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A systematic study on the effect of the electrochemical exfoliation of graphite was conducted to provide new insights on the structure and material properties. Graphene-like structures are produced at scale currently using the wet chemical approaches, which is usually followed by an additional reduction step. The electrochemical exfoliation constitutes a promising alternative method for green, fast, and safe industrial exploitation, due to its low cost, mild conditions, basic equipment requirement and eco-friendlier electrolytes. Additionally, crystal structure of graphene related materials demonstrates less defective sights due to the high speed of exfoliation. A thorough investigation was conducted on critical parameters of the electrochemical process. The parameters of concentration, voltage, temperature and sonication assistance were studied using the randomized block design approach for various electrolytes. After the evaluation and screening of the materials with several characterization techniques, three optimization routes were selected, which included a modified Hummers' method, exfoliation based on the surface energy of pure DMF, and violent pH neutralization. The production of graphene oxide nanoplatelets was achieved, with high oxidation rates, high crystallinity and limited imperfections. The materials were consisted of less than 10 layers and up to 5 layers as demonstrated by the low crystallite size, which was also demonstrated for GO that underwent post-treatment optimization. Higher yields were achieved with electrolytes known for their strong oxidative effect, while the hydrogen peroxide electrolyte and the ionic liquid demonstrated lower exfoliation rates.
Georgios Konstantopoulos; Eleni Fotou; Afroditi Ntziouni; Konstantinos Kordatos; Costas A. Charitidis. A systematic study of electrolyte effect on exfoliation efficiency and green synthesis of graphene oxide. Ceramics International 2021, 1 .
AMA StyleGeorgios Konstantopoulos, Eleni Fotou, Afroditi Ntziouni, Konstantinos Kordatos, Costas A. Charitidis. A systematic study of electrolyte effect on exfoliation efficiency and green synthesis of graphene oxide. Ceramics International. 2021; ():1.
Chicago/Turabian StyleGeorgios Konstantopoulos; Eleni Fotou; Afroditi Ntziouni; Konstantinos Kordatos; Costas A. Charitidis. 2021. "A systematic study of electrolyte effect on exfoliation efficiency and green synthesis of graphene oxide." Ceramics International , no. : 1.
Self-assembling peptides and carbon nanomaterials have attracted great interest for their respective potential to bring innovation in the biomedical field. Combination of these two types of building blocks is not trivial in light of their very different physico-chemical properties, yet great progress has been made over the years at the interface between these two research areas. This concise review will analyze the latest developments at the forefront of research that combines self-assembling peptides with carbon nanostructures for biological use. Applications span from tissue regeneration, to biosensing and imaging, and bioelectronics.
Petr Rozhin; Costas Charitidis; Silvia Marchesan. Self-Assembling Peptides and Carbon Nanomaterials Join Forces for Innovative Biomedical Applications. Molecules 2021, 26, 4084 .
AMA StylePetr Rozhin, Costas Charitidis, Silvia Marchesan. Self-Assembling Peptides and Carbon Nanomaterials Join Forces for Innovative Biomedical Applications. Molecules. 2021; 26 (13):4084.
Chicago/Turabian StylePetr Rozhin; Costas Charitidis; Silvia Marchesan. 2021. "Self-Assembling Peptides and Carbon Nanomaterials Join Forces for Innovative Biomedical Applications." Molecules 26, no. 13: 4084.
Silver nanoparticles (AgNPs) exert profound physicochemical, biological, and antimicrobial properties, therefore, they have been extensively studied for a variety of applications such as food packaging and cultural heritage protection. However, restrictions in their stability, aggregation phenomena, and toxicity limit their extensive use. Hence, the use of functional substrates that promote the silver nanoparticles’ growth and allow the formation of uniform-sized, evenly distributed, as well as stable nanoparticles, has been suggested. This study reports on the fabrication and the characterization of hydrophilic polymer spheres including nanoparticles with intrinsic antifungal properties. Poly (methacrylic acid) microspheres were synthesized, employing the distillation precipitation method, to provide monodisperse spherical substrates for the growth of silver nanoparticles, utilizing the co-precipitation of silver nitrate in aqueous media. The growth and the aggregation potential of the silver nanoparticles were studied, whereas the antifungal activity of the produced nanostructures was evaluated against the black mold-causing fungus Aspergillus niger. The produced structures exhibit dose-dependent antifungal activity. Therefore, they could potentially be employed for the protection and preservation of cultural heritage artifacts and considered as new agents for food protection from fungal contamination during storage.
Panagiotis Kainourgios; Leto-Aikaterini Tziveleka; Ioannis Kartsonakis; Efstathia Ioannou; Vassilios Roussis; Costas Charitidis. Silver Nanoparticles Grown on Cross-Linked Poly (Methacrylic Acid) Microspheres: Synthesis, Characterization, and Antifungal Activity Evaluation. Chemosensors 2021, 9, 152 .
