526 results
Search Results
2. Proactive Effect of Algae-Based Graphene Support on the Oxygen Evolution Reaction Electrocatalytic Activity of NiFe.
- Author
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González-Ingelmo, María, Granda, Marcos, Ruiz, Begoña, Fuente, Enrique, Sierra, Uriel, Rocha, Victoria G., González, Zoraida, Álvarez, Patricia, and Menéndez, Rosa
- Subjects
OXYGEN evolution reactions ,GRAPHENE ,GRAPHENE oxide ,CARBON paper ,DISCONTINUOUS precipitation ,AGAR - Abstract
The preparation of graphene materials from biomass resources is still a challenge, even more so if they are going to be employed as supports for electrocatalysts for water splitting. Herein, we describe the preparation and characterization of graphene oxides (GOs) from solid macroalgae waste obtained after processing an agar–agar residue. The structural and morphological characterization of the obtained GO confirm the presence of a lamellar material that is composed of few layers with an increased number of heteroatoms (including nitrogen) if compared with those observed in a GO obtained from graphite (reference). Three-dimensional electrodes were prepared from these GOs by depositing them onto a fibrous carbon paper, followed by electrodeposition of the catalyst, NiFe. The electrocatalytic performance of these hybrid systems for the oxygen evolution reaction (OER) showed a proactive effect of both graphene materials toward catalysis. Moreover, the electrode prepared from the algae-based graphene showed the highest electrocatalytic activity. This fact could be explained by the different structure of the algae-based graphene which, due to differences in the nucleation growth patterns and electroactive sites developed during the electrodeposition process, produced more reactive NiFe species (higher oxidation state). [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
3. Fabrication and Characterization of Diaphragm Headphones Based on Graphene Nanocomposites.
- Author
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Hwang, Shun-Fa, Liu, Hsien-Kuang, Liao, Wei-Chong, and Cheng, Yi Kai
- Subjects
HEADPHONES ,SOUND pressure ,GRAPHENE ,NANOCOMPOSITE materials ,SCANNING electron microscopes ,LASER measurement - Abstract
The goal of this paper is to fabricate innovative diaphragm headphones using graphene oxide paper (GOP) and GOP/epoxy nanocomposites (GOPC). Initially, graphene oxide suspension is fabricated, and the vacuum filtration method is adopted to make GOP. Then, vacuum bag molding is used to fabricate GOPC from GOP. Hot pressing and associated molds are adopted to fabricate line-indented (GOPC-L) or curve-indented patterns (GOPC-C) on the GOPC. The performances of one kind of GOP and three kinds of GOPC diaphragm headphones are analyzed based on their sound pressure level (SPL) curves achieved by the Soundcheck measurement system. There are four important processing parameters that will influence the performance of the diaphragm, including material type GOP versus GOPC, indented pattern type, sonication time on suspension, and graphene weight fraction in suspension. Compliances of various diaphragms are measured by the Klippel LPM laser measurement system. The results indicate that effects of sonication time and graphene weight fraction on SPL of GOP and GOPC headphones are in reverse, and this is associated with their difference on compliance (modulus), mass, damping ratio, and microstructure uniformity. Either GOPC-L or GOPC-C seems to improve the microstructure of the GOPC, and leads to better SPL performance. The correlation between the previous four factors and SPLs of four kinds of diaphragm headphones is proposed by using scanning electron microscope (SEM) to examine the microstructure of these diaphragms. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
4. Analytical Modeling of Wave Absorption Performance in Gradient Graphene/Polymer Nanocomposites.
- Author
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Zhao, Qin, Li, Fang, and Liu, Jili
- Subjects
POLYMERIC nanocomposites ,ELECTROMAGNETIC wave absorption ,MAXWELL equations ,GRAPHENE ,IMPEDANCE matching ,SHAPE memory polymers - Abstract
Due to the low impedance matching caused by the high dielectric permittivity of graphene, the strong absorption of electromagnetic waves by graphene/polymer nanocomposites is challenging. In this paper, an analytical model for microwave absorption based on Maxwell's equation and the effective medium theory, considering the interface effect, was constructed to explore the effect of the gradient distribution of graphene in the polymer matrix on its microwave absorption performance. The outcome indicated that the impedance of the composites matched well with the air, and its attenuation ability for electromagnetic waves was obviously improved as the graphene concentration was distributed in a gradient form. For instance, when the thickness of the material is 10 mm, based on the optimal concentration of the homogeneous composites being 0.7 wt%, the graphene concentration range of the gradient composites is set to 0.7–0.9 wt% and distributed in three gradient forms of linear, parabolic, and 0.5 power. The results show that the microwave absorption performance is significantly improved compared with the homogeneous composites. Among them, the effective bandwidth on the 0.5 power distribution is 5.2 GHz, 0.5 GHz higher than that of the homogeneous composites. The minimum reflection loss (RL) is as low as −54.7 dB, which is 26.26 dB lower than that of the homogeneous composites. This paper contributes to the design and application of gradient absorbing structures. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
5. Planar Micro-Supercapacitors with High Power Density Screen-Printed by Aqueous Graphene Conductive Ink.
- Author
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Wang, Youchang, Zhang, Xiaojing, Zhu, Yuwei, Li, Xiaolu, and Shen, Zhigang
- Abstract
Simple and scalable production of micro-supercapacitors (MSCs) is crucial to address the energy requirements of miniature electronics. Although significant advancements have been achieved in fabricating MSCs through solution-based printing techniques, the realization of high-performance MSCs remains a challenge. In this paper, graphene-based MSCs with a high power density were prepared through screen printing of aqueous conductive inks with appropriate rheological properties. High electrical conductivity (2.04 × 10
4 S∙m−1 ) and low equivalent series resistance (46.7 Ω) benefiting from the dense conductive network consisting of the mesoporous structure formed by graphene with carbon black dispersed as linkers, as well as the narrow finger width and interspace (200 µm) originating from the excellent printability, prompted the fully printed MSCs to deliver high capacitance (9.15 mF∙cm−2 ), energy density (1.30 µWh∙cm−2 ) and ultrahigh power density (89.9 mW∙cm−2 ). Notably, the resulting MSCs can effectively operate at scan rates up to 200 V∙s−1 , which surpasses conventional supercapacitors by two orders of magnitude. In addition, the MSCs demonstrate excellent cycling stability (91.6% capacity retention and ~100% Coulombic efficiency after 10,000 cycles) and extraordinary mechanical properties (92.2% capacity retention after 5000 bending cycles), indicating their broad application prospects in flexible wearable/portable electronic systems. [ABSTRACT FROM AUTHOR]- Published
- 2024
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- View/download PDF
6. Experimental Investigation into the Preparation Process of Graphene-Reinforced Aluminum Matrix Composites by Friction Stirring Processing.
- Author
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Chen, Gaohong, Yu, Mei, Dong, Hongrui, and Liu, Jianhua
- Abstract
Graphene has been considered an ideal reinforcement in aluminum alloys with its high Young's modulus and fracture strength, which greatly expands the application range of aluminum alloys. However, the dispersion of graphene and the interfacial reaction between graphene and the aluminum matrix limit its application due to elevated temperature. Friction stirring processing (FSP) is regarded as a promising technique to prepare metal matrix composites at lower temperatures. In this paper, FSP was used to prepare graphene-nanoplates-reinforced aluminum composites (GNPs/Al). The corresponding effects of the process parameters and graphene content on GNPs/Al were thoroughly studied. The results showed that plastic strain, heat input, and graphene content were the key influencing factors. Large degrees of plastic strain can enhance the dispersion of graphene by increasing the number of stirring passes and the ratio of stirring to welding velocity, thereby improving the strength of GNPs/Al. Low heat input restricts the plastic flow of graphene in the matrix, whereas excessive heat input can promote interfacial reactions and lead to the formation of a more brittle phase, Al
4 C3 . This is primarily associated with the stirring velocity and welding velocity. High graphene content levels can improve the material strength by refining the grain size, improving the load transfer ability, and acting as a precipitate to prevent dislocation movement. These findings make a contribution to the development of advanced aluminum alloys with graphene reinforcement, offering broader application potential in industries. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF
7. Fabrication of Laser-Induced Graphene Based Flexible Sensors Using 355 nm Ultraviolet Laser and Their Application in Human–Computer Interaction System.
- Author
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Sun, Binghua, Zhang, Qixun, Liu, Xin, Zhai, You, Gao, Chenchen, and Zhang, Zhongyuan
- Subjects
HUMAN-computer interaction ,MICE (Computers) ,GRAPHENE ,DETECTORS ,WEARABLE technology ,DIGITAL technology ,ULTRAVIOLET lasers ,INTELLIGENT sensors - Abstract
In recent years, flexible sensors based on laser-induced graphene (LIG) have played an important role in areas such as smart healthcare, smart skin, and wearable devices. This paper presents the fabrication of flexible sensors based on LIG technology and their applications in human–computer interaction (HCI) systems. Firstly, LIG with a sheet resistance as low as 4.5 Ω per square was generated through direct laser interaction with commercial polyimide (PI) film. The flexible sensors were then fabricated through a one-step method using the as-prepared LIG. The applications of the flexible sensors were demonstrated by an HCI system, which was fabricated through the integration of the flexible sensors and a flexible glove. The as-prepared HCI system could detect the bending motions of different fingers and translate them into the movements of the mouse on the computer screen. At the end of the paper, a demonstration of the HCI system is presented in which words were typed on a computer screen through the bending motion of the fingers. The newly designed LIG-based flexible HCI system can be used by persons with limited mobility to control a virtual keyboard or mouse pointer, thus enhancing their accessibility and independence in the digital realm. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
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8. Benefits of Printed Graphene with Variable Resistance for Flexible and Ecological 5G Band Antennas.
