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Acid mine drainage (AMD) is a mining-related problem that is causing harm to the natural ecosystem. The AMD originates from oxidized and sulfide ore stockpiles and contains high concentrations of dissolved copper and other contaminants. Therefore, many applications have been taken account into to process this highly acidic stream. In this research, Aspen Plus software is employed to simulate and analyze copper and water recovery efficiency of AMD generated from the stockpile of the Erdenetiin Ovoo deposit in at Gal Sentii LLC, Mongolia. The simulation incorporates a membrane filtration train consisting of ultrafiltration (UF) followed by two stages of nanofiltration (NF1 and NF2), modeled under steady-state conditions using the ELECNRTL thermodynamic method. Results show that the integrated system achieves high copper removal efficiency, with NF1 and NF2 reaching 98.99% and 100% separation, respectively. Water recovery remained effective throughout the process, reaching 90.08% in UF, 83.14% in NF1, and 99.90% in NF2. Total water hardness was reduced from 5918.81 mg/L to 0 mg/L, meeting the Mongolian MNS 4943: 2015 standard for clean water. Although the permeate remained slightly acidic (pH~ 3.67-3.93), the simulation confirms that membrane-based treatment is a viable strategy for both copper recovery and AMD remediation in cold-climate mining environments such as Mongolia.
Photocatalysis is a green technology that plays a vital role in achieving sustainable development goals and ensuring a clean environment. Metal oxide materials, in particular, have gained tremendous attention for their versatility in fields such as catalysis, semiconductors, ceramics, sensors, and energy storage. In this work, the sol-gel method has been used to synthesize CuO–ZnO composite particles. To understand their structural transformations, CuO–ZnO composite materials' thermal decomposition and phase evolution. Thermal analysis is crucial for determining the optimal calcination temperature during synthesis. We studied mass loss and phase transitions to identify the temperature, which affects vital photocatalytic parameters including crystallization, particle size, and surface area. To examine thermal stability and temperature-specific mechanisms, we analyzed samples dried at 120°C and 500°C using ThermogravimetryDifferential Thermal Analysis (TG-DTA), Fourier-transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD). Thermal kinetic evaluation using the Coats Redfern method resulted in an activation energy of 38.63 kJ/mol with a strong correlation coefficient of R2=0.94, indicating reliable thermal decomposition behavior. These values reflect moderate thermal stability, which is favorable for the formation of active photocatalytic phases without excessive energy input. We then characterized the composite's chemical composition using Raman spectroscopy while examining its optical and morphology properties through Ultraviolet-visible (UV-Vis) spectroscopy and Atomic force microscopy (AFM). These findings contribute to understanding the thermal stability, crystallization behavior, and phase interactions of CuO–ZnO composites, supporting their use in photocatalysis and functional materials. The results contribute to a better understanding of the temperature-dependent transformations in CuO–ZnO materials and provide a quantitative basis for their potential applications in photocatalysis and multifunctional materials. Future work will aim to include naturally occurring Cu2O phases in the composite structure to improve green photocatalytic efficiency and expand the use of the material in cleaning up the environment.
Transparent conducting oxide (TCO) thin films are widely used in modern optical and optoelectronic technologies, including solar cells, sensor displays, and light emitting diodes. Among the various TCO materials, indium tin oxide (ITO) is the most commonly used. However, due to the increasing scarcity of indium metal in recent years, its high extraction cost, extensive water usage and pollution during mining, and toxic effects on human health, aluminum-doped zinc oxide (AZO) has been investigated as a potential alternative. By preparing AZO thin films in an aqueous environment under laboratory conditions, it becomes possible to produce low-cost and safer TCOs on an industrial scale while minimizing environmental pollution. In this study, a total of four AZO thin films were fabricated using two methods: sol gel and nanoparticle-based synthesis. Two of these films were thermally annealed at 500 °C for 2 hours. The optical properties of the films were analyzed using UV-Visible spectroscopy (UV-VIS), and surface morphology changes due to annealing were characterized using atomic force microscopy (AFM). The AZO thin films prepared by both methods exhibited absorption in the ultraviolet (UV) region and transmittance of 70–80% in the visible region, with optical band gap energies ranging from 3.22 to 3.24 eV. In terms of surface morphology, the unannealed AZO films were relatively rough and non-uniform, whereas after annealing, the surface became smoother and more homogeneous. These results indicate that AZO thin films can be successfully fabricated using aqueous-based synthesis methods.
