Electric Intensity Research Articles

Exploring the dynamic fracture performance of epoxy/cement based piezoelectric composites with complex interfaces

Dynamic intensity factors (IFs) are the key parameters in comprehending and forecasting dynamic fracture behavior of piezoelectric composites. A domain-independent interaction integral (DII-integral) is developed to extract the dynamic stress intensity factors (SIFs) and electric displacement intensity factor (EDIF). The DII-integral is theoretically proved that there is no need to consider the electromechanical material derivatives and complicated material interfaces have no effect on the application of the method. Evaluating the results with the published data yields a good agreement and good domain-independence of the proposed I-integral is checked for multi-interface piezoelectric composites. The numerical simulations show that the amplitudes of the dynamic IFs decrease as the size of piezoelectric particle increases and crack damage is prevented as the number of piezoelectric particles increases. The peak values of the dynamic IFs are not monotonically related to the distance between the particles due to the superposition of elastic waves. The dynamic IFs increase when the volume percentage of piezoelectric fiber rises, while the opposite change is observed in laminated composites. Generally, the dynamic IFs of fiber-reinforced composites are smaller (larger) than that of laminated composites when the volume fraction of piezoelectric ceramics is higher (lower) than 40 percent.

Nanoscale electric field sensing using a levitated nano-resonator with net charge

The nanomechanical resonator based on a levitated particle exhibits unique advantages in the development of ultrasensitive electric field detectors. We demonstrate a three-dimensional, high-sensitivity electric field measurement technology using the optically levitated nanoparticle with known net charge. By scanning the relative position between nanoparticle and parallel electrodes, the three-dimensional electric field distribution with microscale resolution is obtained. The measured noise equivalent electric intensity with charges of 100 e reaches the order of 1 μV ⋅ cm − 1 ⋅ Hz − 1 / 2 at 1.4 × 10 − 7 mbar . Linearity analysis near resonance frequency shows a measured linear range over 91 dB limited only by the maximum output voltage of the driving equipment. This work may provide an avenue for developing a high-sensitivity electric field sensor based on an optically levitated nano-resonator.

FCO2: Green Infrastructure Supporting Indonesia Carbon Neutral 2060

Climate change is often a problem in almost every country. This is inseparable from the crucial problems related to climate change issues experienced by Indonesia from year to year. One of them is the issue of increasing carbon emissions caused by various energy sectors, the automotive transportation industry, and home industries. The Climate Transparency 2021 report states that although Indonesia has proposed increasing the use of renewable energy in the fields of electricity, transportation, and industry (Climate Transparency, 2021), in addition, Indonesia does not yet have a gradual strategy related to stopping the use of coal and there is no policy that is able to encourage competition between renewable energy. and coal. Indonesia is committed to the world and targets the achievement of carbon neutrality by 2060 through the submission of the Long Term Strategy on Low Carbon and Climate Resilience 2050 document to the UNFCCC which is the mandate of the Paris Agreement which has been ratified into Law no. 16 of 2016 which contains the Ratification of the Paris Agreement To The United Nations Framework Convention On Climate Change. The method used in making this paper is a descriptive method with a quantitative approach based on literature review. Where in this method describes the consequences that occur from an increase in carbon emissions, solutions in dealing with problems caused by carbon emissions. The method used in collecting data in this proposal is secondary data, namely data sourced from library materials, both from articles and official websites such as the website of the Badan Pusat Statistik Indonesia. In order to achieve Indonesia's target of carbon neutral 2060, an infrastructure innovation called FCO2 was made which has an effectiveness of 80% in reducing carbon emissions. The carbon emission reduction system used in FCO2 is in the form of filtration, which functions to filter the air and exhaust gases from the carbon content caused by various industrial and vehicle activities. On the other hand, FCO2also has a part that will function in spraying disinfectant into the air to kill microorganisms, such as viruses, bacteria in the air. The disinfectant used uses natural ingredients, which are made from lime and betel leaf. In addition, so that the use of FCO2 can provide more optimal results, it is also necessary to support the government, private, and community sectors to play a major role in expanding green open space infrastructure evenly.