- Author
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Cherevko, Alexander G., Krygin, Alexey S., Ivanov, Artem I., Soots, Regina A., and Antonova, Irina V.
- Subjects
GRAPHENE ,ANTENNA design ,ANTENNAS (Electronics) ,5G networks ,SCREEN process printing - Abstract
The possibility of creating antennas of the 5G standard (5.2–5.9 GHz) with specified electrodynamic characteristics by printing layers of variable thickness using a graphene suspension has been substantiated experimentally and by computer simulation. A graphene suspension for screen printing on photographic paper and other flexible substrates was prepared by means of exfoliation from graphite. The relation between the graphene layer thickness and its sheet resistance was studied with the aim of determining the required thickness of the antenna conductive layer. To create a two-sided dipole, a technology has been developed for the double-sided deposition of graphene layers on photographic paper. The electrodynamic characteristics of graphene and copper antennas of identical design are compared. The antenna design corresponds to the operating frequency of 2.4 GHz. It was found that the use of graphene as a conductive layer made it possible to suppress the fundamental (first) harmonic (2.45 GHz) and to observe radiation at the second harmonic (5.75 GHz). This effect is assumed to observe in the case when the thickness of graphene is lower than that of the skin depth. The result indicates the possibility of changing the antenna electrodynamic characteristics by adjusting the graphene layer thickness. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
9. Recent Developments in Carbon Nanotube Membranes for Water Purification and Gas Separation.
- Author
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Sears, Kallista, Dumée, Ludovic, Schütz, Jürg, She, Mary, Chi Huynh, Hawkins, Stephen, Duke, Mikel, and Gray, Stephen
- Subjects
CARBON nanotubes ,WATER purification ,GAS separation membranes ,MEMBRANE separation ,GRAPHENE ,POROUS materials - Abstract
Carbon nanotubes (CNTs) are nanoscale cylinders of graphene with exceptional properties such as high mechanical strength, high aspect ratio and large specific surface area. To exploit these properties for membranes, macroscopic structures need to be designed with controlled porosity and pore size. This manuscript reviews recent progress on two such structures: (i) CNT Bucky-papers, a non-woven, paper like structure of randomly entangled CNTs, and (ii) isoporous CNT membranes, where the hollow CNT interior acts as a membrane pore. The construction of these two types of membranes will be discussed, characterization and permeance results compared, and some promising applications presented. [ABSTRACT FROM AUTHOR]
- Published
- 2010
- Full Text
- View/download PDF
10. State-Space Formulation for Buckling and Free Vibration of Axially Functionally Graded Graphene Reinforced Nanocomposite Microbeam under Axially Varying Loads.
- Author
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Liu, Dongying, Su, Junxiang, Zhao, Li, and Shen, Xudong
- Subjects
FREE vibration ,EULER-Bernoulli beam theory ,MICROMECHANICS ,NANOCOMPOSITE materials ,GRAPHENE ,STRAINS & stresses (Mechanics) ,FUNCTIONALLY gradient materials - Abstract
This paper focuses on the size-dependent free vibration and buckling behaviors of the axially functionally graded (AFG) graphene platelets (GPLs) reinforced nanocomposite microbeams subjected to axially varying loads (AVLs). With various axial grading patterns, the GPL nano-reinforcements are distributed throughout the polymer matrix against microbeam length, and the improved Halpin–Tsai micromechanics model and the rule of mixture are adopted to evaluate the effective material properties. Eigenvalue equations of the microbeams governing the static stability and vibration are derived based on the modified couple stress Euler–Bernoulli beam theory via the state-space method, and are analytically solved with the discrete equilong segment model. The effects of axial distribution patterns, weight fraction, and geometric parameters of GPLs, as well as different types of AVLs, on the size-dependent buckling load and natural frequency are scrutinized in detail. The results show that the synchronized axial distributions of GPLs and AVLs could improve the buckling resistance and natural frequency more powerfully. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
11. Carbon-Based Functional Nanomaterials as Tools for Controlling the Kinetics of Tribochemical Reactions.
- Author
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Ozimina, Dariusz, Kulczycki, Andrzej, Janas, Dawid, Desaniuk, Tomasz, and Deliś, Maciej
- Subjects
FULLERENES ,CHEMICAL kinetics ,NANOSTRUCTURED materials ,ELECTRIC charge ,ELECTRIC discharges ,JET fuel - Abstract
The aim of this article is to experimentally determine the role of the environment, consisting of a base oil (PAO), carbon nanomaterials, and optional other additives, as well as the kind of metal in contact with the lubrication film, in the stimulation of zinc dialkyldithiophosphate (ZDDP) additives' effectiveness during protective film formation. This paper focuses on the role of carbon nanostructures in energy transportation and conversion during tribological processes. An antistatic additive (ASA) (not used in lubricating oils) for jet fuels was added to disturb the process of energy conduction (electric charges) through the lubricant film and thus determine how this disturbance affects the kinetics of the ZDDP triboreaction and, consequently, the linear wear. To achieve this research goal, two types of tribological testing devices were used: an Anton Paar tribometer (TRB) and a triboelectric tribometer (TET). The novelty of the present research is in the use of the method for disturbing the flow of charge/energy through the lubricant film with an antistatic additive for jet fuels, ASA, to influence the impact of this energy on the antiwear properties of ZDDP. The following conclusions were drawn: (1) carbon-based nanostructures, i.e., CNTs, AuCNTs, graphene, and fullerenes, are able to change the rate of chemical reactions of ZDDP during tribological processes; (2) CNTs have the ability to catalyze tribochemical reactions of ZDDP, while graphene and fullerenes are not able to perform this effectively; (3) AuCNT takes the role of an inhibitor during ZDDP's triboreaction; and (4) by discharging electric charge/energy, ASA, in cooperation with CNT and AuCNT significantly reduces the rate of the ZDDP reaction. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
12. Recent Progress of Cement-Based Materials Modified by Graphene and Its Derivatives.
- Author
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Li, Houxuan, Zhao, Ge, and Zhang, Hong
- Subjects
GRAPHENE ,CONCRETE durability ,THERMAL conductivity ,ELECTRIC conductivity ,METAL ions ,ANALYSIS of heavy metals - Abstract
Graphene, with its excellent properties and unique structure, has been extensively studied in the context of modifiable cement-based materials. However, a systematic summary of the status of numerous experimental results and applications is lacking. Therefore, this paper reviews the graphene materials that improve the properties of cement-based materials, including workability, mechanical properties, and durability. The influence of graphene material properties, mass ratio, and curing time on the mechanical properties and durability of concrete is discussed. Furthermore, graphene's applications in improving interfacial adhesion, enhancing electrical and thermal conductivity of concrete, absorbing heavy metal ions, and collecting building energy are introduced. Finally, the existing issues in current study are analyzed, and the future development trends are foreseen. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
13. Investigation on Adsorption of Polar Molecules in Vegetable Insulating Oil by Functional Fossil Graphene.
- Author
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Liang, Suning, Yang, Zhi, Shao, Xianjun, Zheng, Yiming, Wang, Qiang, and Huang, Zhengyong
- Subjects
POLAR molecules ,INSULATING oils ,VEGETABLE oils ,GRAPHENE ,PHYSISORPTION ,MICROPOLAR elasticity - Abstract
As a new engineering dielectric, vegetable insulating oil is widely used in electrical equipment. Small polar molecules such as alcohol and acid will be produced during the oil-immersed electrical equipment operation, which seriously affects the safety of equipment. The polar molecule can be removed by using functional fossil graphene materials. However, the structural design and group modification of graphene materials lack a theoretical basis. Therefore, in this paper, molecular dynamics (MD) and quantum mechanics theory (Dmol
3 ) were utilized to study the adsorption kinetics and mechanism of graphene (GE), porous graphene (PGE), porous hydroxy graphene (HPGE), and porous graphene modified by hydroxyl and carboxyl groups (COOH-HPGE) on polar small molecules in vegetable oil. The results show that graphene-based materials can effectively adsorb polar small molecules in vegetable oil, and that the modification of graphene materials with carboxyl and hydroxyl groups improves their adsorption ability for polar small molecules, which is attributed to the conversion of physical adsorption to chemical adsorption by the modification of oxygen-containing groups. This study provides a theoretical basis for the design and preparation of graphene materials with high adsorption properties. [ABSTRACT FROM AUTHOR]- Published