Secreted phosphoprotein 1 (Spp1) encoding osteopontin (OPN), a matrix cell protein with pro-inflammatory and pro-necrotic tissue properties, plays a crucial role in the onset and progression of idiopathic pulmonary fibrosis (IPF). In order to treat IPF by taking advantage of Spp1, we herein developed an inhalable system composed of calcium phosphate/ poly (lactic-co-glycolic acid) (PLGA) core-shell nanoparticles which are loaded with CRISPR/ Cas9 system targeting Spp1 to investigate its therapeutic potential. Specifically, the plasmid encoding Cas9 and single-guide RNA (sgRNA) selectively targeting Spp1 gene was first condensed by calcium phosphate to form Cas9 complexes, which was then encapsulated by PLGA to formulate into a gene-editing inhalable delivery system (termed CaP/Cas9/PLGA). Interestingly, the aerosolized inhaled delivery of CaP/Cas9/PLGA nanoparticles results in the effective traverse of mucosal barriers to fibrotic lungs, where they are internalized by lung cells without inducing noticeable cytotoxicity. Following endo/lysosomal escape and gene expression of CRISPR system, the disruption of Spp1 gene by Cas9/sgRNA induces the mutation frequency exceeding 30 %, resulting in efficient down-regulation of OPN level. In a bleomycin-induced pulmonary fibrosis mouse model, the inhalation of aerosolized CaP/Cas9/PLGA complexes significantly attenuates fibrosis development and improves lung function with undetectable systemic toxicity. This current study defines an innovative inhalable gene-editing formulation and offers a promising gene therapy modality for treating IPF.
As an alternative way to separation of biological molecules, silica coated magnetite ore particles were prepared through two step synthetic method including ball milling of iron ore powder followed by silica coating with Stöber method. As synthesized silica coated magnetic ore particles were composed mainly of magnetite and other accompanying minerals such as hematite and Al 2 O 3, ZrO 2. The particles were irregular in shape, with average size of 0.4±0.3 µm as demonstrated with SEM. Field dependent magnetization showed that silica-coated magnetite ore particles are soft ferromagnet with coercivity of 320Oe and remanent magnetization of 2.26 emu/g. Using these particles, genomic DNA was successfully separated from E. coli with sufficient yield and purity comparable to those obtained with a commercial magnetic separation kit, demonstrating their potential for bioseparation from diverse biological sources.
Lipid nanoparticle (LNP)-mRNA formulations have revolutionized the field of nucleic acid therapeutics, yet their broader clinical application is constrained by inflammatory side effects and oxidative stress, particularly in the context of inflammatory diseases. Herein, we report the rational design and synthesis of a lipoic acid-based ionizable lipid library to address these limitations. By leveraging the antioxidant properties and thiol-mediated uptake potential of lipoic acid, we identified LA-A2B2CD3 as an optimal candidate through a structure–activity relationship study and design of experiment (DOE) optimization. LA-A2B2CD3 LNPs exhibited superior reactive oxygen species scavenging, enhanced mRNA translation, and reduced inflammatory cytokine production in vitro and in vivo. Mechanistic studies revealed that the efficient cellular uptake and the transdermal delivery capacity of LA-A2B2CD3 heavily rely on the reducible disulfide ring of lipoic acid. Application of LA-A2B2CD3 LNPs for the localized transdermal delivery of Cas9 mRNA and CD93 sgRNA in a murine model of psoriasis resulted in effective CD93 genome editing and the inhibition of the CD93–p38 MAPK–AKT–SMAD2/3 pathway, leading to significant therapeutic improvement. This work presents a robust, biocompatible LNP platform with minimized immunogenicity and strong potential for genome-editing therapies in inflammatory conditions, offering a transformative approach for the mRNA-based treatment of skin and other inflammation-related disorders.
