Journal articles on the topic 'Novel Corrosion Sensing'

In this study, a piezoelectric active sensing-based time reversal method was investigated for monitoring pipeline internal corrosion. An effective method that combines wavelet packet energy with a Convolutional Neural Network (CNN) was proposed to identify the internal corrosion status of pipelines. Two lead zirconate titanate (PZT) patches were pasted on the outer surface of the pipeline as actuators and sensors to generate and receive ultrasonic signals propagating through the inner wall of the pipeline. Then, the time reversal technique was employed to reverse the received response signal in the time domain, and then to retransmit it as an excitation signal to obtain the focused signal. Afterward, the wavelet packet transform was used to decompose the focused signal, and the wavelet packet energy (WPE) with large components was extracted as the input of the CNN model to rapidly identify the corrosion degree inside the pipeline. The corrosion experiments were conducted to verify the correctness of the proposed method. The occurrence and development of corrosion in pipelines were generated by electrochemical corrosion, and nine different depths of corrosion were imposed on the sample pipeline. The experimental results indicated that the classification accuracy exceeded 99.01%. Therefore, this method can quantitatively monitor the corrosion status of pipelines and can pinpoint the internal corrosion degree of pipelines promptly and accurately. The WPE-CNN model in combination with the proposed time reversal method has high application potential for monitoring pipeline internal corrosion.

Wearable sensors are pioneering devices to monitor health issues that allow the constant monitoring of physical and biological parameters. The immunity towards electromagnetic interference, miniaturization, detection of nano-volumes, integration with fiber, high sensitivity, low cost, usable in harsh environments and corrosion-resistant have made optical wearable sensor an emerging sensing technology in the recent year. This review presents the progress made in the development of novel wearable optical sensors for vital health monitoring systems. The details of different substrates, sensing platforms, and biofluids used for the detection of target molecules are discussed in detail. Wearable technologies could increase the quality of health monitoring systems at a nominal cost and enable continuous and early disease diagnosis. Various optical sensing principles, including surface-enhanced Raman scattering, colorimetric, fluorescence, plasmonic, photoplethysmography, and interferometric-based sensors, are discussed in detail for health monitoring applications. The performance of optical wearable sensors utilizing two-dimensional materials is also discussed. Future challenges associated with the development of optical wearable sensors for point-of-care applications and clinical diagnosis have been thoroughly discussed.

In the last two decades, a significant number of innovative sensing systems based on optical fiber sensors have been exploited in the engineering community due to their inherent distinctive advantages such as small size, light weight, immunity to electromagnetic interference (EMI) and corrosion, and embedding capability. A lot of optical fiber sensor-based monitoring systems have been developed for continuous measurement and real-time assessment of diversified engineering structures such as bridges, buildings, tunnels, pipelines, wind turbines, railway infrastructure, and geotechnical structures. The purpose of this review article is devoted to presenting a summary of the basic principles of various optical fiber sensors, innovation in sensing and computational methodologies, development of novel optical fiber sensors, and the practical application status of the optical fiber sensing technology in structural health monitoring (SHM) of civil infrastructure.