Optimization and commissioning of the EPIC commensal radio transient imager for the long wavelength array

ABSTRACT Next-generation aperture arrays are expected to consist of hundreds to thousands of antenna elements with substantial digital signal processing to handle large operating bandwidths of a few tens to hundreds of MHz. Conventionally, FX correlators are used as the primary signal processing unit of the interferometer. These correlators have computational costs that scale as $\mathcal {O}(N^2)$ for large arrays. An alternative imaging approach is implemented in the E-field Parallel Imaging Correlator (EPIC) that was recently deployed on the Long Wavelength Array station at the Sevilleta National Wildlife Refuge (LWA-SV) in New Mexico. EPIC uses a novel architecture that produces electric field or intensity images of the sky at the angular resolution of the array with full or partial polarization and the full spectral resolution of the channelizer. By eliminating the intermediate cross-correlation data products, the computational costs can be significantly lowered in comparison to a conventional FX or XF correlator from $\mathcal {O}(N^2)$ to $\mathcal {O}(N \log N)$ for dense (but otherwise arbitrary) array layouts. EPIC can also lower the output data rates by directly yielding polarimetric image products for science analysis. We have optimized EPIC and have now commissioned it at LWA-SV as a commensal all-sky imaging back-end that can potentially detect and localize sources of impulsive radio emission on millisecond timescales. In this article, we review the architecture of EPIC, describe code optimizations that improve performance, and present initial validations from commissioning observations. Comparisons between EPIC measurements and simultaneous beam-formed observations of bright sources show spectral-temporal structures in good agreement.

A coupled thermal-electrical-structural model for balloon-based thermoplasty treatment of atherosclerosis

Objectives The outcome of balloon-based atherosclerosis thermoplasty is closely related to the temperature/stress distribution during the treatment. For precise prediction of a required thermal lesion in the heterogeneous and thin atherosclerotic vessel, a numerical model incorporating heat-induced tissue expansion or shrinkage and the strain caused by balloon dilation is necessary. Methods A fully coupled thermal-electrical-structural new model was established. The model features a heterogeneous structure including eccentric plaque, healthy artery and surrounding tissue. Tissue expansion/shrinkage and hyperelasticity material model were taken into consideration. Different heating strategies and plaque mechanical properties were investigated. The temperature distribution was compared with the traditional thermal-electrical coupled model. The possibility of thermoplasty treatment using balloons with different sizes was also explored. Results The temperature, the electrical intensity and the stress during the thermoplasty were obtained. Lower stress was found in the heating region where tissue shrinkage occurred. The ablation depth was predicted to be ∼0.42 mm larger without coupling the biomechanical influence. The mechanical properties and input condition significantly affect the temperature and stress distribution considering the small dimensions of the tissue. Besides, with a 12.5% reduction of balloon diameter, the largest Von Mises stress decreases by 25.4%. Conclusions It is confirmed that a coupled thermal-electrical-structural model is needed for precise temperature prediction in the balloon-based thermoplasty of the heterogeneous and thin tissue. The model presented may help with future development of optimized treatment planning considering both ablation depth and minimum stress.

Use of stimulatory responsive soft nanoparticles for intracellular drug delivery.

Drug delivery has made tremendous advances in the last decade. Targeted therapies are increasingly common, with intracellular delivery highly impactful and sought after. Intracellular drug delivery systems have limitations due to imprecise and non-targeted release profiles. One way this can be addressed is through using stimuli-responsive soft nanoparticles, which contain materials with an organic backbone such as lipids and polymers. The choice of biomaterial is essential for soft nanoparticles to be responsive to internal or external stimuli. The nanoparticle must retain its integrity and payload in non-targeted physiological conditions while responding to particular intracellular environments where payload release is desired. Multiple internal and external factors could stimulate the intracellular release of drugs from nanoparticles. Internal stimuli include pH, oxidation, and enzymes, while external stimuli include ultrasound, light, electricity, and magnetic fields. Stimulatory responsive soft nanoparticulate systems specifically utilized to modulate intracellular delivery of drugs are explored in this review.