The development of sustainable and biodegradable materials has gained considerable attention due to increasing concerns regarding environmental pollution caused by synthetic polymers [1,2]. Among various biopolymers, keratin is a promising material derived from renewable sources such as wool and feathers. It exhibits excellent biodegradability and functional properties suitable for bioplastic applications [3]. However, keratin-based biofilms often suffer from poor mechanical strength and water solubility, which limit their practical applications. To address these limitations, starch, a widely available polysaccharide, has been incorporated into keratin matrices to improve film formation and mechanical properties [4,5]. In this study, novel keratin-starch biofilms were developed, and polychromatic X-ray irradiation was employed as a cross-linking and sterilization technique. X-ray irradiation has been widely used to enhance the mechanical and thermal properties of biopolymers by inducing cross-linking between molecular chains [6,7]. Keratin-starch mixtures were successfully processed into soluble and insoluble biofilms, with the insoluble films subjected to X-ray irradiation at doses of 3 kGy, 6 kGy, and 9 kGy. The effects of irradiation on cross-linking, heat resistance, and molecular interactions were analyzed using Fourier Transform Infrared Spectroscopy (FTIR), mechanical characterization techniques, and Atomic Force Microscopy (AFM). The results showed that increasing the X-ray dose led to enhanced cross-linking, improving the mechanical stability and thermal resistance of the keratin-starch biofilms. FTIR analysis revealed modifications in molecular bonding, indicating the formation of a more stable polymer network. AFM characterization demonstrated structural changes in the biofilm surface, suggesting improved homogeneity at higher irradiation doses. These findings highlight the potential of X-ray-induced cross-linking in developing sustainable biopolymer materials with enhanced properties for applications in packaging, biomedical, and agricultural fields. References 1. Sharma, R., Ray, A. R., & Pal, K., J. Clean. Prod. 258, 120840 (2020). 2. Kumar, S., & Park, J. W., Carbohydr. Polym. 257, 117618 (2021). 3. Zoccola, M., Aluigi, A., Vineis, C., et al., Biomacromolecules 13, 621 (2012). 4. Jiménez, A., Fabra, M. J., Talens, P., & Chiralt, A., Food Bioprocess Technol. 5, 2058 (2012). 5. Aluigi, A., Vineis, C., Tonin, C., & Ferrero, F., Polym. Degrad. Stab. 92, 173 (2007). 6. Spagnuolo, M., Raimondo, M., & Rusciano, G., Macromol. Chem. Phys. 224, 2200345 (2023). 7. González, A., & Alvarez, I., Food Packag. Shelf Life 25, 100505 (2020).
While numerous studies have explored the fabrication of 2D MoS₂, research utilizing natural rock sources remains largely unexplored. Highly pure MoS2 powder was attained from natural rock from Erdenetiin Ovoo deposit by petrographic method. Then two types of ultrasonication solvent-based exfoliation methods were applied. The physicochemical properties were explored using Ultraviolet-visible spectrometry, X-ray diffraction, Scanning electron microscopy, Raman spectrometry, and Cyclic voltammetry. Using salt during solvent-based exfoliation helped attaining more few-layer nanosheet with more bandgap energy. By the Pourbaix analysis, the electrochemical stability of 2D MoS2 samples were defined, which is crucial for their applications in electrochemistry.
The Erdenetiin Ovoo Cu-Mo porphyry deposit in Mongolia is the largest copper mine corporation in the nation. In this study, we investigate the grinding properties of biotite granodiorite and granodiorite rock alteration relative to variations in mine depth, with a specific focus on their correlation with mineral composition. The Bond Work Index experimental tests are applied to the Cu-Mo porphyry ore from the Erdenet Mining Corporation in Mongolia. The samples used in this study were collected representing 10 composites of 5 different depth levels with an interval of ~90 m within the 1175-725 m sampling elevation. The chemical, surface analytical, and mineralogical characterizations of the two types of biotite granodiorite and granodiorite ores are performed using Inductively Coupled Plasma, X-ray fluorescence, and X-ray diffractometer methods. Results of the chemical analysis indicate that the Cu and Mo percentages of both biotite granodiorite and granodiorite consistently decreased with depth profiling. The X-ray diffractometer data of mineral composition are used in setting up the prediction of the Bond Work Index estimation model. An equation-based approach to the Bond Work Index estimation model demonstrates a strong linear correlation (R²=0.895) with the measured Bond Work Index from experimental tests, with the highest Bond Work Index measured at 19.06 kWh/t. Our experimental results indicate that strong correlations were identified between the major mineral phases and the Bond Work Index values through the integration of ore hardness and mineralogical data.
