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1.
Small ; 20(38): e2400824, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38764257

RESUMO

Halide perovskite, renowned for its multifunctional properties, shows considerable promise for realizing self-charging power systems. In this study, a lead-free methylammonium bismuth iodide (MA3Bi2I9) perovskite is used to create a self-charging power unit (SPU). This involves constructing a hybrid piezoelectric-triboelectric nanogenerator (Hybrid-TENG) and utilizing MA3Bi2I9 for energy storage as an anode in a lithium-ion battery (LIB). Initially, MA3Bi2I9 nanorods are synthesized and composited with a polystyrene-block-poly(ethylene-ran-butylene)-block-polystyrene polymer. The dielectric and mechanical properties of composite films having perovskite loading content are investigated. The optimized Hybrid-TENG exhibits superior performance, generating a voltage of 537 V, current density of 13.2 µA cm- 2, and maximum power density of 3.04 mW cm-2, which can be attributed to the high piezoelectric coefficient of MA3Bi2I9 nanorods (≈20.6 pm V-1). A MA3Bi2I9 thin film, serving as an electrode in LIB, demonstrates a high specific capacity of 2378.9 mAh cm-3 (578.8 mAh g-1) with a capacity retention of ≈87.5% over 100 cycles, underscoring its stable performance. Furthermore, a Hybrid-TENG is employed to charge the MA3Bi2I9-based LIB, thus realizing an SPU for driving portable electronics. This study highlights the promising potential of perovskites for developing efficient nanogenerators and LIBs, paving the way for sustainable energy solutions in small-scale electronics.

2.
Int J Phytoremediation ; 23(3): 300-306, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33180560

RESUMO

In this study, the pseudo wastewater containing Zn, Fe, Cu ions was clean-up by a combination of physical adsorption onto activated carbon medium and phytoaccumulation using Acrostichum aureum Linn. plants. The adsorption capability of the activated carbon for the Fe, Cu, and Zn ions was 3.05, 3.72, and 2.85 mg·g - 1, respectively, at the saturation. The phytoaccumulation performance was proved by analyzing the individual residual ash collected after pyrolysis up to 1000 °C of the leaf, stem, and root of the plants. Thermal analyses of thermogravimetry data showed that the weight of the residual ash of the phytoremediated leaf, stem, and root of the plants was 37.0, 19.0, and 65.7 wt.%, respectively. Energy-dispersive X - ray spectroscopy determined the amount of Fe element in the residual ash of phytoremediated root is 7.05 wt.%, while that of the initial root is 1.18 wt.%. Conclusively, it can be proved that combining physical and biological processes is feasible to treat wastewater containing metal ions.


Assuntos
Poluentes Químicos da Água , Purificação da Água , Adsorção , Biodegradação Ambiental , Carvão Vegetal , Concentração de Íons de Hidrogênio , Cinética , Poluentes Químicos da Água/análise
3.
Zygote ; 28(6): 447-452, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32772939

RESUMO

Experiments were conducted to study in vitro maturation of prepubertal goat oocytes and their developmental potential after chemical activation. In Experiment 1, cumulus-oocytes complexes collected from the ovaries of prepubertal goats slaughtered at a local abattoir were matured in vitro in TCM-199-based medium supplemented with 10 µg/ml luteinizing hormone (LH) (treatment 1) or 10 µg/ml LH + 0.1 mM l-cysteine (treatment 2). In Experiment 2, mature oocytes were activated with either 5 µM ionomycin or 7% ethanol. After 18 h, some oocytes were randomly fixed and stained to evaluate their chromatin status, while others were cultured in embryo culture medium to study their further development. In Experiment 3, oocytes activated with 5 µM ionomycin were cultured for 7 days in one of the four different culture media [Charles Rosenkrans medium (CR-1), TCM-199, potassium simplex optimization medium (KSOM) and synthetic oviductal fluid (SOF)] to study their developmental potential. The maturation rate in control, treatment 1, and treatment 2 media did not differ from each other (P > 0.05). However, the lowest degeneration of oocytes was observed in treatment 3 (P < 0.05) when compared with the other two groups. The proportion of activated oocytes was higher, while non-activated oocytes were lower in ionomycin group when compared with the group activated with ethanol (P < 0.05). The proportions of oocytes cleaved were 65.7, 56.8, 61.0 and 54.4% in CR-1, TCM-199, KSOM and SOF medium, respectively, with no significant difference. However, further development of cleaved oocytes was better in KSOM followed by SOF.


