2nd World Conference on Materials Science and Nanotechnology

Microemulsions are multicomponent systems that are macroscopically isotropic and optically transparent, but are heterogeneous at the nanoscale, being composed of micelles with sizes on the order of tens or a few hundred nanometers, as opposed to regular emulsions whose micelles are around 1 mm in size. Recently, such mixtures have found application in wastewater treatment, as extraction systems and/or nanoreactors for photodegradation of various classes of pollutants, given their more environmentally benign nature as compared to classic organic solvent. Among these pollutants are drug residues and one major subclass, of increasing concern, is represented by antidepressant drugs, which have started to be manufactured and prescribed more and more in modern-day Western societies in particular. In this work, we present some results of our experiments on the preparation, characterization, and application of some microemulsion systems for the separation and concentration of several tricyclic antidepressant drugs from contaminated waters. Several Winsor II-type systems based on ester oils and a nonionic surfactant have shown very high extraction efficiencies into small volumes of water-in-oil microemulsions, leaving behind large volumes of purified water, sometimes even with a possibility of re-using the same microemulsions for further extractions with efficiencies still in the high range.

The current wood adhesives technologies rely mainly on formaldehyde-based adhesives produced from petrochemicals. Moreover, these adhesives are derived from non-renewable sources, which are known to be carcinogenic and have other serious health effects. Therefore, there is an increasing interest in the use of renewable and biodegradable sources for the evolution of environmentally friendly adhesives for interior wood applications. The canola meal (the remnant after oil extraction from the canola seed) contains about 36 – 39% (8.5% moisture basis) and can be used as a low-value feed for the animals. Moreover, its protein content is currently exploring other applications such as in adhesive technology and it can be used as an alternative to the widely used formaldehyde-based adhesives. Canola proteins (CP) as adhesives have many unique properties such as ease of handling, low cost, low pressing temperatures, and the ability to bind wood with relatively high moisture content. On the other hand, it has relatively low adhesion strength and low water resistance which are the major drawbacks. This study will address these issues by modifying CP adhesive with carbon nanotubes (CNT). CNTs are one of the most encouraging strengthening nanofillers with extraordinary tensile modulus and strength, it has been proven to significantly improve the physical and mechanical properties of the nanocomposites. Generally, this study will intend to improve the water-resistance and adhesive strength of the CP adhesive by incorporating different concentrations of the CNT into the protein matrix. This study comprises two parts: incorporation of CNT and functionalized CNT (FCNT) into the CP matrix. Incorporation of CNT at 1% (w/w) enhanced the adhesive strength from 5.98, 1.80, and 5.42 to 9.20, 5.64, and 7.44 at percentage increments of 53.85, 213.33, and 37.27% for dry, wet, and soaked strength respectively. The presence of the carbonyl group in the CNT after purification as well as the polyvinylpyrrolidone (PVP) helped to attain this improvement in water resistance and adhesion. In the second part, functionalization of the CNT greatly improved the shear strength at 1% FCNT concentration to 10.62, 8.10, and 8.13 at 77.59, 350, and 50% increase for dry, wet, and soaked strength respectively. The introduction of the carboxylic group by functionalization significantly improved the mechanical and thermal properties of the CP due to a proper dispersion giving rise to better hydrophobic and cohesive interactions between the wood and adhesive. These results proved an enhanced water resistance and adhesion of the CP contributed by the CNT and its functionalization.

In recent decades, photonic crystals have evolved as interesting photonic structures and play an important role in the field of biological detection. Because of their ability to control light propagation, photonic crystals have a significant effect on the design of a wide range of photonic biosensors. Here we present computational methods for studying the optical properties of light under various refractive indices of photonic structures. We build photonic structures with defects whose refractive index changes when a medical sample is injected into the defect, which serves as the basis for an optical sensor. As a result, we could identify glucose concentration in urine or blood samples, cell type, and so on by identifying resonance peaks in the transmission spectrum. Our results show that a photonic band gap with an FWHM of 1033 nm can be observed at wavelengths of 1933 nm and 2966 nm with a sensitivity of 965 nm/RIU, a factor quality of 1892.542, and a high merit figure of 756.863 RIU-1 for a one-dimensional ternary photonic structure (ABC) containing a defect and for another two-dimensional based on silicon rods arranged as a square structure in an air bottom with two waveguides and a nanocavity, we report that we observed the maximum sensitivity of 1350 nm/RIU. As a result, the suggested biosensors have the potential to be a miniaturized structure with high sensitivity in glucose concentration or cancer cell detection models.