- 2023
- Full Text
- View/download PDF
14. An Ultra-Broadband and Highly-Efficient Metamaterial Absorber with Stand-Up Gradient Impedance Graphene Films.
- Author
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Wu, Bian, Chen, Biao, Ma, Shuai, Zhang, Ding, and Zu, Hao-Ran
- Subjects
GRAPHENE ,METAMATERIALS ,CONDUCTIVE ink ,IMPEDANCE matching ,ELECTROMAGNETIC interference ,PRINT materials - Abstract
Metamaterial absorbers (MMAs) that absorb electromagnetic waves among an ultra-broad frequency band have attracted great attention in military and civilian applications. In this paper, an ultra-broadband and highly-efficient MMA is presented. The unit cell of the proposed MMA was constructed with two cross-placed stand-up gradient impedance graphene films, which play a key role in improving impedance matching. Considering the trade-off between absorbing performance and processing complexity, in our design, we adopted the stand-up graphene films that have a gradient with three orders of magnitude in total. The simulated results of the proposed absorber show an ultra-broadband absorption (absorptivity > 90%) from 1.8 GHz to 66.7 GHz and a highly-efficient absorption (absorptivity > 97%) in the range of 2–21.7 GHz and 39.6–57 GHz. The field analysis was adopted to explain the mechanism of the proposed absorber. To validate this design, a prototype of 20 × 20 units was processed and assembled. The graphene films were processed with graphene conductive ink using screen print technology. The measured results are in good agreement with the simulated ones. The proposed absorber may find potential applications in the field of stealth technologies and electromagnetic interference. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
15. A Review on Carrier Mobilities of Epitaxial Graphene on Silicon Carbide.
- Author
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Norimatsu, Wataru
- Subjects
CHARGE carrier mobility ,SILICON carbide ,GRAPHENE ,INTERFACE structures ,TELECOMMUNICATION ,SURFACE structure - Abstract
Graphene growth by thermal decomposition of silicon carbide (SiC) is a technique that produces wafer-scale, single-orientation graphene on an insulating substrate. It is often referred to as epigraphene, and has been thought to be suitable for electronics applications. In particular, high-frequency devices for communication technology or large quantum Hall plateau for metrology applications using epigraphene are expected, which require high carrier mobility. However, the carrier mobility of as-grown epigraphene exhibit the relatively low values of about 1000 cm
2 /Vs. Fortunately, we can hope to improve this situation by controlling the electronic state of epigraphene by modifying the surface and interface structures. In this paper, the mobility of epigraphene and the factors that govern it will be described, followed by a discussion of attempts that have been made to improve mobility in this field. These understandings are of great importance for next-generation high-speed electronics using graphene. [ABSTRACT FROM AUTHOR]- Published
- 2023
- Full Text
- View/download PDF
16. The Effect of Copper–Graphene Composite Architecture on Thermal Transport Efficiency.
- Author
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Kazakov, Arseny M., Korznikova, Galiia F., Tuvalev, Ilyas I., Izosimov, Artem A., and Korznikova, Elena A.
- Subjects
THERMAL efficiency ,THERMAL conductivity ,COPPER crystals ,MOLECULAR dynamics ,GRAPHENE - Abstract
This paper presents the results of molecular dynamic modeling, revealing that inserting confined graphene layers into copper crystal reduces the thermal conductivity of the whole composite, and the coefficient of thermal conductivity κ decreases upon an increase in the number of graphene layers. The injection of one, two, and three layers of 15 nm graphene leads to a change in the coefficient of thermal conductivity from 380 W/(m·K) down to 205.9, 179.1, and 163.6 W/(m·K), respectively. Decreasing the length of graphene layers leads to a decrease in the density of defects on which heat is dissipated. With one, two, and three layers of 8 nm graphene, the coefficient of thermal conductivity of the composite is equal to 272.6, 246.8, and 240.8 W/(m·K), appropriately. Meanwhile the introduction of an infinite graphene layer results in the growth of κ to 414.2–803.3 W/(m·K). [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
17. Knittle Pressure Sensor Based on Graphene/Polyvinylidene Fluoride Nanocomposite Coated on Polyester Fabric.
- Author
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Maharjan, Surendra, Samoei, Victor K., Jayatissa, Ahalapitiya H., Noh, Joo-Hyong, and Sano, Keiichiro
- Subjects
PRESSURE sensors ,POLYVINYLIDENE fluoride ,NANOCOMPOSITE materials ,COATED textiles ,GRAPHENE ,POLYESTER fibers - Abstract
In this paper, a knittle pressure sensor was designed and fabricated by coating graphene/Polyvinylidene Fluoride nanocomposite on the knitted polyester substrate. The coating was carried out by a dip-coating method in a nanocomposite solution. The microstructure, surface properties and electrical properties of coated layers were investigated. The sensors were tested under the application of different pressures, and the corresponding sensor signals were analyzed in terms of resistance change. It was observed that the change in resistance was 55% kPa
−1 with a sensitivity limit of 0.25 kPa. The sensor model was created and simulated using COMSOL Multiphysics software, and the model data were favorably compared with the experimental results. This investigation suggests that graphene-based nanocomposites can be used in knittle pressure sensor applications. [ABSTRACT FROM AUTHOR]- Published
- 2023
- Full Text
- View/download PDF
18. Multifunctional Motion Sensing Enabled by Laser-Induced Graphene.
- Author
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Deng, Bowen, Wang, Zongyuan, Liu, Weiguang, and Hu, Bin
- Subjects
POLYIMIDES ,TACTILE sensors ,CAPACITIVE sensors ,PRESSURE sensors ,GRAPHENE ,STRAIN sensors ,ADHESIVE tape - Abstract
The development of flexible sensors based on laser-induced graphene (LIG) has recently attracted much attention. It was commonly generated by laser-ablating commercial polyimide (PI). However, the weak mechanical extensibility of PI limits the development and diversified applications of LIG-based sensors. In this work, we adopted medical polyurethane (PU) tapes to peel off the LIG generated on PI and developed flexible and wearable sensors based on the proposed LIG/PU composite structure. Compared with other methods for LIG transfer, PU tape has many advantages, including a simplified process and being less time-consuming. We characterized the LIG samples generated under different laser powers and analyzed the property differences introduced by the transfer operation. We then studied the impact of fabrication mode on the strain sensitivity of the LIG/PU and optimized the design of a LIG/PU-based strain sensor, which possessed a gauge factor (GF) of up to 263.6 in the strain range of 75–90%. In addition, we designed a capacitive pressure sensor for tactile sensing, which is composed of two LIG/PU composite structures and a PI space layer. These LIG flexible devices can be used for human motion monitoring and tactile perception in sports events. This work provides a simple, fast, and low-cost way for the preparation of multifunctional sensor systems with good performance, which has a broad application prospect in human motion monitoring. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
19. Influence of UV Ageing on Properties of Printed PLA Containing Graphene Nanopowder.
- Author
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Czechowski, Leszek, Kedziora, Slawomir, Museyibov, Elvin, Schlienz, Markus, Szatkowski, Piotr, Szatkowska, Martyna, and Gralewski, Jacek
- Subjects
POLYLACTIC acid ,GRAPHENE ,MANUFACTURING processes ,DYNAMIC mechanical analysis ,COMPOSITE structures ,DIFFERENTIAL scanning calorimetry - Abstract
The present paper analyses the properties of printed polylactic acid (PLA) samples with admixtures of graphene nanopowder (GNP) at wt. 1%, 2% and 4%. The pure polylactide and admixed polylactide printed samples were examined to determine their chemical-physical properties, stiffness, and strength parameters. The tests of tensile, dynamic mechanical analysis (DMA), difference thermogravimetric (TG), and differential scanning calorimetry (DSC) were executed before and after UV (ultraviolet) treatment. The first part of the paper shows the process of manufacturing granulates and filaments mixed with graphene. The second part of the paper concerns the results of the tests made on printed samples. The analysed samples were printed using a Prusa i3 MK3 printer. It transpired that the content of graphene at 1% improved the mechanical parameters of the printed composite by organising its structure. Increasing the amount of graphene caused the values of the measured parameters to drop. This research indicates how important it is to determine the optimal values of nanoadditives in biopolymers. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
20. Study and Analysis of the Effect of Polyamide Seamless Knitted Fabric with Different Graphene Content on the Blood-Flow Velocity of Human-Skin Microcirculation.
