List of Abstracts 2022: POSTER SESSION B
Date: October 20, 2022
Boron-doped diamond (BDD) is an outstanding electrode material due to its wide potential window, fouling resistance, and robustness (10.1021/cr068076m). Nanostructuring can further improve its electrochemical performance towards electrodes and supercapacitors. So far, several methods for producing porous BDD films with large surface area (SA) were proposed such as electrochemical etching (10.1016/j.diamond.2018.11.016) or reactive ion etching (10.1002/cctc.202000938). Although these methods produce nanoporous BDD material they possess several limitations, i.e. not sufficiently robustness, environmentally problematic, limited to conductive diamond, etc.. Here, we present a novel approach for creating highly porous BDD structure based on molten salt thermal etching (MSTE) which is facile, environmentally friendly, low-cost method and universal also for intrinsic diamond. We show that by optimization of the MSTE parameters (temperature, time), the nanoporous BDD structure can be obtained keeping its atomic BDD structure as confirmed by scanning electron microscopy and Raman spectroscopy, respectively. The increase in the specific surface area has led to improved capacitive properties. Due to its anti-fouling properties, the BDD electrodes are also advantageous for the detection of biomolecules with phenol and hydroxyl groups. Using MSTE treated BDD as a working electrode for detection of 4-nitrophenol we achieved 33% higher anodic current density peak for the phenol group compared to the non-etched BDD material.
The paper describes the features of obtaining an equiaxed ultrafine-grained microstructure of the zircalloy by large shear deformations with a vortex metal flow for use in nuclear power engineering. Ащк change the structure, the method of radial shear rolling was used. This made it possible to obtain long rods with an equiaxed structure with a grain size of 300-700 nm. A study was used over the entire sample cross-section using the TEM, SEM and EBSD methods.
The study presented the experience of refinement Zr-2.5Nb alloy structure to 300-600 nm equiaxial ultrafine grained state in long bars. The bar has been subjected to huge plastic deformation of more than 30 mm/mm with notable vortex character of plastic flow in the bar volume. These facts provide good conditions for significant structure refinement. The work is based on the method of warm radial-displacement rolling which can be used to improve the structure of subproducts for fuel rods or plugs.
Highly polymorphic iron and cobalt sulfides represent attractive material because of their unique electronic, optical, magnetic, mechanical and catalytic properties. Bimetallic Fe-Co sulfide represent desirable materials because of their enhanced catalytic characteristics compared to its monometallic counterparts. Pulsed laser irradiation of a solid target created by equimolar mixture of FeS2 and CoS2 powders results in ablation and deposition of thin nanostructured films on Ta substrates, which were analysed using scanning and transmission electron microscopy, EDS, X-ray and electron diffraction, X-ray photoelectron, FTIR and Raman spectroscopy. These complementary analyses revealed that the film on Ta consists of the bimetallic sulfide Cobaltpentlandite (FeCo8S8) and Smythite (Fe3S4) phase. The ternary Fe-Co-S based coat exhibit Fenton and solar light catalytic activity which was examined on methylene blue and methylene orange degradation.
Carbazole and its derivatives are widely used as optical, electroactive materials for excellent electron donations and host materials due to their excellent triple energies and good hole carrying properties. On the other hands tricarbazole structures shown that can be used in the electronic field and has space-carrying properties. These compounds still retain the high thermal energy and space carrying properties of carbazoles. In addition, tricarbazole derivatives generally exhibit higher glass transition temperatures and they also act as slightly stronger donors .
In this study, considering the information given in the literature Suzuki-Miyaura coupling reaction were carried out using as an electron acceptor for -CN, -F groups and as an electron donor for tricarbazole moiety. The synthesized tricarbazole derivative TC-FCN is characterized by 1H-NMR, 13C-NMR and elemental analysis. The UV-Vis and thermal properties (TGA, DTA) of the synthesized novel tricarbazole derivative TC-FCN was investigated. Metal oxide-DSSCs were fabricated using this molecule. The current-voltage characterization of fabricated DSSC’s was performed by AM 1.5 simulated. The short current (Jsc), open circuit voltage (Voc), conversion efficiency (n%) and fill factor (FF) of DSSC’s were determined. ACKNOWLEDGEMENTS: This work were supported by Eskisehir Technical Commission of Scientific Research Project under Grant No. 22ADP086 and Research Fund of Eskişehir Osmangazi University by project Number: FCD-2022-2261.
A wide range of capabilities have been made possible by the ferroelectrics class of materials, which exhibit a variety of interactions between their electrical, mechanical, and thermal properties. These features must be incorporated into semiconductor technologies in order to produce integrated systems. To this purpose, well-known ferroelectric materials, such as the perovskite class, present serious challenges that restrict their use in integrated systems. The last ten years have seen a revival in interest in this field due to the discovery of ferroelectricity in materials based on hafnium oxide. A variety of ferroelectric capabilities could soon be found in integrated circuits thanks to the recent confirmation of ferroelectricity in aluminum scandium nitride. The future of these material systems in diverse applications is discussed in this study.
In the past decade, research into growth and practical application of semitransparent anodic titania nanotubes (TNTs) has been focused on titanium deposited onto one side of the planar conducting oxides. Whereas, the study of TNTs grown on a double sided substrates is still not explored. In this study, a simple anodization method was used to fabricate double sided semitransparent electrodes. Two symmetric electrodes consisting either of aligned (TNTs (a)) or spaced (TNTs (s)) titania nanotubes grown onto the both sides of the indium tin oxide (ITO) coated glass, and one asymmetric material obtained by developing aligned-TNTs onto one side and spaced nanotubes onto the other one were synthesized. The optical, morphological and structural properties together with the photoelectrochemical activities of the prepared materials were investigated. It was shown that all obtained samples exhibit anatase phase after annealing at 450°C. The TNTs(a)/ITO/TNTs(a) electrode has demonstrated a photocurrent (12.7 μAcm-2 at +0.5 V) ten times higher than its spaced counterpart ((TNTs(s)/ITO/TNTs(s), 1.2 μAcm-2 at +0.5 V). The high donor concentration of 6.4 × 10^20 cm-3 as well as the low charge transfer resistance can explain the good photoresponse of the TNTs(a)/ITO/TNTs(a) electrode. Our results suggest that double sided semitransparent materials based on TNTs can be a promising candidate to be used in photoelectrochemical devices.