Articular cartilage (AC) defects are challenging to cure due to their avascular nature and limited healing potential, resulting in degenerative diseases such as osteoarthritis (OA). Various clinical techniques intend to repair the AC defects; however, load-bearing and complete functional tissue recapitulation remain significant hurdles. To resolve these concerns, we developed a novel three-dimensional (3D) bioprintable hypoxia mimicking nano bioink, including a combination of polyethylene glycol diacrylate (PEGDA) hydrogel encapsulated with umbilical cord-derived mesenchymal stem cells (UMSCs) and cobalt nanowires (Co NWs) as a hypoxia inducing agent. Cobalt (Co) is documented for its hypoxic effects in vitro by stabilizing hypoxia-inducible factor (HIF-1α), a chief regulator of stem cell fate. The current research investigates the impact of Co NWs on the chondrogenic differentiation of UMSCs in the PEGDA hydrogel system. In this study, the hypoxia mimicking nano bioink (PEGDA+Co NW) was rheologically optimized to bioprint geometrically stable cartilaginous constructs. The bioprinted 3D constructs were investigated for their physico-chemical characterization, swelling-degradation behavior, mechanical properties, cell proliferation, and the expression of chondrogenic markers by histological, immunofluorescence, and reverse transcription-quantitative PCR (RT-qPCR) methods. The results disclosed that, compared to the control (PEGDA) group, the hypoxia-mimicking nano bioink (PEGDA+Co NW) group outperformed in print fidelity and mechanical properties. Furthermore, live/dead staining and DNA content demonstrated that adding low amounts of Co NWs (< 20 ppm) into PEGDA hydrogel supported UMSCs adhesion and proliferation with no significant cytotoxicity. Histological and immunofluorescence staining of the PEGDA+Co NW bioprinted structures revealed the production of type 2 collagen (COL2) and sulfated glycosaminoglycans (GAGs), rendering it a viable option for cartilage repair. This was further corroborated by a significant increase in the hypoxia-mediated chondrogenic and limited hypertrophic/osteogenic marker expression. In conclusion, the hypoxia-mimicking hydrogel system, including PEGDA and Co2+ ions, synergistically directs the UMSCs toward the chondrocyte lineage without using expensive growth factors and provides an alternative strategy for translational applications in the cartilage tissue engineering field.

Mesoporous silica nanoparticles (MSN) is known as one of the best material of nanotechnology for drug delivery application due to its unique properties along with biocompatibility and non-toxicity. However, the major challenge for nanomaterials is the release of drugs that could not be specified to target, thus reduced its efficiency. Since the cancer cell is more acidic than normal cell, an effort was made to incorporate the acidic responsive polymer to assist the performance of MSN. Thus, this study evaluate the potential of poly (styrene-co-maleic anhydride) (SMA) to coat the MSN pre-loaded with the model drug, quercetin (QT) in a thin film. The samples have been characterized for functional group, crystallinity, topography and morphology imaging, surface parameters and hydration analysis. The materials were fabricated within incorporation ratio of MSN/QT: polymer at 1:2,1:4, 1:6 and 1:8. The release performance of QT in neutral pH shows that MSN/QT released maximum rate of QT within 4 hours, while no release was observed from MSN/QT/SMA. Meanwhile in acidic pH, MSN/QT profile burst 50% release of drugs within 3 hours, while, the slow and sustain release was observed by MSN/QT/SMA until it reached 33.5% within 20 hours. This behavior was contributed to the morphology, solubility and chemical interaction between MSN/QT and the polymer. From this study, efficient encapsulation of polymer as carrier-drug molecules can be suggested as an alternative to the drug delivery application.

