Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 57
Filtrar
1.
Nanomaterials (Basel) ; 14(6)2024 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-38535694

RESUMO

We describe the creation of a conductive microcavity based on the assembly of two pieces of carbon nanotube buckypaper for the entrapment of two enzymes, horseradish peroxidase (HRP) and glucose oxidase (GOx), as well as a redox mediator: 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid diammonium salt (ABTS). The hollow electrode, employing GOx, HRP, and the mediator, as an electrochemical enzyme cascade model, is utilized for glucose sensing at a potential of 50 mV vs. Ag/AgCl. This bienzyme electrode demonstrates the ability to oxidize glucose by GOx and subsequently convert H2O2 to water via the electrical wiring of HRP by ABTS. Different redox mediators (ABTS, potassium hexacyanoferrate (III), and hydroquinone) are tested for HRP wiring, with ABTS being the best candidate for the electroenzymatic reduction of H2O2. To demonstrate the possibility to optimize the enzyme cascade configuration, the enzyme ratio is studied with 1 mg HRP combined with variable amounts of GOx (1-4 mg) and 2 mg GOx combined with variable amounts of HRP (0.5-2 mg). The bienzyme electrode shows continuous operational stability for over a week and an excellent storage stability in phosphate buffer, with a decay of catalytic current by only 29% for 1 mM glucose after 100 days.

2.
Talanta ; 269: 125494, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38043339

RESUMO

A new type of buckypaper of MWCNT with entrapped Nimodipine (NMD) drug was constructed. NMD features a nitroaromatic group that is electroreducible, and a dihydropyridine ring that can be electrooxidized. From the perspective of the nitroaromatic group's reductive capability, we have devised amperometric and voltammetric analytical strategies, including both differential pulse and linear voltammetric techniques. These methods are implemented using glassy carbon electrodes (GCE) modified with buckypaper (BP) disks composed of multiwalled carbon nanotubes (MWCNT), which are capable of adsorbing NMD. Furthermore, by capitalizing on the oxidative capacity of the dihydropyridine ring, we have designed strategies that involve amperometry using screen-printed electrodes (SPE) modified with BP-MWCNT mini discs within a Batch Injection Analysis Cell (BIAS) designed for SPE. The developed sensor was applied successfully to determine the drug in commercial tablets. The analytical parameters of this sensor were adequate, with a recovery value of 98.24 % and detection and quantification limits of 7.01 mgL-1 and 23.35 mgL-1, respectively using the DPV method.


Assuntos
Nanotubos de Carbono , Nanotubos de Carbono/química , Nimodipina , Eletrodos , Técnicas Eletroquímicas , Limite de Detecção
3.
Nano Lett ; 23(22): 10259-10266, 2023 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-37805929

RESUMO

WS2 nanotubes present many new technologies under development, including reinforced biocompatible polymers, membranes, photovoltaic-based memories, ferroelectric devices, etc. These technologies depend on the aspect ratio (length/diameter) of the nanotubes, which was limited to 100 or so. A new synthetic technique is presented, resulting in WS2 nanotubes a few hundred micrometers long and diameters below 50 nm (aspect ratios of 2000-5000) in high yields. Preliminary investigation into the mechanistic aspects of the two-step synthesis reveals that W5O14 nanowhisker intermediates are formed in the first step of the reaction instead of the ubiquitous W18O49 nanowhiskers used in the previous syntheses. The electrical and photoluminescence properties of the long nanotubes were studied. WS2 nanotube-based paper-like material was prepared via a wet-laying process, which could not be realized with the 10 µm long WS2 nanotubes. Ultrafiltration of gold nanoparticles using the nanotube-paper membrane was demonstrated.

4.
Nanomaterials (Basel) ; 13(18)2023 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-37764525

RESUMO

This study aims to exploit the distinctive properties of carbon nanotube materials, which are particularly pronounced at the microscopic scale, by deploying fabrication techniques that allow their features to be observed macroscopically. Specifically, we aim to create a semiconductor device that exhibits flexibility and the ability to modulate its electromagnetic wave absorption frequency by means of biasing. Initially, we fabricate a sheet of carbon nanotubes through a vacuum filtration process. Subsequently, phosphorus and boron elements are separately doped into the nanotube sheet, enabling it to embody the characteristics of a PN diode. Measurements indicate that, in addition to the fundamental diode's current-voltage relationship, the device also demonstrates intriguing transmission properties under the TEM mode of electromagnetic waves. It exhibits a frequency shift of approximately 2.3125 GHz for each volt of bias change. The final result is a lightweight and flexible carbon-based semiconductor microwave filter, which can conform to curved surfaces. This feat underscores the potential of such materials for innovative and effective electromagnetic wave manipulation.