ACKNOWLEDGEMENTS: This work was supported by the National Science Centre, Poland via grant no 2020/02/Y/ST8/00030 and the Czech Science Foundation via grant GAČR 21-05030K.
Here we report the synthesis route for glass surface functionalization by ZnO nanorods and nanowires-based Cu2O heterojunction. In the first step, ZnO elongated structures were grown on a seeded substrate following the classic hydrothermal method, and their thickness can be controlled by polyethyleneimine (PEI) concentration. In the second step, ZnO/Cu2O heterojunctions were fabricated by immersion of ZnO grown substrate upside-down into the copper sulfate solution with glucose as a reducing agent. After characterization of prepared ZnO/Cu2O heterojunction by SEM, TEM, and XRD, its application capability for waste-water treatment was successfully demonstrated on Estriol (E3) hormone degradation under UV light by using a continuous Drip Flow Biofilm Reactor. Furthermore, functionalized glasses were shown to be effective for designing self-cleaning surfaces. The photocatalytic-induced self-cleaning ability was demonstrated by resazurin-based smart ink and tert-butyl alcohol-based methylene blue ink.
Nanostructured materials are attractive for applications in many industries that demand low-cost manufacturing. Thin-films based on organics are easy to process thanks to their solubility and flexibility, which is advantageous for implementation into mass production. Nowadays, thin organic-based films are successfully used in optical and electronic devices that are made via two basic approaches: bottom-up and top-down. The present study compares various nonthermal plasma sources as tools for removal of organic layers in the scope of top-down methods. Atmospheric-pressure plasma etching is proposed here as a dry, efficient and controllable method for decomposition of organic nanolayers with respect to their thickness without affecting the substrate material. The selection of applied plasma sources is based on different geometry, power input or working and surrounding gas, with respect to areal uniformity and thermal sensitivity of organic coatings. Stearic acid (SA) layers were evaporated on soda-lime glass substrates. Initial layer thickness of 70 nm was evaluated using confocal profilometry. Water contact angle measurements (WCA) of plasma-activated glass were carried out to optimize plasma parameters suitable for efficient decomposition. FTIR analysis was used for detection of SA layer decomposition after plasma exposure. XPS was carried out to reveal the chemical nature of parallel mechanisms involved in plasma-glass interaction. The impact of the tested plasmas on the morphology of soda-lime glass substrate was analysed using AFM.
ACKNOWLEDGEMENTS: This research has been supported by the project LM2018097 funded by the Ministry of Education, Youth and Sports (R&D Centre for Low-Cost Plasma and Nanotechnology Surface Modifications).
Titania films were prepared by sol-gel synthesis using titanium(IV) butoxide or titanium(IV) isopropoxide as precursors. Silver-doped titania films were prepared by one or two step sol-gel method using silver nitrate precursor in addition to the previous mentioned ones. Thin layers on glass substrate were obtained by dip-coating method. The effect of heat treatment in the range of 500°C - 750°C on the films was studied. The structure of obtained films was observed by SEM and the different allotropic modifications of TiO2 was monitored by Raman spectroscopy. The photocatalytic efficiency of obtained films was determined using time dependent degradation of Resazurin ink under UV light irradiation.
NiO is a p-type metal oxide semiconductor with a wide band gap. NiO films are also used in energy-efficient smart windows with controllable radiant energy output, variable reflectance mirrors, and high-contrast, non-emissive information displays. Nickel oxide (NiO) films are produced by many physical and chemical techniques such as electron beam evaporation, spray pyrolysis and spin coating. In this study, the synthesis and physical characterization of Al doped NiO nanostructures deposited onto glass substrates by the sol-gel process using spin coating method and also device application of p-NiO:Al/n-Si heterojunction structure was investigated. In both the characterization and device application process, the effect of Al incorporation has been investigated. Nickel (II) acetate tetrahydrate and aluminium acetate were used as a starting material and for Al doping, respectively. Al doping ratios were kept as 1, 3 and 5%. The coating solution was dropped onto substrate, which was rotated at 3000 rpm for 30 s using a spin coater. After the spin coating process the film was dried at 300 oC for 15 min in a furnace to evaporate the solvent and to remove organic residuals. This coating/drying procedure was repeated for ten times onto glass substrate and four times on silicon substrate and then the films were annealed at 500oC in air for 2 h.
The structural, morphological and optical properties of the prepared NiO films were scrutinized with X-ray diffractometer (XRD), atomic force microscopy (AFM) and scanning electron microscopy (SEM) and Schimadzu 2450 UV - Vis spectrometer, respectively.
The crystal structure of the NiO film was determined to be a cubic structure in polycrystal nature. From the spectral data, the grain size, texture coefficient, dislocation density and lattice constants of the NiO film were calculated. Both AFM and SEM investigation were performed to analysis the surface morphology of the films. Depending on the Al doping, it was observed the improvement on the surface properties. The band gaps were calculated within the scope of the optical property and an increase in the band gap was observed with the Al incorporation. All the heterojunctions based on NiO film showed rectifying property and all the diode parameters such as ideality factor, barrier height, etc. were calculated and analyzed depending on the Al incorporation. ACKNOWLEDGEMENTS: This work was supported by Eskisehir Technical Commission of Scientific Research Project under Grant No. 22ADP060 and 22LÖP154 and The Scientific and Technological Research Council of Turkey (TUBITAK) 2209-A University Students Research Projects Support Program through App. No: 1919B012100472.