AMA StylePanagiotis Kainourgios, Leto-Aikaterini Tziveleka, Ioannis Kartsonakis, Efstathia Ioannou, Vassilios Roussis, Costas Charitidis. Silver Nanoparticles Grown on Cross-Linked Poly (Methacrylic Acid) Microspheres: Synthesis, Characterization, and Antifungal Activity Evaluation. Chemosensors. 2021; 9 (7):152.
Chicago/Turabian StylePanagiotis Kainourgios; Leto-Aikaterini Tziveleka; Ioannis Kartsonakis; Efstathia Ioannou; Vassilios Roussis; Costas Charitidis. 2021. "Silver Nanoparticles Grown on Cross-Linked Poly (Methacrylic Acid) Microspheres: Synthesis, Characterization, and Antifungal Activity Evaluation." Chemosensors 9, no. 7: 152.
We present a constitutive framework for modeling the nonlinear elastic behavior of α-Germanium (Ge). Starting with all possible phase changes Ge sustains under compression, we correspond to each space group of every phase the arithmetic symmetry group by viewing Ge as a multilattice. We then focus on the mother α phase of Ge. Confining ourselves to weak transformation neighborhoods and adopting the Cauchy–Born rule we work with the classical symmetries of continuum mechanics. Since there is no available representation theory for the symmetry group of α-Ge, we use integrity basis theory to find the most general expression for the arguments of the energy. Using energy’s expression we evaluate the stress tensor in its most general form. We then study two problems of increasing difficulty: simple tension/compression and anti-plane shear. For the first class of problems we give closed form solutions, while the anti-plane shear problem complicates the equations dramatically; we give conditions for the solvability of the field equations ruling the shift vector.
D. Sfyris; D.A. Dragatogiannis; C. Charitidis. Nonlinear elastic constitutive modeling of α-Ge. International Journal of Non-Linear Mechanics 2021, 134, 103737 .
AMA StyleD. Sfyris, D.A. Dragatogiannis, C. Charitidis. Nonlinear elastic constitutive modeling of α-Ge. International Journal of Non-Linear Mechanics. 2021; 134 ():103737.
Chicago/Turabian StyleD. Sfyris; D.A. Dragatogiannis; C. Charitidis. 2021. "Nonlinear elastic constitutive modeling of α-Ge." International Journal of Non-Linear Mechanics 134, no. : 103737.
This study aims to examine how core–shell super absorbent polymers (SAPs) can be effective in relation to recycling processes by using them as triggerable materials in coating binders. Super absorbent polymers are partially cross-linked, three-dimensional polymer networks that can absorb and retain water. Coatings based on an acrylic binder, including SAPs, were applied onto plastic substrates of acrylonitrile–butadiene–styrene/polycarbonate. The incorporation of 1 wt.% and 5 wt.% SAPs into the coatings resulted in the debonding of the coatings from the substrates under a steam treatment. The trigger mechanism for the core–shell hydrophilic SAPs relies on the different abilities of the core and shell materials to be swollen. Therefore, under the influence of steam, SAPs can enhance their shape due to water absorption and the breaking of the inorganic shell. This results in the reduction of the attachment between the primer layer and both the top coating and the substrate, thus enabling the detachment of the top coating from the corresponding substrate. The obtained results from this study can be considered as potential formulations for plastic recycling applications in industries.
Ioannis Kartsonakis; Panagiotis Goulis; Costas Charitidis. Triggerable Super Absorbent Polymers for Coating Debonding Applications. Polymers 2021, 13, 1432 .
AMA StyleIoannis Kartsonakis, Panagiotis Goulis, Costas Charitidis. Triggerable Super Absorbent Polymers for Coating Debonding Applications. Polymers. 2021; 13 (9):1432.
Chicago/Turabian StyleIoannis Kartsonakis; Panagiotis Goulis; Costas Charitidis. 2021. "Triggerable Super Absorbent Polymers for Coating Debonding Applications." Polymers 13, no. 9: 1432.
Schematic representation of the QSAR modeling workflow in this study, which produced the model predicting genotoxicity of multi-walled carbon nanotubes (MWCNTs).
Marianna Kotzabasaki; Iason Sotiropoulos; Constantinos Charitidis; Haralambos Sarimveis. Machine learning methods for multi-walled carbon nanotubes (MWCNT) genotoxicity prediction. Nanoscale Advances 2021, 3, 3167 -3176.
AMA StyleMarianna Kotzabasaki, Iason Sotiropoulos, Constantinos Charitidis, Haralambos Sarimveis. Machine learning methods for multi-walled carbon nanotubes (MWCNT) genotoxicity prediction. Nanoscale Advances. 2021; 3 (11):3167-3176.
