| 1. |
- Colozza, Noemi, et al.
(författare)
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A Paper-Based Potentiometric Sensor for Solid Samples : Corrosion Evaluation of Reinforcements Embedded in Concrete Structures as a Case Study
- 2020
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Ingår i: ChemElectroChem. - : Wiley. - 2196-0216. ; 7:10, s. 2274-2282
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Tidskriftsartikel (refereegranskat)abstract
- Herein, we present the first paper-based device for facing one of the worldwide concerns of the Modern age: the corrosion-induced deterioration of reinforced concrete. Indeed, the monitoring of corrosion extent in reinforced concrete constructions has been acknowledged as a priority for public safety. In this work, the porosity properties of a paper-based screen-printed Ag/AgCl electrode were exploited for realising a smart analytical tool to be directly applied on the solid surface of concrete for the evaluation of corrosion. The analysis was carried out by measuring the electrochemical potential between the metallic reinforcement and the sensor, needing only 70 mu L of electrolyte solution. The sensor was firstly tested in the laboratory using reinforced concrete samples and then applied on the real outdoor artwork Music Collection Session by Arman (Milan, Italy). A summary of the main available non-destructive techniques for corrosion monitoring is reported to provide a critic overview.
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| 2. |
- Colozza, Noemi, et al.
(författare)
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Multiparametric analysis by paper-assisted potentiometric sensors for diagnostic and monitoring of reinforced concrete structures
- 2021
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Ingår i: Sensors and actuators. B, Chemical. - : Elsevier. - 0925-4005 .- 1873-3077. ; 345
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Tidskriftsartikel (refereegranskat)abstract
- Reinforced concrete has been employed worldwide as a leading building material for public and private structures as well as in modern sculptural art. Although the unrivalled mechanical strength and modelling versatility of this material, several interrelated processes are responsible for its progressive degradation (e.g., carbonation, penetration of aging-promoting agents), decreasing its long-last durability and representing a risk for the public security or the cultural heritage. With the aim to tackle this issue, the present work reports a novel configuration of a screen-printed sensor, obtained by the combination of flexible and robust polyester support and wax-printed filter paper device for the direct application on the concrete surface. Our sensor consists of a polyester-printed three-electrochemical cell that allows dual measurements on reinforced concrete, namely (i) the evaluation of corrosion probability of the metallic reinforcements (which outperforms the half-cell potential standard method) and (ii) the employment of a pH-sensitive iridium oxide film for the measurement of the pH of concrete. The paper was used as a porous material capable of ensuring the electrochemical connection between the Ag/AgCl printed electrode and the concrete solid matrix, acting also as a protective envelope for the electrode. After the laboratory tests, which revealed the noteworthy performances of the sensors in distinguishing among different levels of corrosion as well as measuring the pH of concrete, the developed sensor was applied for on-site measurement at the Giacomo Manzu Museum (Ardea, Italy), demonstrating its suitability for the real application to cultural heritage conservation. Overall, this easy-to-handle and non-invasive diagnostic device provides an innovative analytical approach for the on-site and prompt multiparametric monitoring of the physico-chemical phenomena that endanger the long-lasting preservation of reinforced concrete structures.
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| 3. |
- Colozza, Noemi, et al.
(författare)
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Vertical-Flow Paper Sensor for On-Site and Prompt Evaluation of Chloride Contamination in Concrete Structures
- 2021
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Ingår i: Analytical Chemistry. - : American Chemical Society (ACS). - 0003-2700 .- 1520-6882. ; 93:43, s. 14369-14374
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Tidskriftsartikel (refereegranskat)abstract
- Corrosion occurring in reinforced concrete has turned into a primary concern of the current century, concrete being the most ubiquitous and predominant material used in the construction industry. Among the many interrelated processes that trigger corrosion of metallic reinforcements, the penetration of chloride ions into the concrete matrix is the most insidious threat. Herein, we developed the first electrochemical device entirely made of paper that allows for the direct, prompt, and noninvasive evaluation of free chloride ion contamination in concrete-based constructions. Our device is based on a three-layer wax-modified filter paper, consisting of two Ag/AgCl screen-printed electrodes that are interfaced by a junction pad in a sandwich-like configuration. Filter paper allows for generating a vertical-flow potentiometric device capable of measuring the electrochemical potential between two solutions containing different concentrations of chloride ions, which are separately drop-cast on the top and bottom layers. After demonstrating the analytical performance of the device, the same principle was applied to the evaluation of the chloride contents in different concrete samples, exploiting paper as a suitable interfacing material for potentiometric measurements on the cement solid surface. Laboratory-prepared concrete samples with known chloride contents were first assessed, and then, the paper-based vertical-flow device was applied to real concrete structures at the Giacomo Manzu Museum (Ardea, Italy) for the evaluation of chloride contamination caused by the proximity to the seaside. The capability of our device to provide timely warning of the risk conditions of concrete-based artifacts was demonstrated.
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| 4. |
- Sassolini, Alessandro, et al.
(författare)
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Screen-printed electrode as a cost-effective and miniaturized analytical tool for corrosion monitoring of re-inforced concrete
- 2019
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Ingår i: Electrochemistry communications. - : Elsevier BV. - 1388-2481 .- 1873-1902. ; 98, s. 69-72
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Tidskriftsartikel (refereegranskat)abstract
- Herein, we report the first electrochemical sensor based on a screen-printed electrode designed to evaluate the corrosion level in iron-reinforced concrete specimens. The combination of an Ag pseudoreference electrode with a gel polymeric electrolyte allows for fast, stable and cost-effective potentiometric measurements, suitable for evaluating the corrosion of iron bars embedded in concrete samples. The sensor was found to be capable of discriminating between a standard non-corroded sample and samples subject to corrosion due to the presence of chloride or carbonate in the concrete matrix. The potential in concrete-based specimens containing carbonate (pH 9, - 0.35 +/- 0.03 V) or chloride (4% w/w, - 0.52 +/- 0.01 V) was found to be more negative than in a standard concrete-based sample ( - 0.251 +/- 0.003 V), in agreement with the ASTM standard C876 method which uses a classical Cu/CuSO4 solid reference electrode. Our results demonstrate that a printed Ag pseudoreference electrode combined with KC1 agar provides an efficient and reliable electrochemical system for evaluating the corrosion of iron bars embedded in concrete-based structures.
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