Asset corrosion is a huge problem for the construction and other industries with an estimated cost of approximately GBP 300 billion in the EU in 2013 [1]. To mitigate this cost and protect metal substrates from corrosion, organic coatings are often used. In 2017 the EU produced 4 million metric tonnes of organically coated steel, a large quantity of which is used for the production of building cladding material [2]. Cladding material is widely used in construction of both commercial, industrial, and residential buildings due to its convenience, speed of construction as well as aesthetic and weather resistant properties. Architects and customers are increasingly using pre-finished coated steel panels to provide a sleek modern design. In order to maintain the required aesthetic value offered by these panels, it is of crucial importance that the coatings provide appropriate protection from the harsh conditions faced by building facades. It is paramount that manufacturers of the cladding can provide reassurances of the long-term coating performance to provide confidence to the end customer. Despite this, coating performance is only currently estimated by accelerated lab-based tests and some short-term outdoor exposure testing. These tests are carried out in conditions that produce results that are often not representative of real life, leading to earlier than expected failure of the product in some conditions. The ability to monitor the environments that the coatings are exposed to, as well as the actual real-time performance of the coating itself, would provide a far better avenue to determine the expected lifetime of the coated product as well as maintenance scheduling and failure prevention. Furthermore, it would reduce the requirement for human inspection and allow remedial maintenance before the damage becomes too significant to warrant replacement. The advantages of in-situ, real time monitoring has long been recognized by the oil and gas industry, however, at this point in time they are the only sector deploying significant corrosion and coating monitoring techniques. However, as we move to a more connected world, with an increase in devices and IOT systems there is increased interest by the construction section in sensing. There has been significant research effort to develop corrosion sensing of concrete embedded rebar [3–5] and it is clear there is an appetite to grow the field of asset monitoring. The research undertaken develops novel deployments of existing techniques as well as new techniques to detect both corrosion of metallic substrates and degradation and failure of the organic coatings. The overall aim is to produce a sensor system that can work autonomously over long periods. This presented difficulties in terms of, powering, communication, durability, deployment, and sensitivity. The ideas explored include capacitive based sensing, magnetic flux leakage, RFID EMI based corrosion sensing and radiofrequency based dielectric sensing. The designed sensors show promise in detecting early stages of corrosion and coating failure as well as indicating the severity of such changes. The work presented will discuss the challenges faced and how they were/are being overcome as well as the current sensor development and results. Koch GH, Varney J, Thompson N, Moghissi O, Gould M, et al. (2012) International measures of prevention, application, and economics of corrosion technologies study. NACE International, Houston. Eurofer. European Steel in Figures 2008-2017. 2018. James A, Bazarchi E, Chiniforush AA, Panjebashi Aghdam P, Hosseini MR, Akbarnezhad A, et al. Rebar corrosion detection, protection, and rehabilitation of reinforced concrete structures in coastal environments: A review. Constr Build Mater [Internet]. 2019;224:1026–39. Available from: https://www.sciencedirect.com/science/article/pii/S0950061819319208 Xie L, Zhu X, Liu Z, Liu X, Wang T, Xing J. A rebar corrosion sensor embedded in concrete based on surface acoustic wave. Measurement [Internet]. 2020;165:108118. Available from: https://www.sciencedirect.com/science/article/pii/S0263224120306564 Fan L, Shi X. Techniques of corrosion monitoring of steel rebar in reinforced concrete structures: A review. Struct Heal Monit [Internet]. 0(0):14759217211030912. Available from: https://doi.org/10.1177/14759217211030911

Corrosion under insulation (CUI) refers to the external corrosion of piping and vessels when they are encapsulated in thermal insulation. To date, very limited information (especially electrochemical data) is available for these “difficult-to-test” CUI conditions. This study was aimed at developing a novel electrochemical sensing method for in situ CUI monitoring and analysis. Pt-coated Ti wires were used to assemble a three-electrode electrochemical cell over a pipe surface covered by thermal insulation. The CUI behavior of X70 carbon steel (CS) and 304 stainless steel (SS) under various operating conditions was investigated using mass loss, linear polarization resistance (LPR), and electrochemical impedance spectroscopy (EIS) measurements. It was found that both the consecutive wet and dry cycles and cyclic temperatures accelerated the progression of CUI. LPR and EIS measurements revealed that the accelerated CUI by thermal cycling was due to the reduced polarization resistance and deteriorated corrosion film. Enhanced pitting corrosion was observed on all tested samples after thermal cycling conditions, especially for CS samples. The proposed electrochemical technique demonstrated the ability to obtain comparable corrosion rates to conventional mass loss data. In addition to its potential for in situ CUI monitoring, this design could be further applied to rank alloys, coatings, and inhibitors under more complex exposure conditions.