Assuntos
Blastocisto , Cabras , Animais , Meios de Cultura , Fertilização in vitro , Ionomicina , Oócitos
4.
BMC Plant Biol ; 19(1): 120, 2019 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-30935415

RESUMO

BACKGROUND: Polyunsaturated fatty acids such as linoleic acid (LA) and α-linolenic acid (ALA) are abundant in vegetable oils and are important for human health. In the body, LA and ALA are respectively converted to the omega-6 fatty acid γ-linolenic acid (GLA) and the omega-3 fatty acid stearidonic acid (SDA) by Δ6 desaturase (D6DES). Currently, dietary GLA and SDA are mainly obtained from marine organisms, but given their benefits to human health, many studies have aimed to enhance their accumulation in transgenic crops. Perilla frutescens (perilla) accumulates more ALA in its seed oil compared to other oilseed crops, making it a good candidate for the production of fatty acids via the fatty acid desaturase D6DES. RESULTS: In this study, we cloned the D6DES gene from Phytophthora citrophthora and confirmed its function in budding yeast. We then transformed the functional D6DES gene under the control of the seed-specific vicilin promoter into the perilla cultivar Yeobsil. The resulting transgenic perilla seeds accumulated significant levels of GLA and SDA, as well as putative C18:2Δ6,9 at minor levels. Developing seeds and leaves also accumulated GLA and SDA, although PcD6DES expression and GLA and SDA levels were much lower in leaves compared to developing seeds. GLA and SDA accumulated in both polar lipids and neutral lipids in mature perilla seeds expressing PcD6DES, especially in neutral lipids. Although the seed weight in PcD6DES perilla was 87-96% that of wild type, the total oil content per seed weight was similar between lines. The PcD6DES perilla plants contained very high content (over 45%) of both GLA and SDA in seed oil. CONCLUSIONS: Thus, PcD6DES perilla plants may represent a feasible alternative to traditional marine sources for the production of omega-3 oil capsules and to evening primrose seed oil for GLA as health food. In addition, these plants can be used to create other transgenic lines harboring additional genes to produce other desirable fish-oil like oils.


Assuntos
Ácidos Graxos Ômega-3/metabolismo , Perilla frutescens/metabolismo , Sementes/metabolismo , Ácido gama-Linolênico/metabolismo , Óleos de Plantas/metabolismo , Plantas Geneticamente Modificadas
5.
Int J Syst Evol Microbiol ; 69(7): 1864-1869, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31046896

RESUMO

An aerobic, Gram-stain-negative, polar-flagellated, rod-shaped bacterium, designated as SC2-7T, was isolated from the dust collector at a pig farm located in Wanju-gun, Jeollabuk-do, Republic of Korea. Growth occurred at 10-37 °C (optimum, 28-30 °C), pH 6.0-10.0 (optimum, 7.0-8.0) and in the presence of 0-3 % (w/v) NaCl (optimum, 0 %) on Reasoner's 2A medium. The phylogenetic tree based on the 16S rRNA gene sequences revealed that strain SC2-7T was a member of the family Comamonadaceae, forming a robust cluster with the genera Alicycliphilus, Oryzisolibacter and Melaminivora. The 16S rRNA gene sequences of strain SC2-7T showed the highest sequence similarities to Alicycliphilus denitrificans K601T (97.2 %), Oryzisolibacter propanilivorax EPL6T (97.0 %), Melaminivora alkalimesophila CY1T (96.9 %), Diaphorobacter polyhydroxybutyrativorans SL-205T (96.6 %), Diaphorobacter nitroreducens NA10BT (96.6 %) and Melaminivora jejuensis KBB12T (96.5 %). The tree based on the gyrA gene sequences also showed that strain SC2-7T fell into a phylogenetic position similar to that based on the 16S rRNA gene sequences. The polar lipids present were phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylglycerol, an unidentified aminolipid and an unidentified phospholipid. The predominant quinone was ubiquione-8. The major fatty acids were summed feature 3 (including C16 : 1ω6c and/or C16 : 1ω7c), C16 : 0 and summed feature 8 (including C18 : 1ω6c and/or C18 : 1ω7c). The genomic DNA G+C content was 69.1 mol%. On the basis of the phenotypic, phylogenetic and chemotaxonomic data presented here, strain SC2-7T represents a novel species of a new genus, for which the name Pulveribacter suum gen. nov., sp. nov., is proposed. The type strain of Pulveribacter suum is SC2-7T (=KACC 19309T=NBRC 113102T).