Chicago/Turabian StyleMarianna Kotzabasaki; Iason Sotiropoulos; Constantinos Charitidis; Haralambos Sarimveis. 2021. "Machine learning methods for multi-walled carbon nanotubes (MWCNT) genotoxicity prediction." Nanoscale Advances 3, no. 11: 3167-3176.
The management of energy consumption in the building sector is of crucial concern for modern societies. Fossil fuels' reduced availability, along with the environmental implications they cause, emphasize the necessity for the development of new technologies using renewable energy resources. Taking into account the growing resource shortages, as well as the ongoing deterioration of the environment, the building energy performance improvement using phase change materials (PCMs) is considered as a solution that could balance the energy supply together with the corresponding demand. Thermal energy storage systems with PCMs have been investigated for several building applications as they constitute a promising and sustainable method for reduction of fuel and electrical energy consumption, while maintaining a comfortable environment in the building envelope. These compounds can be incorporated into building construction materials and provide passive thermal sufficiency, or they can be used in heating, ventilation, and air conditioning systems, domestic hot water applications, etc. This study presents the principles of latent heat thermal energy storage systems with PCMs. Furthermore, the materials that can be used as PCMs, together with the most effective methods for improving their thermal performance, as well as various passive applications in the building sector, are also highlighted. Finally, special attention is given to the encapsulated PCMs that are composed of the core material, which is the PCM, and the shell material, which can be inorganic or organic, and their utilization inside constructional materials.
Christina Podara; Ioannis Kartsonakis; Costas Charitidis. Towards Phase Change Materials for Thermal Energy Storage: Classification, Improvements and Applications in the Building Sector. Applied Sciences 2021, 11, 1490 .
AMA StyleChristina Podara, Ioannis Kartsonakis, Costas Charitidis. Towards Phase Change Materials for Thermal Energy Storage: Classification, Improvements and Applications in the Building Sector. Applied Sciences. 2021; 11 (4):1490.
Chicago/Turabian StyleChristina Podara; Ioannis Kartsonakis; Costas Charitidis. 2021. "Towards Phase Change Materials for Thermal Energy Storage: Classification, Improvements and Applications in the Building Sector." Applied Sciences 11, no. 4: 1490.
Cementitious structures have prevailed worldwide and are expected to exhibit further growth in the future. Nevertheless, cement cracking is an issue that needs to be addressed in order to enhance structure durability and sustainability especially when exposed to aggressive environments. The purpose of this work was to examine the impact of the Superabsorbent Polymers (SAPs) incorporation into cementitious composite materials (mortars) with respect to their structure (hybrid structure consisting of organic core—inorganic shell) and evaluate the microstructure and self-healing properties of the obtained mortars. The applied SAPs were tailored to maintain their functionality in the cementitious environment. Control and mortar/SAPs specimens with two different SAPs concentrations (1 and 2% bwoc) were molded and their mechanical properties were determined according to EN 196-1, while their microstructure and self-healing behavior were evaluated via microCT. Compressive strength, a key property for mortars, which often degrades with SAPs incorporation, in this work, practically remained intact for all specimens. This is coherent with the porosity reduction and the narrower range of pore size distribution for the mortar/SAPs specimens as determined via microCT. Moreover, the self-healing behavior of mortar-SAPs specimens was enhanced up to 60% compared to control specimens. Conclusively, the overall SAPs functionality in cementitious-based materials was optimized.
Irene A. Kanellopoulou; Ioannis A. Kartsonakis; Costas A. Charitidis. The Effect of Superabsorbent Polymers on the Microstructure and Self-Healing Properties of Cementitious-Based Composite Materials. Applied Sciences 2021, 11, 700 .
AMA StyleIrene A. Kanellopoulou, Ioannis A. Kartsonakis, Costas A. Charitidis. The Effect of Superabsorbent Polymers on the Microstructure and Self-Healing Properties of Cementitious-Based Composite Materials. Applied Sciences. 2021; 11 (2):700.
Chicago/Turabian StyleIrene A. Kanellopoulou; Ioannis A. Kartsonakis; Costas A. Charitidis. 2021. "The Effect of Superabsorbent Polymers on the Microstructure and Self-Healing Properties of Cementitious-Based Composite Materials." Applied Sciences 11, no. 2: 700.