Electricity and Heat Demand in Steel Industry Technological Processes in Industry 4.0 Conditions

The publication presents heat and electricity management in the Polish steel industry. The paper is based on actual data on heat and electricity consumption and intensity by processes in the steel industry in Poland in Industry 4.0 conditions. Two steel production processes are used in Poland: EAF Electric Arc Furnace and BOF Basic Oxygen Furnace. The analysis is an analysis of actual data is used to characterise the electricity and heat consumption by processes in the Polish steel industry. The analysis shows that the EAF technology is always more electricity intensive and the BOF technology more heat intensive. On the basis of conducted analysis, it can be concluded that pro-environmental innovations in the steel industry should first aim to reduce the electricity consumption of EAF technology and the heat consumption of BOF. An analysis of data for Poland for the period 2004–2020 shows that both cases occurred. The study shows that the heat consumption of BOF technologies has been steadily decreasing since 2010, and the electricity consumption of EAF technologies has been decreasing throughout the period under review. It can be concluded from this that the Polish steel industry is adapting to pro-environmental requirements and, through the introduction of technological innovations, is moving towards the concept of sustainable steel production according to green steel principles. The decrease in energy intensity (means electricity) of steel produced according to EAF technology is an important issue, as the high energy intensity of EAF processes affects the overall energy intensity of the steel production in Poland. In the future, the use of new innovative technological solutions, including solutions based on Industry 4.0 principles, should help the Polish steel industry to further reduce the level of electricity and heat consumption. The driving force behind the investment is the boom in the steel market. The authors made a short-term forecasts of steel production (2022–2025). The annual forecasts determined and analyses made were used to determine the heat and energy consumption of the Polish steel industry up to 2025.

Fabrication and Properties of a Hybrid Biocompatible Nanofiber Mesh Constituted of Polycaprolactone and Self-Assembly Peptide

Conventional therapeutic methods for organ and tissue deficiencies include surgical reconstruction, organ transplantation, medical devices treatment, synthetic prosthesis and so on, of which the application is limited when donors exhibit a low availability and impaired organs and tissues cannot well perform their functions. Tissue Engineering (TE) can harmonize with regional organs or tissues, ensure optimal degradation time for novel structure rebirth, facilitate cell adhesiveness, contribute to cell procreation and differentiation in tissue scaffolds, etc., making it an alternative option for treating pathological obstacles. Artificial polymers such as polycaprolactone (PCL) and nature materials such as peptides are adopted for the fabrication of nanofiber scaffolds. The study first engineered porous PCL scaffolds for examining the fiber morphology and the diameter alternations considering the change of single variable condition of the solution concentration, voltage and electrode distance, etc., thereby finding the basic conditions for producing nanofiber scaffolds with good formation. With the increase in solution concentration, the more obvious molecule entanglement can limit the jet stretching, thereby enlarging the fiber diameters. Voltage negatively impacts the fiber diameters, and elevated voltage can strengthen the electric intensity, thereby leading to a complete stretching of cone jets and making fiber diameters thinner. Besides, increased electrode distance is followed by expanded flight distance and decreased electrode intensity (constant voltage), as a result, fibers become narrower. Nanofiber substance exhibits the optimal performance under the condition of solution concentration: 6%, voltage: 50kV, and electrode distance: 150mm. Subsequently, nanofiber scaffolds were fabricated based on the respective preparation of PCL/P11-4 and PCL/P11-8 polymer solutions. Both P11-4 and P11-8 presented uneven distribution in PCL scaffolds, which involved various PCL nanofiber substances with abundant peptides. PCL nanofiber scaffolds saw the breakage of P11-4 and P11-8 fibers.