- Author
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Zhang, Yixing, Jin, Zimin, Chen, Jiaxue, Zhao, Mingtao, Sun, Yuqiang, and Song, Yijing
- Subjects
MICROCIRCULATION ,GRAPHENE ,MEDICAL textiles ,POLYAMIDES ,VELOCITY ,TEXTILES - Abstract
In this paper, four kinds of polyamide yarns with different graphene contents and three kinds of seamless knitting structures were used. The scheme of samples was established according to the comprehensive experimental design method, and 12 pieces of knitted fabric samples were woven on the seamless knitting machine. Through testing and analyzing the influence of each sample on the blood-flow rate of human-surface-skin microcirculation, the research shows that the higher the content of graphene in the veil, the better the promotion effect of the fabric prepared under this process condition on the blood-flow rate of human-surface-skin microcirculation. Sample 11# with the veil type of GP-0.8% and fabric weave of 1+1 simulated ribbed stitch has the strongest effect in this experiment, with a promotion multiple of 1.2189, and the influence of tissue structure is not obvious. The relevant performance test data and experimental research results in this paper provide empirical data support for developing medical or health textiles related to promoting the blood-flow velocity of skin microcirculation. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
21. Recent Advances in the Preparation and Application of Two-Dimensional Nanomaterials.
- Author
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Guo, Ying-Tong and Yi, Sha-Sha
- Subjects
CHEMICAL vapor deposition ,NANOSTRUCTURED materials ,SURFACE chemistry ,LIQUID phase epitaxy ,RENEWABLE energy sources ,ELECTROCATALYSIS ,ELECTROMAGNETIC wave absorption - Abstract
Two-dimensional nanomaterials (2D NMs), consisting of atoms or a near-atomic thickness with infinite transverse dimensions, possess unique structures, excellent physical properties, and tunable surface chemistry. They exhibit significant potential for development in the fields of sensing, renewable energy, and catalysis. This paper presents a comprehensive overview of the latest research findings on the preparation and application of 2D NMs. First, the article introduces the common synthesis methods of 2D NMs from both "top-down" and "bottom-up" perspectives, including mechanical exfoliation, ultrasonic-assisted liquid-phase exfoliation, ion intercalation, chemical vapor deposition, and hydrothermal techniques. In terms of the applications of 2D NMs, this study focuses on their potential in gas sensing, lithium-ion batteries, photodetection, electromagnetic wave absorption, photocatalysis, and electrocatalysis. Additionally, based on existing research, the article looks forward to the future development trends and possible challenges of 2D NMs. The significance of this work lies in its systematic summary of the recent advancements in the preparation methods and applications of 2D NMs. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
22. Two-Step Thermal Transformation of Multilayer Graphene Using Polymeric Carbon Source Assisted by Physical Vapor Deposited Copper.
- Author
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Huang, Yong, Ni, Jiamiao, Shi, Xiaoyu, Wang, Yu, Yao, Songsong, Liu, Yue, and Fan, Tongxiang
- Subjects
COPPER films ,CARBON films ,GRAPHENE ,SEMICONDUCTOR devices ,DIELECTRIC films ,GRAPHENE synthesis ,AMORPHOUS carbon ,COPPER - Abstract
Direct in situ growth of graphene on dielectric substrates is a reliable method for overcoming the challenges of complex physical transfer operations, graphene performance degradation, and compatibility with graphene-based semiconductor devices. A transfer-free graphene synthesis based on a controllable and low-cost polymeric carbon source is a promising approach for achieving this process. In this paper, we report a two-step thermal transformation method for the copper-assisted synthesis of transfer-free multilayer graphene. Firstly, we obtained high-quality polymethyl methacrylate (PMMA) film on a 300 nm SiO
2 /Si substrate using a well-established spin-coating process. The complete thermal decomposition loss of PMMA film was effectively avoided by introducing a copper clad layer. After the first thermal transformation process, flat, clean, and high-quality amorphous carbon films were obtained. Next, the in situ obtained amorphous carbon layer underwent a second copper sputtering and thermal transformation process, which resulted in the formation of a final, large-sized, and highly uniform transfer-free multilayer graphene film on the surface of the dielectric substrate. Multi-scale characterization results show that the specimens underwent different microstructural evolution processes based on different mechanisms during the two thermal transformations. The two-step thermal transformation method is compatible with the current semiconductor process and introduces a low-cost and structurally controllable polymeric carbon source into the production of transfer-free graphene. The catalytic protection of the copper layer provides a new direction for accelerating the application of graphene in the field of direct integration of semiconductor devices. [ABSTRACT FROM AUTHOR]- Published
- 2023
- Full Text
- View/download PDF
23. Laser Texturing to Increase the Wear Resistance of an Electrophoretic Graphene Coating on Copper Substrates.
- Author
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Baiocco, Gabriele, Genna, Silvio, Salvi, Daniel, and Ucciardello, Nadia
- Subjects
ELECTROPHORETIC deposition ,WEAR resistance ,COPPER plating ,ELECTROLYTIC polishing ,COPPER ,COPPER surfaces - Abstract
In the present paper, different surface preparations are investigated with the aim of increasing the wear behaviour of an electrophoretic graphene coating on a copper plate. The study was divided into two steps: In the first step (pre-tests), to detect the most promising pretreatment technology, five different surface preparations were investigated (electropolishing, sandblasting, degreasing and pickling, laser cleaning and laser dots).In the second step, on the basis of the results of the first step, a 3
2 full factorial plan was developed and tested; three treatment types (pickled and degreased, laser-cleaned, and laser dots) and three different voltages (30, 45 and 60 V) were adopted. Analysis of variance (ANOVA) was used to evaluate their influence on wear resistance; in particular, the maximum depth and width of the wear tracks and the coating break distance were investigated. The results of this study show that, in optimal conditions, laser treatment (particularly laser dots) canlead to as high as a four-fold increase in wear resistance. [ABSTRACT FROM AUTHOR]- Published
- 2023
- Full Text
- View/download PDF
24. Design of Tunable Broadband Graphene-Based Metasurface with Amplitude-Phase Modulation.
- Author
-
Jiang, Huixia, Sheng, Lili, Luo, Yumei, Meng, Liang, and Cao, Weiping
- Subjects
BEAM steering ,MILLIMETER wave antennas ,MILLIMETER waves ,TELECOMMUNICATION satellites ,ELECTROMAGNETIC waves ,COPLANAR waveguides ,FERMI level - Abstract
Due to the growing scarcity of spectrum resources in the low-frequency band, the requirement of beam-reconfigurable antennas in the millimeter wave band is urgent. In this paper, a W-band graphene-based metasurface working in a broad bandwidth is proposed with reflective amplitude coding. Here, graphene sheets play a dual role in radiating and regulating electromagnetic waves. By adjusting the Fermi levels of graphene, the reflective amplitude and phase of the metasurface can be modulated simultaneously, enabling multi-beam switching and beam deflection in far-field. The proposed metasurface achieves amplitude-phase modulation within a significantly wide bandwidth which covers 75–91.5 GHz and 99.3–115 GHz. By optimizing the coding patterns, the proposed graphene-based metasurfaces are able to not only realize 2-D beam steering, but also achieve beam switching from single beam to four beams at 87 GHz. The proposed design provides a novel solution for the flexible manipulation of millimeter waves, which can be applied to various fields such as vehicle radar, satellite communication, 6G wireless communication, and beyond. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
25. Review on Graphene-, Graphene Oxide-, Reduced Graphene Oxide-Based Flexible Composites: From Fabrication to Applications.
- Author
-
Razaq, Aamir, Bibi, Faiza, Zheng, Xiaoxiao, Papadakis, Raffaello, Jafri, Syed Hassan Mujtaba, and Li, Hu
- Subjects
GRAPHENE ,NATURAL fibers ,GRAPHENE oxide ,COMPOSITE materials ,WEARABLE technology ,THERMAL stability - Abstract
In the new era of modern flexible and bendable technology, graphene-based materials have attracted great attention. The excellent electrical, mechanical, and optical properties of graphene as well as the ease of functionalization of its derivates have enabled graphene to become an attractive candidate for the construction of flexible devices. This paper provides a comprehensive review about the most recent progress in the synthesis and applications of graphene-based composites. Composite materials based on graphene, graphene oxide (GO), and reduced graphene oxide (rGO), as well as conducting polymers, metal matrices, carbon–carbon matrices, and natural fibers have potential application in energy-harvesting systems, clean-energy storage devices, and wearable and portable electronics owing to their superior mechanical strength, conductivity, and extraordinary thermal stability. Additionally, the difficulties and challenges in the current development of graphene are summarized and indicated. This review provides a comprehensive and useful database for further innovation of graphene-based composite materials. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
26. Graphene-Based Materials for the Separator Functionalization of Lithium-Ion/Metal/Sulfur Batteries.
- Author
-
Huang, Zongle, Sun, Wenting, Sun, Zhipeng, Ding, Rui, and Wang, Xuebin
- Subjects
LITHIUM sulfur batteries ,ELECTRIC vehicle batteries ,ELECTRIFICATION ,ELECTRIC vehicles ,LITHIUM-ion batteries - Abstract
With the escalating demand for electrochemical energy storage, commercial lithium-ion and metal battery systems have been increasingly developed. As an indispensable component of batteries, the separator plays a crucial role in determining their electrochemical performance. Conventional polymer separators have been extensively investigated over the past few decades. Nevertheless, their inadequate mechanical strength, deficient thermal stability, and constrained porosity constitute serious impediments to the development of electric vehicle power batteries and the progress of energy storage devices. Advanced graphene-based materials have emerged as an adaptable solution to these challenges, owing to their exceptional electrical conductivity, large specific surface area, and outstanding mechanical properties. Incorporating advanced graphene-based materials into the separator of lithium-ion and metal batteries has been identified as an effective strategy to overcome the aforementioned issues and enhance the specific capacity, cycle stability, and safety of batteries. This review paper provides an overview of the preparation of advanced graphene-based materials and their applications in lithium-ion, lithium-metal, and lithium-sulfur batteries. It systematically elaborates on the advantages of advanced graphene-based materials as novel separator materials and outlines future research directions in this field. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