Rapid communication systems with high frequency and the rapid growth of intelligent electronics are increasing the level of electromagnetic pollution in the world. High-performance electromagnetic induction (EMI) shielding material is a critical technology for suppressing or controlling undesirable EM radiation. In this work, we developed a tree gum-based MWCNT nanocomposite film, an ultra-flexible EMI material with outstanding shielding effectiveness. Biodegradability, hydrocolloid properties, and environmental friendliness of tree gum kondagogu contribute to the formation of eco-friendly nanocomposites. The conjugation of gum kondagogu with sodium alginate via free hydroxyl and carboxyl groups generates hydrogen bonding, enhancing the mechanical and barrier properties of the nanocomposite film. The resultant nanocomposite film shows ultra flexibility, strong mechanical properties and superior EMI shielding. The microstructures, electrical conductivities, and EMI shielding performances as functions of carbon nanotube content were detailedly investigated. Moreover, they exhibit sufficient conductive reliability and stability upon the repeated bending and stretching cycles. This nanocomposite film has ~100µm thickness, and its shielding effectiveness is as high as 30 dB in the X-band (8-12GHz) frequency range. More importantly, its specific EMI shielding effectiveness can reach ~ 2531 dB cm -2 g-1, surpassing the best values for metals and carbon-based composite materials. The excellent flexibility of this nanocomposite film also provides consistent EMI shielding performance in continuous mechanical deformation. The ultra-flexible nanocomposite films with superior EMI shielding have promising potential for flexible EMI shield applications.
Synthetic saponite (Sap) was modified with hexadecyltrimethylammonium (HDTMA) cations leading to highly hydrophobic material. Subsequently, the organoclay was functionalized with variable amounts of methylene blue (MB). The suspensions of Sap/HDTMA/MB were filtered through Teflon membranes to prepared thin films. The synthesis of composites with polycaprolactone (PCL) with the functionalized silicate films was performed via melt diffusion at the interface of the film and the polymer. Pristine silicate and modified materials, as well as the final composites with the modified surface, were characterized by a combination of analytical techniques including UV-Vis absorption, fluorescence spectroscopy, XRD measurements, X-ray tomography and scanning electron microscopy(SEM).
The XRD diffraction patterns of PCL_Sap/HDTMA/MB nanocomposite films are similar to that of the neat PCL indicating the successful incorporation of Sap/HDTMA/MB into the PCL surface.
SEM images were recorded to characterize the topography of the surface and the thickness of silicate film on the PCL membrane. SEM was able to capture the PCL_Sap/HDTMA/MB composite phase on the membrane surface in the form of a thin film. The actual film thickness was about 5 μm. A similar value was proven using X-ray tomography.
Some of the prepared specimens exhibited high photoactivity. The optical properties and photoactivity of the dye reflected the concentration of the dye in the materials. The samples with a higher concentration of methylene blue exhibited a higher tendency to form H-aggregates which led to the quenching of luminescence. In the samples of lower concentrations of methylene blue, the formation of monomers is more likely to occur.
Wide-bandgap materials can have a large energy band depending on the cutoff wavelength, so they are suitable for detecting UV light. MgO is a remarkable member of metal oxides thanks to being a stable material both chemically and thermally [1]. MgO has low electrical conductivity, but this low electrical conductivity can be solved by doping with a high conductivity n-type semiconductor material [2].
A series of Mg1−x Inx O (0≤ x ≤ 1) films produced on glass substrates by sol-gel spin-coating method in this study. The crystal structure and optical properties of the Mg1−x Inx O films characterized by X-ray diffraction and UV-vis spectroscopy. XRD results showed that the films are polycrystalline structure but undoped MgO films (x=0) were formed in almost amorphous phase. The optic characteristics of the films were analyzed by using their transmittance and reflectance spectra obtained by a double beam spectrophotometer equipped with an integrating sphere. The optical properties (band gap, optical constant) of the films were characterized. The morphological properties of the films were examined by scanning electron microscopy (SEM).
REFERENCES: [1] A. Taser, M. Eş Güldüren, H. Güney, Tuning PL emission energy and bandgap with Ni dopant of MgO thin films, Ceramics International 2021, 47, 15792-15800.; [2] K-Yu Chen, H-Tuan Vu, C-Chiang Yang, C-Chien Hsu, Y-Kuin Su, Amorphous MgInO Ultraviolet Solar-Blind Photodetectors, IEEE Access, 2019, 7, 103250-103254.
ACKNOWLEDGEMENTS: This work was supported by Eskisehir Technical University Commission of Scientific Research Projects under Grant No. 22ADP048.
The effect of processing and structure parameters on the resulting PVDF/CeO2 nanofiber membrane was studied experimentally and also by using molecular simulations. In this preliminary study we were focused on the stability of resulting nanocomposite.
PVDF nanofibrous membrane has been prepared by electrospinning and its surface was modified by CeOx NPs by immersion in a water colloidal solution with CeOx NPs. Two ways of the deposition of CeOx nanoparticles on the PVDF nanofiber membrane were used: (1) deposition of CeOx NPs on the pristine electrospun membrane and (2) the immediate deposition CeOx NPs on the plasma treated electrospun membrane. We investigated the effect of plasma treatment on the amount of CeOx NPs deposited on PVDF nanofiber surfaces and on the Ce3+/Ce4+ ratio in CeOx NPs deposited on PVDF. Results showed a significant increase of CeOx NPs amount on the plasma treated PVDF membrane.