5.
ACS Appl Mater Interfaces ; 15(25): 30039-30051, 2023 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-37309875

RESUMO

Amorphous polymer-derived silicon-oxycarbide (SiOC) ceramics have a high theoretical capacity and good structural stability, making them suitable anode materials for lithium-ion batteries. However, SiOC has low electronic conductivity, poor transport properties, low initial Couloumbic efficiency, and limited rate capability. Therefore, there is an urgent need to explore an efficient SiOC-based anode material that could mitigate the abovementioned limitations. In this study, we synthesized carbon-rich SiOC (SiOC-I) and silicon-rich SiOC (SiOC-II) and evaluated their elemental and structural characteristics using a broad spectrum of characterization techniques. Li-ion cells were fabricated for the first time by pairing a buckypaper composed of carbon nanotubes with SiOC-I or SiOC-II as the anode. When mixed with graphene nanoplatelets, the SiOC-II/GNP composites exhibited improved electrochemical performance. High specific capacity (average specific capacity of 744 mAh/g at a 0.1C rate) was achieved with the composite anode (25 wt % SiOC-II and 75% GNP), which was much better than that of monolithic SiOC-I, SiOC-II, or GNPs. This composite also exhibited excellent cycling stability, achieving 344 mAh/g after 260 cycles at a 0.5C rate and high reversibility. The enhanced electrochemical performance is attributed to better electronic conductivity, lower charge-transfer resistance, and short ion diffusion length. Due to their superior electrochemical performance, SiOC/GNP composites with CNT buckypaper as a current collector can be considered a promising anode material for LiBs.

6.
Int J Biol Macromol ; 242(Pt 1): 124726, 2023 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-37172702

RESUMO

Plastic waste is one cause of climate change. To solve this problem, packaging films are increasingly produced from biodegradable polymers. Eco-friendly carboxymethyl cellulose and its blends have been developed for such a solution. Herein, a unique strategy is demonstrated to improve the mechanical and barrier properties of carboxymethyl cellulose/poly(vinyl alcohol) (CMC/PVA) blended films for the packaging of nonfood dried products. The blended films were impregnated with buckypapers containing different combinations of multiwalled carbon nanotubes, two-dimensional molybdenum disulfide (2D MoS2) nanoplatelets, and helical carbon nanotubes (HCNTs). Compared to the blend, the polymer composite films exhibit significant increases in tensile strength (~105 %, from 25.53 to 52.41 MPa), Young's modulus (~297 %, from 155.48 to 617.48 MPa), and toughness (~46 %, from 6.69 to 9.75 MJ m-3). Polymer composite films containing HCNTs in buckypapers offer the highest toughness. For barrier properties, the polymer composite films are opaque. The water vapor transmission rate of the blended films decreases (~52 %, from 13.09 to 6.25 g h-1 m-2). Moreover, the maximum thermal-degradation temperature of the blend rises from 296 to 301 °C, especially for the polymer composite films with buckypapers containing MoS2 nanosheets that contribute to the barrier effect for both water vapor and thermal-decomposition gas molecules.


Assuntos
Nanotubos de Carbono , Álcool de Polivinil , Carboximetilcelulose Sódica , Vapor , Molibdênio , Celulose , Resistência à Tração
7.
Mikrochim Acta ; 190(5): 175, 2023 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-37022492

RESUMO

Carbon nanomaterials (CNMs) have some excellent properties that make them ideal candidates as sorbents for solid-phase extraction (SPE). However, practical difficulties related to their handling (dispersion in the atmosphere, bundling phenomena, reduced adsorption capability, sorbent loss in cartridge/column format, etc.) have hindered their direct use for conventional SPE modes. Therefore, researchers working in the field of extraction science have looked for new solutions to avoid the above-mentioned problems. One of these is the design of CNM-based membranes. These devices can be of two different types: membranes that are exclusively composed of CNMs (i.e. buckypaper and graphene oxide paper) and polysaccharide membranes containing dispersed CNMs. A membrane can be used either as a filter, operating under flow-through mode, or as a rotating device, operating under the action of magnetic stirring. In both cases, the main advantages arising from the use of membranes are excellent results in terms of transport rates, adsorption capability, high throughput, and ease of employment. This review covers the preparation/synthesis procedures of such membranes and their potential in SPE applications, highlighting benefits and shortcomings in comparison with conventional SPE materials (especially, microparticles carbonaceous sorbents) and devices. Further challenges and expected improvements are addressed too.

