Search Results (672)

In a world of miniaturized electronics, there is a rapidly increasing need for reliable, efficient, and compact energy storage systems with low-loss dielectrics. To address this need, this work proposes the development of compact, micro-capacitive energy storage devices compatible with IC processing so that they can be integrated monolithically on-chip. There are two main approaches to the fabrication of integrated on-chip micro-supercapacitor energy storage devices: interdigitated electrode (IDE) devices and parallel plate electrode (PPE) devices. As part of the design of such systems, this study aims to investigate the behavior of current density-voltage (J-V) in homogeneous and heterogeneous IDE and PPE devices to determine whether the anomalies between the interfaces of dielectric materials in such structures affect their leakage current. The ultimate goal is to design a solid-state capacitor energy storage module with low-loss dielectrics, high energy densities, and improved areal capacitance density that can offer a high number of charge/discharge cycles for portable power electronics. An understanding of J-V characteristics is crucial in achieving this objective. Specifically, this paper will explore and investigate nanolaminate, solid-state PPE, and IDE capacitive energy storage “modules” fabricated using nanolithographic techniques. The dielectric layers in these structures are composed of alternating nanolaminate layers of thin higher-k Al${}_2$O${}_3$ and lower-k SiO${}_2$. Recent findings have shown that capacitive energy storage devices made from a large number of these on-chip multilayer nanolaminate energy storage PPE (MNES-PPE) structures that utilize the interfacial anomalies of thin high-k/SiO${}_2$ nanolaminates could have the potential to overcome many of the limitations of current compact energy storage technologies. Preliminary projections indicate that these high-density nanolaminate capacitors with laminate thicknesses around 5 nm could produce devices with high volumetric energy densities ($\sim 290$ J/cm${}^3$) that are significantly higher than conventional supercapacitors ($\sim 20$ J/cm${}^3$). Full article

The comparative study of TiN and VN interaction at mechanical alloying (MA) of the equimolar TiN-VN mixture in a ball mill and after high pressure, high temperature (HPHT) sintering of the cBN-TiN-VN charge, which contains 35 vol.% of this mixture, is presented. MA for five hours or HPHT sintering at 2000–2300 °C results in the formation of Ti_xV_1−xN_y and V_xTi_1−xN_y solid solutions containing 8–10 at.% of vanadium or titanium. Preliminary processing of the initial powder mixture in a ball mill promotes the occurrence of solid-state reactions during HPHT sintering of composites and influences their physical characteristics. Full article

Recycling plant-based materials for various applications not only reduces the harm to the environment but also presents an excellent green source for nanomaterial synthesis. Being chiral and biodegradable makes cellulose, which is an organic polymer, an economic and easy-to-access plant-derived green material. Cellulose can be synthesized into nanostructures for a vast array of high-demand applications, such as drug delivery; biomedicines, which includes “biosensors and diagnostics”; medical implants; skin tissue healing; wastewater treatment; touch screen technology; electronic skin; human–machine interfaces; flexible devices; energy storage devices; clothes; packaging; and cosmetics. The daily newspapers that are delivered to our homes can be one of the best sources of cellulose for us. Our work in this study concentrated on removing nanocrystalline cellulose from newspapers. To begin, we deinked the newspapers and then the deinked pulp was transformed into its nanostructures, or nanocrystalline cellulose, to achieve a high aspect ratio, on the one hand, using chemicals like NaOH, thiourea, etc., and on the other side, via a mechanical process. We used a variety of characterization techniques, including scanning electron microscopy to study morphological properties, X-ray diffraction, and dynamic light scattering for dimensional analysis, Fourier transforms infrared spectroscopy for thermogravimetric analysis, and others, to confirm that the synthesized materials had achieved the intended outcomes. A high aspect ratio enables us to create surfaces with a huge surface area with very little synthetic material. The final product, which was created by synthesis, has been discovered to have features that are identical to those of nanocrystalline cellulose, which is available for purchase in the market for use in laboratory purposes. To make nanocomposites, this nanocrystalline cellulose can be combined with various organic and inorganic polymers, which can be further used as a base material for energy storage devices. In this paper, we compared our materials at different time durations used in synthesis. Full article