27. A Tunable Terahertz Absorber Based on Double-Layer Patterned Graphene Metamaterials.
- Author
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Tang, Xin, Jia, Haoduo, Liu, Luyang, Li, Ming, Wu, Dai, Zhou, Kui, Li, Peng, Tian, Langyu, Yang, Dingyu, and Wang, Weijun
- Subjects
TERAHERTZ materials ,GRAPHENE ,METAMATERIALS ,ELECTRON mobility ,FERMI energy ,OPTOELECTRONIC devices ,COPPER-zinc alloys ,METAL foams - Abstract
Graphene is widely used in tunable photonic devices due to its numerous exotic and exceptional properties that are not found in conventional materials, such as high electron mobility, ultra-thin width, ease of integration and good tunability. In this paper, we propose a terahertz metamaterial absorber that is based on patterned graphene, which consists of stacked graphene disk layers, open ring graphene pattern layers and metal bottom layers, all separated by insulating dielectric layers. Simulation results showed that the designed absorber achieved almost perfect broadband absorption at 0.53–1.50 THz and exhibited polarization-insensitive and angle-insensitive characteristics. In addition, the absorption characteristics of the absorber can be adjusted by changing the Fermi energy of graphene and the geometrical parameters of the structure. The above results indicate that the designed absorber can be applied to photodetectors, photosensors and optoelectronic devices. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
28. An Overview of Recycling Wastes into Graphene Derivatives Using Microwave Synthesis; Trends and Prospects.
- Author
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Balqis, Nuralmeera, Mohamed Jan, Badrul, Simon Cornelis Metselaar, Hendrik, Sidek, Akhmal, Kenanakis, George, and Ikram, Rabia
- Subjects
GRAPHENE ,WASTE recycling ,GRAPHENE synthesis ,INDUSTRIAL wastes ,MICROWAVE heating ,WASTE products ,CRYSTAL lattices - Abstract
It is no secret that graphene, a two-dimensional single-layered carbon atom crystal lattice, has drawn tremendous attention due to its distinct electronic, surface, mechanical, and optoelectronic properties. Graphene also has opened up new possibilities for future systems and devices due to its distinct structure and characteristics which has increased its demand in a variety of applications. However, scaling up graphene production is still a difficult, daunting, and challenging task. Although there is a vast body of literature reported on the synthesis of graphene through conventional and eco-friendly methods, viable processes for mass graphene production are still lacking. This review focuses on the variety of unwanted waste materials, such as biowastes, coal, and industrial wastes, for producing graphene and its potential derivatives. Among the synthetic routes, the main emphasis relies on microwave-assisted production of graphene derivatives. In addition, a detailed analysis of the characterization of graphene-based materials is presented. This paper also highlights the current advances and applications through the recycling of waste-derived graphene materials using microwave-assisted technology. In the end, it would alleviate the current challenges and forecast the specific direction of waste-derived graphene future prospects and developments. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
29. Insights into the Mechanism of Graphene Acting on Water and Chloride Ion Permeability of Cement-Based Materials.
- Author
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Dong, Jianmiao, Zhuang, Jiaqiao, Li, Wanjin, Zou, Mingxuan, He, Qi, and Luo, Shuqiong
- Subjects
CHLORIDE ions ,GRAPHENE ,PERMEABILITY ,SCANNING electron microscopes ,STRENGTH of materials ,PORTLAND cement ,PASTE ,CRYSTAL morphology - Abstract
Due to its excellent mechanical properties and high aspect ratio, graphene can significantly improve the water and chloride ion permeability resistance of cementitious materials. However, few studies have investigated the effect of graphene size on the water and chloride ion permeability resistance of cementitious materials. The main issues are as follows: How do different sizes of graphene affect the water and chloride ion permeability resistance of cement-based materials, and by what means do they affect these properties? To address these issues, in this paper, two different sizes of graphene were used to prepare graphene dispersion, which was then mixed with cement to make graphene-reinforced cement-based materials. The permeability and microstructure of samples were investigated. Results show that the addition of graphene effectively improved both the water and chloride ion permeability resistance of cement-based materials significantly. The SEM (scanning electron microscope) images and XRD (X-ray diffraction) analysis show that the introduction of either type of graphene could effectively regulate the crystal size and morphology of hydration products and reduce the crystal size and the number of needle-like and rod-like hydration products. The main types of hydrated products are calcium hydroxide, ettringite, etc. The template effect of large-size graphene was more obvious, and a large number of regular flower-like cluster hydration products were formed, which made the structure of cement paste more compact and thus significantly improved the resistance to the penetration of water and chloride ions into the matrix of the concrete. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
30. STM Study of the Initial Stage of Gold Intercalation of Graphene on Ir(111).
- Author
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Mikšić Trontl, Vesna, Jedovnicki, Ivan, and Pervan, Petar
- Subjects
SCANNING tunneling microscopy ,GRAPHENE ,GOLD ,GRAPHITE intercalation compounds - Abstract
In this paper, we present a study of the sub-monolayer gold intercalation of graphene on Ir(111) using scanning tunnelling microscopy (STM). We found that Au islands grow following different kinetics than growth on Ir(111) without graphene. Graphene appears to increase the mobility of Au atoms by shifting the growth kinetics of Au islands from dendritic to a more compact shape. Graphene on top of intercalated gold exhibits a moiré superstructure, with parameters significantly different from graphene on Au(111) but almost identical to graphene on Ir(111). The intercalated Au monolayer shows a quasi-herringbone reconstruction with similar structural parameters as on Au(111). [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
31. Novel Graphene-Based Materials as a Tool for Improving Long-Term Storage of Cultural Heritage.
- Author
-
Gorgolis, George, Ziemann, Steffen, Kotsidi, Maria, Paterakis, George, Koutroumanis, Nikos, Tsakonas, Christos, Anders, Manfred, and Galiotis, Costas
- Subjects
POLYVINYL alcohol ,CULTURAL property ,VOLATILE organic compounds ,TEMPERATURE control ,NANOCOMPOSITE materials ,TECHNOLOGICAL innovations ,ACETALDEHYDE ,FORMALDEHYDE - Abstract
The very serious problem of temperature and humidity regulation, especially for small and medium-sized museums, galleries, and private collections, can be mitigated by the introduction of novel materials that are easily applicable and of low cost. Within this study, archive boxes with innovative technology are proposed as "smart" boxes that can be used for storage and transportation, in combination with a nanocomposite material consisting of polyvinyl alcohol (PVA) and graphene oxide (GO). The synthesis and characterization of the PVA/GO structure with SEM, Raman, AFM, XRD, Optical Microscopy, and profilometry are fully discussed. It is shown that the composite material can be integrated into the archive box either as a stand-alone film or attached onto fitting carriers, for example, those made of corrugated board. By applying the PVA/GO membrane this way, even with strong daily temperature fluctuations of ΔT = ±24.1 °C, strong external humidity fluctuations can be reduced by −87% inside the box. Furthermore, these humidity regulators were examined as Volatile Organic Compounds (VOCs) adsorbers since gas pollutants like formic acid, formaldehyde, acetic acid, and acetaldehyde are known to exist in museums and induce damages in the displayed or stored items. High rates of VOC adsorption have been measured, with the highest ones corresponding to formic acid (521% weight increase) and formaldehyde (223% weight increase). [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
32. Anti-High-Power Microwave RFID Tag Based on Highly Thermal Conductive Graphene Films.
- Author
-
Liu, Xueyu, Song, Rongguo, Fu, Huaqiang, Zhu, Wei, Luo, Kaolin, Xiao, Yang, Zhang, Bohan, Wang, Shengxiang, and He, Daping
- Subjects
GRAPHENE ,RADIO frequency identification systems ,MICROWAVES ,ELECTRIC spark ,DESIGN protection - Abstract
In this paper, a radio frequency identification (RFID) tag is designed and fabricated based on highly electrical and thermal conductive graphene films. The tag operates in the ultrahigh-frequency (UHF) band, which is suitable for high-power microwave environments of at least 800 W. We designed the protection structure to avoid charge accumulation at the antenna's critical positions. In the initial state, the read range of the anti-high-power microwave graphene film tag (AMGFT) is 10.43 m at 915 MHz. During the microwave heating experiment, the aluminum tag causes a visible electric spark phenomenon, which ablates the aluminum tag and its attachment, resulting in tag failure and serious safety issues. In contrast, the AMGFT is intact, with its entire read range curve growing and returning to its initial position as its temperature steadily decreases back to room temperature. In addition, the proposed dual-frequency tag further confirms the anti-high-power microwave performance of graphene film tags and provides a multi-scenario interactive application. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
33. Two-Dimensional Films Based on Graphene/Li 4 Ti 5 O 12 and Carbon Nanotube/Li 4 Ti 5 O 12 Nanocomposites as a Prospective Material for Lithium-Ion Batteries: Insight from Ab Initio Modeling.
- Author
-
Shunaev, Vladislav V., Petrunin, Alexander A., Zhan, Haifei, and Glukhova, Olga E.