Thermoplastic nanocomposites were fabricated in order to deliver a suitable material for thermal management devices, commonly processed by injection molding or 3D printing. Scalable manufacturing of Carbon Nanotubes (CNTs) and multi-functional polymers with good thermal conductivity and ease of handling was demonstrated in the present study. The standard grade polyethylene reinforced with CNTs, was formed by melt mixing. Polyethylene glycol was used for concentrating CNTs in a masterbatch for its plasticizing properties, ensuring safe handling and even dispersion of CNTs. Through characterization of morphology and thermal properties, an interconnected CNTs network was established, which enhanced the heat transfer at high concentration by changing the main conduction path from polymer crystal lattice to CNTs conductive network. Moreover, it was shown that modification in the matrix crystallinity is key to maximize the phonon and electron conduction interfaces and achieve advances in thermal conductivity beyond 68% and 100% achieved for 15 wt% content of CNTs compared to neat PE and [email protected] matrices, respectively, within this study.
Georgios Konstantopoulos; Panagiotis Maroulas; Dimitrios A. Dragatogiannis; Stefanos Koutsoumpis; Apostolos Kyritsis; Costas A. Charitidis. The effect of interfacial resistance and crystallinity on heat transfer mechanism in carbon nanotube reinforced polyethylene. Materials & Design 2020, 199, 109420 .
AMA StyleGeorgios Konstantopoulos, Panagiotis Maroulas, Dimitrios A. Dragatogiannis, Stefanos Koutsoumpis, Apostolos Kyritsis, Costas A. Charitidis. The effect of interfacial resistance and crystallinity on heat transfer mechanism in carbon nanotube reinforced polyethylene. Materials & Design. 2020; 199 ():109420.
Chicago/Turabian StyleGeorgios Konstantopoulos; Panagiotis Maroulas; Dimitrios A. Dragatogiannis; Stefanos Koutsoumpis; Apostolos Kyritsis; Costas A. Charitidis. 2020. "The effect of interfacial resistance and crystallinity on heat transfer mechanism in carbon nanotube reinforced polyethylene." Materials & Design 199, no. : 109420.
The aim of this study is to synthesize an organic core-shell co-polymer with a different glass transition temperature (Tg) between the core and the shell that can be used for several applications such as the selective debonding of coatings or the release of encapsulated materials. The co-polymer was synthesized using free radical polymerization and was characterized with respect to its morphology, composition and thermal behavior. The obtained results confirmed the successful synthesis of the co-polymer copolymer poly(methyl methacrylate)@poly(methacrylic acid-co-ethylene glycol dimethacrylate), [email protected](MAA-co-EGDMA), which can be used along with water-based solvents. Furthermore, the Tg of the polymer’s core PMMA was 104 °C, while the Tg of the shell P(MAA-co-EGDMA) was 228 °C, making it appropriate for a wide variety of applications. It is worth mentioning that by following this specific experimental procedure, methacrylic acid was copolymerized in water, as the shell of the copolymer, without forming a gel-like structure (hydrogel), as happens when a monomer is polymerized in aqueous media, such as in the case of super-absorbent polymers. Moreover, the addition and subsequent polymerization of the monomer methyl methacrylate (MAA) into the mixture of the already polymerized PMMA resulted in a material that was uniform in size, without any agglomerations or sediments.
Panagiotis Goulis; Ioannis A. Kartsonakis; Costas A. Charitidis. Synthesis and Characterization of a Core-Shell Copolymer with Different Glass Transition Temperatures. Fibers 2020, 8, 71 .
AMA StylePanagiotis Goulis, Ioannis A. Kartsonakis, Costas A. Charitidis. Synthesis and Characterization of a Core-Shell Copolymer with Different Glass Transition Temperatures. Fibers. 2020; 8 (11):71.
Chicago/Turabian StylePanagiotis Goulis; Ioannis A. Kartsonakis; Costas A. Charitidis. 2020. "Synthesis and Characterization of a Core-Shell Copolymer with Different Glass Transition Temperatures." Fibers 8, no. 11: 71.
This work describes a novel methodology for the quality assessment of a Fused Filament Fabrication (FFF) 3D printing object during the printing process through AI-based Computer Vision. Specifically, Neural Networks are developed for identifying 3D printing defects during the printing process by analyzing video captured from the process. Defects are likely to occur in 3D printed objects during the printing process, with one of them being stringing; they are mostly correlated to one of the printing parameters or the object’s geometries. The defect stringing can be on a large scale and is usually located in visible parts of the object by a capturing camera. In this case, an AI model (Deep Convolutional Neural Network) was trained on images where the stringing issue is clearly displayed and deployed in a live environment to make detections and predictions on a video camera feed. In this work, we present a methodology for developing and deploying deep neural networks for the recognition of stringing. The trained model can be successfully deployed (with appropriate assembly of required hardware such as microprocessors and a camera) on a live environment. Stringing can be then recognized in line with fast speed and classification accuracy. Furthermore, this approach can be further developed in order to make adjustments to the printing process. Via this, the proposed approach can either terminate the printing process or correct parameters which are related to the identified defect.