Molecular modeling simulations were used for the deep understanding of the anchoring of modifying CeO2 nanoparticles onto the crystallographic planes of the pristine PVDF polymer nanofibers. The modeling has shown that the dominant PVDF (100) plane is suitable for anchoring CeO2 NPs. In this respect, the PVDF (100) plane is comparable to the less exposed PVDF (010) plane, and both planes show a stronger interaction with CeO2 compared to PVDF (0-10) plane. Molecular modeling also revealed preferred crystallographic orientations of anchored CeO2 NPs: these are the catalytically active planes (100), (110), and (111). The successful surface modification and the finding that CeO2 NPs on the dominant PVDF (100) surface can preferentially exhibit these crystallographic orientations thus provides the possibility of various practical applications of the CeO2NPs/PVDF membrane.
Elementary nanofibrous layers show low mechanical properties, especially tensile strength and abrasion resistance. In order to overcome these disadvantages, they are combined with carrier substrates and cover materials. A critical factor for the usability of nanofibrous layers in composite structures is to ensure sufficient adhesion between the carrier medium, the nanofibrous layer and the cover material. The adhesion between the layers is fundamental for the processability of the composite structures into the final products. To ensure sufficient adhesion of the individual components, additional adhesives are commonly used, which, in addition to the ecological burden, bring additional technological steps and costs to the production. One of the possibilities for achieving sufficient adhesion without the use of adhesives is the utilization of the physical component of adhesion by means of plasma activation of surfaces prior to electrospinning.
The article deals with new technology for the production of a flat nanofibrous structure using AC-electrospinning and the development of a new type of spinning electrode. Simulations of the distribution of the electric field around the electrode were performed. The dependencies of the electric field intensity on the design parameters of the electrode were determined. Based on the performed simulations, a suitable technical and technological solution of the electrode for the production of a flat nanofibrous structure was designed. The functionality of the designed technological system was verified experimentally. The results of the experiments demonstrated the high potential of the designed system for the production of flat nanofibrous structures.
For the first time, incorporation of up to 50% of graphene (w/w) in to hybrid polymer nanofibers was achieved via electrospinning in alternating current. In this way, a new SPE sorbent based on a polycaprolactone nanofibrous hybrid with graphene nanoparticles was prepared. The optimization of the development of graphene-enriched fibers included the determination of limitations and the study of the influence of spinning conditions and the concentration of graphene itself on the properties of the final product. The resulting structure in the form of solid fibrous sheets with good strength and elasticity could be cut up into stand-alone extraction discs. The nanofibrous disk was stirred in a large-volume sample followed by direct elution in a vial intended for HPLC analysis. Optimization of the SPE procedure involved conditioning, sample volume, time of extraction, and elution solvent. Based on the preliminary study, 50% graphene doped nanofibers (w/w) demonstrated significantly several times higher elevated retention of the sorbent compared to native PCL nanofibers. As a result, unique highly efficient polymer nanomaterial enriched with high amount of graphene was fabricated and applied for preconcentration of environmental pollutants. Desorption in an HPLC vial for direct injection into HPLC was described for the first time, which significantly reduced sample handling and possible errors.
The article focuses on the issue of the spinning process in AC electrospinning. The aim of the conducted study was to identify the possible influence of the material type of the spinning electrode on the nanofibers formed. As part of the work, studies were carried out on our own test spinning equipment intended for the production of nanofibers. The electrodes were made of three different materials: stainless steel, aluminum alloy and plastic. Productivity experiments and individual partial nanofibrous structures related to individual electrodes were performed on these electrodes. The mentioned structures were examined using an SEM microscope and also statistically evaluated. Other parts of the article are simulations of the electrostatic field for the used electrodes.
The advantage of polymer nanofibers (NFs) forming nonwoven mats by electrospinning is their large surface area, high porosity, and good pore interconnectivity. Thus, the polymer mats are excellent as carriers or semipermeable membranes. However, they are not self-supporting, which opens the task of ensuring their good adhesion to underlying support, e.g., nonwoven polypropylene (PP) textile. Vice-versa, the nanofibrous mats can be carriers of drugs, proteins, or micro/nanoparticles. We have already demonstrated that plasma-processed polycaprolactone (PCL) mats are perspective materials for constructing artificial tissues or drug delivery systems [1,2,3]. The PCL was selected in these studies because it is a biodegradable polymer used in many FDA-approved surgical implants and drug delivery devices. It has good mechanical properties and long-term stability in vivo. Yet, like any other synthetic polymer, it imposes problems due to its hydrophobicity and inertness. In this work, we demonstrate that plasma processing is an efficient method for modifying synthetic polymers when the engineering of nanofibrous composites is required. First, we demonstrated that plasma treatment of PP nonwoven textile increases the adhesion of electrospun nanofibrous mat collected on it. For this purpose, low-pressure capacitively coupled plasma or atmospheric pressure plasma jet can be both efficient, but atmospheric pressure plasma has the advantage of being easier implemented in the production lines. Second, we obtained uniform and dense immobilization of lignin-based nanoparticles on the PCL plasma-processed mats.
REFERENCES: [1] S. Miroshnichenko et al., Nanomaterials 9 (2019) 637.; [2] E. Permyakova et. al, Materials & Design 153 (2018) 60.; [3] I. Nemcakova et\,al. Int. J. Mol. Sci. 2020.
Electrospinning technology was used in a one-step and multi-stage process for the development of modified polyurethane nanofiber membranes (PUR) for targeted capture of selected components of pyrolysis gas - hydrogen (H2) and carbon dioxide (CO2);
First, a multi-stage process with modifying substances in the form of palladium and platinum nanoparticles was used for targeted H2 sorption. Chloride salts of said metals and hydrazine were used as reducing agents for the synthesis of these nanoparticles. The reaction took place directly in the spinning solution, where PUR was deposited as a steric stabilizer.
Second, selected amines triethylenetetramine (TETA) and tetraethylenepentamine (TEPA) were used to capture CO2 in a one-step process.