When increasing the working speeds and revolutions of production machines, a state can be reached in which resonance occurs. In the area of the resonance peak, the most effective way to reduce the vibration amplitude is to increase the damping of the mechanical system. One way is to use passive material damping. Polymers are among the materials with good material damping, but their stiffness and strength are not satisfactory for common engineering applications. However, composites with a polymer matrix find application in mechanical engineering in the field of machinery and production technology. To increase damping in mechanical systems with steel components while the contact stiffness is maximum, high material damping can be inserted into mechanical system. Of course, the weight and stiffness of that system are also increased, but these values are negligible compared to the other weight and stiffness of other components. These high damping materials manifest themselves most significantly in the area of resonant working speeds. The presented polymer application is for rotor bearing casing in which the polymer-concrete is inserted into the mechanical system by filling in the free space between the casing and the housing body. The application showed the reduction of acoustic emission maximum amplitudes of 67% and 33% when excitation amplitudes are up to 5g and above 10g, respectively. In the case of the FFT spectrum of acoustic emission, the reduction was 85% and 51%. Before application, the analysis of four polymer-concrete samples with different compositions was made, logarithmic decrements were measured by two experimental methods and then one composition for mentioned application was selected.

LaFeSi nanoparticles have gained significant attention in recent years due to their magnetic properties and potential applications in self-regulating magnetic hyperthermia. Self-regulating magnetic hyperthermia is a therapeutic approach that uses magnetic nanoparticles with a specific Curie temperature to generate heat and selectively destroy cancer cells. When the nanoparticles are exposed to an alternating magnetic field, they produce heat until they reach their Curie temperature, at which point they stop generating heat, preventing overheating and damage to healthy tissue. LaFeSi nanoparticles are biocompatible and presents first-order magnetic transition with Curie temperature around 200 K whereas the addition of hydrogen to the LaFeSi nanoparticle can raise its Curie temperature around 315 K, making it suitable for self-regulating magnetic hyperthermia applications. In this work, we fabricated LaFeSi parent alloy by arc melting technique. Then we sealed the arc-melted ingots into silica-glass ampoules and heat treated at 1050 C° for 10 days. Lastly, we milled the samples under H2 atmosphere at 400 rpm speed with different durations to hydrogenate the powders. XRD patterns showed that there is a maximum 2.1% lattice expansion with milling as a result of the interstitial doping of the H atom in the cubic lattice. VSM measurements reveals that TC can be tuned in the range of 195 K to 350 K via H doping. Maximum specific absorbtion rate was calculated as 108 W/g using magneto-thermal measurements. Overall, the combination of first-order transition, hydrogenation, and magnetic hyperthermia may hold promise for the development of new, more effective nanoparticle-based cancer therapies.

Fe3O4 nanoparticles (NPs) have gained significant attention in biomedical applications due to their biocompatibility and easy metabolization by the human body. It is crucial to characterize the size of Fe3O4 NPs, as their efficiency is highly dependent on their size in the medical field. To synthesize Fe3O4 nanoparticles, a coprecipitation method was employed with citric acid as a surfactant to prevent NP aggregation in aqueous suspension. Particle size characterization was performed using Direct Particle Tracking (DPT) and Dynamic Light Scattering (DLS) techniques. Computer simulation of NP diffusion and imaging followed by DPT size analysis demonstrated that DPT can be used in the early stages of synthesis to determine if the sample is suitable for the intended purpose. DPT and DLS techniques were both utilized to provide size characterization of NPs in suspension, whit DLS as reference. The results indicate that DPT provides a direct size distribution without any prior assumptions and is relatively fast with simple sample preparation. Moreover, the results obtained from DPT are in good agreement with those obtained from the DLS procedure. For further details, please refer to the extended paper.

