Nano-Structures & Nano-Objects最新文献

In recent years, hydrogels based on acrylic acid and acrylamide have been widely used for easy polymerization and biocompatibility. On the other hand, due to energy saving and high reaction speed, curing systems with ultraviolet radiation have been expanded, which are considered in this study for synthesizing hydrogels and the flexible agent of the hydrogel network. The strength and stability of hydrogels are among the problems that are considered in their construction, and the strength of the network against solvent absorption leads to their many uses. In this study, the use of urethane acrylate as a flexible network agent has been used in the construction of a UV-curable hydrogel. For this purpose, at first, urethane acrylate with polyethylene glycol, isophorone diisocyanate, and hydroxyethyl methacrylate was synthesized and, after characterization, used in the hydrogel structure. The hydrogels were synthesized using an equal ratio of acrylamide and acrylic acid, various percentages of nano-chitosan (3, 6, 9, and 11), photo-initiator, and water under ultraviolet radiation. The accuracy of the hydrogel chemical structure was confirmed by FTIR analysis. The swelling ability and fluidity behavior of prepared hydrogels were investigated by weight measurement test and rheometry. According to the rheological test results and swelling capability, the sample containing 6 % w/w nano-chitosan was selected as the optimum sample. Then, the effect of urethane acrylate with different amounts of 10, 20, and 30 % on the swelling ability and elasticity behavior of hydrogels was studied. The results showed that hydrogel containing 10 % by weight of urethane acrylate had a four-fold equilibrium swelling with preservation of the network's structure.

Hydrogen is seen as a very promising, environmentally friendly, and sustainable energy carrier, presenting an appealing substitute for fossil fuels. Photocatalysis, derived hydrogen from water splitting, is often regarded as the most effective method for meeting long-term sustainability goals and satisfying growing energy needs. This article provides a concise overview of the process by which hydrogen is produced by water splitting, using various MOFs and MOF on MOF photocatalysts. MOFs are a very promising category of porous crystalline materials that exhibit a wide range of uses. The extensive investigation of MOFs has resulted in the development of MOF on MOF hybrid materials. This study also elucidates the synthetic approaches that explain the interaction between the host and guest MOFs. Next, the text delves into a comprehensive analysis of the structural variety to showcase how MOF on MOF hybrids facilitates progress in photocatalytic applications. Despite their potential, MOFs still face several constraints that need to be addressed. This work emphasizes the main obstacles in the area of water splitting and suggests the potential use of photocatalysts for this purpose. The extensive surface area of MOF on MOF hybrids also amplifies hydrogen generation during photocatalysis, assisted by effective separation and transmission of electron holes. These photocatalysts generate environmentally friendly hydrogen from water, promoting global progress without causing damage to the environment and perhaps contributing to the development of renewable energy sources. The review concludes by examining possible avenues for future research in the field of photocatalysis for the production of sustainable hydrogen as an energy source.