The Erdenetiin Ovoo represents the largest Cu-Mo porphyry deposit in Mongolia. This study focuses on the primary ore types of the deposit-biotite granodiorite (BGDP) and granodiorite (GDIR)-examining their mineral composition and associations. Specifically, granodiorite is analyzed for its petrographic and mineragraphic properties. Utilizing the petrographic and mineragraphic method, mineral associations, alterations, and formation types are investigated, comparing these findings with results obtained from the TESCAN Integrated Mineral Analyzer (TIMA), a sophisticated automated quantitative technique. TIMA method is employed to determine mineral composition, liberation, association, and their grain size analysis rapidly and accurately, integrating Scanning Electron Microscopy (SEM), Back-Scattering Electron Microscopy (BSE), and Electron-Dispersive X-ray Spectroscopy (EDX). Petrographic and mineragraphic analysis identifies the origin of the minerals, their content, and textural relationships. The samples used in this research are collected from six boreholes for each rock type (BGDP and GDIR), with approximately 90-meter interval into the core of the orebody. The study focuses on the relationship between these results and their respective depths. From analysis of modal mineralogy, k-feldspar and quartz are found to constitute approximately two-thirds of the content in both ore types, with k-feldspar becoming more dominant as depth increases. Chalcopyrite as the primary valuable mineral, is predominantly associated and interlocked with pyrite and magnetite, as determined by petrographic and mineragraphic analysis. Petrographic and mineragraphic characterizations are attributed to a conclusion that from the primary sulfide zones at current operation level, pyrite-chalcopyrite-magnetite and quartz-molybdenite veins are formed in inclusion structure as the elevation level decreases to 635 m. In the mineral association quantitative analysis, gangue minerals such as biotite, carbonate, clay, and silicate minerals, particularly muscovite, are associated with both ore types. In the false-color images obtained from TIMA analysis, muscovite and quartz are identified as the most common minerals in composition and are frequently associated with both ore types, compared to the petrographic method.
Эрдэнэтийн Овоо зэс-молибдений ордын түвшин гүнзгийрэх тусам хүдрийн агуулга буурч, хатуулаг нэмэгдэн уул уурхай, геологийн нөхцөл олборлох ба боловсруулах процесс сөргөөр нөлөөлж эхлээд байна. Энэхүү судалгааны ажлаар ордын чулуулгийн эрдэсийн массыг тархалт, мөнлөг хоорондын харилцаа үйлчлэл, ассоциаци ба эрдэс чөлөөлөгдөлийн нөлөө, шинж төрхийн уурхай ашиглалтын түвшнээс хамааруулан TIMA болон физик-химийн багажит анализын бусад аргууд ашиглан хийж гүйцэтгэсэн. Ордын баруун хойд хэсгийн TRM 6 цооногоос (1175–635 метр гүнээс) биотит-гранодиорит (BGDP) болон гранодиорит (GDIR) чулуулгийн дээжүүдийг 1175–635 метрийн гүнээс хамааруулан (90 метрийн гүний интервалтай) L1–L6 түвшинд бэлтгэсэн. Уурхайн цаашдын ашиглалтын түвшин гүнзгийрэх тусам 16.95–19.06 кВт∙ц/тн болж хүдрийн хатуулаг, Бондын ажлын индекс өссөн зүй тогтол ажиглагдсан. Мөн BGDP чулуулгийн хувьд чулуулал бүрдүүлэгч эрдсүүдийн тархалт их, тухайлбал хээрийн жонш L4 (905–815 метр) түвшинд хамгийн их 47.53%, кварц 29.38%, пироксен 10.80%, шаврын эрдэс 4.73%-ийн массын тархалттай болохыг тогтоосон. Энэхүү судалгааны ажил нь хүдэр бутлалт, нунтаглалтын тоног төхөөрөмжийн хүчин чадал нь эрдсийн хамгийн их чөлөөлөгдөх үзүүр бүхий -75 мкм нунтаглалтын ангийн бэлтгэхэд хүрэлцэх үү, шаварлаг эрдсүүдийн есч бий агуулга металл авалтад сөргөөр нөлөөлөв, хам угтрал ихэсч чөлөөлөгдөх үзүүрийг бууруулах эрсдэл үүсэх өндөр магадлалтай. Иймд элсэн эрдсүүдийн агуулга, чөлөөлөгдлийн түвшин энэвтэрэй, эрдэсүүдийн зүй тогтол, ассоциаци ба харилцан үйлчлэл зэргийг бэлтгэлийн дэвшилтэт техник технологийн үйлдлүүдэд нэвтрүүлэх шаардлагатай гэж үзэж байна.