The samples were characterized by a number of analytical and testing methods, for example to investigate surface chemistry, Zeta potential, structure, morphology, phase composition, mechanical properties, sorption capacity, etc.
The results of all tests revealed the influence of technological parameters on the main studied parameter of sorption capacity, which is crucial for the design of functional units working as a H2 and CO2 trap. The results are especially useful for finding relationships: technology structure properties that are important for the design of a membrane with maximum sorption capacity maintaining air permeability, necessary for a membrane capturing selected components of pyrolysis gas.
Laminated glass is produced in civil engineering industries by layering two or more glass sheets between which a polymer interlayer is placed. The role of this interlayer is to increase residual load-bearing capacity after breakage and prevents the release of broken glasses due to their high adhesion to the safety film. Compared to “standard” PVB interlayers, a new generation of SentryGlas® ionoplast interlayer is tougher, 100 times stiffer, and performs better over a more comprehensive temperature range. The ionoplast interlayer in laminated glass does not depend on the type of its support and has more significant resistance to aging and clarity. Low adhesion of ionoplast to glass is a technical problem that limits its use, e.g., in producing thin laminated safety glasses and photovoltaic panels. At CEPLANT, by applying atmospheric-pressure plasma to the air side of the glass as well as the ionoplast prior laminating process, there was confirmed a significant improvement in the adhesion of the ionoplast interlayer. During a research project ongoing with the OGB s.r.o. company, we tried to determine the optimal conditions for plasma cleaning and activation of float glass and ionoplast intended for lamination. This research included a study of the DCSBD plasma nanomodification and dry cleaning effect on the float glass surface and a comparison with cleaning using solvents and detergents or an ultrasonic cleaner. This effect was analyzed using modern surface analyses, including the measurement of WCA, SFE, adhesion test, XPS, roughness, and VIS transparency.
ACKNOWLEDGEMENTS: This research has been supported by the project FW03010109 funded by the Technology Agency of the Czech Republic (program TREND).
Laminated glass (LG) consists of at least two panes bonded together by some transparent elastomeric interlayer, most commonly and traditionally polyvinyl butyral (PVB). SentryGlas ionoplast interlayers are significantly stiffer than standard PVBs. Thus, laminates with SentryGlas, as a new generation of interlayer developed for high-performance applications (e.g. hurricane zones), can bear greater loads or - at the same load - can be reduced in glass thickness. However, LG with standard SentryGlas interlayers is affected by glass orientation, specifically the adhesion performance is significantly reduced when SentryGlas interlayer is combined with air side of glass sheet. This research studied the plasma surface nanomodification of SentryGlas ionoplast material for adhesion improvement and sufficient surface uniformity required for LG. Plasma modification of the ionoplast surface was done by low temperature atmospheric plasmas generated in ambient air and nitrogen using i) well-known Diffuse Coplanar Surface Barrier Discharge (DCSBD) and ii) a novel source of remote plasma based on coplanar DBD technology. The adhesion measurements of the plasma-modified ionoplast surface were performed by 180 degree peel adhesion test. The wettability was assessed by water contact measurement of sessile droplets. The surface chemistry was investigated by X-ray Photoelectron Spectroscopy (XPS). The results show that the adhesion and wettability of the SentryGlas ionoplast interlayer after the plasma treatment can be significantly improved even in a short treatment time (5 s). The XPS analysis confirmed that high surface power density DCSBD plasma actives the ionoplast surface significantly more than the novel source of remote atmospheric plasma. However, it seems that the plasma generated by the later plasma system put much less thermal load on the ionoplast surface with the same adhesion results as achieved using DCSBD. The capability of both plasma systems to carry out large area plasma nanomodification of rough SentryGlas ionoplast surface is also discussed. ACKNOWLEDGEMENTS: This research has been supported by the project FW03010109 funded by the Technology Agency of the Czech Republic (program TREND).
Nanoparticles of thermochromic complex pigment bis- (diethylammonium) tetrachlorocuprate (II) with chemical formula [NH2(C2H5)2]2CuCl4 (abbreviated DEA-CuCl4) was prepared by crystallization and subsequent grinding in a cryomill. Nanoparticles were incorporated into a flexible hydro insulating transparent silicone matrix. The surface properties, especially surface hydrophobicity and elasticity of the resulting composite, as well as color indication of thermal changes and resistance to mold were tested.
Conducting polymers have developed into a promising class of pseudocapacitive electrode materials for supercapacitors. Among them, polypyrrole (PPy) has recently attracted increasing interest as a low cost electrode material, due to its high capacitance, large electrical conductivity, facile synthesis, cost-effectiveness and low toxicity. Various supramolecular structures of PPy can be prepared (nano- and micro- tubes, spheres, wires, etc.) with different properties and behavior. The pseudocapacitance of PPy comes from the faradic process. However, PPy-based electrodes undergo structural instability induced by the recurrent volumetric swelling and shrinking of PPy during the charge and discharge process. To overcome this issue, nanostructuring of PPy using carbonaceous fillers (i.e., carbon/PPy) turned out to be a promising approach. Carbonaceous fillers exhibiting good electrical conductivity and high specific surface area are also used as electrical double-layer (EDL) capacitor electrode, and thus can enhance the specific capacity of carbon/PPy electrode. The morphology and textural properties of carbon/PPy nanostructures should affect the overall performance of the electrode. Thus, this work investigates the impact of the carbon/PPy nanostructures morphology on the electrochemical performance of the electrodes using carbonaceous fillers of various shapes and PPy of various supramolecular structures. Cellulose nanofibrils (CNF) as abundant natural material is used as a flexible substrate for the electrochemically active carbon/PPy. The electrode films were prepared by in situ polymerization of pyrrole monomer in the presence of CNF and carbonaceous filler. The physico-chemical and electrochemical properties of the electrodes were investigated.