Assuntos
Comamonadaceae/classificação , Poeira , Fazendas , Filogenia , Animais , Técnicas de Tipagem Bacteriana , Composição de Bases , Comamonadaceae/isolamento & purificação , DNA Bacteriano/genética , Ácidos Graxos/química , Genes Bacterianos , Fosfolipídeos/química , RNA Ribossômico 16S/genética , República da Coreia , Análise de Sequência de DNA , Suínos , Ubiquinona/química
6.
Chemphyschem ; 19(13): 1627-1634, 2018 07 05.
Artigo em Inglês | MEDLINE | ID: mdl-29603536

RESUMO

Polymeric binder distribution within electrodes is crucial to guarantee the electrochemical performance of lithium-ion batteries (LIBs) for their long-term use in applications such as electric vehicles and energy-storage systems. However, due to limited analytical tools, such analyses have not been conducted so far. Herein, the adhesion properties of LIB electrodes at different depths are measured using a surface and interfacial cutting analysis system (SAICAS). Moreover, two LiCoO2 electrodes, dried at 130 and 230 °C, are carefully prepared and used to obtain the adhesion properties at every 10 µm of depth as well as the interface between the electrode composite and the current collector. At high drying temperatures, more of the polymeric binder material and conductive agent appears adjacent to the electrode surface, resulting in different adhesion properties as a function of depth. When the electrochemical properties are evaluated at different temperatures, the LiCoO2 electrode dried at 130 °C shows a much better high-temperature cycling performance than does the electrode dried at 230 °C due to the uniform adhesion properties and the higher interfacial adhesion strength.

7.
Proc Natl Acad Sci U S A ; 111(18): 6566-9, 2014 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-24760831

RESUMO

Here we present a simple and fast method to reliably image polarization charges using charge gradient microscopy (CGM). We collected the current from the grounded CGM probe while scanning a periodically poled lithium niobate single crystal and single-crystal LiTaO3 thin film on the Cr electrode. We observed current signals at the domains and domain walls originating from the displacement current and the relocation or removal of surface charges, which enabled us to visualize the ferroelectric domains at a scan frequency above 78 Hz over 10 µm. We envision that CGM can be used in high-speed ferroelectric domain imaging and piezoelectric energy-harvesting devices.

8.
Rep Prog Phys ; 79(7): 076501, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-27308889

RESUMO

The interfaces of polar oxide heterostructures can display electronic properties unique from the oxides they border, as they require screening from either internal or external sources of charge. The screening mechanism depends on a variety of factors, including the band structure at the interface, the presence of point defects or adsorbates, whether or not the oxide is ferroelectric, and whether or not an external field is applied. In this review, we discuss both theoretical and experimental aspects of different screening mechanisms, giving special emphasis to ways in which the mechanism can be altered to provide novel or tunable functionalities. We begin with a theoretical introduction to the problem and highlight recent progress in understanding the impact of point defects on polar interfaces. Different case studies are then discussed, for both the high thickness regime, where interfaces must be screened and each interface can be considered separately, and the low thickness regime, where the degree and nature of screening can be manipulated and the interfaces are close enough to interact. We end with a brief outlook toward new developments in this rapidly progressing field.

9.
Small ; 11(31): 3750-4, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25929761

RESUMO

Highly ordered and well-aligned PbTiO3/TiN core-shell nanotubes are fabricated via an anodic aluminum oxide templating route followed by TiN and TiO2 atomic layer deposition deposition and a subsequent PbO vapor reaction. PbTiO3/TiN nanotubes keep their original shape after the vapor phase reaction, and they display well-defined piezoresponse hysteresis curves with remnant piezoresponse of 38 pm V(-1) .