The flotation process is used to extract copper-molybdenum sulfide minerals from ore. The selection of the flotation technology scheme largely depends on factors such as the composition of sulfide ore in the ore body, grain size, and characteristics of the ore mineral association. The chemical and mineralogical analysis of flotation products was collected from the Erdenetiin Ovoo Cu-Mo porphyry deposit. The deposit is the largest porphyry copper-molybdenum deposit in Mongolia. The aim of this study was to demonstrate the occurrence mechanism of copper minerals in flotation tailing using the fully automated Tescan Integrated Mineral Analyzer. The chemical analysis of the flotation products (feed, concentrates and tailings) sample was conducted by X-ray fluorescence, and the mineralogical composition of the flotation feed sample was characterized using X-ray diffraction. The copper content of the flotation tailing was 0.024%. Mineralogical characterization results showed that almost all copper minerals occurred within coarse gangue particles, the primary and secondary copper minerals were accumulated in the size fractions less than 150 μm and 13.5 μm, respectively. The finest grain size distribution was observed in secondary copper particles of size -19 μm. Chalcopyrite was the main copper-bearing mineral, and it was closely associated with K-feldspar and silicate in the flotation tailings. The flotation tailing sample still contained 24.1 wt% liberated primary copper (chalcopyrite) and 24.13 wt% secondary copper due to their extremely fine grain size particle. The mineral map derived from Tescan Integrated Mineral Analyzer analysis revealed that copper minerals mainly occurred as finely disseminated and fully enclosed structures within gangue minerals.
The Erdenetiin Ovoo Cu-Mo porphyry deposit in Mongolia is the largest copper mine corporation in the nation. In this study, we investigate the grinding properties of biotite granodiorite and granodiorite rock alteration relative to variations in mine depth, with a specific focus on their correlation with mineral composition. The Bond Work Index experimental tests are applied to the Cu-Mo porphyry ore from the Erdenet Mining Corporation in Mongolia. The samples used in this study were collected representing 10 composites of 5 different depth levels with an interval of ~90 m within the 1175-725 m sampling elevation. The chemical, surface analytical, and mineralogical characterizations of the two types of biotite granodiorite and granodiorite ores are performed using Inductively Coupled Plasma, X-ray fluorescence, and X-ray diffractometer methods. Results of the chemical analysis indicate that the Cu and Mo percentages of both biotite granodiorite and granodiorite consistently decreased with depth profiling. The X-ray diffractometer data of mineral composition are used in setting up the prediction of the Bond Work Index estimation model. An equation-based approach to the Bond Work Index estimation model demonstrates a strong linear correlation (R²=0.895) with the measured Bond Work Index from experimental tests, with the highest Bond Work Index measured at 19.06 kWh/t. Our experimental results indicate that strong correlations were identified between the major mineral phases and the Bond Work Index values through the integration of ore hardness and mineralogical data.
Biosynthesis of Silver Nanoparticles with Antimicrobial Activity Using Novel Yeast Strains Enkhmaa M, Ganzorig Ch, Chinzorig R, Boldbaatar J Department of Chemical and Biological Engineering, National University of Mongolia, Ulaanbaatar, Mongolia Email: boldbaatar_j@num.edu.mn Silver nanoparticles (AgNPs) were biosynthesized using novel yeast strains isolated from Mongolian plants, specifically Candida tropicalis, Candida norvegensis, and Kloeckera apiculata. The synthesis was achieved within 24 hours at 30°C under laboratory conditions. The resulting AgNPs were characterized using Near-Infrared (NIR) spectroscopy, Dynamic Light Scattering (DLS), and Fourier Transform Infrared (FTIR) spectroscopy. Characterization revealed nanoparticle sizes ranging from 54.9 to 108.2 nm and indicated the presence of functional biomolecules involved in nanoparticle synthesis. FTIR analysis identified distinct stretching vibrations at 3425.9–3208.1 cm⁻¹, 1641.5–1638.1 cm⁻¹, and 2125.6–2108.4 cm⁻¹, corresponding to biomolecular interactions with silver ions. The biosynthesized AgNPs exhibited significant antimicrobial activity, showing strong inhibitory effects against Staphylococcus aureus and Escherichia coli. These findings suggest the potential of Mongolian yeast strains as eco-friendly, biological agents for silver nanoparticle production with promising applications in antimicrobial treatment.