The quantum systems with cylindrical symmetry, such as atoms and molecules in cylindrical geometries, were studied. A technique for solving the stationary Schrödinger differential equation in cylindrical coordinates was presented. The separation of variables method and special functions were used. The boundary condition specifies the value of the wave function must be zero at the edges of the cylinder. A wave function was found whose square modulus shows the probability of finding a particle in a state characterized by numbers (n, m, s), inside a cylindrical region. This probability density can be used to calculate various physical properties of the particle, such as its energy levels and angular momentum, which can be used to predict its behavior and properties. The results can be used to find the probability of interactions between atoms and molecules (for example, helium and hydrogen) and carbon nanotubes or nanowires. This research can be valuable in fields such as chemistry, physics, and materials science, including electronics, energy storage, and biomedical devices. where understanding the behavior of atoms and molecules in cylindrical geometries is important. It also offers a powerful tool for predicting the properties and behavior of these systems, which can aid in the design and development of new materials and technologies.

The subject of the project is the verification on a real scale of the technology for producing a catalytic system of engine exhaust gases with a mass reduction of approx.20%, meeting the Euro IV, V and VI emission standards using an innovative method of using waste, the so called „washcoat” from the recovery of precious metals used to make the active layer of the catalyst. The share of recycled precious metals is up to 20%. The intermediate layer consist of 70% washcoat mainly containing aluminium oxide and up to 20% washcoat with recycled precious metals. The active layer consists of precious metals, i.e. platinium, palladium and rhodium, in the right ratio and amount per 1 liter of catalytic block to achieve the specified emission standard. Due to the qualification of rare earth materials as critical, it allows to reduce the use of raw materials to 20% depending on the monolith model. The project integrates activities aimed at economic growth with social activities and contributes to maintaining natural balance. The project focuses on a low-carbon economy and resilience to climate change.

In recent years, the problem of increasing electricity consumption for various types of cooling has become urgent[1]. Magnetic cooling is a good alternative to compression cooling, as it has high efficiency[1,2] and is more environmentally friendly[3]. Refrigeration machines with molecular magnets deserve special attention. Due to the fact that they have a large surface area, a large magnetic moment and a large magnetocaloric effect, they are good candidates for the basis of magnetic refrigerators. In this paper, the magnetocaloric effect in a fullerite crystal is tested using molecular dynamics methods. In our work, we use a model of the dynamics of large molecules. The interaction between particles is described by the Lennard-Jones potential. The equations of motion of particles are solved by the fourth-order Runge-Kutta method. The fullerite crystal forms a face-centered cubic lattice, in the nodes of which the fullerene C60 molecules are located. This crystal is placed in a cube with a side of 6 nm, the reflection from the faces of which occurs in an absolutely elastic way. The cube is filled with monatomic helium gas. To determine the presence of the magnetocaloric effect, the dynamics of the system is modeled in the presence of an external magnetic field and without it. Fullerenes interact with the magnetic field by means of encapsulated particles having a magnetic moment. The results of this work confirm the presence of a magnetocaloric effect in fullerite.

In the present study, the effects of aluminium (Al) addition and sintering temperature have been investigated on the thermal stability and mechanical behaviour of Fe-42wt.% Ni-2wt.% Y2O3-2wt.% Ti (2Ti), and Fe-42wt.% Ni-2wt.% Y2O3-2wt.% Ti-2wt.% Al (2AlTi) alloy compositions prepared through mechanical alloying followed by spark plasma sintering (SPS). The SPS was performed at 1050 and 1100 °C for the 2Ti alloy with an applied load of 60 MPa for a holding period of 5 min, whereas the 2AlTi alloy was subjected to sintering only at 1100 °C under the same sintering condition. The sintered 2Ti alloy shows a huge grain coarsening (1800 nm) compare to 2AlTi (441 nm) with a subsequent decrease in mechanical properties drastically revealing its instability at 1100 °C. To enhance the thermal stability of the 2Ti alloy, 2wt.% of Al was introduced to obtain new alloy composition, named the 2AlTi. The spark plasma sintered (SPSed) samples were studied through EBSD analysis to understand the microstructural features using an inverse pole figure, microstrain using kernel average misorientation, and texture analysis using the Pole figures. Mechanical properties such as hardness, nanoindentation hardness & elastic modulus, and compression strength properties were investigated and correlated with microstructural details.