The study presents research results on the closing conditions of internal metallurgical discontinuities during the hot elongation operation of the Zr-1%Nb alloy ingot using physical and numerical modeling. Research on the influence of thermal and deformation parameters of elongation operations on the rheological behavior of the Zr-1% Nb alloy was conducted using the Gleeble 3800 metallurgical process simulator. Modeling of the influence of thermal-mechanical parameters of hot elongation operations in combinations of rhombic and flat anvils on the closure of metallurgical discontinuities was performed with the help of the FORGE®NxT 2.1 program. Based on the results of the research, recommendations were made regarding the forging elongation technology and the geometry of working tools, which ensure the closure of metallurgical discontinuities during the operations of hot elongation of the Zr-1% Nb alloy ingot.
This contribution focuses on monitoring the mobility of sulfapyridine in different soil types. The main difference in the used types of soil was the content of soil organic matter. Simple sorption and desorption experiments in buffer solutions with different pH values were made. Adsorbed and desorbed amount of sulfapyridine was measured using UV-VIS and liquid chromatography. The water solution of sulfapyridine was used for experiments in real conditions when a plastic tube was put into the soil and watered with an aqueous antibiotic solution. For the following days, tubes were taken out of soils, separated and adsorbed amount was measured with UV-VIS. In addition, computed tomography was used to make models for absolute permeability. From these measurements, the diffusion coefficient was determined along with adsorbed and desorbed amount of sulfapyridine in different types of soils and in different values of pH. It was confirmed that the pH value and type of soil has an influence on the sorption of used antibiotic.
The paper is focused on assessment of the influence of biochar on the soil physico-chemical properties (particle density, dry density, porosity, water retention capacity and maximum water holding capacity, oxidizable carbon content, total nitrogen content, phosphorus, potassium and magnesium content). The selected and examined soil types were: cambisol, fluvisol, chernozem
and regosol. There were two types of biochar used for analysis - NovoTerra and Sonnenerde. Soil samples were dried to constant weight and adjusted to grain-size fraction under 2 mm, respectively 0,25 mm. The oxidizable carbon content was measured by oxidation using a mixture of potassium dichromate and sulphuric acid (Walkley-Black method), the total nitrogen content was measured by kjeldahlization and P, K and Mg content was measured using Mehlich 3 extraction and ICP-OES spectrometer. The results show that biochar has a significant influence on soil characteristics depending on the type of biochar and soil we use for biochar application.
Natural organic matter is a complex pool of organic substances which can affect the transport of both beneficial and harmful species in soil systems. The occurrence of pharmaceuticals as soil pollutants has become one of the new environmental threats. The mobility of drug contaminants in soils and their availability for plants is largely controlled by their sorption. Soils have a "self-cleaning" ability which depends on the content of organic matter. Interactions between drugs and soil organic mattes can lead to the partial immobilization of these pollutants and suppression of their mobility in soil resulting in the pollution of drinking water resources, crop and consequently food contamination. In this contribution, the soils with different contents of organic matter were selected to assess their sorption abilities to widely used pharmaceutical diclofenac (non-steroidal anti-inflammatory drug that is frequently prescribed to reduce inflammation and pain). Stability of formed complexes and drug leachability in water were also studied to determine the immobilization degree of pharmaceutical in studied soils. The effect of organic matter on binding ability of soils as well as the leachability of diclofenac at different pH values are compared and discussed.
Foliar application of nanofertilizers is currently regarded as a promising alternative to conventional soil fertilization. For successful development of nanofertilizers, firstly, a better understanding of interactions of nanoparticles with the leaf surface is needed. In the framework of this study a globally available cereal grain Hordeum Vulgare (barley) was chosen as model plant. Gold nanoparticles (Au NPs) were chosen as model particles for foliar application. Two synthesis methods were used established photoreduction with citric acid and phytochemical synthesis using Aegopodium Podagraria (ground elder) extract. In both cases the reducing agent was acting also as surface stabilizer. Au NPs formation was confirmed by UV-VIS spectroscopy. To our knowledge it is the first time A. Podagraria extract was used for Au NPs synthesis. The morphology of the produced particles was characterized by transmission electron microscopy (TEM). The interaction of Au NPs with the adaxial side of barley leaves was studied by low-vacuum scanning electron microscopy (SEM). It was established that citrate stabilized Au NPs agglomerates evenly distribute in droplet-leaf contact areas avoiding stomates. Plant extract stabilized Au NPs form a film in the contact areas and accumulate on all leaf parts - stomates, trichomes and lamina. It was shown that Au NPs produced via green phytochemical synthesis have improved interaction with the leaf surface of barley.
Sol-gel three step methods has been used to obtain Cu2O/SnO2/WO3 heterostructure powder, deposed as film by spray pyrolysis. The porous morphology of the final heterostructure was constructed starting with fiber like WO3 with act as substrate for SnO2 development and SnO2/WO3 provide the nucleation and grow sites for Cu2O formation. The elemental analysis confirms that the samples are homogeneous in composition and have an oxygen excess due to the annealing treatments. The photocatalytic properties were tested in the presence of three pesticides (pirimicarb PIR, S-metolachlor S-MCh and metalaxyl MET) chosen based on their resilience and toxicity. The photocatalytic activity of the Cu2O/SnO2/WO3 heterostructure is superior to that of SnO2/WO3 and WO3 samples. The highest photocatalytic efficiency was obtained toward S-MCh (86%) using Cu2O/SnO2/WO3 sample and the lowest correspond to MET (12%) removal using WO3 mono-component sample. The TOC analysis indicates that not all the removal efficiency can be attributed to mineralization and by-products formation is possible. The photocatalytic mechanism corresponds to a Z-scheme charge transfer where Cu2O exhibit reduction potential and WO3 oxidation potential.
