-composition search as implemented in evolutionary algorithm USPEX [7–9]. Among the Fe-H system two potentially high-T_C FeH₅ and FeH₆ phases in the pressure range from 150 to 300 GPa were predicted and were found to be superconducting within Bardeen-Cooper-Schrieffer theory, with T_C values of up to 46 K. Several new thorium hydrides were predicted to be stable under pressure using evolutionary algorithm USPEX, including ThH₃, Th₃H₁₀, ThH₄, ThH₆, ThH₇ and ThH₁₀. Fcc-ThH₁₀ was found to be the highest-temperature superconductor with T_C in the range 221–305 K at 100 GPa. Actinide hydrides show, i.e. AcH₁₆ was predicted to be stable at 110 GPa with T_C of 241 K.

To continue this theoretical study, we performed an experimental synthesis of Th-H phases at high-pressures including ThH₁₀. Obteined results can be found in Ref. [10].

Acknowledgement.This work was supported by RFBR foundation № 19-03-00100 and facie foundation, grant UMNIK № 13408GU/2018.

References:

[1] D. Duan et al., Sci. Rep. 4, 6968 (2018)

[2] A.P. Drozdov et al. Nature. 525, 73–76 (2015)

[3] A.G. Kvashnin at al. J. Phys. Chem. C, 122 4731–4736 (2018)

[4] A.G. Kvashnin et al. ACS Applied Materials & Interfaces 10, 43809-43816 (2018)

[5] I.A. Kruglov et al. Sci. Adv. 4, eaat9776. (2018)

[6] D.V. Semenok et al. J. Phys. Chem. Lett. 8, 1920–1926 (2018)

[7] A.O. Lyakhov et al. Comp. Phys. Comm. 184, 1172–1182 (2013)

[8] A.R. Oganov et al. J. Chem. Phys. 124, 244704 (2006)

[9] A.R. Oganov et al. Acc. Chem. Res. 44 227–237 (2011)

[10] D.V. Semenok et al. Mat. Today., 33, 36–44 (2020)

Enhanced Electrocatalytic Activities by Substitutional Tuning of Nickel-based Ruddlesden-Popper Catalysts for the Oxidation of Urea and Small Alcohols

Stevenson, K. J.¹

1 – Skolkovo Institute of Science and Technology, Moscow, Russia

k.stevenson@skoltech.ru

The electrooxidation of urea continues to attract considerable interest as an alternative to the oxygen evolution reaction (OER) as the anodic reaction in the electrochemical generation of hydrogen due to the lower potential required to drive the reaction and the abundance of urea available in waste streams. In this talk the effect of Sr substitution in a series of La_2-xSrxNiO_4+δRuddlesden-Popper catalysts on the electrooxidations of urea, methanol, and ethanol are presented. We demonstrate that activities toward the urea oxidation reaction increase with increasing Ni oxidation state. The 75 % Sr-substituted La_0.5Sr_1.5NiO_4+δ catalyst exhibits a mass activity of 588 mA and 7.85 A for the electrooxidation of urea in 1 M KOH containing 0.33 M urea, demonstrating the potential applications of Ni-based Ruddlesden-Popper materials for direct urea fuel cells and low-cost hydrogen production.[1] Additionally, we find the same correlations between Ni oxidation state and activities for the electrooxidations of methanol and ethanol, as well as identify processes that result in catalyst deactivation for all three oxidations. This demonstration of how systematically increasing Ni – O bond covalency by raising the formal oxidation state of Ni above +3 serves to increase catalyst activity for these reactions acts as a governing principle for the rational design of catalysts for the electrooxidation of urea and other small molecules going forward [2]

References:

[1] Forslund, R. P.; Alexander, C. T.; Abakumov, A. M.; Johnston, K. P.; Stevenson, K. J. “Enhanced Electrocatalytic Activities of Nickel-based Ruddlesden-Popper Catalysts for the Oxidation of Urea and Small Alcohols By Active Site Variation,” ACS Catal. 2019,9(3), 2664–2673.

[2] Forslund, R. P.; Hardin, W. G.; Rong, X; Abakumov, A. M.; Filimonov, D.; Alexander, C. T.; Mefford, J. T.; Iyer, H.; Kolpak, A. M.; Johnston, K. P; Stevenson, K. J. “Exceptional Electrocatalytic Oxygen Evolution Via Tunable Charge Transfer Interactions in La_0.5Sr_1.5Ni_1-xFe_xO_4+δ Ruddlesden-Popper Oxides,” Nature Comm. 2018,9(1)3150.