All-inorganic lead halide perovskite quantum dots (QDs) have gained widespread interest due to their outstanding optical and electronic properties that can be easily adjustable. The optical characteristics of QDs depend on the ratio of different halide ions present. Modification of the surface of the synthesized QDs using specific reagents such as trimethyl silyl halogenides reduces the concentration of surface defects resulting in controlled emission spectra and improved quantum yield. This research is focused on modifying the optical properties of CsPbBr3 QDs by treating their surface with various amounts of (CH3)3Si-Cl solution. The emission wavelength of CsPbBr3 was found to shift from approximately 510 to 430 nm by increasing the quantity of (CH3)3Si-Cl solution used for surface modification. The results to be presented in the conference suggest the potential development of advanced perovskite-based optoelectronic devices with enhanced performance and functionality. The authors acknowledge financial support from the European Regional Development Fund (project No 01.2.2-LMT-K-718-03-0048) under a grant agreement with the Research Council of Lithuania (LMTLT).

Halide perovskite quantum dots (QDs) are emerging as a promising materials for a wide range of optoelectronic applications, due to their exceptional photoelectric performance and excellent optical properties. Among these materials, the all-inorganic metal halide perovskite CsPbX3 (where X = I, Br, Cl) QDs are particularly appealing because of their remarkable thermal and photostability. However, to fully realize their potential in optoelectronic devices, it is essential to develop novel synthesis techniques that allow for the tailoring of their optical properties. In this study, we report a post-synthesis modification method using ZnX2 (where X = Cl and I) solutions to selectively modify the optical properties of CsPbBr3 QDs. By changing the concentration of ZnX2 solutions used for post-synthesis modification, we show that the optical properties of CsPbBr3 QDs can be tailored. Specifically, we demonstrate that virtually all emission wavelengths can be obtained from a single CsPbBr3 QDs batch by selecting the appropriate zinc halogenide and its concentration. Our results provide a new perspective for the development of novel optoelectronic devices including photovoltaics, light-emitting diodes, and sensors. The authors acknowledge financial support from the European Regional Development Fund (project No 01.2.2-LMT-K-718-03-0048) under a grant agreement with the Research Council of Lithuania (LMTLT).

The use of CsPbX3 (X = Cl, Br, I) perovskite quantum dots (QDs) has demonstrated tremendous potential for various optoelectronic applications due to exceptional physical properties of these materials. However, the most commonly used hot-injection synthesis method possesses several drawbacks, for instance, long synthesis time and limited reproducibility. To address these issues, we proposed an ultrasound-induced hot-injection synthesis method that enables highly reliable, simple, and fast synthesis of CsPbX3 perovskite QDs. The suggested method employs ultrasound to induce nucleation and growth of CsPbX3 perovskite QDs during the hot-injection process. Extremely fluorescent perovskite QDs were obtained using this method after optimization of synthesis conditions. Furthermore, the obtained results also confirmed that the suggested synthesis method is extremely reproducible and significantly reduces the synthesis if compared to the conventional hot-injection method. The suggested method can be employed in a large scale perovskite QDs production making them accessible to applications in light emitting diodes, photodetectors, solar panels, lasers and so on. In this study we will show the benefits of the proposed method in comparison with the conventional hot-injection method. However, further studies are still necessary to find out the mechanisms behind the ultrasound-induced nucleation and growth of perovskite QDs. The authors acknowledge financial support from European Regional Development Fund (project No 01.2.2-LMT-K-718-03-0048) under a grant agreement with the Research Council of Lithuania (LMTLT).