Civil engineering assets and geo-structures continually deteriorate during their lifetime, particularly in harsh environments that may be contaminated with corrosive substances. However, efficient and constant structural health monitoring and accurate prediction of the service-life of these assets can help to ensure their safety, performance, and health conditions and enable proper maintenance and rehabilitation. Nowadays, many of the largest cities throughout the world are situated in coastal zones, leading to a dramatic increase in the construction of nearshore geo-structures/infrastructures which are vulnerable to corrosion attacks resulting from salinity contamination. Additionally, seawater intrusion can threaten the quality and the sustainability of fresh groundwater resources, which are a crucial resource in coastal areas. To address these issues, detection of salinity in soil utilizing a novel polymer optical fibre Bragg grating (POFBG) sensor was investigated in this research. Experiments were carried out at different soil water contents with different salinities to assess the sensor’s response in a representative soil environment. The sensitivity of the POFBG sensor to salinity concentrations in water and soil environment is estimated as 58 ± 2 pm/%. The average standard error value in salinity is calculated as 0.43% for the samples with different soil water contents. The results demonstrate that the sensor is a promising and practical tool for the measurement and monitoring with high precision of salinity contamination in soil.

Distributed chemical sensing is demonstrated using standard acrylate coated optical fibers. Swelling of the polymer coating induces strain in the fiber’s silica core provoking a local refractive index change which is detectable all along an optical fiber by advanced distributed sensing techniques. Thermal effects can be discriminated from strain using uncoated fiber segments, leading to more accurate strain readings. The concept has been validated by measuring strain responses of various aqueous and organic solvents and different chain length alkanes and blends thereof. Although demonstrated on a short range of two meters using optical frequency-domain reflectometry, the technique can be applied to many kilometer-long fiber installations. Low-cost and insensitive to corrosion and electromagnetic radiation, along with the possibility to interrogate thousands of independent measurement points along a single optical fiber, this novel technique is likely to find applications in environmental monitoring, food analysis, agriculture, water quality monitoring, or medical diagnostics.

Distributed pressure sensing schemes for human positioning and plantar mapping is desired to be unconstrained for human activity in their daily life in the form of a floor and mat. On the other hand, an optical fiber has several advantages such as lightweight, minimal material, and resistance to corrosion and electromagnetic interference. Additionally, a novel hetero-core optic fiber nerve sensor is only sensitive to be bending action of the sensor portion and the fiber transmission line is unaffected to external disturbance as pressure and temperature fluctuation because of its single-mode stable propagation scheme. Therefore, the hetero-core fiber optic sensor could be suitable for the distributed pressure sensing in human natural activity and be placed in various sites. In this paper, we proposed several smart mat applications in the form of a thin mat in the floor for human positioning and sole pressure mapping mat using the hetero-core optic fiber sensors. We successfully demonstrated the distributed pressure sensing mat using hetero-core sensors to detect human positioning with their circumstance and sole pressure mapping.

Aircraft routinely operate in atmospheric environments that, over time, will impact their structural integrity. Material protection and selection schemes notwithstanding, recurrent exposure to chlorides, pollution, temperature gradients, and moisture provide the necessary electrochemical conditions for the development and profusion of corrosion in aircraft structures. For aircraft operators, this becomes an important safety matter as corrosion found in a given aircraft must be assumed to be present in all of that type of aircraft. This safety protocol and its associated unscheduled maintenance requirement drive up the operational costs of the fleet and limit the availability of the aircraft. Hence, there is an opportunity at present for developing novel sensing technologies and schemes to aid in shifting time-based maintenance schedules towards condition-based maintenance procedures. In this work, part of the ongoing development of a multiparameter integrated corrosion sensor is presented. It consists of carbon nanotube/polyaniline polymer sensors and commercial-off-the-shelf sensors. It is being developed primarily for monitoring environmental and material factors for the purpose of providing a means to more accurately assess the structural integrity of aerospace aluminium alloys through fusion of multiparameter sensor data. Preliminary experimental test results are presented for chloride ion concentration, hydrogen gas evolution, humidity variations, and material degradation.