- Subjects
NANOCOMPOSITE materials ,GRAPHENE ,LITHIUM-ion batteries ,CARBON nanotubes ,CHARGE transfer ,FERMI level - Abstract
The combination of spinel Li
4 Ti5 O12 (LTO) with carbon nanostructures, such as graphene (G) and carbon nanotubes (CNTs), provides all of the required properties for modern chemical power sources such as Li-ion batteries (LIBs) and supercapacitors (SCs). G/LTO and CNT/LTO composites demonstrate a superior reversible capacity, cycling stability, and good rate performances. In this paper, an ab initio attempt to estimate the electronic and capacitive properties of such composites was made for the first time. It was found that the interaction between LTO particles and CNTs was higher than that with graphene due to the larger amount of transfer charge. Increasing the graphene concentration raised the Fermi level and enhanced the conductive properties of G/LTO composites. For CNT/LTO samples, the radius of CNT did not affect the Fermi level. For both G/LTO and CNT/LTO composites, an increase in the carbon ratio resulted in a similar reduction in quantum capacitance (QC). It was observed that during the charge cycle in the real experiment, the non-Faradaic process prevailed during the charge cycle, while the Faradaic process prevailed during the discharge cycle. The obtained results confirm and explain the experimental data and improve the understanding of the processes occurring in G/LTO and CNT/LTO composites for their usages in LIBs and SCs. [ABSTRACT FROM AUTHOR]- Published
- 2023
- Full Text
- View/download PDF
34. Effect of Temperatures and Graphene on the Mechanical Properties of the Aluminum Matrix: A Molecular Dynamics Study.
- Author
-
Huang, Jingtao, Li, Mingwei, Chen, Jiaying, Cheng, Yuan, Lai, Zhonghong, Hu, Jin, Zhou, Fei, Qu, Nan, Liu, Yong, and Zhu, Jingchuan
- Subjects
METALLIC composites ,MOLECULAR dynamics ,GRAPHENE ,MECHANICAL properties of metals ,TEMPERATURE effect ,ALUMINUM composites - Abstract
Graphene has become an ideal reinforcement for reinforced metal matrix composites due to its excellent mechanical properties. However, the theory of graphene reinforcement in graphene/aluminum matrix composites is not yet well developed. In this paper, the effect of different temperatures on the mechanical properties of the metal matrix is investigated using a classical molecular dynamics approach, and the effects of the configuration and distribution of graphene in the metal matrix on the mechanical properties of the composites are also described in detail. It is shown that in the case of a monolayer graphene-reinforced aluminum matrix, the simulated stretching process does not break the graphene as the strain increases, but rather, the graphene and the aluminum matrix have a shearing behavior, and thus, the graphene "pulls out" from the aluminum matrix. In the parallel stretching direction, the tensile stress tends to increase with the increase of the graphene area ratio. In the vertical stretching direction, the tensile stress tends to decrease as the percentage of graphene area increases. In the parallel stretching direction, the tensile stress of the system tends to decrease as the angle between graphene and the stretching direction increases. It is important to investigate the effect of a different graphene distribution in the aluminum matrix on the mechanical properties of the composites for the design of high-strength graphene/metal matrix composites. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
35. Investigation on the Electrical Conductivity of Graphene/Cement Composites by Alternating Current Method.
- Author
-
Jin, Ming, Li, Wenwei, Ma, Yuefeng, Zeng, Haoyu, Huang, Minghui, Lu, Chao, and Yang, Guo
- Subjects
ALTERNATING currents ,ELECTRIC conductivity ,SMART materials ,GRAPHENE ,CEMENT composites ,SCANNING electron microscopy - Abstract
This paper is concerned with an analysis of the electrical conductivity of graphene/cement composites by means of DC (direct current) and AC (alternating current) techniques. Moreover, the micrograph and element composition of composites have been characterized through SEM (scanning electron microscopy) and EDS (energy-dispersive spectrometers) techniques, respectively. Results revealed that a percolation transition region Φ2–Φ1 (Φ2 and Φ1 values are determined as 0.8% and 1.8%, respectively) can be observed in the S-shaped curve. In addition, the logistic model has been recommended to characterize the relationship between the conductivity and the graphene concentration, which ranged from 0.001% to 2.5%. The micrographs obtained by SEM technique clearly indicate a complete conductive network as well as agglomeration of graphene slices when the graphene content reaches the threshold value. Furthermore, graphene slices can be distinguished from the cement hydration products by means of the analysis of element composition obtained through the EDS technique. It is promising to apply the graphene/cement composites as intelligent materials. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
36. Effect of Defects in Graphene/Cu Composites on the Density of States.
- Author
-
Kim, Song Mi, Park, Woo Rim, Park, Jun Seok, Song, Sang Min, and Kwon, Oh Heon
- Subjects
COPPER ,GRAPHENE ,FERMI energy ,DENSITY functional theory ,MANUFACTURING processes ,BORON nitride - Abstract
The process of handling and bonding copper (Cu) and graphene inevitably creates defects. To use graphene/Cu composites as electronic devices with new physical properties, it is essential to evaluate the effect of such defects. Since graphene is an ultrathin anisotropic material having a hexagonal structure, an evaluation of graphene/Cu composites containing defects was conducted taking into account the inherent structural characteristics. The purpose of this study is to evaluate defects that may occur in the manufacturing process and to present a usable basic method for the stable design research and development of copper/graphene composites essential for commercialization of copper/graphene composites. In the future, when performing analytical calculations on various copper/graphene composites and defect shapes in addition to the defect conditions presented in this paper, it is considered that it can be used as a useful method considering defects that occur during application to products of desired thickness and size. Herein, density functional theory was used to evaluate the behavior of graphene/Cu composites containing defects. The density of states (DOS) values were also calculated. The analysis was implemented using three kinds of models comprising defect-free graphene and two- and four-layered graphene/Cu composites containing defects. DOS and Fermi energy levels were used to gage the effect of defects on electrical properties. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
37. Study on the Effect of Freeze–Thaw Action on the Electrical Conductivity and Sensing Properties of Graphene-Based Cement Composites.
- Author
-
Chen, Huihui, Xu, Ning, Jiang, Peng, and Jiang, Linhua
- Subjects
ELECTRIC conductivity ,CEMENT composites ,THERMAL conductivity ,TENSILE strength ,GRAPHENE - Abstract
Graphene can effectively improve the mechanical and electrical properties of cement-based materials due to its excellent tensile strength, thermal conductivity and electrical conductivity. In this paper, the effects of freeze–thaw on the conductivity and sensing properties of graphene-based cement materials were investigated. After the preparation of graphene-based cement materials, they were subjected to different times of freeze–thaw action. The experiments were designed to analyze the influence of freeze–thaw on the electrical conductivity, humidity sensitivity, thermosensitivity and pressure sensitivity of graphene-based cement composites. The results show that the influence of freeze–thaw on the electrical conductivity of graphene is mainly manifested in the influence on the resistivity and the extension of the polarization time, and the influence on the percolation transition zone is small. After freeze–thaw, the polarization time of the specimen decreases with the increase of the relative water content. The temperature has a great influence on the polarization effect of graphene-based cement composites and the composites with graphene content of the zone B still show satisfactory pressure-sensitive property after freeze–thaw. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
38. Progress in Research and Application of Graphene Aerogel—A Bibliometric Analysis.
- Author
-
Chai, Bowen, Zhang, Wanlin, Liu, Yuanyuan, Zhu, Shuang, Gu, Zhanjun, and Zhang, Hao
- Subjects
BIBLIOMETRICS ,AEROGELS ,GRAPHENE ,ENERGY storage ,WEB databases - Abstract
In recent years, graphene aerogel (GA) has been widely used as a 3D porous stable network structure material. In order to identify the main research direction of GA, we use the bibliometric method to analyze its hot research fields and applications from the Web of Science database. First, we collected all relevant literature and analyzed its bibliometrics of publication year, country, institution, etc., where we found that China and Chinese Academy of Sciences are the most productive country and institute, respectively. Then, the three hot fields of fabrication, energy storage, and environmental protection are identified and thoroughly discussed. Graphene aerogel composite electrodes have achieved very efficient storage capacity and charge/discharge stability, especially in the field of electrochemical energy storage. Finally, the current challenges and the future development trends are presented in the conclusion. This paper provides a new perspective to explore and promote the related development of GA. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
39. The Compliance of the Upper Critical Field in Magic-Angle Multilayer Graphene with the Pauli Limit.
- Author
-
Talantsev, Evgueni F.