8.
Membranes (Basel) ; 13(1)2023 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-36676878

RESUMO

Single-walled carbon nanotube buckypapers (SWCNT-bps) coated with a metal-organic framework ZIF-8 layer were used as supports for the preparation of Pebax® 3533 TFC membranes by both phase inversion and spin coating techniques. Upon proper characterization of the materials by X-ray diffraction, IR spectroscopy, thermogravimetry and electron microscopy, the obtained membranes were tested in gas separation experiments with a 15:85 CO2/N2 mixture. These experiments proved that the ZIF-8 layer prevented from the penetration of the polymer selective film into the SWCNT-bp support, giving rise to a highly permeable selective membrane. The optimum membrane was achieved by the spin-coating method, with better permeation results than that prepared by the phase inversion method, obtaining a CO2 permeance of 566 GPU together with a CO2/N2 selectivity of 20.9.

9.
Molecules ; 27(22)2022 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-36431774

RESUMO

Pharmaceutical products such as antibiotics, analgesics, steroids, and non-steroidal anti-inflammatory drugs (NSAIDs) are new emerging pollutants, often present in wastewater, potentially able to contaminate drinking water resources. Adsorption is considered the cheapest and most effective technique for the removal of pollutants from water, and, recently, membranes obtained by wet filtration method of SWCNT aqueous solutions (SWCNT buckypapers, SWCNT BPs) have been proposed as self-standing porous adsorbents. In this paper, the ability of graphene oxide/single-walled carbon nanotube composite membranes (GO-SWCNT BPs) to remove some important NSAIDs, namely Diclofenac, Ketoprofen, and Naproxen, was investigated at different pH conditions (pH 4, 6, and 8), graphene oxide amount (0, 20, 40, 60, and 75 wt.%), and initial NSAIDs concentration (1, 10, and 50 ppm). For the same experimental conditions, the adsorption capacities were found to strongly depend on the graphene oxide content. The best results were obtained for 75 wt.% graphene oxide with an adsorption capacity of 118 ± 2 mg g-1 for Diclofenac, 116 ± 2 mg g-1 for Ketoprofen, and 126 ± 3 mg g-1 for Naproxen at pH 4. Overall, the reported data suggest that GO-SWCNT BPs can represent a promising tool for a cheap and fast removal of NSAIDs from drinking water resources, with easy recovery and reusability features.


Assuntos
Água Potável , Poluentes Ambientais , Cetoprofeno , Diclofenaco/química , Cetoprofeno/química , Naproxeno/química , Anti-Inflamatórios não Esteroides/química
10.
Artigo em Inglês | MEDLINE | ID: mdl-36226889

RESUMO

Current technologies for the manufacture of fiber-reinforced polymer composites are energy-intensive, environmentally unfriendly, and time-consuming and require expensive equipment and resources. In addition, composites typically lack key nonstructural functionalities (e.g., electrical conductivity for deicing, lightning strike protection, and structural health monitoring), which are crucial to many applications such as aerospace and wind energy. Here, we present a new approach for rapid and energy-efficient manufacturing of multifunctional composites without using traditional expensive autoclaves, ovens, or heated molds used for curing of composites. Our approach is predicated on embedding a thin conductive nanostructured paper in the composite layup to act as a resistive heater for triggering frontal polymerization of the matrix thermosetting resin of the composite laminate. Upon passing electric current, the nanostructured paper quickly heats up and initiates frontal polymerization, which then rapidly propagates through the thickness of the laminate, resulting in rapid curing of composites (within seconds to few minutes) irrespective of the size of the composite laminate. The integrated nanostructured paper remains advantageous during the service of the composite part by imparting new functionalities (e.g., deicing) to the cured composite, owing to its excellent electrical conductivity and electrothermal properties. In this work, we first study the influence of several composite processing parameters on the electrothermal properties of the nanostructured paper and determine the power required for rapid initiation of frontal polymerization. We then successfully fabricate a 10 cm × 10 cm composite panel within 1 min using only 4.49 kJ of energy, which is 4 orders of magnitude less than the energy consumed by the traditional bulk, oven-curing technique. Detailed experiments are conducted to provide an in-depth understanding of the effect of heater position, tooling material, and input power on frontal curing of composite laminates. The multifunctional response of produced composites is demonstrated by performing a deicing experiment, where a 50 × 50 × 3 mm3 cube of ice is completely melted within 3 min using an input power of 77 W.