This study introduces a nano smart material to develop a novel sensor for Structural Health Monitoring (SHM) of mechanical and civil systems. Mechanical, civil, and environmental systems need to become self-sensing and intelligent to preserve their integrity, optimize their performance, and provide continuous safety for the users and operators. Present smart materials and structures have fundamental limitations in their sensitivity, size, cost, ruggedness, and weight. Smart materials developed using nanotechnology have the potential to improve the way we generate and measure motion in devices from the nano to the macro scale in size. Among several possible smart nanoscale materials, Carbon Nanotubes (CNT) have aroused great interest in the research community because of their remarkable mechanical, electrochemical, piezoresistive, and other physical properties. To address the need for new intelligent sensing based on CNT, this study presents piezoresistivity and electrochemical properties and preliminary experiments that can be applied for SHM. This study is anticipated to develop a new multifunctional sensor which can simultaneously monitor strain, stress and corrosion on a structure with a simple electric circuit.

Tubular structures are critical components in infrastructure such as power plants. Throughout their life, they are subjected to extreme conditions or suffer from defects such as corrosion and cracks. Although regular inspection of these components is necessary, such inspection is limited by safety-related risks and limited access for human inspection. Robots can provide a solution for automatic inspection. The main challenge, however, lies in integrating sensors for nondestructive evaluation with robotic platforms. As part of developing a versatile lizard-inspired tube inspector robot, in this study the authors propose to integrate electromagnetic acoustic transducers into a modular robotic gripper for use in automated ultrasonic inspection. In particular, spiral coils with cylindrical magnets are integrated into a novel friction-based gripper to excite Lamb waves in thin cylindrical structures. To evaluate the performance of the integrated sensors, the gripper was attached to a robotic arm manipulator and tested on pipes of different outer diameters. Two sets of tests were carried out on both defect-free pipes and pipes with simulated defects, including surface partial cracking and corrosion. The inspection results indicated that transmitted and received signals could be acquired with an acceptable signal-to-noise ratio in the time domain. Moreover, the simulated defects could be successfully detected using the integrated robotic sensing system.

Shape memory materials are materials with special functions set of sensing and actuation in one. The shape memory alloy is one of the most important materials in shape memory materials. Shape memory alloy is a kind of alloy that alloy with initial shape in low temperature by the plastic deformation and fixed into another shape, by heating to a temperature above the critical, can be restored into the initial shape. The characteristic of shape memory alloy mainly has the shape memory effect and super elastic effect. Nickel titanium memory alloy is not used in the fracture of limbs, in recent years are also used in the spine and femoral head fracture. Nickel titanium memory alloy has good biocompatibility, and has the characteristics of super elasticity, low magnetic, wear resistance, fatigue resistance, corrosion resistance, as a novel material for internal fixation in the treatment of sports injuries are widely used.

In this paper, some recent piezoelectric wafer active sensors (PWAS) progress achieved in our laboratory for active materials and smart structures (LAMSS) at the University of South Carolina: http: //www.me.sc.edu/research/lamss/ group is presented. First, the characterization of the PWAS materials shows that no significant change in the microstructure after exposure to high temperature and nuclear radiation, and the PWAS transducer can be used in harsh environments for structural health monitoring (SHM) applications. Next, PWAS active sensing of various damage types in aluminum and composite structures are explored. PWAS transducers can successfully detect the simulated crack and corrosion damage in aluminum plates through the wavefield analysis, and the simulated delamination damage in composite plates through the damage imaging method. Finally, the novel use of PWAS transducers as acoustic emission (AE) sensors for in situ AE detection during fatigue crack growth is presented. The time of arrival of AE signals at multiple PWAS transducers confirms that the AE signals are originating from the crack, and that the amplitude decay due to geometric spreading is observed.