Polydopamine is considered to be an organic substance that is almost universally applicable to cover all kinds of materials including nanomaterials. Considering the possible use of polydopamine in the water purification process, the article is focused on the change of selected properties of the chosen material (graphene oxide and the hybrid compound graphene oxide-C60) after being coated with polydopamine. Attention was paid to changes in thermal stability and surface morphology. In particular, changes in surface morphology could positively affect the sorption capabilities of original materials in relation to organic pollutants.
The target of this project was to develop, test, and manufacture a fog collector inspired by the concept of spider nets. The micro-nano fibrous was used as a functional element, which is similar to spider nets in texture and high specific surface. The study deals with collectors based on biodegradable fibers. The importance of using fibrous structures with a high specific surface is in the ability to retain moisture for a longer period of time, not just the drainage of condensed water. Firstly, several textile and filament materials were evaluated to gain a balance between humidity capturing and its retaining for the longest possible time. Observed materials were nanocomposite yarns of various parameters; nano-micro fibrous layers of PVB and PVA polymers made of the centrifugal spinneret; conventional recycled textile materials, and metal wire. The architectural concept was aimed at the application and construction of fog collectors directly at the final destination place as well as the subsequent extinction of the structure. Therefore significant selection factors for the final fog capturing system were biodegradability and also material´s design potential. A substantial part of the study was the creation of the methodology and the actual implementation of this specific measurement based on weight changes due to mist in the atmosphere. The second part of the project deals with designing and constructing a fog collector on a semi-scale. The result is a functional semi-scale fog collector with the ability to retain moisture with its subsequent gradual release.
Frequent use of pharmaceuticals and their improper disposal increasingly contribute to environmental pollution [1,2]. Many commonly used pharmaceuticals are not completely removed in the wastewater treatment process, which may lead to the contamination of drinking water [3]. Therefore, we aimed to develop new photocatalytic materials for water remediation. Titanium(IV) oxide, a commonly used photocatalyst, requires high photoactivation energy, which can be provided only by ultraviolet-range light. To overcome this issue, the surface of TiO2 was grafted with peripherally substituted metallophthalocyanines (MPc) - photosensitizers capable of absorbing both ultraviolet and visible light. The composites were prepared using a simple and efficient chemical deposition procedure. The photocatalytic activity of the composites was assessed in drug degradation tests carried out either using Photocube™ or in a reactor composed of three vessels containing an aqueous solution of the drug and the photocatalyst. The mixtures were stirred and irradiated with either ultraviolet, visible or white light. Drug concentration throughout the experiment was determined using HPLC-DAD. The physicochemical properties of the most active materials were determined, and the conditions of photodegradation experiments were optimized.
The results of the sulfamethoxazole photocatalytic removal showed that the degradation rates strongly depend on the type of the phthalocyanine peripheral groups and central metal ion. Further experiments carried out using naproxen proved that the composite preparation method, as well as the type and power of the irradiation source, affect the overall result of the photodegradation process. Moreover, during the experiments under simulated solar irradiation, naproxen transformation products were degraded faster using MPc-TiO2 composites than neat TiO2. ACKNOWLEDGEMENTS: This study was supported by Poznan University of Medical Sciences, Poland (grant No SDUM-GB30/03/21). M.F. thanks the Center of Excellence “Towards Personalized Medicine” operating under the Excellence Initiative—Research University at Nicolaus Copernicus University in Torun, Poland.
REFERENCES: [1] Lesser, L.E. et al., Survey of 218 organic contaminants in groundwater derived from the world’s largest untreated wastewater irrigation system: Mezquital Valley, Mexico, Chemosphere. 198 (2018) 510-521.; [2] Behera et al., Occurrence and removal of antibiotics, hormones and several other pharmaceuticals in wastewater treatment plants of the largest industrial city of Korea, Sci. Total Environ. 409 (2011) 4351-4360.; [3] Simazaki, D. et al., Occurrence of selected pharmaceuticals at drinking water purification plants in Japan and implications for human health, Water Res. 76 (2015) 187-200.
The photocatalytic activity for H2 production from water, without presence of hole scavengers, of thermally reduced TiO2 nanoparticles (H-500, H-700) and neat Anatase were followed by in situ Continuous Wave Light induced EPR technique (CW-LEPR), in order to correlate the H2 evolution rates with the electronic fingerprints of the photoexcited systems. Under UV irradiation, photoexcited electrons move from deep in the lattice towards surface exposed Ti sites. These photogenerated redo-ox sites mediate (e- + h+) recombination and are the crucial electronic factor affecting catalysis. In the best performant system (H-500) we observe a synergic combination of mobile electrons, which dynamically create diverse types of Ti3+ sites, including interstitial Ti3+, and formation of singly ionized electrons trapped in oxygen vacancies (VO•). The interplay of these species feed successfully surface exposed Ti4+ sites, which become a catalytically active, fast reacting Ti4+↔Ti3+ state that is key for the H2 evolution process.
Porous carbon materials such as carbon felt, vitreous carbon, carbon textile, carbon sponge, and carbon fibers can be processed as electrode materials for electro-oxidation of harmful contaminants due to their relatively low cost, good thermal, chemical, and mechanical stability, and excellent electrical conductivity. Furthermore, the kinetics of undergoing electrochemical processes may be tuned by additional treatments, such as surface termination modification or thin oxide/carbon-based coatings.
Here, we present the results of acetaminophen electro-oxidation at carbon felt electrodes (CFE) subjected to advanced oxidative modification processes (thermal, chemical, and plasma chemical) in own-designed modular electrolyzers. The modification goal was to enhance CFE efficiency toward hydroxyl radicals electro-generation and oxygen evolution reaction suppression. Utilized oxidation techniques deliver single-step, straightforward, eco-friendly, and stable physiochemical reformation of carbon felt surfaces. The modifications caused minor changes in specific surface area and total pore volume, corroborating surficial morphology. The degradation mechanism of paracetamol at treated carbon felt anodes was proposed accordingly with detected intermediate products. The estimation of the cost-effectiveness of removal processes, in terms of energy consumption, was also elaborated.