Konstantinos Paraskevoudis; Panagiotis Karayannis; Elias P. Koumoulos. Real-Time 3D Printing Remote Defect Detection (Stringing) with Computer Vision and Artificial Intelligence. Processes 2020, 8, 1464 .
AMA StyleKonstantinos Paraskevoudis, Panagiotis Karayannis, Elias P. Koumoulos. Real-Time 3D Printing Remote Defect Detection (Stringing) with Computer Vision and Artificial Intelligence. Processes. 2020; 8 (11):1464.
Chicago/Turabian StyleKonstantinos Paraskevoudis; Panagiotis Karayannis; Elias P. Koumoulos. 2020. "Real-Time 3D Printing Remote Defect Detection (Stringing) with Computer Vision and Artificial Intelligence." Processes 8, no. 11: 1464.
The purpose of this study is to investigate a novel exploitation approach for a mass livestock byproduct, namely sheep wool fibres. In order to fulfil this aim, wool fibre toughened epoxy composites with an amount of 2.4, 4.1 and 5.7 phr were prepared via the hot press method. Initially, mechanical assessment of the composites was executed, in order to evaluate their mechanical integrity. The flexural and shear strength tests showed that the wool fibre-epoxy composites maintain their mechanical properties for up to 4.1 phr and no degradation is detected. Subsequently, the thermal properties were tested. Thermogravimetric analysis proved that adding wool fibres as toughening agent in epoxy matrix can prolong the endurance of the material while reaching high temperatures. The coefficient of thermal conductivity decreased by 30% compared to neat epoxy, something that is also confirmed through simulation, proving that wool fibre-epoxy composites can be considered as a promising insulating material, while exploiting a natural waste.
Dionisis Semitekolos; Katerina Pardou; Pantelitsa Georgiou; Panagiota Koutsouli; Iosif Bizelis; Loukas Zoumpoulakis. Investigation of mechanical and thermal insulating properties of wool fibres in epoxy composites. Polymers and Polymer Composites 2020, 1 .
AMA StyleDionisis Semitekolos, Katerina Pardou, Pantelitsa Georgiou, Panagiota Koutsouli, Iosif Bizelis, Loukas Zoumpoulakis. Investigation of mechanical and thermal insulating properties of wool fibres in epoxy composites. Polymers and Polymer Composites. 2020; ():1.
Chicago/Turabian StyleDionisis Semitekolos; Katerina Pardou; Pantelitsa Georgiou; Panagiota Koutsouli; Iosif Bizelis; Loukas Zoumpoulakis. 2020. "Investigation of mechanical and thermal insulating properties of wool fibres in epoxy composites." Polymers and Polymer Composites , no. : 1.
Additive manufacturing holds promise for the fabrication of three-dimensional scaffolds with precise geometry, to serve as substrates for the guided regeneration of natural tissue. In this work, a bioinspired approach is adopted for the synthesis of hybrid hydroxyapatite hydrogels, which were subsequently printed to form 3D scaffolds for bone tissue engineering applications. These hydrogels consist of hydroxyapatite nanocrystals, biomimetically synthesized in the presence of both chitosan and l-arginine. To improve their mechanical properties, chemical crosslinking was performed using a natural crosslinking agent (genipin), and their rheology was modified by employing an acetic acid/gelatin solution. Regarding the 3D printing process, several parameters (flow, infill and perimeter speed) were studied in order to accurately produce scaffolds with predesigned geometry and micro-architecture, while also applying low printing temperature (15 °C). Following the printing procedure, the 3D scaffolds were freeze dried in order to remove the entrapped solvents and therefore, obtain a porous interconnected network. Evaluation of porosity was performed using micro-computed tomography and nanomechanical properties were assessed through nanoindentation. Results of both characterization techniques, showed that the scaffolds' porosity as well as their modulus values, fall within the corresponding range of the respective values of cancellous bone. The biocompatibility of the 3D printed scaffolds was assessed using MG63 human osteosarcoma cells for 7 days of culturing. Cell viability was evaluated by MTT assay as well as double staining and visualized under fluorescence microscopy, while cell morphology was analyzed through scanning electron microscopy. Biocompatibility tests, revealed that the scaffolds constitute a cell-friendly environment, allowed them to adhere on the scaffolds' surface, increase their population and maintain high levels of viability.
K. Zafeiris; D. Brasinika; A. Karatza; Elias Koumoulos; I.K. Karoussis; K. Kyriakidou; C.A. Charitidis. Additive manufacturing of hydroxyapatite–chitosan–genipin composite scaffolds for bone tissue engineering applications. Materials Science and Engineering: C 2020, 119, 111639 .
AMA StyleK. Zafeiris, D. Brasinika, A. Karatza, Elias Koumoulos, I.K. Karoussis, K. Kyriakidou, C.A. Charitidis. Additive manufacturing of hydroxyapatite–chitosan–genipin composite scaffolds for bone tissue engineering applications. Materials Science and Engineering: C. 2020; 119 ():111639.
Chicago/Turabian StyleK. Zafeiris; D. Brasinika; A. Karatza; Elias Koumoulos; I.K. Karoussis; K. Kyriakidou; C.A. Charitidis. 2020. "Additive manufacturing of hydroxyapatite–chitosan–genipin composite scaffolds for bone tissue engineering applications." Materials Science and Engineering: C 119, no. : 111639.
Editorial: Recent Trends in Optical and Mechanical Characterization of Nanomaterials
Stefan G. Stanciu; Loredana Latterini; Costas A. Charitidis. Editorial: Recent Trends in Optical and Mechanical Characterization of Nanomaterials. Frontiers in Chemistry 2020, 8, 564014 .
AMA StyleStefan G. Stanciu, Loredana Latterini, Costas A. Charitidis. Editorial: Recent Trends in Optical and Mechanical Characterization of Nanomaterials. Frontiers in Chemistry. 2020; 8 ():564014.
Chicago/Turabian StyleStefan G. Stanciu; Loredana Latterini; Costas A. Charitidis. 2020. "Editorial: Recent Trends in Optical and Mechanical Characterization of Nanomaterials." Frontiers in Chemistry 8, no. : 564014.
In the present work, an assessment of the corrosion behavior of mild steel in the presence of an organic corrosion inhibitor loaded into hybrid composite materials is performed. Hybrid organic–inorganic nanocontainers based on cerium and titanium oxides were fabricated via a combination of radical polymerization together with the coprecipitation method and sol-gel technique. The corrosion inhibition role of these hybrid materials loaded with an inhibitor is considered. A set of characterization assays addressing morphology, composition and structural aspects of the exposed steels is illustrated, along with electrochemical evaluations. The results reveal enhanced stimuli responsive anticorrosion ability of the produced hybrid materials. Furthermore, upon corrosion, new compounds are formed onto the exposed areas of the treated metals. The conducted experiments shed light on the corrosion mechanisms for steel alloys as well as the actuation of the fabricated composite materials, paving the way for future developments in this area.
Ioannis A. Kartsonakis; Costas A. Charitidis. Corrosion Protection Evaluation of Mild Steel: The Role of Hybrid Materials Loaded with Inhibitors. Applied Sciences 2020, 10, 6594 .
AMA StyleIoannis A. Kartsonakis, Costas A. Charitidis. Corrosion Protection Evaluation of Mild Steel: The Role of Hybrid Materials Loaded with Inhibitors. Applied Sciences. 2020; 10 (18):6594.
Chicago/Turabian StyleIoannis A. Kartsonakis; Costas A. Charitidis. 2020. "Corrosion Protection Evaluation of Mild Steel: The Role of Hybrid Materials Loaded with Inhibitors." Applied Sciences 10, no. 18: 6594.
Life cycle assessment is a methodology to assess environmental impacts associated with a product or system/process by accounting resource requirements and emissions over its life cycle. The life cycle consists of four stages: material production, manufacturing, use, and end-of-life. This study highlights the need to conduct life cycle assessment (LCA) early in the new product development process, as a means to assess and evaluate the environmental impacts of (nano)enhanced carbon fibre-reinforced polymer (CFRP) prototypes over their entire life cycle. These prototypes, namely SleekFast sailing boat and handbrake lever, were manufactured by functionalized carbon fibre fabric and modified epoxy resin with multi-walled carbon nanotubes (MWCNTs). The environmental impacts of both have been assessed via LCA with a functional unit of ‘1 product piece’. Climate change has been selected as the key impact indicator for hotspot identification (kg CO2 eq). Significant focus has been given to the end-of-life phase by assessing different recycling scenarios. In addition, the respective life cycle inventories (LCIs) are provided, enabling the identification of resource hot spots and quantifying the environmental benefits of end-of-life options.
Fotini Petrakli; Anastasia Gkika; Alexandra Bonou; Panagiotis Karayannis; Elias Koumoulos; Dionisis Semitekolos; Aikaterini-Flora Trompeta; Nuno Rocha; Raquel Santos; Guy Simmonds; Glen Monaghan; Giorgio Valota; Guan Gong; Costas Charitidis. End-of-Life Recycling Options of (Nano)Enhanced CFRP Composite Prototypes Waste—A Life Cycle Perspective. Polymers 2020, 12, 2129 .
AMA StyleFotini Petrakli, Anastasia Gkika, Alexandra Bonou, Panagiotis Karayannis, Elias Koumoulos, Dionisis Semitekolos, Aikaterini-Flora Trompeta, Nuno Rocha, Raquel Santos, Guy Simmonds, Glen Monaghan, Giorgio Valota, Guan Gong, Costas Charitidis. End-of-Life Recycling Options of (Nano)Enhanced CFRP Composite Prototypes Waste—A Life Cycle Perspective. Polymers. 2020; 12 (9):2129.
Chicago/Turabian StyleFotini Petrakli; Anastasia Gkika; Alexandra Bonou; Panagiotis Karayannis; Elias Koumoulos; Dionisis Semitekolos; Aikaterini-Flora Trompeta; Nuno Rocha; Raquel Santos; Guy Simmonds; Glen Monaghan; Giorgio Valota; Guan Gong; Costas Charitidis. 2020. "End-of-Life Recycling Options of (Nano)Enhanced CFRP Composite Prototypes Waste—A Life Cycle Perspective." Polymers 12, no. 9: 2129.
Bioinspired scaffolds mimicking natural bone-tissue properties holds great promise in tissue engineering applications towards bone regeneration. Within this work, a way to reinforce mechanical behavior of bioinspired bone scaffolds was examined by applying a physical crosslinking method. Scaffolds consisted of hydroxyapatite nanocrystals, biomimetically synthesized in the presence of collagen and l-arginine. Scaffolds were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy (SEM), microcomputed tomography, and nanoindentation. Results revealed scaffolds with bone-like nanostructure and composition, thus an inherent enhanced cytocompatibility. Evaluation of porosity proved the development of interconnected porous network with bimodal pore size distribution. Mechanical reinforcement was achieved through physical crosslinking with riboflavin irradiation, and nanoindentation tests indicated that within the experimental conditions of 45% humidity and 37 °C, photo-crosslinking led to an increase in the scaffold’s mechanical properties. Elastic modulus and hardness were augmented, and specifically elastic modulus values were doubled, approaching equivalent values of trabecular bone. Cytocompatibility of the scaffolds was assessed using MG63 human osteosarcoma cells. Cell viability was evaluated by double staining and MTT assay, while attachment and morphology were investigated by SEM. The results suggested that scaffolds provided a cell friendly environment with high levels of viability, thus supporting cell attachment, spreading and proliferation.
Despoina Brasinika; Elias P. Koumoulos; Kyriaki Kyriakidou; Eleni Gkartzou; Maria Kritikou; Ioannis K. Karoussis; Costas A. Charitidis. Mechanical Enhancement of Cytocompatible 3D Scaffolds, Consisting of Hydroxyapatite Nanocrystals and Natural Biomolecules, Through Physical Cross-Linking. Bioengineering 2020, 7, 96 .
AMA StyleDespoina Brasinika, Elias P. Koumoulos, Kyriaki Kyriakidou, Eleni Gkartzou, Maria Kritikou, Ioannis K. Karoussis, Costas A. Charitidis. Mechanical Enhancement of Cytocompatible 3D Scaffolds, Consisting of Hydroxyapatite Nanocrystals and Natural Biomolecules, Through Physical Cross-Linking. Bioengineering. 2020; 7 (3):96.
Chicago/Turabian StyleDespoina Brasinika; Elias P. Koumoulos; Kyriaki Kyriakidou; Eleni Gkartzou; Maria Kritikou; Ioannis K. Karoussis; Costas A. Charitidis. 2020. "Mechanical Enhancement of Cytocompatible 3D Scaffolds, Consisting of Hydroxyapatite Nanocrystals and Natural Biomolecules, Through Physical Cross-Linking." Bioengineering 7, no. 3: 96.
In this work, a methodology is presented in order to assess the microstructure of Portland Cement through advanced characterisation. Nanoindentation is used to determine reduced elastic modulus and hardness, which are involved in the design of construction materials. Elemental mapping and X-ray scanning microtomography were also used to establish structure-property relations through porosity distribution and morphology as well as phase identification by nanoindentation and image analysis. The variation of carbon nanotubes (CNTs) concentration between 0.02 and 1.0 wt% demonstrated alterations in phase composition, and thus the effect of CNTs reinforcement in hydration progress was clarified. Characterisation by all techniques identified 0.5 wt% concentration as promising due to the formation of higher density hydrated phases, even though total porosity was not minimized. This fact was explained by nanoindentation as enhanced Calcium-Silicate-Hydrates connectivity in the porous network was detected. The voids of cement were filled with low stiffness hydrated gel phases as a result of enhanced hydration in the presence of CNTs.
George Konstantopoulos; Elias Koumoulos; Anna Karatza; Costas Charitidis. Pore and phase identification through nanoindentation mapping and micro-computed tomography in nanoenhanced cement. Cement and Concrete Composites 2020, 114, 103741 .
AMA StyleGeorge Konstantopoulos, Elias Koumoulos, Anna Karatza, Costas Charitidis. Pore and phase identification through nanoindentation mapping and micro-computed tomography in nanoenhanced cement. Cement and Concrete Composites. 2020; 114 ():103741.
Chicago/Turabian StyleGeorge Konstantopoulos; Elias Koumoulos; Anna Karatza; Costas Charitidis. 2020. "Pore and phase identification through nanoindentation mapping and micro-computed tomography in nanoenhanced cement." Cement and Concrete Composites 114, no. : 103741.
Carbon Fibres (CFs) are widely used in textile-reinforced composites for the construction of lightweight, durable structures. Since their inert surface does not allow effective bonding with the matrix material, the surface treatment of fibres is suggested to improve the adhesion between the two. In the present study, different surface modifications are compared in terms of the mechanical enhancement that they can offer to the fibres. Two main advanced technologies have been investigated; namely, plasma treatment and electrochemical treatment. Specifically, active screen plasma and low-pressure plasma were compared. Regarding the electrochemical modification, electrochemical oxidation and electropolymerisation of monomer solutions of acrylic and methacrylic acids, acrylonitrile and N-vinyl pyrrolidine were tested for HTA-40 CFs. In order to assess the effects of the surface treatments, the morphology, the physicochemical properties, as well as the mechanical integrity of the fibres were investigated. The CF surface and polymeric matrix interphase adhesion in composites were also analysed. The improvement of the carbon fibre’s physical–mechanical properties was evident for the case of the active screen plasma treatment and the electrochemical oxidation.
Dionisis Semitekolos; Aikaterini-Flora Trompeta; Iryna Husarova; Tamara Man’Ko; Aleksandr Potapov; Ol'ga Romenskaya; Yana Liang; Xiaoying Li; Mauro Giorcelli; Hanshan Dong; Alberto Tagliaferro; Costas A. Charitidis. Comparative Physical–Mechanical Properties Assessment of Tailored Surface-Treated Carbon Fibres. Materials 2020, 13, 3136 .
AMA StyleDionisis Semitekolos, Aikaterini-Flora Trompeta, Iryna Husarova, Tamara Man’Ko, Aleksandr Potapov, Ol'ga Romenskaya, Yana Liang, Xiaoying Li, Mauro Giorcelli, Hanshan Dong, Alberto Tagliaferro, Costas A. Charitidis. Comparative Physical–Mechanical Properties Assessment of Tailored Surface-Treated Carbon Fibres. Materials. 2020; 13 (14):3136.
Chicago/Turabian StyleDionisis Semitekolos; Aikaterini-Flora Trompeta; Iryna Husarova; Tamara Man’Ko; Aleksandr Potapov; Ol'ga Romenskaya; Yana Liang; Xiaoying Li; Mauro Giorcelli; Hanshan Dong; Alberto Tagliaferro; Costas A. Charitidis. 2020. "Comparative Physical–Mechanical Properties Assessment of Tailored Surface-Treated Carbon Fibres." Materials 13, no. 14: 3136.
Nanotechnology, as a mature enabling technology, has great potential to boost societal welfare. However, nanomaterials' current and foreseen applications raise serious concerns about their impact on human health and the environment. These concerns emerge because a reliable risk assessment in nanotechnology is yet to be achieved. The reasons for such a shortcoming are the inherent difficulties in characterizing nanomaterials properties. The interaction of characterization with modeling is an open issue and, due to overarching concerns about the reliability of research results, usually framed within the context of research integrity. This essay explores the connection between these different, but deeply intertwined concerns and the way they enable the production of responsible nanotechnology, i.e., nanotechnology devoted to societal welfare.
Ioannis Xiarchos; Athanasios K. Morozinis; Panagiotis Kavouras; Costas A. Charitidis. Nanocharacterization, Materials Modeling, and Research Integrity as Enablers of Sound Risk Assessment: Designing Responsible Nanotechnology. Small 2020, 16, e2001590 .
AMA StyleIoannis Xiarchos, Athanasios K. Morozinis, Panagiotis Kavouras, Costas A. Charitidis. Nanocharacterization, Materials Modeling, and Research Integrity as Enablers of Sound Risk Assessment: Designing Responsible Nanotechnology. Small. 2020; 16 (36):e2001590.
Chicago/Turabian StyleIoannis Xiarchos; Athanasios K. Morozinis; Panagiotis Kavouras; Costas A. Charitidis. 2020. "Nanocharacterization, Materials Modeling, and Research Integrity as Enablers of Sound Risk Assessment: Designing Responsible Nanotechnology." Small 16, no. 36: e2001590.