Development of Properties Control Methods for Magnetorheological Medium to Regulate the Stiffness of Exoskeleton Variable-Length Link

Introduction. The article investigated one of the problems of creating exoskeletons — controlling the properties of magnetic rheological fluid in links of variable length with adjustable stiffness. Based on the research of domestic and foreign authors, the development and urgency of the topic was evaluated. The disadvantage of known exoskeleton models has been specified, i.e., the use of absolutely solid links, whose dynamics does not convey the dynamics of the human musculoskeletal system. The scientific research aimed at the formation of a new direction in the development of exoskeletons that accurately simulate the biomechanics of movements. Materials and Methods. Different states of structures of variable-length links with a magnetorheological fluid were studied. It has been noted that the links work on the principle of magnetic shock absorbers and consist of a piston rod, electromagnetic coils, and a housing filled with magnetorheological fluid. The ordering effect of an external magnetic field on the particles of a magnetorheological fluid was visualized and mathematically presented. The significance of such factors as time, charge density, magnetic field strength, as well as vectors of electric and magnetic induction, electric intensity and electric current density for this system was shown. The input parameter affecting the behavior of the magnetorheological fluid was determined. This was the magnetic field intensity. It was shown that the viscosity of the liquid varied depending on the shape of the magnetic particles (oblong or oblate ellipsoid). Results. The dependences that were fundamental for solving the task were investigated and visualized. The magnetic field strength and the angle between the vector directed along a straight line connecting the centers of two micron particles, and the vector of the external magnetic field strength were taken as the basic parameters. It was shown how the magnetic moment, voltage and its antisymmetric part depended on them. It was established that to control the properties of a magnetorheological fluid, it was required to change: – the external magnetic field intensity; – the angle between the external magnetic field intensity and the orientation vector between the dipoles. Two values of force were compared: one – for a given link design, and the other — fixed when walking in the lower leg of a person. The consistency of these indicators was established. Discussion and Conclusion. The scientific research results allowed us to present: – a method for controlling the properties of a magnetorheological fluid by an external magnetic field; – a variable-length link model with adjustable stiffness. The results obtained can be used in modeling multilink structures to create comfortable exoskeletons that interact synchronously with the human musculoskeletal system as a single human-machine system. The development is applicable to solving significant social and economic problems.

Shaping the energy transition in the residential sector: Regulatory incentives for aligning household and system perspectives

The regulatory framework influences households’ decisions in the context of the energy transition, affecting the potential for CO2 emissions savings and the operation of the electrical network infrastructure. In this paper, the profitability and optimal operation of alternative home energy systems (HESs) consisting of photovoltaics (PV), battery energy storage (BES), and either a gas condensing boiler (GB) or an electrical air-to-water heat pump (HP) is investigated for the case of a German single-family house and across alternative regulatory scenarios. Two policy reforms are considered: (i) an alternative design of network tariffs, the objectives of which are the financial sustainability and the efficient operation of the power grid, as well as the cost reflectivity of such charges; and (ii) a CO2-oriented reform of energy taxes and surcharges on retail energy prices. For the latter, the real-time carbon intensity of grid electricity is estimated and priced in dynamic retail electricity rates. After the optimization of the operation of each alternative HES under such alternative sets of price signals, a simulation over a 20-year planning horizon is carried out in order to evaluate each option in terms of profitability, impact on CO2 emissions and grid integration. The findings show how a change of regulatory framework can foster a low-carbon-oriented and grid-friendly adoption and operation of energy technologies. In the case under analysis, a regulatory shift: (i) results in a decrease of up to 17% in the discounted lifetime costs of the HP heating, thereby steering the household’s adoption decision towards a reduction of up to 63% in CO2 emissions; (ii) induces a grid-oriented operation of the HP and the BES, reducing coincident peak demand by up to 62%. The implications of such a regulatory shift are discussed in relation to the effectiveness, cost efficiency and distributional fairness of the energy transition in the residential sector.