10.
ACS Appl Mater Interfaces ; 16(2): 1999-2011, 2024 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-38175621

RESUMO

Bone regeneration remains a critical concern across diverse medical disciplines, because it is a complex process that requires a combinatorial approach involving the integration of mechanical, electrical, and biological stimuli to emulate the native cellular microenvironment. In this context, piezoelectric scaffolds have attracted considerable interest owing to their remarkable ability to generate electric fields in response to dynamic forces. Nonetheless, the application of such scaffolds in bone tissue engineering has been limited by the lack of a scaffold that can simultaneously provide both the intricate electromechanical environment and the biocompatibility of the native bone tissue. Here, we present a pioneering biomimetic scaffold that combines the unique properties of piezoelectric and topographical enhancement with the inherent osteogenic abilities of hydroxyapatite (HAp). Notably, the novelty of this work lies in the incorporation of HAp into polyvinylidene fluoride-co-trifluoro ethylene in a freestanding form, leveraging its natural osteogenic potential within a piezoelectric framework. Through comprehensive in vitro and in vivo investigations, we demonstrate the remarkable potential of these scaffolds to accelerate bone regeneration. Moreover, we demonstrate and propose three pivotal mechanisms─(i) electrical, (ii) topographical, and (iii) paracrine─that collectively contribute to the facilitated bone healing process. Our findings present a synergistically derived biomimetic scaffold design with wide-ranging prospects for bone regeneration as well as various regenerative medicine applications.


Assuntos
Regeneração Óssea , Alicerces Teciduais , Engenharia Tecidual , Osteogênese , Osso e Ossos , Durapatita/farmacologia
11.
Adv Sci (Weinh) ; 11(39): e2406678, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39159132

RESUMO

Alzheimer's disease (AD) is the most frequent neurodegenerative disorder in the elderly aged over 65. The extracellular accumulation of beta-amyloid (Aß) aggregates in the brain is considered as the major event worsening the AD symptoms, but its underlying reason has remained unclear. Here the piezoelectric characteristics of Aß aggregates are revealed. The vector piezoresponse force microscopy (PFM) analysis results exhibit that Aß fibrils have spiraling piezoelectric domains along the length and a lateral piezoelectric constant of 44.1 pC N-1. Also, the continuous sideband Kelvin probe force microscopy (KPFM) images display that the increment of charge-induced surface potential on a single Aß fibril is allowed to reach above +1700 mV in response to applied forces. These findings shed light on the peculiar mechano-electrical surface properties of pathological Aß fibrils that exceed those of normal body components.


Assuntos
Doença de Alzheimer , Peptídeos beta-Amiloides , Microscopia de Força Atômica , Peptídeos beta-Amiloides/metabolismo , Doença de Alzheimer/metabolismo , Doença de Alzheimer/patologia , Microscopia de Força Atômica/métodos , Humanos
12.
Adv Sci (Weinh) ; 11(17): e2310094, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38408139

RESUMO

Electrolyte additives with multiple functions enable the interfacial engineering of Li-metal batteries (LMBs). Owing to their unique reduction behavior, additives exhibit a high potential for electrode surface modification that increases the reversibility of Li-metal anodes by enabling the development of a hierarchical solid electrolyte interphase (SEI). This study confirms that an adequately designed SEI facilitates the homogeneous supply of Li+, nonlocalized Li deposition, and low electrolyte degradation in LMBs while enduring the volume fluctuation of Li-metal anodes on cycling. An in-depth analysis of interfacial engineering mechanisms reveals that multilayered SEI structures comprising mechanically robust LiF-rich species, electron-rich P-O species, and elastic polymeric species enabled the stable charge and discharge of LMBs. The polymeric outer SEI layer in the as-fabricated multilayered SEI could accommodate the volume fluctuation of Li-metal anodes, significantly enhancing the cycling stability Li||LiNi0.8Co0.1Mn0.1O2 full cells with an electrolyte amount of 3.6 g Ah-1 and an areal capacity of 3.2 mAh cm-2. Therefore, this study confirms the ability of interfacial layers formed by electrolyte additives and fluorinated solvents to advance the performance of LMBs and can open new frontiers in the fabrication of high-performance LMBs through electrolyte-formulation engineering.