In recent years, wireless sensor networks have emerged as a reliable method for structural health monitoring. The powering methods for these wireless sensors have become an important factor. In several applications, wireless sensors must be operated in locations that are difficult or even impossible to access, and these systems often have a desired operational life span that exceeds conventional batteries lifetime. Replacing the batteries is labor intensive and time consuming. It is very difficult or even impossible to replace batteries of embedded sensors in concrete or composite structures. Therefore, novel powering methods such as energy harvesting or wireless power transmission are necessary to guarantee long life spans for wireless sensors. This article presents a laser-powered wireless ultrasonic device, which is a wireless active sensor with wireless laser power transmission that provides long-lasting structural health monitoring. The laser beam is captured by a GaInP photovoltaic cell. The cell has a high spectral responsivity for the 532-nm laser beam. A supercapacitor is used to store and supply power to the device. Furthermore, to solve the line-of-sight issue, a smart component called the fiber optic bolt is also developed using a large-core hard polymer-clad fiber. The wireless ultrasonic device includes the actuator and the sensor interface to evaluate the structural damages. To demonstrate the feasibility of the device, we carried out the basic Lamb wave pitch-catch test to detect the structural damage (such as cracks and artificial corrosion) in an aircraft lug (which is an example of an inaccessible aircraft structure). Our investigations show that the results of the proposed wireless sensing system are in accordance with those of the wired system. This indicates the feasibility for implementing the proposed system for wireless structural health monitoring.

Abstract. Due to the delayed construction and commissioning of a German repository for intermediate- and low-level radioactive waste, waste inventories from several decades are now located at the interim storage sites, the safe custody of which must also be ensured for an indefinite period of interim storage. The usual practice in the interim storage facilities is recurrent inspections, which are carried out almost exclusively manually and without electronic comparative recordings as well as without mechanical documentation and archiving. Remote or automated inspection does not take place. The inspections are carried out visually and are therefore very subjective and thus subject to errors. Manual performance is labor intensive and requires the use of personnel exposed to radiation. Neither are uniform inspection criteria of the visual inspections applied, nor are the inspections performed uniformly between sites. Based on these facts, the Institute for Technology and Management in Construction, Department of Deconstruction and Decommissioning of Conventional and Nuclear Buildings, together with the Institute for Photogrammetry and Remote Sensing, is developing an automated drum inspection system as part of the funding measure FORKA – Research for the Deconstruction of Nuclear Facilities. EMOS is a mobile inspection unit that remotely and automatically records the entire surface of the drum, including lid and bottom, optically; evaluates it analytically; and both stores it electronically and outputs the results in the form of an inspection report. In this way, recurring inspections of the drum stock can be completed under the same inspection conditions each time. A decisive advantage is the possibility of carrying out the inspection remotely in order to reduce the radiation dose to the employees on site. The optical evaluation, display and output of the results will ensure a more precise inspection and analysis of the drum surfaces through software to be specially developed than is possible through manual and visual inspections as currently performed in the interim storage facilities. The continuous monitoring of the stored drums will be facilitated and also the tracing of possible damage development through the comparison of archived measurement results is a novel and powerful tool that helps to increase and ensure the safety aspects of interim storage in the long term. Changes in drum geometry as well as in the surface condition (e.g. corrosion formation, etc.) can be identified at an early stage with the help of the inspection unit, and measures can be taken at an early stage to counteract the loss of integrity of the storage containers.

We developed a novel method to monitor mass flow based on distributed fiber optical temperature sensing. Examination of the temporal and spatial temperature distribution along the entire length of a locally heated fluidic conduit reveals heat flow under forced convection. Our experimental results are in good agreement with two-dimensional finite element analysis that couples fluid dynamic and heat transfer equations. Through analysis of the temperature distribution bidirectional flow rates can be measured over three orders of magnitude. The technique is not flow intrusive, works in harsh conditions, including high-temperatures, high pressures, corrosive media, and strong electromagnetic environments. We demonstrate a first experimental implementation on a short fluidic system with a length of one meter. This range covers many applications such as low volume drug delivery, diagnostics, as well as process and automation technology. Yet, the technique can, without restrictions, be applied to long range installations. Existing fiber optics infrastructures, for instance on oil pipelines or down hole installations, would only require the addition of a heat source to enable reliable flow monitoring capability.