Professor Stevenson is Full Professor and Provost at the Skolkovo Institute for Science and Technology in Moscow, Russia. His interests are aimed at elucidating and controlling chemistry at interfaces vital to many energy storage and energy conversion technologies. He has published over 280 papers, six patents, and six book chapters. He is the founding director of Skoltech’s Center for Energy Science and Technology. In 2019, Skoltech became the youngest university in the world and only university in the Russian Federation to be ranked in top 100 Nature Index of Top Young Universities.

Electrochemical synthesis of copolymers containing porphyrine derivatives and their activity towards CO₂

Sachin Kochrekar,^1,2 Ajit Kalekar,² Shweta Mehta,^3,4 Pia Damlin,² Mikko Salomäki,² Sari Granroth,⁵ Niko Meltola,⁶ Kavita Joshi,^3,4Carita Kvarnström²

¹Turku University Graduate School (UTUGS) Doctoral Programme in Physical and Chemical Sciences, FI-20014 Turku, Finland

²Turku University Centre for Materials and Surfaces (MatSurf), Department of Chemistry, University of Turku, Vatselankatu 2, FI-20014 Turku, Finland.

³Physical and Materials Chemistry Division, CSIR-National Chemical Laboratory, Pune 411008 India.

⁴Academy of Scientific and Innovative Research (AcSIR), Ghaziabad-200112, UP, India.

⁵Laboratory of Materials Science, University of Turku, FI-20014, Turku, Finland.

⁶ArcDia International Oy Ltd, Lemminkäisenkatu 32, FI-20521-Turku, Finland.

carkva@utu.fi

This study reports the electropolymerization of novel keto functionalized octaethyl metal porphyrins (Zn⁺² and Ni⁺²) in presence of 4,4 bipyridine (4,4´ BPy) as bridging nucleophile on FTO surface. The polymer films were characterized by electrochemical, spectroscopic (UV–Vis, XPS, FT-IR and Raman spectroscopy) and microscopic (AFM and SEM) techniques. The absorption and electronic spectra establish the binding of monomer units in the polymer film, retaining most of the spectroscopic properties of the monomer with slight shift and peak broadening. The surface morphology reveals heterogeneous polymerization. Through computational studies, we aim to get insight into the effect of metal center (Zn⁺² and Ni⁺²) and presence of the keto group on the porphyrin unit. The first 4,4´ BPy prefers meso position next to β-keto group in ZnOEPK whereas it prefers opposite meso position in NiOEPK further leading to linear and branched orientation with the introduction of second 4,4´ BPy, respectively. The interaction between the polymer films in the absence and presence of CO₂ suggests a similar mechanism for both the polymers. The role of the 4,4´ BPy in the polymer unit in association with the activity with CO₂ is emphasized.

Acknowledgement. The authors acknowledge the Magnus Ehrnrooth foundation and Business Finland for financial support.

Carita Kvarnström

Professor of Materials Chemistry

Department of Chemistry

University of Turku

Finland

1996 PhD, Åbo Akademi University, Åbo-Turku Finland

1996–2008 Assistant and Associate Professor, Åbo Akademi University, Åbo-Turku Finland

2009- Full Professor in Materials Chemistry University of Turku, Finland

2010–2014 Director for Turku University Centre for Materials and Surfaces

2017–2016 Head of Laboratory of Materials and Chemical Analysis

2017–2019 Head of Department

Honors or Awards

1996 The Alftan prize for meritorious thesis published awarded by The Finnish Chemists Society

1996 The Elvings prize for the best thesis published at the Åbo Akademi University

1997 Representative for Finland at Scientia Europea 2. Organized by Académie des Sciences (French Academy of Sciences) France.

2006 The Pehr Brahe prize for meritorious research work awarded by the Foundation of Åbo Akademi University.

2020 Member of Finnish Academy of Science and Letters

Research Interests

Conjugated polymers, composite materials, graphene and graphene oxide, ionic liquids, CO₂ conversion, in situ spectroelectrochemistry, electrochemistry

Publications; 137 peer reviewed international scientific journals, 3 patent applications