11.
Bioelectrochemistry ; 148: 108254, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36122427

RESUMO

A novel membraneless ß-glucan/O2 enzymatic fuel cell was developed by combining a bioanode based on buckypaper modified with co-immobilized Agaricus meleagris pyranose dehydrogenase (AmPDH) and Rhodothermus marinus ß-glucosidase (RmBgl3B) (RmBgl3B-AmPDH/buckypaper) with a biocathode based on solid graphite modified with Myrothecium verrucaria bilirubin oxidase (MvBOx/graphite). AmPDH was connected electrochemically with the buckypaper using an osmium redox polymer in a mediated reaction, whereas MvBOx was connected with graphite in a direct electron transfer reaction. The fuel for the bioanode was produced by enzymatic hydrolysis of ß-glucan by the exoglucanase RmBgl3B into d-glucose, which in turn was enzymatically oxidised by AmPDH to generate a current response. This design allows to obtain an efficient enzymatic fuel cell, where the chemical energy converted into electrical energy is higher than the chemical energy stored in complex carbohydrate based fuel. The maximum power density of the assembled ß-glucan/O2 biofuel cell reached 26.3 ±â€¯4.6 µWcm-2 at 0.36 V in phosphate buffer containing 0.5 % (w/v) ß-glucan at 40 °C with excellent stability retaining 68.6 % of its initial performance after 5 days. The result confirms that ß-glucan can be employed as fuel in an enzymatic biofuel cell.


Assuntos
Fontes de Energia Bioelétrica , Grafite , beta-Glucanas , Agaricales , Eletrodos , Enzimas Imobilizadas , Glucose , Osmio , Fosfatos , Polímeros , Rhodothermus , beta-Glucosidase
12.
Nanomaterials (Basel) ; 12(14)2022 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-35889624

RESUMO

A new concept of hollow electrode based on the assembly of two buckypapers creating a microcavity which contains a biocatalyst is described. To illustrate this innovative concept, hollow bioelectrodes containing 0.16-4 mg bilirubin oxidase in a microcavity were fabricated and applied to electroenzymatic reduction of O2 in aqueous solution. For hemin-modified buckypaper, the bioelectrode shows a direct electron transfer between multi-walled carbon nanotubes and bilirubin oxidase with an onset potential of 0.77 V vs. RHE. The hollow bioelectrodes showed good storage stability in solution with an electroenzymatic activity of 30 and 11% of its initial activity after 3 and 6 months, respectively. The co-entrapment of bilirubin oxidase and 2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) in the microcavity leads to a bioelectrode exhibiting mediated electron transfer. After 23 h of intermittent operation, 5.66 × 10-4 mol of O2 were electroreduced (turnover number of 19,245), the loss of catalytic current being only 54% after 7 days.

13.
Molecules ; 27(13)2022 Jun 23.
Artigo em Inglês | MEDLINE | ID: mdl-35807300

RESUMO

Water decontamination is an important challenge resulting from the incorrect disposal of heavy metal waste into the environment. Among the different available techniques (e.g., filtration, coagulation, precipitation, and ion-exchange), adsorption is considered the cheapest and most effective procedure for the removal of water pollutants. In the last years, several materials have been tested for the removal of heavy metals from water, including metal-organic frameworks (MOFs), single-walled carbon nanotubes (SWCNTs), and graphene oxide (GO). Nevertheless, their powder consistency, which makes the recovery and reuse after adsorption difficult, is the main drawback for these materials. More recently, SWCNT buckypapers (SWCNT BPs) have been proposed as self-standing porous membranes for filtration and adsorption processes. In this paper, the adsorption capacity and selectivity of Pb2+ (both from neat solutions and in the presence of other interferents) by SWCNT BPs were evaluated as a function of the increasing amount of GO used in their preparation (GO-SWCNT buckypapers). The highest adsorption capacity, 479 ± 25 mg g-1, achieved for GO-SWCNT buckypapers with 75 wt.% of graphene oxide confirmed the effective application of such materials for cheap and fast water decontamination from lead.