We have developed a breakthrough strategy for predictive physicochemical performance improvement and unlocking new functionalities of additively manufactured extreme lattice metamaterials. This strategy is being implemented via predictive fine-tuning nanoscale interlayer vibrational interactions among the transition domains of nanocomponents. The developed strategy is founded on the newly discovered collective atomic vibrations phenomenon, which is observed in transition zones of multilayer nanostructures. For the predictive excitation and adjustment of this phenomenon, we propose the incorporation of low-dimensional nanocarbon-based multilayer interfaces into the transition zones of nanocomponents via a multistage technological chain. In particular, this chain includes a combination of a set of techniques: the conversion of all components into the nanoscale; plasma-driven functionalization and assembly with multilayer nano-enhanced interfaces; the initiation of allotropic phase conversions driven by energy; micro- and nanoscale manipulation assisted by surface acoustic waves during ion-assisted pulse plasma processing and functionalizing; pulse plasma doping by atoms of various chemical elements; exciting the oriented self-assembly by using high-frequency electromagnetic fields; the resonant acoustic mixing of all nanocomponents; and growing high-end extreme lattice metamaterial elements through high-precision multi-material additive manufacturing as well as the use of a data-driven nanoscale inverse designing and manufacturing strategy. Full article

Oral drug administration is among the most popular options in terms of patient compliance. The absorption window’s influence enables the majority of commercially available modified-release dosage forms to have the desired physiological impact. In order to achieve the desired activity against the body’s challenges, the formulator must keep the dosage form in the stomach, which is the aim of gastroretentive drug delivery (GRDD). In this process of maintaining the gastrointestinal (GI) tract, influenced by the nature of excipients and driven by the type of formulation to achieve therapeutic goals, a GRDD system is comparable to an improvised CDDS (control drug delivery system) before it reaches the absorption site. The most prevalent kind of preferred modified release system in use is solid oral dosage forms. To achieve the desired release profile, fewer doses are required when using these forms. Each drug candidate has a unique GIT absorption window, so there are many challenges. Solvability characteristics, pH-dependent variables, stability, physiological region, etc. Due to the barriers that have been added to this system, many products have been created. This review article contains nanomaterials used in GRDDS as novel drug delivery, factors affecting, and challenges to formulate nanomaterials, evaluation and advance technology used for application of nanomaterials. Full article

Graphene oxide (GO) has attracted significant attention due to its unique optical properties and tunable surface chemistry, making it an excellent platform for optical sensing applications. Combining GO with metallic nanoparticles allows for the fabrication of highly sensitive surface-enhanced Raman scattering (SERS) substrates for analytical purposes. Here, we report our research on chemical strategies to decorate GO paper with Au nanostars (AuNSs) for the SERS detection of methylene blue, a water pollutant model. Several preparative approaches were employed to evaluate their sensitivity to detect MB molecules, including polyelectrolytes, distinct graphene-based materials, and the deposition method of the AuNSs. Full article

The objective of our work was to study the behavior of glass that is subjected to electronic bombing. In the context of this work, we first studied theoretically the establishment of electrons in a material—in this case, glass. We postponed the penetration of the electrons according to their acceleration and the density of the material, then we established the electric field within the material according to the fluence, thus referring to the conditions enabling the destruction of the material. However, for some materials this breakdown depends on several parameters. In the second step of the study we were interested in the realization of an electron cannon to provide a bundle of focused and energetic electrons; more precisely, we discuss this on basis of the practical design. In this instrument, the electrons are accelerated under high tension. We chose to postpone in this work the thermal current as a function of the tension, and we subsequently discuss the assembly chosen. Full article

One of the most interesting objects in terms of use in biomedicine are hybrid structures based on magnetic nanoparticles (NPs) and NPs of noble metals, which make it possible to simultaneously introduce two types of ligands onto the surface of NPs for their further use for photodynamic cancer therapy (PDT) (a combination of a photosensitizer (PS) for therapy and a fluorophore (FP) for platform detection). The synthesis and research of Fe₃O₄-Au NPs with a “dumbbell” structure as the bifunctional platform for the therapy of oncological diseases was the purpose of this work. Full article

Curcumin, an active ingredient in turmeric, has various biological activities, but its low solubility and limited bioavailability hinder its therapeutic use. To address this, we created dual pH- and thermo-sensitive nanogels (NGs) from poly-N-isopropylacrylamide (PNIPAm) and polyacrylamide (PAAm) [P(NIPAAm-co-AAm) NGs] for delivering curcumin (Cur). We characterized the NGs using various techniques and found them to be biocompatible and low in toxicity. We conducted in vitro experiments to demonstrate the pH- and temperature-sensitive loading and release of Cur by controlling the swelling and deswelling of the NGs. The PNIPAm-co-PAAm copolymer we synthesized showed ~65% Cur loading. The NGs’ zeta potential decreased with increasing pH, and they underwent a phase transition at 40 °C with concentration-dependent properties. Almost 100% of Cur was released from the NGs after four hours at pH 5.5 and 40 °C. Therefore, these newly synthesized NGs have the potential for solid-tumor-targeted therapy by releasing the drug based on physical stimuli such as pH and temperature. Full article