УЧАСНИКИ РИНКУ ЕЛЕКТРИЧНОЇ ЕНЕРГІЇ ЯК СУБ'ЄКТИ ПРАВОВІДНОСИН У СФЕРІ ЕЛЕКТРОЕНЕРГЕТИКИ

Background. One of the features of relations in the field of electric power industry should be considered their special subject composition. In the electric power industry, there was a reform related to the introduction of a competitive electricity market, which qualitatively changed the rules for the organization and functioning of the electricity market, which determines the relevance of the study. The purpose is to study market participants who are part of a special composition of subjects of legal relations. The objectives of the study are to clarify the correlation of the concepts of economic relations in the field of electricity and the electricity market; correlation between the concepts of a participant in the electricity market and a participant in relations in the field of electricity; sectoral nature of legal relations in the electricity market; peculiarities of the conceptual and terminological apparatus of the Law of Ukraine "On the Electricity Market"; which entities are participants in the electricity market and the peculiarities of their legal status; specifics of the legal status of an active consumer as a participant in the electricity market. Methods. The research is based on the use of systemic, structural methods, methods of analysis and synthesis, induction and deduction, formal-legal and logical-legal methods of scientific research. Results. The results of the study consist of the formulation of theoretical provisions and practical proposals for improving the legislation of Ukraine. Conclusions. Conclusions are drawn about the non-identity of the concepts of economic relations in the field of electric power industry and the electricity market. Subjects of organizational and economic powers are not recognized as participants in the electricity market. The concept of participants in the electricity market is covered by the general concept of participants in relations in the field of electricity. Legal relations in the market are complex, the core of which is economic legal relations. The conceptual and terminological apparatus of the Law of Ukraine "On the Electricity Market" has close structural links with the general concepts of economic law, which are normatively enshrined in the Commercial Code of Ukraine. The general list of market participants enshrined in the law is not exhaustive. It is proposed to supplement it with an aggregator. Market participants – business entities – are classified into two groups. An active consumer has the right to carry out activities for the production of electricity under the mechanism of self-production, which is not an economic activity, as well as the right to sell this electricity or provide other services on the basis of contracts.

Виклики та диспропорції у забезпеченні промисловості робочою силою

Structural changes in the economy, caused by current and potential changes in the needs of society for survival in today's conditions and reconstruction of the country in the post-war period. With the change of the industry structure, new requirements appear for the workforce, its qualifications, quantitative involvement in various spheres of activity. The work offers a systematization of current and potential challenges and disparities in providing industry with labor force. The dynamics of demand and supply of labor in industry, their ratio, are characterized, and a conclusion is made that there is no critical situation related to meeting the needs of industry in labor. According to general forecasts of the labor market, a shortage of personnel is expected, but the industry has a different situation by branch. The leader in the number of job shortages compared to other industries and spheres of activity is the processing industry, in the extractive industry almost a balance between supply and demand has been achieved. In the field of electricity and gas supply, the number of unemployed is almost twice as high as the demand. Only in the field of water supply and sanitation is there a labor shortage. The work emphasizes the importance of countering modern challenges and the formation of the workforce according to the needs of industry. Among the military challenges, such aspects as reduction of jobs, mass emigration of labor force, imbalance by regions and professions, high level of unemployment due to labor shortage due to asymmetry between demand and supply of labor force, loss of labor force due to mobilization and death, diminization of the labor market are highlighted. , liberalization of labor relations. The challenges inherited due to the defects of the Ukrainian peacetime economy are outlined. Emphasis is placed on the reduction of the social security of workers in the conditions of martial law, which is due to the introduction of changes in the labor legislation. The problems of the efficiency of the use of human capital, imbalance in wages, sectoral structural disparities and economic inactivity among young people are highlighted. The potential challenges of labor force development in Ukraine are outlined.