Assuntos
Grafite , Metais Pesados , Nanotubos de Carbono , Poluentes Químicos da Água , Adsorção , Descontaminação , Tecnologia , Água , Poluentes Químicos da Água/análise
14.
Heliyon ; 8(12): e12633, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36643332

RESUMO

This study describes the fabrication of novel buckypaper membranes through the dispersion of multi-walled carbon nanotubes (MWCNTs) in the presence of surfactants metal oxide nano-catalysis Zinc oxide and magnesium oxide (ZnO and MgO) glycerol carbonate separately. Following vacuum filtration of the scattered solutions, self-supporting membranes known as buckypapers (BPs) were produced. The suggested membranes were employed for the efficient removal of heavy metals. The obtained data indicated that the incorporation of both glycerol carbonates prepared by two different nano metal oxides enhanced the permeability of MWCNTs membranes rejection efficiency. The characterization of the synthesized metal oxide nanoparticles, as well as the physicochemical and morphological properties of the membranes, were investigated. The rejection capabilities of membranes for the heavy metal ions were examined. Moreover, the suggested MWCNTs/ZnO nano-catalyst glycerol carbonate BP membrane displayed high rejection efficiency for heavy metals (Cd2+, Cu2+, Co2+, Ni2+, and Pb2+) than that prepared from the MgO nano-catalyst one.

15.
Materials (Basel) ; 14(20)2021 Oct 19.
Artigo em Inglês | MEDLINE | ID: mdl-34683796

RESUMO

With the rapid development of the aerospace field, traditional energy absorption materials are becoming more and more inadequate and cannot meet the requirements of having a light weight, high energy absorption efficiency, and high energy absorption density. Since existing studies have shown that carbon nanotube (CNT) buckypaper is a promising candidate for energy absorption, owing to its extremely high energy absorption efficiency and remarkable mass density of energy absorption, this study explores the application of buckypaper as the landing buffer material in a manned lunar lander. Firstly, coarse-grained molecular dynamics simulations were implemented to investigate the compression stress-strain relationships of buckypapers with different densities and the effect of the compression rate within the range of the landing velocity. Then, based on a self-designed manned lunar lander, buckypapers of appropriate densities were selected to be the energy absorption materials within the landing mechanisms of the lander. For comparison, suitable aluminum honeycomb materials, the most common energy absorption materials in lunar landers, were determined for the same landing mechanisms. Afterwards, the two soft-landing multibody dynamic models are established, respectively, and their soft-landing performances under three severe landing cases are analyzed, respectively. The results depicted that the landers, respectively, adopting the two energy absorption materials well, satisfy the soft-landing performance requirements in all the cases. It is worth mentioning that the lander employing the buckypaper is proved to demonstrate a better soft-landing performance, mainly reflected in reducing the mass of the energy absorption element by 8.14 kg and lowing the maximum center-of-mass overload of the lander by 0.54 g.

16.
Nanomicro Lett ; 13(1): 66, 2021 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-34138327

RESUMO

Lightweight, flexibility, and low thickness are urgent requirements for next-generation high-performance electromagnetic interference (EMI) shielding materials for catering to the demand for smart and wearable electronic devices. Although several efforts have focused on constructing porous and flexible conductive films or aerogels, few studies have achieved a balance in terms of density, thickness, flexibility, and EMI shielding effectiveness (SE). Herein, an ultrathin, lightweight, and flexible carbon nanotube (CNT) buckypaper enhanced using MXenes (Ti3C2Tx) for high-performance EMI shielding is synthesized through a facile electrophoretic deposition process. The obtained Ti3C2Tx@CNT hybrid buckypaper exhibits an outstanding EMI SE of 60.5 dB in the X-band at 100 µm. The hybrid buckypaper with an MXene content of 49.4 wt% exhibits an EMI SE of 50.4 dB in the X-band with a thickness of only 15 µm, which is 105% higher than that of pristine CNT buckypaper. Furthermore, an average specific SE value of 5.7 × 104 dB cm2 g-1 is exhibited in the 5-µm hybrid buckypaper. Thus, this assembly process proves promising for the construction of ultrathin, flexible, and high-performance EMI shielding films for application in electronic devices and wireless communications.