Tungsten oxide (WO₃) and zinc oxide (ZnO) are n-type semiconductors with numerous applications in photocatalysis. The objective of this study was to synthesize and characterize different types of nanostructures (WO₃, WO₃-Mo, TiO₂, and TiO₂-ZnO) for a comparison of hybrid and pure nanostructures to use them as a photoanodes for hydrogen production. With the aim of comparing the properties of both samples, field emission scanning electron microscopy (FE-SEM) and confocal laser-Raman spectroscopy have been employed to study the morphology and composition and crystallinity, respectively. Finally, water splitting tests were conducted to compare the photoelectrochemical properties of the photoanodes. Full article

Considering the snowballing of electronic devices with the widespread usage of miniaturized energy storage gadgets, the need for sustainable, flexible, lightweight, and higher-power-density devices to supplement the global fossil fuel challenges and depletion is gathering attention. In this regard, polymer/ceramics nanocomposites have recently accrued more attention as a promising material for future energy storage technology, which requires a breakdown strength and high dielectric constant. High dielectric constant, which is caused by interface polarization and electric polarization, could be created by the inclusion of conductive hybrid fillers of MXene (V₂C) and ZnO particles into the polymers to form a nanocomposite with improved dielectric constant. Herein, quantum mechanical calculations are employed to investigate the charge distribution and the bonding that exist between the ceramic/ceramic boundary area of V₂C Mxene–ZnO in the polypyrrole matrix. The nonuniform distribution of charges is expected to improve the dielectric response for energy storage applications. In addition, the structure of the ternary nanocomposite can also be improved by the interfacial ionic bonding of the hybrid fillers. Furthermore, to understand the electron migration mechanism, the electron localization function and the density of state of the V₂C–ZnO are studied. Full article

The formation of CaSi₂ films on Si(111) with the molecular-beam epitaxy (MBE) of CaF₂ under fast electron-beam irradiation was investigated. The method of a high-planarity CaSi₂ film synthesis assisted by electron-beam irradiation was developed. We combined two approaches to reduce the film roughness: the post-growth electron irradiation and codeposition of additional Si during CaF₂ growth. The application of the solid-phase epitaxy technique at the initial stage of film growth allowed for us to reduce surface roughness down to 1–2 nm. Full article

The development of bacterial resistance toward existing antibiotics is a universal problem for human and animal health as well as for food security. In an attempt to overcome this problem, nanotechnology has contributed in the form of nanoformulations. However, these are associated with risks and drawbacks including environmental toxicity, cell injury, issues of high production cost and the scarcity of active ingredients. On the other hand, the green synthesis of nanoformulations via biological methods is a simple, innovative, ecofriendly, cost effective and advanced approach for the treatment of lethal infections caused by multidrug-resistant organisms such as staphylococcus aureus. About 30% of humans are asymptomatic carriers of S. aureus in their upper respiratory tract. Clinical diseases caused by S. aureus infections range from mild to severe and may be manifested in the form of pneumonia, osteomyelitis, skin and deep tissue infections. Here, we prepared plant-mediated gold nanoparticles from Camellia sinensis and Cocos nucifera. The green biocompatible nanoparticles were characterized by using UV-Visible spectroscopy (UV-Vis. spectroscopy), X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), dynamic light scattering (DLS) and Fourier transform infrared spectroscopy (FTIR). Moreover, these green gold nanoparticles were investigated for their antimicrobial activity by checking their minimum inhibitory concentrations (MICs). We found that the newly developed bio-nanoparticles showed strong activity against the multidrug-resistant Staphylococcus aureus. Full article

Obtaining the characteristics of the dispersions of synthesized nanoparticles such as concentration and particle size is an important task in the nanotechnology and biomedicine industries and in many other fields. A rapidly developing method for such needs is nanoparticle tracking analysis (NTA). This technique enables the visualization and recording of nanoparticles sized from dozens of nanometers to a couple of micrometers moving under the Brownian motion. The key point of obtaining precise information about a nanodispersion is video processing, which allows for the quick analysis of the sample without damaging it. Samples of polystyrene and gold nanoparticles with different characteristics were dispersed in water and studied using the NTA device. Dynamic light scattering and transmission electron microscopy were used as the reference methods for nanoparticle characterization. This study also represents the main advantages and drawbacks of using the NTA method in the study of nanoparticle samples of various concentration levels. Full article