Quantum shells versus quantum dots: suppressing Auger recombination in colloidal semiconductors.

Colloidal semiconductor nanocrystals (NCs) have attracted a great deal of attention in recent decades. The quantum efficiency of many optoelectronic processes based on these nanomaterials, however, declines with increasing optical or electrical excitation intensity. This issue is caused by Auger recombination of multiple excitons, which converts the NC energy into excess heat, whereby reducing the efficiency and lifespan of NC-based devices, including lasers, photodetectors, X-ray scintillators, and high-brightness LEDs. Recently, semiconductor quantum shells (QSs) have emerged as a viable nanoscale architecture for the suppression of Auger decay. The spherical-shell geometry of these nanostructures leads to a significant reduction of Auger decay rates, while exhibiting a near unity photoluminescence quantum yield. Here, we compare the optoelectronic properties of quantum shells against other low-dimensional semiconductors and discuss their emerging opportunities in solid-state lighting and energy-harvesting applications.

Clinical Practice Guidelines for the Use of Electroconvulsive Therapy.

Clinical Practice Guidelines for the Use of Electroconvulsive Therapy.

Centralized Cloud Service Providers in Improving Resource Allocation and Data Integrity by 4G IoT Paradigm

Due to the expansion of Internet of Things (IoT), the extensive wireless, and 4G networks, the rising demands for computing calls and data communication for the emergent EC (EC) model. By stirring the functions and services positioned in the cloud to the user proximity, EC could offer robust transmission, networking, storage, and transmission capability. The resource scheduling in EC, which is crucial to the accomplishment of EC system, has gained considerable attention. This manuscript introduces a new lighting attachment algorithm based resource scheduling scheme and data integrity (LAARSS-DI) for 4G IoT environment. In this work, we introduce the LAARSS-DI technique to proficiently handle and allot resources in the 4G IoT environment. In addition, the LAARSS-DI technique mainly relies on the standard LAA where the lightning can be caused using the overall amount of charges saved in the cloud that leads to a rise in electrical intensity. Followed by, the LAARSS-DI technique designs an objective function for the reduction of cost involved in the scheduling process, particularly for 4G IoT environment. A series of experimentation analyses is made and the outcomes are inspected under several aspects. The comparison study shown the improved performance of the LAARSS-DI technology to existing approaches.

China's enhanced urban wastewater treatment increases greenhouse gas emissions and regional inequality

Sustainable water pollution control requires understanding of historical trajectories and spatial characteristics of greenhouse gas (GHG) emissions from wastewater treatment plants (WWTPs), which remains inadequately studied. Here, we establish plant-level monthly operational emissions inventories of China's WWTPs in 2009–2019. We show that urban wastewater treatment has been enhanced with 80% more chemical oxygen demand being removed annually. However, this progress is associated with 180% more GHG emissions at the national level, up to 58.3 Mt CO2 eq in 2019. We found significant seasonality in GHG emissions. Increasing sludge yield and electricity intensity became primary drivers after 2015 because of stricter standards, causing GHG emissions increase 12.9 and 8.3% until 2019. GHG emissions from urban wastewater treatment show high spatial difference at province, city and plant levels, with different sludge disposal and energy mix approaches combined with different influent and effluent conditions in WWTPs across China. Stricter effluent standard resulted in similar GHG emissions growth pattern in cities. We argue WWTPs focus on resource recovery in developed areas and higher operational efficiency in developing areas.