13.
Nat Commun ; 15(1): 387, 2024 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-38195614

RESUMO

Switchable tribological properties of ferroelectrics offer an alternative route to visualize and control ferroelectric domains. Here, we observe the switchable friction and wear behavior of ferroelectrics using a nanoscale scanning probe-down domains have lower friction coefficients and show slower wear rates than up domains and can be used as smart masks. This asymmetry is enabled by flexoelectrically coupled polarization in the up and down domains under a sufficiently high contact force. Moreover, we determine that this polarization-sensitive tribological asymmetry is widely applicable across various ferroelectrics with different chemical compositions and crystalline symmetry. Finally, using this switchable tribology and multi-pass patterning with a domain-based dynamic smart mask, we demonstrate three-dimensional nanostructuring exploiting the asymmetric wear rates of up and down domains, which can, furthermore, be scaled up to technologically relevant (mm-cm) size. These findings demonstrate that ferroelectrics are electrically tunable tribological materials at the nanoscale for versatile applications.

14.
Phys Rev Lett ; 110(17): 177601, 2013 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-23679778

RESUMO

We used x-ray Bragg projection ptychography (BPP) to map spatial variations of ferroelectric polarization in thin film PbTiO3, which exhibited a striped nanoscale domain pattern on a high-miscut (001) SrTiO3 substrate. By converting the reconstructed BPP phase image to picometer-scale ionic displacements in the polar unit cell, a quantitative polarization map was made that was consistent with other characterization. The spatial resolution of 5.7 nm demonstrated here establishes BPP as an important tool for nanoscale ferroelectric domain imaging, especially in complex environments accessible with hard x rays.

15.
ACS Appl Mater Interfaces ; 15(22): 26660-26669, 2023 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-37212378

RESUMO

Here, we investigate the nonlinear relationship between the content of solid electrolytes in composite electrodes and the irreversible capacity via the degree of nanoscale uniformity of the surface morphology and chemical composition of the solid electrolyte interphase (SEI) layer. Using electrochemical strain microscopy (ESM) and X-ray photoelectron spectroscopy (XPS), changes of the chemical composition and morphology (Li and F distribution) in SEI layers on the electrodes as a function of solid electrolyte contents are analyzed. As a result, we find that the solid electrolyte content affects the variation of the SEI layer thickness and chemical distributions of Li and F ions in the SEI layer, which, in turn, influence the Coulombic efficiency. This correlation determines the composition of the composite electrode surface that can maximize the physical and chemical uniformity of the solid electrolyte on the electrode, which is a key parameter to increase electrochemical performance in solid-state batteries.

16.
ACS Appl Mater Interfaces ; 15(27): 32707-32716, 2023 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-37377389

RESUMO

Two-dimensional (2D) siloxene is attracting considerable research interest recently principally owing to its inherent compatibility with silicon-based semiconductor technology. -The synthesis of siloxene has been mostly limited to multilayered structures using traditional topochemical reaction procedures. Herein, we report high-yield synthesis of single to few-layer siloxene nanosheets by developing a two-step interlayer expansion and subsequent liquid phase exfoliation procedure. Our protocol enables high-yield production of few-layer siloxene nanosheets with a lateral dimension of up to 4 µm and thickness ranging from 0.8 to 4.8 nm, corresponding to single to a few layers, well stabilized in water. The atomically flat nature of exfoliated siloxene can be exploited for the construction of 2D/2D heterostructure membranes via typical solution processing. We demonstrate highly ordered graphene/siloxene heterostructure films with synergistic mechanical and electrical properties, which deliver noticeably high device capacitance when assembled into a coin cell symmetric supercapacitor device structures. Additionally, we demonstrate that the mechanically flexible exfoliated siloxene-graphene heterostructure enables its direct use in flexible and wearable supercapacitor applications.

17.
Adv Sci (Weinh) ; 10(2): e2204248, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36394076

RESUMO

Engineering active sites of metal nanoparticle-based heterogeneous catalysts is one of the most prerequisite approaches for the efficient production of chemicals, but the limited active sites and undesired oxidation on the metal nanoparticles still remain as key challenges. Here, it is reported that the negatively charged surface of copper nanoparticles on the 2D [Ca2 N]+ ∙e- electride provides the unrestricted active sites for catalytic selective sulfenylation of indoles and azaindoles with diaryl disulfides. Substantial electron transfer from the electride support to copper nanoparticles via electronic metal-support interactions results in the accumulation of excess electrons at the surface of copper nanoparticles. Moreover, the surface-accumulated excess electrons prohibit the oxidation of copper nanoparticle, thereby maintaining the metallic surface in a negatively charged state and activating both (aza)indoles and disulfides under mild conditions in the absence of any further additives. This study defines the role of excess electrons on the nanoparticle-based heterogeneous catalyst that can be rationalized in versatile systems.