Introduction to the Center for Nanoscience and Nanotechnology J. Boldbaatar, M. Otgon-Ujin, D. Maral, O. Erdenechimeg, Ch. Ganzorig Department of Chemical and Biological Engineering, National University of Mongolia, Ulaanbaatar, Mongolia Email: ch_ganzorig@num.edu.mn Founded in 2008, the center has swiftly become a focal point for nanotechnology research and education in Mongolia. Over the years, it has undertaken a plethora of nanotechnology projects catering to both local and international communities. A significant part of the center’s mission revolves around capacity building in nanoscience. Recognizing the need for specialized knowledge and skills in the field, the center has initiated master’s programs in 2009, ensuring access to cutting edge research and training for postgraduate students. Not resting on its laurels, the center further expanded its educational outreach by introducing bachelor's programs in 2014. This expansion has enabled a continuous supply of skilled professionals trained right from the undergraduate level, strengthening the field's talent pool. In a strategic move in 2021, the center shifted its primary focus, rebranding its activities to emphasize the application of nanotechnology in the realm of natural and biological resources. This shift demonstrates the center's commitment to harnessing the potential of nanotechnology in diverse sectors. Now, the center is channeling its resources and expertise into six distinct research priorities. Foremost, a Simulation and Computation for delving into the computational aspects of nanotechnology, this priority aims to harness the power of simulations to understand and predict nanoscale phenomena. Another category of Nanomaterial is dedicated to the synthesis, characterization, and application of novel nanomaterials, which are the building blocks of nanotechnology. Moreover, an emerging field, Organic Electronics and Devices, focuses on developing electronics and devices using organic compounds, offering flexibility and potentially more sustainable production methods. Based on vast number of biological resources of Mongolia, Nanobiotechnology bridges between biology and nanotechnology, this interdisciplinary priority aims to create innovations that can revolutionize healthcare, agriculture, and more. Moreover, recognizing the importance of sustainable mining and construction, our Mining, Civil and Environmental Engineering area seeks to integrate nanotechnology for environmental protection and optimized resource utilization. Finally, going beyond pure research, Science Education and Entrepreneurship priority underscores the importance of educating the next generation and fostering a spirit of entrepreneurship in the field of science education and nanotechnology. In essence, the center continues to evolve, reflecting the dynamic nature of the nanoscience field and positioning itself at the forefront of technological and educational advancements.
Determinations the potentials of silver nanoparticle biosynthesis by yeast strains isolated from wild berries M. Enkhmaa¹, R. Chinzorig², Ch. Ganzorig¹ J. Boldbaatar¹ ¹ Laboratory of Nanomaterial, Department of Chemical and Biological Engineering, center for Nanoscience and nanotechnology, National University of Mongolia ² e-lab, Department of Chemical and Biological Engineering, School of Engineering and Technology, National University of Mongolia The preparation of nanomaterials involves chemical, physical, and biological methods. Recently, there has been a growing interest in the eco-friendly synthesis of highly biocompatible nanoparticles for biomedical applications. Yeasts, known for releasing enzymes and metabolic products, offer a unique extracellular synthesis route for nanomaterials, promising innovative solutions in the field. In this study yeast strains were isolated from the Vaccinium vitis-idaea, Padua asiatica, and Lonicera caerulea respectively in Mongolia. The three yeast strains were selected based on the ability to utilize carbon sources. They were further identified using API 20C AUX to be yeast species Candida tropicalis, Candida norvegensis, and Kloeckera apiculate. The AgNPs produced by Candida tropicalis, Kloeckera apiculate, and