- Subjects
GRAPHENE ,SUPERLATTICES ,SUPERCONDUCTORS ,SUPERCONDUCTIVITY ,MAGIC squares - Abstract
The Pauli limiting field represents a fundamental magnetic field at which the superconducting state collapses due to the spin-paramagnetic Cooper pair-breaking effect. Cao et al. (Nature 2021, 595, 526) reported that the magic-angle twisted trilayer graphene (MATNG, N = 3) exhibits the upper critical field which exceeds the Pauli limiting field by two to three times. This observation was interpreted as a violation of the Pauli-limiting field in MAT3G. Similar conclusions were recently reported by the same research group in MATNG (N = 4, 5) superlattices (Park, J.M. et al. Nat. Mater.2022, 21, 877). Here, we point out that Cao et al. (Nature 2021, 595, 526) calculated the Pauli limiting field by the use of reduced form (to the weak-coupling limit) of full equation of the theory of the electron–phonon-mediated superconductivity. Considering that in the same paper, Cao et al. (Nature 2021, 595, 526) reported that MATNGs are strong coupled superconductors, we calculate the Pauli limiting field for a strong coupled case and show that the observed upper critical fields in MATNGs comply with the Pauli limit. This implies that there is no violation of the Pauli limiting field in the Moiré multilayer graphene superlattices. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
40. Flake Graphene as an Innovative Additive to Grease with Improved Tribological Properties.
- Author
-
Djas, Małgorzata, Matuszewska, Anna, Borowa, Beata, Kowiorski, Krystian, Wieczorek, Piotr, Małek, Marcin, and Chlanda, Adrian
- Subjects
GRAPHENE ,TRIBOLOGY ,GRAPHENE oxide ,PLASTIC additives ,ADDITIVES - Abstract
The paper presents the results of research on the use of flake graphene as an additive to plastic grease in order to improve its tribological properties. The influence of concentration (0.25–5.00 wt.%) and the form of graphene (graphene oxide, reduced graphene oxide) on selected properties of the base grease were investigated. It has been found that the addition of graphene flakes improves the anti-wear properties of the lubricant. The greatest improvement in the properties of the lubricant was achieved by using graphene at a concentration of 4.00 wt.%; the reduction in the average diameter of the wear scar was almost 70% for GO and RGO, compared to the base lubricant without the addition of graphene. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
41. Application of Grazing-Incidence X-ray Methods to Study Terrace-Stepped SiC Surface for Graphene Growth.
- Author
-
Roschin, Boris S., Argunova, Tatiana S., Lebedev, Sergey P., Asadchikov, Victor E., Lebedev, Alexander A., Volkov, Yuri O., and Nuzhdin, Alexander D.
- Subjects
GRAPHENE ,ATOMIC force microscopy ,GRAPHENE synthesis ,X-ray reflectometry ,X-rays - Abstract
The synthesis of graphene by the graphitization of SiC surface has been driven by a need to develop a way to produce graphene in large quantities. With the increased use of thermal treatments of commercial SiC substrates, a comprehension of the surface restructuring due to the formation of a terrace-stepped nanorelief is becoming a pressing challenge. The aim of this paper is to evaluate the utility of X-ray reflectometry and grazing-incidence off-specular scattering for a non-destructive estimate of depth-graded and lateral inhomogeneities on SiC wafers annealed in a vacuum at a temperature of 1400–1500 °C. It is shown that the grazing-incidence X-ray method is a powerful tool for the assessment of statistical parameters, such as effective roughness height, average terrace period and dispersion. Moreover, these methods are advantageous to local probe techniques because a broad range of spatial frequencies allows for faster inspection of the whole surface area. We have found that power spectral density functions and in-depth density profiles manifest themselves differently between the probing directions along and across a terrace edge. Finally, the X-ray scattering data demonstrate quantitative agreement with the results of atomic force microscopy. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
42. Electrical Properties of In Situ Synthesized Ag-Graphene/Ni Composites.
- Author
-
Wang, Jingqin, Hu, Dekao, Zhu, Yancai, and Guo, Peijian
- Subjects
FUSION welding ,GRAPHENE synthesis ,ELECTRIC welding ,ELECTRIC conductivity ,GRAPHENE oxide ,IGNITION temperature - Abstract
Ag/Ni composite contact materials are widely used in low-voltage switches, appliances, instruments, and high-precision contacts due to their good electrical conductivity and processing properties. The addition of small amounts of additives can effectively improve the overall performance of Ag/Ni contact materials. Graphene has good applications in semiconductors, thermal materials, and metal matrix materials due to its good electrical and thermal conductivity and mechanical properties. In this paper, Ag-graphene composites with different added graphene contents were prepared by in situ synthesis of graphene oxide (GO) and AgNO
3 by reduction at room temperature using ascorbic acid as a reducing agent. The Ag-graphene composites and nickel powder were ball-milled and mixed in a mass ratio of 85:15. The Ag-graphene/Ni was tested as an electrical contact material after the pressing, initial firing, repressing, and refiring processes. Its fusion welding force and arc energy were measured. The results show a 12% improvement in electrical conductivity with a graphene doping content of approximately 0.3 wt% compared to undoped contacts, resulting in 33.8 IACS%. The average contact fusion welding force was 49.49 cN, with an average reduction in the fusion welding force of approximately 8.04%. The average arc ignition energy was approximately 176.77 mJ, with an average decrease of 13.06%. The trace addition of graphene can improve the overall performance of Ag/Ni contacts and can promote the application of graphene in electrical contact materials. [ABSTRACT FROM AUTHOR]- Published
- 2022
- Full Text
- View/download PDF
43. Graphene: A Path-Breaking Discovery for Energy Storage and Sustainability.
- Author
-
Goyal, Deepam, Dang, Rajeev Kumar, Goyal, Tarun, Saxena, Kuldeep K., Mohammed, Kahtan A., and Dixit, Saurav
- Subjects
ENERGY storage ,QUANTUM Hall effect ,GRAPHENE ,SOLAR cells ,FUEL cells - Abstract
The global energy situation requires the efficient use of resources and the development of new materials and processes for meeting current energy demand. Traditional materials have been explored to large extent for use in energy saving and storage devices. Graphene, being a path-breaking discovery of the present era, has become one of the most-researched materials due to its fascinating properties, such as high tensile strength, half-integer quantum Hall effect and excellent electrical/thermal conductivity. This paper presents an in-depth review on the exploration of deploying diverse derivatives and morphologies of graphene in various energy-saving and environmentally friendly applications. Use of graphene in lubricants has resulted in improvements to anti-wear characteristics and reduced frictional losses. This comprehensive survey facilitates the researchers in selecting the appropriate graphene derivative(s) and their compatibility with various materials to fabricate high-performance composites for usage in solar cells, fuel cells, supercapacitor applications, rechargeable batteries and automotive sectors. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
44. Effect of the Addition of Graphene Nanoplatelets on the Thermal Conductivity of Rocket Kerosene: A Molecular Dynamics Study.
- Author
-
Guo, Xiaodie, Chen, Xuejiao, Zhao, Jinpeng, Zhou, Wenjing, and Wei, Jinjia
- Subjects
THERMAL conductivity ,PERCOLATION theory ,MOLECULAR dynamics ,KEROSENE ,NANOPARTICLES ,GRAPHENE ,BROWNIAN motion ,NANOFLUIDS - Abstract
Rocket kerosene plays an important role in the regenerative cooling process of rocket thrust chambers. Its thermal conductivity determines the cooling efficiency and the tendency to coke in rocket kerosene engines. In this paper, graphene nanoplatelets (GNPs) were introduced into rocket kerosene to improve its thermal conductivity. Molecular dynamics simulation was used to investigate the thermal conductivity of the composite system and its underlying thermal conductivity mechanism. Firstly, by studying the effect of the mass fraction of GNPs, it was found that, when the graphene mass fraction increases from 1.14% to 6.49%, the thermal conductivity of the composite system increases from 4.26% to 17.83%, which can be explained by the percolation theory. Secondly, the influence of the size of GNPs on the thermal conductivity of the composite system was studied. Basically, the thermal conductivity was found to increase by increasing the aspect ratio of GNPs, indicating that GNPs with a higher aspect ratio are more conducive to improving the thermal conductivity of rocket kerosene. By carefully analyzing the effect of the size of GNPs on thermal conductivity, it was concluded that the thermal conduction enhancement by adding GNPs is determined by the combined effect of the percolation theory and the Brownian motion. The results of the temperature effect study showed that the ratio of thermal conductivity to rocket kerosene increased from 1.16 to 1.26 and from 1.07 to 1.11 for the composite systems, with graphene sizes of 41.18 Å × 64.00 Å and 24.14 Å × 17.22 Å in the temperature range of 293 K to 343 K, respectively. It is further proved that the Brownian motion of GNPs has a non-negligible effect on the thermal conductivity of the composite system. This work provides microscopic insights into the thermal conduction mechanism of GNPs in nanofluids and will offer practical guidance for improving the thermal conductivity of rocket kerosene. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
45. Influence of Graphene Nanoplates on Dispersion, Hydration Behavior of Sulfoaluminate Cement Composites.
- Author
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Cui, Kai, Chang, Jun, Sabri, Mohanad Muayad Sabri, and Huang, Jiandong
- Subjects
SULFOALUMINATE cement ,CEMENT composites ,GRAPHENE ,PORTLAND cement ,DISPERSION (Chemistry) ,HYDRATION kinetics - Abstract
Sulfoaluminate cement (SAC) is a low carbon ecological cement with good durability and is widely used in various projects. In addition, graphene nanoplates (GNPs) have excellent thermal, electrical, and mechanical properties and are excellent nano-filler. However, the hydration behavior of GNPs on SAC is still unclear. In this paper, the effect of GNPs on SAC hydration was investigated by isothermal calorimetry, and the hydration kinetic model and hydration kinetic equation of SAC was established, explaining the differences in cement hydration processes with and without GNPs on SAC based on a hydration kinetic model. Results indicate that the hydration exotherm of SAC mainly includes five stages: the initial stage, the induction stage, the acceleration stage, the deceleration stage, and the stable stage. The addition of GNPs promoted the hydration exotherm of SAC and accelerated the hydration reaction. Different from the hydration reaction of Portland cement, the hydration reaction of SAC is mainly a diffusion–reaction process. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
46. Tribological Behavior of Reduced Graphene Oxide–Al 2 O 3 Nanofluid: Interaction among Testing Force, Rotational Speed and Nanoparticle Concentration.