Nanowires based bio-chemical sensors are of great interest due to their high sensitivity and simple fabrication process. For sensing applications, the surface of semiconductor nanowire is usually functionalized with specific receptors to be sensitive to chemical and biological molecules. The surface functionalization allows to immobilize biomolecules on NW surface and enables a direct detection of disease-related molecules. The modelling of physical and chemical processes in biosensors is important for the device optimization and for further improvement in sensing selectivity. We introduce computational model of NW field effect transistor-based biosensor using COMSOL Multiphysics. We consider n-doped Si NW covered with an array of y-shaped nanopillars designed to detect biomolecules. The model allows to study the concentration distribution in the analyte and the surface coverage of adsorbed species. The calculations of surface coverage of adsorbed species are time dependent. The Semiconductor module is used together with Chemical Reactions Engineering and AC module in COMSOL Multiphysics to calculate the potential distribution in the system and the drain current dependence on species concentration in analyte. Calculations show that NW current is very sensitive to concentration variations of biomolecules.

The article considers a solid circular cylinder. The lower face of which is glued to a non-deformable plane. And the upper face of the body experiences an axial compressive effect, which implies an initial movement towards the bottom of the cylinder. In this case, the remaining part of the cylinder, which is free from the specified impact, will bend according to the laws of elastic deformation. The mathematical model represents stationary equations of equilibrium in displacements, which are closed by conditions imposed on all boundaries of a cylindrical body. The numerical solution methodology includes the use of finite difference relations and the simple iteration method. In the axisymmetric case, the stress-free conditions give two recurrence relations for displacements suitable for use in the iteration method. On the corner line of the main cylinder, these relations take a special form. For a more accurate search for a solution, a logarithmic mesh refinement was used. Systematic calculations of the stress-strain state of the cylinder were carried out and profiles of free surfaces were constructed. The stresses located at the internal points of the cylinder were calculated. Having considered the resulting stress field, useful conclusions were obtained. The calculation results were calculated using a program written in the Matlab.

Previously, there were developed in our laboratory a new technique for deposition of photonic crystal lines consisting of SiO2 close-packed microspheres onto a glass surface at increased temperature and lower SiO2-concentration. Here we vary temperature and SiO2-concentration conditions for deposition of silica microspheres onto ITO and FTO. We have discovered that ITO and FTO need inevitably higher temperature and lower concentration compared with glass for the growth of the separated photonic crystal lines upon its surface. Whereas fine deposition of continuous SiO2-opal film onto ITO substrate with precisely even width was observed at the room temperature and normal concentration as it was previously discovered for the glass. Moreover, we coated glass-supported continuous SiO2-opal film with gold using thermal vacuum sputtering, as a result photonic stop-band slightly shrank due to the decreased transparency of the material. However, this material can be used as a SERS-active substrate because of the presence of naturally formed hotspots between the gold-coated spheres on its surface. Afterwards, continuous/lined ETPTA photonic crystals were prepared using photocurable resin polymerization reaction and SiO2-opals as a template. As a result photonic stop-band were red-shifted and extensively deepened. Finally, manifold infiltration of continuous/lined ETPTA-opal with water-ethanol solution of gold nanoparticles (NPs) were conducted by repeating up to 30 cycles of dipping, drying and washing steps. Gold NPs infiltration provides positive effect of deepening photonic stop-band of ETPTA-opals related to the resonant absorption of NPs, as it was previously discovered in our laboratory, however, last 15 cycles does not yield anymore. The project is supported by the Russian Science Foundation (grant No. 22-23-00585).

Nanotechnology breakthroughs today lead to new discoveries in medical sciences. Carbon dots are low-toxicity and biocompatible nanomaterials with sizes less than 10 nanometers that exhibit unique optical properties. The fundamental ingredients that make them emissive particle are their carbon backbone, their functional groups, and surface deficits. Carbon dots have great light stability and are resistant to photobleaching, which makes them an excellent choice for bio-imaging. Here in this study curcumin – a beta-diketone molecule with two aromatic rings - as a known natural anti-inflammatory and anti-oxidant compound was used for the synthesis of carbon dots by hydrothermal method as the carbon source. The effects of the presence of amino acids with aromatic side chain, urea and citric acid on the quantum yield and spectral properties of the synthesized carbon dots were investigated. The highest quantum yield was achieved by having curcumin, tyrosine, and citric acid in the reaction.