Microelectrodes have a number of advantages over macroelectrodes for quantitative electroanalysis and monitoring, including reduced iR drop, a high signal-to-noise ratio and reduced sensitivity to convection. Their use in molten salts has been generally precluded by the combined materials challenges of stresses associated with thermal cycling and physical and corrosive chemical degradation at the relatively high temperatures involved. We have shown that microfabrication, employing high precision photolithographic patterning in combination with the controlled deposition of materials, can be used to successfully address these challenges. The resulting molten salt compatible microelectrodes (MSMs) enable prolonged quantitative microelectrode measurements in molten salts (MSs). This paper reports the fabrication of novel MSM disc electrodes, chosen because they have an established ambient analytical response. It includes a detailed set of electrochemical characterisation studies which demonstrate both their enhanced capability over macroelectrodes and over commercial glass pulled microelectrodes, and their ability to extract quantitative electroanalytical information from MS systems. MSM measurements are then used to demonstrate their potential for shedding new light on the fundamental properties of, and processes in, MSs, such as mass transport, charge transfer reaction rates and the selective plating/stripping and alloying reactions of liquid Bi and other metals; this will underpin the development of enhanced MS industrial processes, including pyrochemical spent nuclear fuel reprocessing.

We described the novel nanocomposite of silver doped ZrO2 combined graphene-based mesoporous silica (ZrO2-Ag-G-SiO2,) in bases of low-cost and self-assembly strategy. Synthesized ZrO2-Ag-G-SiO2 were characterized through X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectrometry (EDX), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), Raman spectroscopy, Nitrogen adsorption-desorption isotherms, X-ray photoelectron spectroscopy (XPS), and Diffuse Reflectance Spectroscopy (DRS). The ZrO2-Ag-G-SiO2 as an enzyme-free glucose sensor active material toward coordinate electro-oxidation of glucose was considered through cyclic voltammetry in significant electrolytes, such as phosphate buffer (PBS) at pH 7.4 and commercial urine. Utilizing ZrO2-Ag-G-SiO2, glucose detecting may well be finished with effective electrocatalytic performance toward organically important concentrations with the current reaction of 9.0 × 10−3 mAcm−2 and 0.05 mmol/L at the lowest potential of +0.2 V, thus fulfilling the elemental prerequisites for glucose detecting within the urine. Likewise, the ZrO2-Ag-G-SiO2 electrode can be worked for glucose detecting within the interferometer substances (e.g., ascorbic corrosive, lactose, fructose, and starch) in urine at proper pH conditions. Our results highlight the potential usages for qualitative and quantitative electrochemical investigation of glucose through the ZrO2-Ag-G-SiO2 sensor for glucose detecting within the urine concentration.

How can STS researchers collaborate with communities to design environmental monitoring devices that more effectively express their experiences and address gaps in regulation? This paper describes and shows the results of a novel method of visualizing environmental emissions of corrosive gases such as hydrogen sulfide (H2S) exposure using photographic paper. H2S is a neurotoxic and flammable gas that smells like rotten eggs and is frequently associated with oil and natural gas extraction. Communities living with oil and gas development in Wyoming report odors of rotten eggs and describe symptoms of H2S exposure. H2S is recognized as an acute and chronic threat to human and environmental health and oil and gas companies are required to have plans in place to prevent and respond to accidental, high concentration releases of H2S. They are not, however, required to monitor, report or prevent routine daily emissions. Yet 15-25% of the oil and gas wells in the US are predicted to contain H2S, and some communities surrounded by multiple wells report chronic, routine exposure. Chronic exposure is difficult to represent with current tools for monitoring H2S because they are designed to measure acute workplace exposure. Informed by STS theories of black boxes and regimes of imperceptibility that focus on the need to revise not only regulations but also material tools of science, this paper describes the development of an indexical approach to visualizing this hazard. In indexical design, the reactive sensing element of a scientific instrument is brought to the foreground. The silver in the photopaper is an index as it tarnishes with H2S exposure. Discolored tests strips can be arranged together to form data-rich maps of the exposure landscape where this discoloration both represents how the gas spreads through a space and is a physical trace of the gas. Preliminary results in the form of data-rich maps show that regulating H2S emissions as primarily accidental is inappropriate and fails to adequately protect human health.