Although the initial study was focused on acetaminophen, achieved results are currently scaled and concerned with emerging, hazardous pollutant groups as anti-inflammatory pharmaceuticals. Moreover, we utilize the 3D printable electrolyzer with a modular design to further reduce their cost. In-situ monitoring of the electrolyte physico-chemical conditions combined with electrolyzer machine learning is also under development.
Carbon allotrope forms, especially graphene or nanocrystalline diamond have become the subject of current research due to their remarkable electrical, thermal, mechanical and chemical properties. Here, their particular use as gas sensors becomes attractive in the sense of technological simplicity and flexibility in various detection principles (chemiresistor, FET and electrochemical). Moreover, they benefit from a large surface area, good electrical conductivity, simple synthesis and tunable surface functionalization.
In the current work, we investigate and compare the responses of different gas sensing layers (graphene oxide, reduced graphene oxide and nanocrystalline diamond) to three different ethanol vapor concentrations (20, 50 and 100 ppm) at room temperature and relative humidity of 40 % with nitrogen as the carrier gas. Moreover, the nanocrystalline diamond sensing layers were functionalized by hydrogen and oxygen, and graphene oxide was thiolated.
The highest sensing response of 2000 % was obtained for the reduced graphene oxide sensing layer to ethanol @ 100 ppm. We present the model describing the differences in electron or hole charge contributions for various sensing layers and surface functionalization. Next, we compare stability, reproducibility and need for regeneration of the fabricated sensors with commercial metal oxides-based sensor.
Achieved high sensitivity of reduced graphene oxide makes it highly perspective also for monitoring other volatile compounds (like acetone) which will be the scope of further research. The properly engineering sensing layers have great potential in many areas such as diagnostics or environmental monitoring.
ACKNOWLEDGEMENTS: The work has been supported by the Mobility project no. PAN-20-21 of the Czech Academy of Sciences and by National Science Centre within the frames of the Preludium program (Grant agreement 2018/29/N/ST8/02356).
Air-stable zerovalent iron nanoparticles (nZVI) are defined as nanoparticles with a compact oxide shell formed by iron oxides and a metallic iron core. Such a shell prevents the iron core from fast oxidation by oxygen and provides easier storage and transportation of material. On the contrary, the oxide shell also blocks reactive iron ions to react with a contaminant. A process called the activation of air-stable zero-valent iron nanoparticles is essential for recovering their reactivity. Nevertheless, those nanoparticles have been reported to have a low selectivity due to reactions with natural reducible species. A relatively new method of enhancement of the reactivity of nZVI particles can be achieved by creating an uniform sulfide shell on nZVI particles (S-nZVI). Modifying nZVI particles using lower valent sulfur compounds (e.g. sodium sulfide) creates a poorly crystalline or amorphous form of FexSy on the surface of nanoparticles. nZVI sulfidation has been proven to improve the reactivity and also significantly increase their selectivity during the process of pollutant removal in a contaminated environment, such as sequestration of Cr(VI). In this contribution, we will present an experimental setup and results of the sulfidation of air-stable nZVI particles. We prepared sulfidated air-stable nZVI particles with comparable efficiency as typically synthetized sulfidated pyrophoric nZVI. Such an approach could offer easier and more comfortable preparation of S-nZVI which could be performed directly at the remediation site.
Multi-hollow surface dielectric barrier discharge (MSDBD) is a plasma source that generates atmospheric-pressure plasma in an array of holes in a ceramic plate. Due to its novel geometry, the working gas flows out from the holes through the discharges, and as a consequence, a remote plasma treatment is accessible up to 5 mm from the substrate. MSDBD has been tested and verified to be efficient in surface modification of a wide range of substrates, low-temperature processing of materials, the decontamination of materials at enlarged distances, and food processing, e.g., grains, seeds, and biofilms.
In this study, different physical and electrical parameters of the discharge, using various working gases, are studied to optimize the plasma properties. On the other hand, multiple parameters are investigated to understand the result of the plasma-activated working gas, which leads to calculating the concentration of hydrogen peroxide (H2O2) proportionate to the distance from the electrode. A better understanding of the behavior of the discharge in different working gases can provide more information related to the reactions carried out on the substrates' surfaces.
ACKNOWLEDGEMENTS: This research has been supported by the project “R&D center for plasma and nanotechnology surface modifications (CEPLANT),” LM2018097 funded by the Ministry of Education, Youth and Sports.
Surfactants coated magnetic nanoparticles have shown greater application potentials in freshwater source treatment processes for their antibacterial properties.
In this work, we prepared magnetic nanoparticles Fe3O4 which surface were modified with Cethyltrimethylammonium bromide (CTAB), tetradecyltrimethylammonium bromide (TTAB) and Carbaethopendecine bromide (Septonex), respectively. Their physicochemical properties and morphology were investigated using thermal analysis (i.e. elemental and thermogravimetric analysis), infrared spectroscopy with Attenuated Total Reflectance (ATR-FTIR), dynamic light scattering (DLS) and transmission electron microscopy (TEM).
The highest surfactant content was obtained for Fe3O4 nanoparticles coated with Cethyltrimethylammonium bromide. The presence of -CH2-, -CH3 and ammonium salt functional groups in infrared spectra implied that all surfactants had been successfully anchored onto the surface of native Fe3O4 nanoparticles. All modified nanoparticles were surface charged and they not tended to agglomerate in deionize water. The highest value of zeta-potential (approximately 40 mV) was obtained for Fe3O4-TTAB. Another characteristic coefficient is polydispersity index (PDI) its relative value was comparable for all modified nanoparticles. The transmission electron microscopy (TEM) analysis showed all modified nanoparticles were approximately spherical morphology with the core size in the range 5-15 nm.