Candida norvegensis at 30°C for 24 hours. The AgNPs samples were characterized using spectroscopy and the microscopic technique of UV-visible (UV-vis), Dynamic Light Scattering (DLS), and Fourier Transform Infrared (FTIR) analyses. The UV-vis spectra demonstrated a broad peak centering at 412 nm to 420 nm. The synthesized Ag NPs exhibited a uniform spherical shape and fine size, with an average size of 54.9 nm to 108.2 nm. FTIR analysis was employed to characterize and identify the potential biomolecules on the synthesized AgNPs. The broad band at 3425.9-3208.1 cm − 1 corresponds to −OH stretching. The band at 1641.5-1638.1 cm − 1 in the yeast extract is due to the C=O stretching vibration of carboxyl moieties. The low peak at 2125.6-2108.4 cm − 1 is attributed to the C=C stretching vibration. These results demonstrated that biomolecules of the yeast extract were responsible for the biosynthesis of AgNPs. The Kirby-Bauer method was used to antibacterial activities of yeast AgNPs against two pathogenic bacteria were determined. The highest antibacterial effect was observed on S.aureus with additional obvious effects on E.coli. Key words: Silver nanoparticles, Yeast, antibacterial activity
We have theoretically investigated the feasibility of constructing a spintronic field-effect transistor with the active channel made of a polymer chain with the antiferromagnetic coupling oriented in the source-to-drain direction. We found two different device function regimes controlling the on-chain spin–charge carrier density by tuning the gate voltage. At higher charge carrier densities, the source–drain current linearly increases with decreasing charge carrier densities. In this regime, no polymer spin-polarized current is observed. Upon reaching a critical gate voltage, the current decreases with decreasing charge densities. It is accompanied by the formation of spin-polarized current, generated by an on-chain process, which can be related to spin–charge spatial distribution symmetry breaking caused either by an application of the source-to-drain voltage (higher spin polarization near the drain), or the breakdown of the Peierls dimerization near chain ends. Numerical simulation of the transistor characteristics suggests that the design of a polymer spintronic field-effect transistor is in principle feasible.
Magnetic CuFe2O4@GO nanocomposite was prepared using coal-derived graphene oxide and its antibacterial and sonophotocatalytic activity was studied. The physicochemical properties of the synthesized nanocomposite were evaluated using Ultraviolet–visible spectrometry, X-ray diffraction, Scanning electron microscopy, and Fourier transform infrared spectroscopy. The nanocomposite was demonstrated as an effective sonophotocatalyst for methyl orange degradation, and it presented antibacterial properties when tested on Gram-negative P. aeruginosa and Gram-positive S. aureus bacteria.
Future generations of electronic products will be enabled by flexible electronic circuits, displays, and sensors based on organic active materials, which could eventually reach the mainstream electronics industry. One of such devices is the organic field-effect transistor (OFET), which are three-terminal devices that are comprised of a gate, source, and drain electrode. In this study, we fabricated a bottom-gate bottom-contact OFET device using copper phthalocyanine (CuPc) as a semiconducting layer. CuPc is a commercially available metal complex, a known p-type semiconducting material. Au/Ti electrode is sputtered on Al gated silicon substrate with thermally grown SiO2 dielectric layer. CuPc films were then deposited over the substrate with patterned electrodes by physical vapor deposition at a rate of 0.35 nm/s, recorded by a quartz crystal microbalance at room temperature under a background pressure of 1.21x10-3 Pa. A thin layer of organic material was also deposited on glass slides and the optical properties of films with different thicknesses were determined by UV-Vis spectrometry and the optical band-gap energy was determined to be 1.64±0.01 eV. The thermal annealing effect on thin-film crystallization morphology was studied with atomic force microscopy (AFM) and contact angle measurement.
In this study, increasing the work function of ITO (Indium Tin Oxide) electrode while reducing that of Al cathode was examined to successfully improve the Voc (Open Circuit Voltage) values of the of Organic PV (Photovoltaic) cells. For MIM (Metal Insulator Metal) type organic PV cells, the Vbi (Built in Potential) results from the Δφ (Work Function Difference) between the anode and cathode electrodes. Using high work function values for the ITOs used as an anode, an improvement in Vbi resulting from Δφ would be expected with organic PV cells. In the cells with Al cathode (named as bilayer cell), a slight increase in PCE from 0.13 % in the case as-cleaned ITO to 0.46 % in the case ITO modified with NO2– terminal group was observed. The FF value for the devices with variously configured ultra-thin layer such as BCP/Al, BCP/C6H5COOLi/Al, Alq3/Al, and Alq3/C6H5COOLi/Al is still larger (1.3 times increased) than those of the other devices with Al and C6H5COOLi/Al cathode electrodes. Introduction
Органик электролюминесцент (EL) төхөөрөмжийн судалгаа хөгжүүлэлт болон үйлдвэрлэлийн явцад тулгарч байдаг томоохон асуудлуудын нэг болох ажиллах ашиглалтын хугацаа болон тогтворжилтыг бууруулдаг гол хүчин зүйл нь деградацийн процесс, түүний үүсэх механизмыг судлах явдал байдаг. Деградацийг бууруулах, дагалдах процессуудыг зогсоох зэрэг судалгааны ажлууд хийгдсээр байгаа хэдий ч одоогоор энэ асуудлыг бүрэн шийдвэрлэж чадаагүй байна. Иймд энэхүү судалгааны ажлаар индий-цагаан тугалгын оксид (ITO), N,N’-дифенил-N,N’-бис(3-метилфенил)-[1,1’-дифенил]-4,4’-диамин (TPD), хөнгөн цагааны трис(8-гидроксихинолин) (Alq3) болон металл Al электрод ашиглан донор/акцептор бүхий давхар үелсэн нимгэн үеийг вакуумд ууршуулан суулгах аргаар ITO(150 нм)//TPD(50 нм)/Alq3(50 нм)/Al(~100 нм) гэсэн бүтэцтэй органик EL төхөөрөмж гарган авсан. Уг төхөөрөмжийн металл электрод болон органик нимгэн үеийн гадаргууд явагдах деградацийн процессыг орчны чийгшил (~80%) болон температур (өрөөний, 80°С, 120°С)-аас хамааруулан хэмжсэн. Атомын хүчний микроскоп (AFM)-ийн аргыг ашиглан органик нимгэн үед үүсэх морфологийн өөрчлөлт, кристаллжих процессын судалгааг хийж гүйцэтгэсэн. Судалгаанд ашиглагдсан органик EL төхөөрөмжийг тогтмол хүчдэлээр ачаалж үйлчлэхэд металл Al электродын гадаргууд бөмбөлөг хэлбэртэй бүтэц (өөрөөр хэлбэл, катодын салалтын процесс) ажиглагдсан бөгөөд мөн давхар үелсэн органик нимгэн үеийн гадаргуу болон гүнд гэрэл үл цацруулагч хар толбо буюу нүх (dark spot) үүсэж деградацийн процессын AFM судалгааг хийж гүйцэтгэсэн болно.
Монгол орны замын эвдрэлээс нь хамааруулан бүсчилсэн 2 байрлалаас замын суурийн үе болон шинээр зам тавихад ашиглаж буй дахин боловсруулсан хольцын химийн болон эрдсийн бүтэц найрлагыг харьцуулан судлав.
Superhydrophobic SiO2 nanoparticle ultra-thin film was fabricated on the surface of cashmere fabric via dip coating method utilizing acetic acid and acidic water. The as-obtained cashmere fabric was characterized by SEM and FTIR analysis, and wetting behavior was determined with contact angle measurement. The stain resistance, pilling and colorfastness grade were also evaluated. Contact angle measurement revealed that cashmere fabric attained a superhydrophobic behavior with a contact angle greater than 150°. The silica nanoparticles were grafted onto surface of cashmere fabric successfully as indicated by the FTIR measurement. Colorfastness and pilling grade were improved in the surface coated cashmere; therefore, the coating process did not impose the adverse effects on the quality of the cashmere fabrics.
We present a model of the charge transport in thin film organic field-effect transistors with the active channel made of linear conjugated chains stacked on the substrate with end-on-orientation. The transport was simulated in a box consisting of 25 polymer chains, in which the delocalized quantum orbital eigenstates of the on-chain hole distribution were calculated. The inter-chain charge transfer was solved semi-classically. The full self-consistent distribution of charge density and electric field was determined for various applied gate and source–drain voltages. We found that the dependence of charge mobility on gate voltage is not monotonic: it first increases with increasing gate voltage for a limited interval of the latter, otherwise it decreases with the gate voltage. Next, we found formation of the second resonant peak for higher gate voltages. The mobility dependence on the gate voltage confirmed that the current flowing through the active semiconductor layer should be described not only as the hole transfer between adjacent repeat units of the neighbouring chains, but also as the transfer of coherences among on-chain repeat units. The presented model can also give a new insight into the charge transport in organic field-effect transistors with a novel vertical architecture.