Abstract Diamond based quantum sensing is a fast-emerging field with both scientific and technological significance. The nitrogen-vacancy (NV) center, a crystal defect in diamond, has become a unique object for microwave sensing applications due to its excellent stability, long spin coherence time and optical properties at ambient condition. In this work, we use diamond NV center as atomic receiver to demodulate On-Off Keying (OOK) signal transmitted in broad frequency range (2-14GHz in a portable benchtop setup). We proposed a unique algorithm of voltage discrimination and demonstrated audio signal transceiving with fidelity above 99%. This diamond receiver is attached to the end of a tapered fiber, having all optic nature, which will find important applications in data transmission tasks under extreme conditions such as strong electromagnetic interference, high temperatures and high corrosion.

Nanomaterials are the foundations of Nanotechnology, which are measured in nanoscales, Carbon nanotubes are one of the interesting nanomaterials, studied for over 25 years because of their superlative properties such as high surface area, electrical and thermal conductivity, high biocompatibility, flexibility, resistance to corrosion and nanosize. According to research, carbon nanotubes are applied in sensing, water treatment, and drug delivery, mainly used to deliver the anticancer drugs. In our work, functionalization of multi walled carbon nanotubes done by covalent and non-covalent functionation methods, covalent functionalization showed better dispersing efficiency in aqueous medium and compatible with biological systems with damaging the crystal lattice of carbon nanotubes. Non covalent functionalization helps to derivatized with active compounds, surface adsorption or attachment of various molecules or antibodies, which subsequently helps in targeting the site and to produce therapeutic effects. Different formulations prepared by functionalized MWCNTs and multiple functionalization of MWCNTs done by binding the drug and antibodies to prepare functionalized MWCNTs 5-Fluorouracil complexes. The Cytotoxicity assay was carried out for the obtained new targeting formulations to analyze the effect of all the formulations on HCT116 cell line. The percentage death was determined based on the viability of the cells in the appropriate vehicle controls. In this study, we report the successful functionalization, binding of 5 Fluorouracil, antibodies to MWCNTs, and cells viability of all prepared formulations for the development of novel carbon based anticancer drug delivery system. Functionalized MWCNTs-5-Fluorouracil antibodies composite at concentration above 2.5 µg/mL exhibited ≥ 50% cytotoxicity post normalization with compound control to negate precipitation observed with the compound. All the formulations showed the precipitations indicating antitumor activity and biocompatibility.

Природа и свойства оксидных пленок, анодно сформированных на металлах и сплавах, зависят от химического состава и энергетического состояния поверхности электрода.Цель статьи: определить состав и параметры оксидных пленок, сформированных в 0.1 М KOH на серебряно-цинковых сплавах (до 30 ат.% Zn включительно) с различной вакансионной дефектностью поверхностного слоя. Повышенная вакансионная дефектность поверхностного слоя сплавов создавалась путем предварительного селективного растворения цинка при различных потенциалах в 0.01 M HNO3 + 0.09 M KNO3. Полученные таким путем сплавы перемещались в 0.1 M KOH для формирования оксидных пленок. Состав пленок контролировался при помощи катодной вольтамперометрии. Толщина пленок рассчитывалась по результатам анодной кулонометриис учетом токовой эффективности, определенной по результатам катодной кулонометрии. Морфология поверхности электрода контролировалась при помощи сканирующей электронной микроскопии (СЭМ). Обнаружено, что концентрация сверхравновесных вакансий, возникающих в поверхностном слое, зависит от потенциала селективного растворения цинка из сплава. На катодных вольтамперограммах сплавов после их анодного окисления регистрируется пик восстановления оксида Ag(I). Токовая эффективность оксидообразования на сплавах Ag-Zn составляет менее 100% и уменьшается с ростом концентрации цинка в сплаве. Толщина оксида Ag(I) на сплавах не превышает 25 нм. СЭМ-изображения демонстрируют равномерное распределение частиц оксида поповерхности электрода. Форма частиц близка к сферической. Основным продуктом окисления сплавов серебра с цинком (до 30 ат.% Zn включительно) с различной вакансионной дефектностью поверхностного слоя является оксид Ag(I). Токовая эффективность и толщина для пленки оксидаAg(I), сформированной на сплавах с повышенной вакансионной дефектностью, меньше, чем для пленки оксида Ag(I), сформированной на чистом серебре. 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