Resource Intensity Trends in the South African Ferrochrome Industry from 2007 to 2020

Processing resource requirements in mineral extractive industries tend to increase over time as ore grades decrease, which consequently increases the environmental footprint of operations and products. This phenomenon may be alleviated by cleaner production interventions. South Africa is the largest global supplier of chromium. This study investigates the impact of cleaner production process improvements on selected resource intensities of the South African ferrochrome industry. Sustainability data, available since the start of regular sustainability reporting in 2007, were used to compile resource intensity trends. This was followed by a review of industry capital projects relating to resource-use optimisation, interrogated in interviews with industry experts, to ascertain their effect on resource intensities. The emergence of a symbiotic relationship with the platinum-group metals industry was identified as a major development, with chromite ore intensity decreasing from 2.54 to 1.98 kg per kg ferrochrome. Electrical energy intensity was observed to decrease from 3.47 to 2.86 kWh per ton ferrochrome, mainly as a result of cleaner smelting technology, though cogeneration fired by furnace off-gases also contributed significantly. The introduction of cleaner production interventions in the South African ferrochrome industry was thus documented to have resulted in decreased resource use intensities.

Antimonopoly Control in the Electric Power Industry (Problems of Legal Regulation of the Subject)

The article reviews the main legal constructions and doctrinal approaches related to the regulation of the subject of antitrust control in the electric power industry. Special attention is paid to the issues of enshrined legal aspects of antitrust control in this domain, as well as to a number of key concepts for competition law in general. Moreover, the objects of antitrust control in the field of electricity’ current state of legal regulation is revealed in the article, as well as the importance of implementing state policy aimed at ensuring the defense of competition by an uninterrupted and effective antitrust control over electric energy and capacity markets functioning.

Anti-plane problem of a nano-sharp crack in one-dimensional hexagonal piezoelectric quasicrystals with the electrically semi-permeable condition

Based on the Gurtin–Murdoch surface/interface theory and the complex potential theory, the problem of an electrically semi-permeable nano-sharp crack in one-dimensional (1D) hexagonal piezoelectric quasicrystals is analyzed. By constructing conformal mapping of the sharp crack, the analytic solutions of the electroelastic field are determined. Meanwhile, the field intensity factors and the energy release rate (ERR) under the electric boundary conditions of semi-permeable are obtained. Numerical examples are given to analyze the effects of the crack size, dielectric constant, electric loading, and mechanic loadings on the dimensionless field intensity factors and the dimensionless ERR. The results show that the impact of the surface effect becomes weaker along with the growth of the crack length, but increases with the increase in the crack angle. The change of the dielectric coefficient has little influence on the dimensionless stress intensity factors (SIFs), but has a strong influence on the dimensionless electric displacement intensity factor (EDIF). The obtained results are helpful to promote the development of nano-quasicrystal composite mechanics and provide an important theoretical support for the design and application of nano-QC materials.

Optimization of Electrical Intensity for Electrochemical Anodic Oxidation to Modify the Surface of Carbon Fibers and Preparation of Carbon Nanotubes/Carbon Fiber Multi-Scale Reinforcements

Carbon fiber (CF) reinforced composites are widely used due to their excellent properties. However, the smooth surface and few functional groups of CFs can lead to fiber fractures and pullout, which reduce the service life of the composites. The overall performance of composites can be improved by growing carbon nanotubes (CNTs) on the CF surface. Before this, CF surface should be modified to enhance the loading amount of catalyst particles and thus make the CNTs more uniform. In this paper, CNTs were grown on a CF surface by one-step chemical vapor deposition to prepare multi-scale CNTs/CF reinforcements, and the effects of different methods on the CF surface modification were explored. After setting four intensities of electrochemical anodic oxidation, i.e., 50 C/g, 100 C/g, 150 C/g and 200 C/g, it was found that the distribution and quantity of CNTs were improved under both the 100 C/g and 150 C/g conditions. Considering the influence of electrical intensity on the (002) interplanar spacing of CFs, which affects the mechanical properties of the samples, 100 C/g was finally selected as the optimal electrochemical treatment intensity. This finding provides a reference for continuous and large-scale modification of CF surfaces to prepare CNTs/CF multi-scale reinforcements.