17.
J Hazard Mater ; 413: 125375, 2021 07 05.
Artigo em Inglês | MEDLINE | ID: mdl-33930951

RESUMO

Industrial effluents contain several organic and inorganic contaminants. Among others, dyes and heavy metals introduce a serious threat to drinking waterbodies. These pollutants can be noxious or carcinogenic in nature, and harmful to humans and different aquatic species. Therefore, it is of high importance to remove heavy metals and dyes to reduce their environmental toxicity. This has led to an extensive research for the development of novel materials and techniques for the removal of heavy metals and dyes. One route to the removal of these pollutants is the utilization of magnetic carbon nanotubes (CNT) as adsorbents. Magnetic carbon nanotubes hold remarkable properties such as surface-volume ratio, higher surface area, convenient separation methods, etc. The suitable characteristics of magnetic carbon nanotubes have led them to an extensive search for their utilization in water purification. Along with magnetic carbon nanotubes, the buckypaper (BP) membranes are also favorable due to their unique strength, high porosity, and adsorption capability. However, BP membranes are mostly used for salt removal from the aqueous phase and limited literature shows their applications for removal of heavy metals and dyes. This study focuses on the existence of heavy metal ions and dyes in the aquatic environment, and methods for their removal. Various fabrication approaches for the development of magnetic-CNTs and CNT-based BP membranes are also discussed. With the remarkable separation performance and ultra-high-water flux, magnetic-CNTs, and CNT-based BP membranes have a great potential to be the leading technologies for water treatment in future.

18.
Mater Sci Eng C Mater Biol Appl ; 120: 111757, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33545898

RESUMO

As a paper-like membrane composed of single-walled carbon nanotube (SWCNT), buckypaper possesses high conductivity, ideal flexibility, large surface area, great thermal/chemical stability and biocompatibility, which has manifested its potential as an alternative support material. However, due to the lack of defects, high quality SWCNT synthesized by arc-discharge method is difficult to be modified with metal nanoparticles for electro-catalysis. In this paper, a novel green strategy has been developed to fabricate SWCNT buckypaper decorated with Cu/reduced graphene oxide (Cu/rGO-BP) for the first time, in which graphene oxide functions as the intermediate between SWCNT and Cu nanoparticles. The fabricated Cu/rGO-BP was applied as a flexible electrode for electrochemical glucose detection. The electrode exhibited excellent electro-catalytic activity for glucose oxidation. The sensor based on Cu/rGO-BP performed a high upper limit of linear range (25 mM), which is close to commercial glucose sensors. The proposed strategy for Cu/rGO-BP fabrication can be extended to modify buckypaper with other metal or metal oxide nanoparticles, and thus opens an innovative route to potential practical applications of flexible buckypaper in wearable bioelectronics.


Assuntos
Técnicas Biossensoriais , Grafite , Técnicas Eletroquímicas , Eletrodos , Glucose
19.
Nanomaterials (Basel) ; 10(12)2020 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-33327367

RESUMO

The applications of pure multi-walled carbon nanotubes (MWCNTs) buckypapers are still limited due to their unavoidable micro/nano-sized pores structures. In this work, polyvinyl alcohol (PVA) was added to a uniform MWCNTs suspension to form MWCNT/PVA buckypapers by vacuum infiltration combined with a hot press method. The results showed an improvement in the thermal, electrical, and electromagnetic interference (EMI) shielding properties due to the formation of dense MWCNTs networks. The thermal and electrical properties rose from 1.394 W/m·k to 2.473 W/m·k and 463.5 S/m to 714.3 S/m, respectively. The EMI performance reached 27.08 dB. On the other hand, ABAQUS finite element software was used to simulate the coupled temperature-displacement performance. The electronic component module with buckypapers revealed a homogeneous temperature and thermal stress distribution. In sum, the proposed method looks promising for the easy preparation of multi-functional nanocomposites at low-cost.

20.
Nanomaterials (Basel) ; 10(11)2020 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-33202635

RESUMO

Buckypaper consisting of a carbon nanotube (CNT) sheet has a great potential for sensing and structural applications due to the exceptional piezoresistive and mechanical properties of CNTs. In this work, buckypaper was impregnated with the epoxy resin to improve the fragility and handling capability. The mechanical properties of the buckypaper/epoxy composite were determined by the tensile and nanoindentation tests. A thermogravimetric analyzer (TGA) was used to evaluate the thermal stability. Strain and temperature sensing performances of the buckypaper/epoxy composite based on the piezoresistive effect were investigated using a meter source. Experimental results indicated that the elastic modulus and ultimate strength of the buckypaper/epoxy composite were increased by 82% and 194%, respectively, in comparison with the pristine buckypaper, while the strain and temperature sensitivities were decreased by 33% and 0.2%, respectively. A significant increase of the tensile strength accompanied with a moderate decrease of the strain sensitivity demonstrates that the overall performance of buckypaper/epoxy composite is better than that of pristine buckypaper.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA