Papers

N. Lagopati, Th.-F. Valamvanos, V. Proutsou, K. Karachalios, N. Pippa, M.-A. Gatou, I.-A. Vagena, S. Cela, E.A. Pavlatou, M. Gazouli, E. Efstathopoulos

Chemosensors 2023, 11(6), 317

Early-stage, precise disease diagnosis and treatment has been a crucial topic of scientific discussion since time immemorial. When these factors are combined with experience and scientific knowledge, they can benefit not only the patient, but also, by extension, the entire health system. The development of rapidly growing novel technologies allows for accurate diagnosis and treatment of disease. Nanomedicine can contribute to exhaled breath analysis (EBA) for disease diagnosis, providing nanomaterials and improving sensing performance and detection sensitivity. Through EBA, gas-based nano-sensors might be applied for the detection of various essential diseases, since some of their metabolic products are detectable and measurable in the exhaled breath. The design and development of innovative nanomaterial-based sensor devices for the detection of specific biomarkers in breath samples has emerged as a promising research field for the non-invasive accurate diagnosis of several diseases. EBA would be an inexpensive and widely available commercial tool that could also be used as a disease self-test kit. Thus, it could guide patients to the proper specialty, bypassing those expensive tests, resulting, hence, in earlier diagnosis, treatment, and thus a better quality of life. In this review, some of the most prevalent types of sensors used in breath-sample analysis are presented in parallel with the common diseases that might be diagnosed through EBA, highlighting the impact of incorporating new technological achievements in the clinical routine.

doi: 10.3390/chemosensors11060317

M.-E. Kassalia, N. Chorianopoulos, G.-J. Nychas, E.A. Pavlatou

Applied Sciences (2023), 13 (7), 4498

The aim of the present study was to investigate the photoinduced properties of nitrogen-doped titanium dioxide (N-TiO2) against the Salmonella ser. Typhimurium bacterial biofilm, under visible-light irradiation. The capability of N-TiO2 nanoparticles working as multipurpose materials with antimicrobial applications, as well as environmental ones, was therefore investigated. The sol–gel method was used to synthesize N-TiO2 particles, which were then characterized by Fourier-transform infrared (FTIR) spectroscopy, dynamic light scattering (DLS), Brunauer–Emmett–Teller (BET) analysis of surface area, scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM/EDS), and transmission electron microscopy (TEM). The results showed that the particles formed were nano-sized and had the expected Ti-O bonds and the presence of elemental N. The as-produced N-TiO2 nanoparticles (NPs) were tested for their antimicrobial activity. The antibacterial photocatalytic testing was performed under visible-light irradiation, on Salmonella Typhimurium biofilm. To form the biofilm, stainless steel (ss) coupons were incubated with three different strains of Salmonella Typhimurium bacteria for 48 h at 15°C in tryptone soy broth (TSB). After the biofilm’s formation, the coupons were placed on a horizontal, rectangular, batch, equipped with a vis-LED irradiation source reactor in the presence of N-TiO2 NPs. After 1, 2, and 3 h of irradiation, sampling of the bacterial population was assessed. The results showed an evident inhibition of proliferation under light irradiation when the N-TiO2 was present, compared to the non-irradiated NPs. It is noteworthy that, during the first 2 h, the TiO2 NPs specimens tended to attract more bacteria on their surface then the control specimens, due to their higher available surface area, which worked as a shelter. There were ~6% viable (remaining) Salmonella cells after the first hour of visible-light irradiation with N-TiO2 NPs.

doi: 10.3390/app13074498

P. Pantelis, G. Theocharous, N. Lagopati, D. Veroutis, D.-F. Thanos, G.-P. Lampoglou, N. Pippa, M.-A. Gatou, I. Tremi, A. Papaspyropoulos, E. Kyrodimos, E.A. Pavlatou, M. Gazouli, K. Evangelou, V.G. Gorgoulis

Antioxidants (2023), 12 (1), 169

The contemporary lifestyle of the last decade has undeniably caused a tremendous increase in oxidative-stress-inducing environmental sources. This phenomenon is not only connected with the rise of ROS levels in multiple tissues but is also associated with the induction of senescence in different cell types. Several signaling pathways that are associated with the reduction in ROS levels and the regulation of the cell cycle are being activated, so that the organism can battle deleterious effects. Within this context, autophagy plays a significant role. Through autophagy, cells can maintain their homeostasis, as if it were a self-degradation process, which removes the “wounded” molecules from the cells and uses their materials as a substrate for the creation of new useful cell particles. However, the role of autophagy in senescence has both a “dark” and a “bright” side. This review is an attempt to reveal the mechanistic aspects of this dual role. Nanomedicine can play a significant role, providing materials that are able to act by either preventing ROS generation or controllably inducing it, thus functioning as potential therapeutic agents regulating the activation or inhibition of autophagy.

doi: 10.3390/antiox12010169

M.-E. Kassalia, Z. Nikolaou, Ε.A. Pavlatou

Applied Sciences (2023), 13 (2), 774

The primary objective of this research is to propose and compile a specific protocol for photocatalytic measurements of modified TiO2 particles under visible-light irradiation. Nitrogen-modified titanium dioxide (N-TiO2) powder was synthesized by the sol–gel method and characterized by X-ray Diffraction Analysis (XRD), Field Emission Scanning Electron Microscopy (FESEM), Transmission Electron Microscopy (TEM), X-ray Photoelectron Spectroscopy (XPS), Raman Spectroscopy (micro-Raman), and Ultraviolet–visible Spectroscopy (UV-Vis). Photocatalytic tests were performed on a specially designed photocatalytic batch reactor to test the ability of the powder to degrade hazardous toxic compounds. Via the Taguchi method, nine experiments (L9) were compiled to examine the factors that affect the photocatalytic activity of the nano-sized powder. The N-TiO2 particles were characterized by the dominance of the crystalline anatase phase, exhibiting crystals in the nano-scale. The Taguchi method was designed to control four selected parameters (pollutant selection among azo dyes, amount of catalyst to pollutant, distance of the photocatalytic cell from the radiation source, and time protocol) with three levels/options each. Conclusions were drawn regarding the way each parameter affects the final degradation of the pollutant. The parameter that proved to affect the degradation of the pollutant to a greater extent was the choice of pollutant, followed by the amount of catalyst. The other two factors almost slightly affect the process, with a similar percentage. Taking into account the abovementioned results, a photocatalytic protocol for testing TiO2 nano-powder activity under visible light irradiation is proposed by using a batch, horizontal, rectangular, vis-LED equipped reactor with reflective walls.

doi: 10.3390/app13020774

D. Manousakis, M.-A. Gatou, N. Lagopati, E.A. Pavlatou

Biomedical Journal of Scientific & Technical Research, 47 (2), 38305-38308 

Carbon quantum dots are a new class of zero-dimensional carbon nanomaterials that due to their low toxicity, high water dispersibility and fluorescent properties, have attracted a lot of attention for biomedical applications. They can be synthesized with many different methods through both bottom-up and top-down approaches. In this mini review we summarize the existing literature regarding the electrochemical exfoliation of pure graphite that produces nanostructures of diameter smaller than 10 nm. We focus on the electrolytes that are used and the voltage applied, as the main factors that contribute on the size, structure, composition and yield of the carbon quantum dots. In order to explain the findings of the literature, we briefly analyze the mechanism of the graphite exfoliation from the ions, under applied voltage. Furthermore, we report on the many advantages that the electrochemical approach has over competing methodologies, that make it an attractive method for mass production of carbon quantum dots, with the intention to be used in biomedical applications.

doi: 10.26717/BJSTR.2022.47.007479

N. Papadopoulou-Fermeli, N. Lagopati, N. Pippa, E. Sakellis, N. Boukos, V.G. Gorgoulis, M. Gazouli, E.A. Pavlatou

Pharmaceutics (2023), 15 (1), 135

The synthesis of titania-based composite materials with anticancer potential under visible-light irradiation is the aim of this study. In specific, titanium dioxide (TiO2) nanoparticles (NPs) chemically modified with silver were embedded in a stimuli-responsive microgel (a crosslinked interpenetrating network (IP) network that was synthesized by poly (N-Isopropylacrylamide) and linear chains of polyacrylic acid sodium salt, forming composite particles. The ultimate goal of this research, and for our future plans, is to develop a drug-delivery system that uses optical fibers that could efficiently photoactivate NPs, targeting cancer cells. The produced Ag-TiO2 NPs, the microgel and the composite materials were characterized through X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), micro-Raman spectroscopy, ultraviolet-visible spectroscopy (UV-Vis), dynamic light scattering (DLS) and transmission electron microscopy (TEM). Our results indicated that Ag-TiO2 NPs were successfully embedded within the thermoresponsive microgel. Either Ag-TiO2 NPs or the composite materials exhibited high photocatalytic degradation efficiency on the pollutant rhodamine B and significant anticancer potential under visible-light irradiation.

doi: 10.3390/pharmaceutics15010135

M.-A. Gatou, N. Lagopati, I.-A. Vagena, M. Gazouli, E.A. Pavlatou

Nanomaterials (2023), 13 (1), 122

Semiconductor photocatalysts, particularly ZnO nanoparticles, were synthesized via the precipitation method using four different precursors (zinc acetate/zinc nitrate/zinc sulfate/zinc chloride) and compared, according to their optical, structural, photocatalytic, and anticancer properties. The materials were characterized via X-ray Diffraction method (XRD), micro-Raman, Fourier Transform Infrared Spectroscopy (FT-IR), Brunauer-Emmett-Teller (BET), Dynamic Light Scattering (DLS), and Field Emission Scanning Electron Microscope (FESEM) analysis. Photocatalysis was conducted under UV and visible light irradiation, using Rhodamine B as the organic pollutant. It was observed that the highest photocatalysis efficiency was obtained by the nanoparticles synthesized from the zinc acetate used as precursor material. A cell-dependent anticancer efficiency of the tested ZnO nanoparticles was also observed, that was also attributed to the different precursors and the synthesis method, revealing that the nanoparticles that were synthesized from zinc acetate were more bioactive among the four tested precursors. Overall, the data revealed that both the enhanced photocatalytic and biological activity of ZnO nanoparticles derived from zinc acetate precursor could be attributed to the reduced crystalline size, increased surface area, as well as the observed hexagonal crystalline morphology.

doi: 10.3390/nano13010122

E. Galata, C.M. Veziri, G.V. Theodorakopoulos, G.Εm. Romanos, E.A. Pavlatou

Membranes (2022), 12 (12), 1181

Graphene oxide (GO) oligo-layered laminates were self-assembled on porous ceramic substrates via their simple dip-coating into aqueous GO dispersions. To augment the stability of the developed composite GO/ceramic membranes and control the morphology and stacking quality of the formed laminate, short-((3-glycidoxypropyl)trimethoxy silane-GLYMO, (3-aminopropyl)triethoxy silane-APTES), and long-chain (polydopamine-PDA) molecules were involved and examined as interfacial linkers. A comparative study was performed regarding the linker’s capacity to enhance the interfacial adhesion between the ceramic surface and the GO deposit and affect the orientation and assemblage characteristics of the adjacent GO nanosheets that composed the formed oligo-layered laminates. Subsequently, by post-filtrating a GO/H2O suspension through the oligo-layered laminate membranes, the respective multi-layered ones have been developed, whereas ethylenediamine (EDA) was used in the suspension as an efficient molecular linker that strongly bonds and interlocks the GO nanosheets. The definition of the best linker and approach was conducted on macroporous α-alumina disks, due to the use of inexpensive raw materials and the ability to fabricate them in the lab with high reproducibility. To validate the concept at a larger scale, while investigating the effect of the porous substrate as regards its micrometer-scale roughness and surface chemistry, specific chemical modifications that yielded membranes with the best gas permeability/selectivity performance were replicated on a commercial single-channel monolith with a ZrO2 microfiltration layer. XRD, Raman, ATR, FESEM, and XPS analyses were conducted to study the structural, physicochemical, surface, and morphological properties of the GO/ceramic composite membranes, whereas permeance results of several gases at various temperatures and trans-membrane pressures were interpreted to shed light on the pore structural features. Concerning the short-chain linkers, the obtained results ascertain that GLYMO causes denser and more uniform assembly of GO nanosheets within the oligo-layered laminate. PDA had the same beneficial effect, as it is a macromolecule. Overall, this study shows that the development of gas-separating membranes, by just dipping the linker-modified substrate into the GO suspension, is not straightforward. The application of post-filtration contributed significantly to this target and the quality of the superficially deposited, thick GO laminate depended on this of the chemically attached oligo-layered one.

doi: 10.3390/membranes12121181  

A.G. Mitsopoulou, E.A. Pavlatou

Education Sciences (2021), 11 (11), 746

The aim of this study is to investigate the predictive factors that predispose secondary school students’ interest in studying STEM (Science, Technology, Engineering, and Mathematics) fields in higher education. For this purpose, an already existing questionnaire was used and modified properly, according to the Greek educational system. The survey was attended by 301 secondary school students, who study in Piraeus, one of the largest cities in Greece. Research findings indicated that the principles of Social Cognitive Career Theory (SCCT) are well supported. It is worth mentioning that this is the first time that such a number of variables had been examined, in order to support the SCCT. In particular, very few studies exist in literature-to the best of our knowledge-investigating the effect of more than four factors influencing students’ interest towards STEM higher studies. Learning experiences, students’ exposure to STEM activities within the school environment and outside of it (OR=0.071, p=0.002), as well as their involvement with high difficulty STEM courses (OR=0.203, p=0.038), appear to be positively correlated with the development of interest towards studies in the STEM fields. In addition, students from low-income families are more likely to follow STEM studies (OR=0.198, p=0.034). On the contrary, it has been revealed that parental educational background only supports the student’s decision to continue studies after high school, without specifying the educational field in higher education (OR=0.769, p=0.703; father’s educational level, OR=0.698, p=0.552; mother’s educational level). Data revealed that outcome expectations and self-efficacy (OR=14.366, p=0.005) are positively related to the procedure of students’ interest development to pursue STEM fields in higher education, while gender seems to be a non-regulatory factor (OR=0.886, p=0.831).

doi: 10.3390/educsci11110746 

N. Papadimitropoulos, E.A. Pavlatou

Interactive Learning Environments, 29 (6)

Physical experiments on real-world systems are proposed as a means to raise learning outcomes and Arduino microcontroller is highlighted as an appropriate tool to perform them. However, experimentation on a real system may encounter various barriers. Therefore, a learning environment was developed in order to perform Arduino experiments on digital entities when the real ones are inaccessible. That was consisted of an Arduino-based pH meter from which measurements were transmitted to three different digital entities: a shoal of goldfish, an ancient Greek temple and an ancient Greek statue. In order to evaluate the learning outcomes of teaching through physical experiments on digital entities, a pre- to post-comparison was conducted on three Greek Junior High Schools. In each school, students were divided into two subgroups. The one group was taught about Acids and Bases through physical Arduino experiments by demonstration, using real instruments and substances, with a simultaneous observation of their effects on the digital entities in real-time, while the other group was taught through the same Arduino experiments by demonstration without the use of the digital entities. The results have demonstrated that students of the former group exhibited greater learning gains regarding Declarative Knowledge than those of the latter one.

doi: 10.1080/10494820.2021.1975302

M.-A. Gatou, P. Bika, Th.Stergiopoulos, P. Dallas, E.A. Pavlatou

Energies (2021), 14 (11), 3197

Covalent organic frameworks comprise a unique class of functional materials that has recently emerged as a versatile tool for energy-related, photocatalytic, environmental, and electro-chromic device applications. A plethora of structures can be designed and implemented through a careful selection of ligands and functional units. On the other hand, porous materials for heavy metal absorption are constantly on the forefront of materials science due to the significant health issues that arise from the release of the latter to aquatic environments. In this critical review, we provide insights on the correlation between the structure of functional covalent organic frameworks and their heavy metal absorption. The elements we selected were Pb, Hg, Cr, Cd, and As metal ions, as well as radioactive elements, and we focused on their removal with functional networks. Finally, we outline their advantages and disadvantages compared to other competitive systems such as ze-olites and metal organic frameworks (MOFs), we analyze the potential drawbacks for industrial scale applications, and we provide our outlook on the future of this emerging field.

doi: 10.3390/en14113197

N. Papadimitropoulos, K. Dalacosta, E.A. Pavlatou

Journal of Science Education and Technology (2021)

A study with K-9 Greek students was conducted in order to evaluate how the declarative knowledge acquisition was affected by incorporating Arduino experiments in secondary Chemistry Education. A Digital Application (DA) that blends the use of the Arduino sensors’ experiments with digital educational material, including Virtual Labs (VLs), was constructed from scratch to be used through the Interactive Board (IB) as a learning tool by three different student groups (N = 154). In the first stage of the learning process, all groups used only the digital material of the DA. In the second stage, the three groups used different learning tools of the DA. Through the IB, the first group used Arduino experiments, the second one the VLs, and the third only static visualizations. A pre- to post-test statistical analysis demonstrated that the first two groups were equivalent in regard to achievement in declarative knowledge tests and of a higher level than the third group. Therefore, it can be concluded that conducting Arduino experiments in a mixed virtual-physical environment results in equivalent learning gains in declarative knowledge as those attained by using VL experimentation through the IB.

doi: 10.1007/s10956-020-09899-5

N. Lagopati, M.-A. Gatou, A. Gogou, E.A. Pavlatou

United Journal of Nanotechnology and Pharmaceutics (2021), 1 (1), 1-7

During the last few decades, the utilization of nanotechnology is exponentially increasing in biomedical engineering applications, such as antibiotics, antimicrobial agents, and anticancer therapies. It is known that a large number of diseases caused by pathogenic microorganisms originate from the fact that these pathogens have developed resistance in commercially available drugs. Thus, the development of novel, effective, non-toxic, and low-cost therapy for better treatment of diseases is imperative. Nanoparticles based on metals and metal oxides have emerged as a promising means of therapy due to their exceptional properties. Among these nanoparticles, zinc oxide nanoparticles (ZnO NPs) have drawn significant attention owing to their eminent biomedical properties. A variety of physical as well as chemical methods is utilized for the ZnO NPs synthesis. However, many of them include the use of hazardous reagents or are energy-consuming. For this reason, green methods are proposed to synthesize ZnO NPs using biological substrates. These methods possess significant benefits, as the extracts contribute positively to the formation and improvement of the antimicrobial activity of ZnO NPs, also acting as reducing and stabilizing agents. In this review, an integrated approach of ZnO NPs bio-synthetic techniques using microorganisms, such as bacteria, fungi and algae, plants and plant extracts, is discussed, shedding light on their comparative advantages.

N. Lagopati, K. Evangelou, P. Falaras, E.-Ph.C.Tsilibary, P. V.S.Vasileiou, S. Havaki, A. Angelopoulou, E.A. Pavlatou, V.G.Gorgoulis

Pharmacology & Therapeutics (2021), 222, 107795

The multivariate condition of cancer disease has been approached in various ways, by the scientific community. Recent studies focus on individualized treatments, minimizing the undesirable consequences of the conventional methods, but the development of an alternative effective therapeutic scheme remains to be held. Nanomedicine could provide a solution, filling this gap, exploiting the unique properties of innovative nanostructured materials. Nanostructured titanium dioxide (TiO2) has a variety of applications of daily routine and of advanced technology. Due to its biocompatibility, it has also a great number of biomedical applications. It is now clear that photo-excited TiO2 nanoparticles, induce generation of pairs of electrons and holes which react with water and oxygen to yield reactive oxygen species (ROS) that have been proven to damage cancer cells, triggering controlled cellular processes. The aim of this review is to provide insights into the field of nanomedicine and particularly into the wide context of TiO2-NP-mediated anticancer effect, shedding light on the achievements of nanotechnology and proposing this nanostructured material as a promising anticancer photosensitizer.

doi: 10.1016/j.pharmthera.2020.107795

N. Lagopati, M.-A. Gatou, D.S. Tsoukleris, E.A. Pavlatou

Nanomedicine & Nanotechnology (2020), 5 (1), 1-12

The transmission of a wide range of diseases, related to the infection by pathogenic microorganisms is a major public health problem that daily endangers the safety of human population. Silver has been thoroughly studied and used against bacteria due to its antimicrobial properties. Nanostructured silver gathers all the advantages of the silver itself, as well as the advanced performance of the nanomaterials. Thus, currently, silver nanoparticles constitute the most widely used kind of nanoparticles in biomedicine, due to their attractive antimicrobial properties. A variety of physical and chemical methods are employed for the AgNPs synthesis. However, many of them include the use of toxic reagents or require large amounts of energy, during the synthesis process. For this reason, many eco-friendly methods are proposed in order to synthesize AgNPs. Hence, biogenic synthesis of AgNPs, utilizing biological resources opens a novel route for the development of alternative production processes. These methods seem to have significant dvantages, as the extracts contribute positively to the formation and enhancement of the antimicrobial activity of AgNPs, also acting as protective agents of the produced particles. In this review an integrated approach of AgNPs bio-synthetic methods using microorganisms, such as bacteria and fungi, plants and plant extracts, as well as several templates, like DNA and viruses is discussed, shedding light on the comparative advantages of them.

doi:10.23880/nnoa-16000185

E. Rosolymou, S. Spanou, C. Zanella, D.S. Tsoukleris, S. Köhler, P. Leisner, E.A. Pavlatou

Coatings (2020), 10 (8), 775

Direct current electrodeposited Sn-Ni/TiOnanostructured coatings were produced by embedding two different doped types of TiO2 particles within the alloy matrix, a commercially available doped carbon-based and doped N,S-TiO2 particles. The structural characteristics of the composite coatings have been correlated with the effect of loading, type of particles in the electrolytic bath, and the applied current density. Regardless of the type of doped particles TiO2, increasing values of applied current density resulted in a reduction of the co-deposition percentage of TiO2 particles and an increase of Tin content into the alloy matrix. The application of low current density values accompanied by a high load of particles in the bath led to the highest codeposition percentage (~3.25 wt.%) achieved in the case of embedding N,S-TiO2 particles. X-ray diffraction data demonstrated that in composite coatings the incorporation of the different types of TiO2 particles in the alloy metal matrix modified significantly the nano-crystalline structure in comparison with the pure coatings. The best photocatalytic behavior under visible irradiation was revealed for the composite coatings with the highest co-deposition percentage of doped N,S-TiO2 particles, that also exhibited enhanced wear resistance and slightly reduced microhardness compared to pure ones.

doi: 10.3390/coatings10080775

N. Lagopati, E.A. Pavlatou

American Journal of Biomedical Science & Research (2020), 9 (1), 47-53

Alginic acid, also known as algin or alginate, is a natural carbohydrate, which is derived from marine brown algae, as well as some microorganisms. It can be used in various applications. In particular, alginate has shown great potential in the areas of wound healing, drug delivery, in vitro cell culture, and tissue engineering, allowing the categorization of it as a promising biomaterial, or a basic component of other biomaterials. The unique characteristics of alginic acid, such as the biocompatibility, the mild required gelation conditions, the low toxicity, the relative low cost and the simple modifications, allow the development of alginate hydrogels, and alginate derivatives with enhanced properties. The aim of this review, is to present an overview of the properties of alginate, shedding light on the current and potential applications and suggesting new perspectives for future studies.

doi: 10.34297/AJBSR.2020.09.001350

D. Koukouzelis, A. Rozaria, N. Pontillo, S. Koutsoukos, E.A. Pavlatou, A. Detsi

Journal of Molecular Liquids (2020), 306, 112929

Surface-enhanced Raman Scattering (SERS) constitutes a powerful molecule detection and identification method. However, the design of a suitable substrate, which combines ease of use with reproducibility, remains a major problem. In this study, the use of silver mesoparticles (AgMPs) as SERS substrate was investigated. A green methodology was applied for the synthesis of the AgMPs, using the novel hydroxyethylammonium ascorbate ionic liquid as the reducing agent and chitosan as the stabilising and homogenising matrix. Experimental design was applied for the optimisation of the AgMPs' synthesis. Scanning electron microscopy (SEM) revealed the flower-shape morphology of the materials. The potential application of AgMPs as SERS using Rhodamine B as the model molecule and promising and reproducible results were obtained in concentrations even at 10−9 M. Dynamic light scattering and SEM confirmed the stability of the synthesised AgMPs over a period of 18 months.

doi: 10.1016/j.molliq.2020.112929

M.-A. Gatou, N. Lagopati, D. Tsoukleris, E.A. Pavlatou

Biomedical Journal of Science & Technology Research (2020), 25 (5), 19426-19436

The global use of crude oil for energy applications has increased during the last decades, leading to an extensive release of oil into the environment as well. Thus, contamination deriving from oil spills and industrial wastewater has been recognized as one of the major environmental issues, imposing a serious threat to both human and marine ecosystem health. Treatment of contamination and pollution caused by crude oil constitutes a quite challenging and elaborate process. Among the conventional technologies applied for oil-water separation, oil absorption process has been widely examined in recent years. Commercial sponges, such as melamine and polyurethane sponges, have attracted great attention in the field of crude oil removal both from seawater and industrial wastewater, due to their low cost, high porous three-dimensional (3D) structure, low density, excellent mechanical properties and remarkable reusability. However, the amphipathic nature of commercial sponges limits their application for oil absorption treatment processes. In order to improve their oil absorption performance, several modification methods have been utilized. In the current manuscript, an overview of various methods used for the superhydrophobic/Superoleophilicity modification of commercially available sponges for oil-water separation, is provided, in order to highlight the potential use of these sponges as a novel, highly efficient, low-cost, recyclable and environmental friendly absorbent for the recovery of spilled crude oil both from seawater and industrial wastewater.

doi: 10.26717/BJSTR.2020.25.004251

K. Dalacosta, E.A. Pavlatou

Computer Applications in Engineering Education (2019), 28 (1), 5–16

This paper presents an educational digital material on "solid crystal structures", in which cartoons agents direct undergraduate students on a learning cycle of understanding concepts from the submicroscopic level and correlate with the corresponding macroscopic‐related properties. Specifically, undergraduate students are given the opportunity to study basic crystal structures starting from structural units, composing the unit cells in a three‐dimensional (3D) pattern that are characterized and related with intermolecular forces within them, and finally leading to basic crystalline solids associated with the macroscopic behavior of solid materials expressed by physical and mechanical properties such as hardness, electrical conductivity, etc. The design of the digital material was focused on the cognitive benefits that students gained after viewing 3D visualizations for which students were able to manipulate the rotation or size of them, to enhance their conceptual understanding addressed to chemistry and engineering, accompanied by cartoons agents. Digital material was constructed to be accessible from and compatible with any web browser without any third‐party plugin. A research using a properly designed questionnaire was conducted in the School of Chemical Engineering in Greece where the evaluation indicated that students preferred using this web material due to its simplicity and their active involvement by self‐controlling the pace and the way of learning.

doi: 10.1002/cae.22169

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