18.
Comput Methods Programs Biomed ; 236: 107561, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37119774

RESUMO

BACKGROUND AND OBJECTIVE: In order to be context-aware, computer-assisted surgical systems require accurate, real-time automatic surgical workflow recognition. In the past several years, surgical video has been the most commonly-used modality for surgical workflow recognition. But with the democratization of robot-assisted surgery, new modalities, such as kinematics, are now accessible. Some previous methods use these new modalities as input for their models, but their added value has rarely been studied. This paper presents the design and results of the "PEg TRAnsfer Workflow recognition" (PETRAW) challenge with the objective of developing surgical workflow recognition methods based on one or more modalities and studying their added value. METHODS: The PETRAW challenge included a data set of 150 peg transfer sequences performed on a virtual simulator. This data set included videos, kinematic data, semantic segmentation data, and annotations, which described the workflow at three levels of granularity: phase, step, and activity. Five tasks were proposed to the participants: three were related to the recognition at all granularities simultaneously using a single modality, and two addressed the recognition using multiple modalities. The mean application-dependent balanced accuracy (AD-Accuracy) was used as an evaluation metric to take into account class balance and is more clinically relevant than a frame-by-frame score. RESULTS: Seven teams participated in at least one task with four participating in every task. The best results were obtained by combining video and kinematic data (AD-Accuracy of between 93% and 90% for the four teams that participated in all tasks). CONCLUSION: The improvement of surgical workflow recognition methods using multiple modalities compared with unimodal methods was significant for all teams. However, the longer execution time required for video/kinematic-based methods(compared to only kinematic-based methods) must be considered. Indeed, one must ask if it is wise to increase computing time by 2000 to 20,000% only to increase accuracy by 3%. The PETRAW data set is publicly available at www.synapse.org/PETRAW to encourage further research in surgical workflow recognition.


Assuntos
Algoritmos , Procedimentos Cirúrgicos Robóticos , Humanos , Fluxo de Trabalho , Procedimentos Cirúrgicos Robóticos/métodos
19.
Nano Lett ; 11(4): 1428-33, 2011 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-21375284

RESUMO

Nanoscale manipulation of surface charges and their imaging are essential for understanding local electronic behaviors of polar materials and advanced electronic devices. Electrostatic force microscopy and Kelvin probe force microscopy have been extensively used to probe and image local surface charges responsible for electrodynamics and transport phenomena. However, they rely on the weak electric force modulation of cantilever that limits both spatial and temporal resolutions. Here we present a field effect transistor embedded probe that can directly image surface charges on a length scale of 25 nm and a time scale of less than 125 µs. On the basis of the calculation of net surface charges in a 25 nm diameter ferroelectric domain, we could estimate the charge density resolution to be as low as 0.08 µC/cm(2), which is equivalent to 1/20 electron per nanometer square at room temperature.


Assuntos
Ferro/química , Micromanipulação/métodos , Modelos Químicos , Nanoestruturas/química , Nanoestruturas/efeitos da radiação , Simulação por Computador , Campos Eletromagnéticos , Eletricidade Estática
20.
ACS Appl Mater Interfaces ; 14(27): 30639-30648, 2022 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-35731963

RESUMO

Conductive atomic force microscopy (C-AFM) is widely used to determine the electronic conductivity of a sample surface with nanoscale spatial resolution. However, the origin of possible artifacts has not been widely researched, hindering the accurate and reliable interpretation of C-AFM imaging results. Herein, artifact-free C-AFM is used to observe the electron conduction channels in Si-based composite anodes. The origin of a typical C-AFM artifact induced by surface morphology is investigated using a relevant statistical method that enables visualization of the contribution of artifacts in each C-AFM image. The artifact is suppressed by polishing the sample surface using a cooling cross-section polisher, which is confirmed by Pearson correlation analysis. The artifact-free C-AFM image was used to compare the current signals (before and after cycling) from two different composite anodes comprising single-walled carbon nanotubes (SWCNTs) and carbon black as conductive additives. The relationship between the electrical degradation and morphological evolution of the active materials depending on the conductive additive is discussed to explain the improved electrical and electrochemical properties of the electrode containing SWCNTs.

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