- Author
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Wang, Chenglong, Sun, Jianlin, Kong, Linghui, and He, Jiaqi
- Subjects
NANOFLUIDS ,RESPONSE surfaces (Statistics) ,GRAPHENE ,METALLIC oxides ,MECHANICAL wear ,SURFACE roughness ,GRAPHITE oxide ,ANALYSIS of variance - Abstract
The tribological properties of nanofluids are influenced by multiple factors, and the interrelationships among the factors are deserving of further attention. In this paper, response surface methodology (RSM) was used to study the tribological behavior of reduced graphene oxide–Al
2 O3 (rGO-Al2 O3 ) nanofluid. The interaction effects of testing force, rotational speed and nanoparticle concentration on the friction coefficient (μ), wear rate (Wr ) and surface roughness (Ra ) of steel disks were investigated via the analysis of variance. It was confirmed that all the three input variables were significant for μ and Wr values, while testing force, nanoparticle concentration and its interaction with testing force and rotational speed were identified as significant parameters for Ra value. According to regression quadratic models, the optimized response values were 0.088, 2.35 × 10−7 mm3 ·N−1 ·m−1 and 0.832 μm for μ, Wr and Ra , which were in good agreement with the actual validation experiment values. The tribological results show that 0.20% was the optimum mass concentration which exhibited excellent lubrication performance. Compared to the base fluid, μ, Wr and Ra values had a reduction of approximately 45.6%, 90.3% and 56.0%. Tribochemical reactions occurred during the friction process, and a tribofilm with a thickness of approximately 20 nm was generated on the worn surface, consisting of nanoparticle fragments (rGO and Al2 O3 ) and metal oxides (Fe2 O3 and FeO) with self-lubrication properties. [ABSTRACT FROM AUTHOR]- Published
- 2022
- Full Text
- View/download PDF
47. Hot-Pressed Super-Elastic Graphene Aerogel with Bidirectional Thermal Conduction Properties as Thermal Interface Materials.
- Author
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Lv, Peng, Zhou, Xiaofeng, and Chen, Songyue
- Subjects
THERMAL interface materials ,THERMOPHYSICAL properties ,GRAPHENE ,AEROGELS ,STRUCTURAL stability ,THERMAL properties - Abstract
Traditional graphene-based films normally possess high thermal conductivity (TC) only along a single direction, which is not suitable for thermal interface materials (TIMs). Here, a graphene film with excellent bidirectional TC and mechanical properties was prepared by hot-pressing super-elastic graphene aerogel (SEGA). Thermal annealing at 1800 °C improves the further restacking of graphene sheets, bringing high structure stability to SEGA for enduring the hot-pressing process. The junctions and nodes between the graphene layers in the hot-pressed SEGA (HPSEGA) film provide bidirectional heat transport paths. The in-plane TC and through-plane TC of HPSEGA film with a thickness of 101 μm reach 740 Wm
−1 K−1 and 42.5 Wm−1 K−1 , respectively. In addition, HPSEGA film with higher thickness still maintains excellent thermal transport properties due to the interconnected structure reducing the effect of the defects. The infrared thermal images visually manifest the excellent thermal-transfer capability and thermal-dissipation efficiency of the HPSEGA films, indicating the great potential as advanced bidirectional TIMs. [ABSTRACT FROM AUTHOR]- Published
- 2023
- Full Text
- View/download PDF
48. The Uncertainty Propagation for Carbon Atomic Interactions in Graphene under Resonant Vibration Based on Stochastic Finite Element Model.
- Author
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Shi, Jiajia, Chu, Liu, Ma, Chao, and Braun, Robin
- Subjects
FINITE element method ,ATOMIC interactions ,RESONANT vibration ,GRAPHENE ,MONTE Carlo method ,RUBIDIUM - Abstract
Graphene is one of the most promising two-dimensional nanomaterials with broad applications in many fields. However, the variations and fluctuations in the material and geometrical properties are challenging issues that require more concern. In order to quantify uncertainty and analyze the impacts of uncertainty, a stochastic finite element model (SFEM) is proposed to propagate uncertainty for carbon atomic interactions under resonant vibration. Compared with the conventional truss or beam finite element models, both carbon atoms and carbon covalent bonds are considered by introducing plane elements. In addition, the determined values of the material and geometrical parameters are expanded into the related interval ranges with uniform probability density distributions. Based on the SFEM, the uncertainty propagation is performed by the Monte Carlo stochastic sampling process, and the resonant frequencies of graphene are provided by finite element computation. Furthermore, the correlation coefficients of characteristic parameters are computed based on the database of SFEM. The vibration modes of graphene with the extreme geometrical values are also provided and analyzed. According to the computed results, the minimum and maximum values of the first resonant frequency are 0.2131 and 16.894 THz, respectively, and the variance is 2.5899 THz. The proposed SFEM is an effective method to propagate uncertainty and analyze the impacts of uncertainty in the carbon atomic interactions of graphene. The work in this paper provides an important supplement to the atomic interaction modeling in nanomaterials. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
49. Evaluation of Mechanical and Electrical Performance of Aging Resistance ZTA Composites Reinforced with Graphene Oxide Consolidated by SPS.
- Author
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Grigoriev, Sergey, Smirnov, Anton, Pinargote, Nestor Washington Solis, Yanushevich, Oleg, Kriheli, Natella, Kramar, Olga, Pristinskiy, Yuri, and Peretyagin, Pavel
- Subjects
ELECTRIC conductivity ,FRACTURE toughness ,BENDING strength ,GRAPHENE oxide ,GRAPHENE ,ZIRCONIUM oxide - Abstract
This paper presents a study of Al
2 O3 –ZrO2 (ZTA) nanocomposites with different contents of reduced graphene oxide (rGO). The influence of the rGO content on the physico-mechanical properties of the oxide composite was revealed. Graphene oxide was obtained using a modified Hummers method. Well-dispersed ZTA-GO nanopowders were produced using the colloidal processing method. Using spark plasma sintering technology (SPS), theoretically dense composites were obtained, which also reduced GO during SPS. The microstructure, phase composition, and physico-mechanical properties of the sintered composites were studied. The sintered ZTA composite with an in situ reduced graphene content of 0.28 wt.% after the characterization showed improved mechanical properties: bending strength was 876 ± 43 MPa, fracture toughness—6.8 ± 0.3 MPa·m1/2 and hardness—17.6 ± 0.3 GPa. Microstructure studies showed a uniform zirconia distribution in the ZTA ceramics. The study of the electrical conductivity of reduced graphene oxide-containing composites showed electrical conductivity above the percolation threshold with a small content of graphene oxide (0.28 wt.%). This electrical conductivity makes it possible to produce sintered ceramics by electrical discharge machining (EDM), which significantly reduces the cost of manufacturing complex-shaped products. Besides improved mechanical properties and EDM machinability, 0.28 wt.% rGO composites demonstrated high resistance to hydrothermal degradation. [ABSTRACT FROM AUTHOR]- Published
- 2022
- Full Text
- View/download PDF
50. Nano-Inclusions Applied in Cement-Matrix Composites: A Review.
- Author
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Bastos, Guillermo, Patiño-Barbeito, Faustino, Patiño-Cambeiro, Faustino, and Armesto, Julia
- Subjects
CEMENT ,NANOSTRUCTURED materials ,NANOSCIENCE ,COMMERCIAL products ,CHEMICAL synthesis - Abstract
Research on cement-based materials is trying to exploit the synergies that nanomaterials can provide. This paper describes the findings reported in the last decade on the improvement of these materials regarding, on the one hand, their mechanical performance and, on the other hand, the new properties they provide. These features are mainly based on the electrical and chemical characteristics of nanomaterials, thus allowing cement-based elements to acquire "smart" functions. In this paper, we provide a quantitative approach to the reinforcements achieved to date. The fundamental concepts of nanoscience are introduced and the need of both sophisticated devices to identify nanostructures and techniques to disperse nanomaterials in the cement paste are also highlighted. Promising results have been obtained, but, in order to turn these advances into commercial products, technical, social and standardisation barriers should be overcome. From the results collected, it can be deduced that nanomaterials are able to reduce the consumption of cement because of their reinforcing effect, as well as to convert cement-based products into electric/thermal sensors or crack repairing materials. The main obstacle to foster the implementation of such applications worldwide is the high cost of their synthesis and dispersion techniques, especially for carbon nanotubes and graphene oxide. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
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