Chitin and chitosan have been proven to have numerous applications in biomedical, pharmaceutical, and industrial fields. In the present study, chitin structural polymer was extracted from potato peel wastes by the use of chemical methods and chitosan biopolymer was generated through the deacetylation of the isolated potato peel chitin. On a dry weight basis, the yield of chitin content of the potato peel wastes is 49.80±1.2 % and the yield of deacetylated potato peel chitin (potato peel chitosan) is 47.60±1.8 %. It was characterized by FTIR and ¹H NMR studies. Consequently, the potato peel chitosan was employed in the synthesis of Chitosan-Silver-Nanocomposite-Sphere (Chi-SNC-Sphere), and other metal nanocomposite of silver (C.g-CSNCs), gold (C.g-CGNCs), and bimetallic (C.g-CS@GNCs). The physicochemical features of the resulting products were characterized using UV-Vis, FT-IR, PXRD, FESEM, TEM, and EDAX. The FESEM unveiled a smooth, spherical, and nonporous surface morphology of the synthesized Chi-SNCs-Sphere, while the remaining three have surfaces that appeared in the form of flakes. As per TEM images, particles were visible in black-spherical (C.g-CSNC) and black-multi-shapes (C.g-CSNC, C.g-CS@GNC) nanostructures. Their sizes were confined within the range of 1–10 nm, with average values of 4.36 nm±0.40–5.85 nm±0.42. On the basis of BET analysis, C.g.CSNCs C.g-CS@GNC and C.g.CGNCs under identical conditions possess the surface area of 69.92 m²g^−1, 52.35 m²g⁻¹, and 49.75 m²g⁻¹ respectively. The nanomaterials were found stable as revealed by the study of zeta potential which is found in the range of +41.3–56.2. The results of the bioassay for antibacterial activity against P. aeruginosa and S. aureus uncovered that the Chi-SNCs-Sphere, C.g-CSNCs, and C.g-CS@GNCs demonstrated superior activities than C.g-CGNCs. According to statistical analysis results of one-way ANOVA of antibacterial results against S. aureus, the P-value F- calculated F-critical was 0.99,1.5 and 3.4 and for P. aeruginosa; P-value, F-calculated, F-critical was 0.80, 0.22 and 5.94 respectively. Minimum inhibitory concentration (MIC) was found most significant for C.g-CSNC (20 µg/mL) due to its higher surface area. These activities could be attributed to the synergistic effect of the metal nanoparticles, potato peel chitosan, and the plant extract that was used for the reduction, stabilization, and biofunctionalization.

Flexible Supercapacitors (SCs) are emerging as sustainable solution to meet the growing demand of robust energy storage systems for intelligent wearable electronic gadgets (IWEGs) because of their benefits, which include high power density and quick charging/discharging. Choice of materials for the fabrication of flexible supercapacitors requires a critical understanding of material properties, mechanism of charge storage, and fabrication techniques. MXenes-a promising family of two-dimensional (2D) materials is emerging as an excellent choice for fabricating flexible electrodes for supercapacitor due to their outstanding hydrophilicity, high surface area, and high conductivity. This review unlocks the potential of this intriguing material as conductive electrodes for flexible supercapacitors. New developments in the use of MXenes and their composites, to create flexible electrodes has been discovered. This review also sheds light on material choices of electrolytes, flexible substrates, and current collectors. A critical understanding of energy storage mechanism with respect to types of ions has also been elaborated. Finally, the advances in some wearable electronic devices based on MXene flexible supercapacitors are discussed. This review highlights the potential of MXenes to offer effective and adaptable energy storage solutions that can completely transform wearable electronics.

The biggest waste stream in the oil and gas sector is produced water. It is made up of both organic and inorganic wastes, both of which, if untreated, are extremely harmful to the environment. This study aims to use Fe-based nanoparticles in an attempt to detoxify produced water. Fe nanoparticles were prepared using green synthesis approach, and their stability was increased by piperazine immobilisation in a chlorinated environment. Experiments on detoxification were carried out under various circumstances in order to determine the effectiveness of detoxification. Variations in the feasible detoxification parameters, including the, the amount of Green Fe nanoparticles immobilised by piperazine, the pH of the reaction medium, the duration of the detoxification process were found to improve the detoxification efficiency. Using Ultra-violet visual ray spectroscopy and Fourier Transform Infrared Spectroscopy, the properties of the prepared Fe naoparticles were analyzed. Chemical and microstructural properties of the nanoparticles were studied using X-Ray Diffraction Spectroscopy, X-ray photoelectron spectroscopy (XPS), Field Emission-Scanning Electron Microscopy and Transmission Electron Microscopy. Detoxification experiments conducted in photocatalytic environment exhibited detoxification efficiency as high as 89.3 %.

In this present study, a facile, sustainable, eco-friendly, and low-cost material was developed using synthesized graphene-oxide (SGO) incorporated with zinc oxide (SGO/ZnO) and its adsorptive performance was compared with commercial graphene oxide (CGO) and synthesized graphene-oxide (SGO) for the removal of fluoride ion from aqueous environment. The materials were characterized using techniques such as Fourier transform spectroscopy (FTIR), Scanning electron microscopy coupled with energy dispersive X-Ray spectroscopy (SEM-EDX), X-ray diffraction (XRD), Zeta potentiometer, Brunauer–Emmett–Teller (BET) measurement, Transmission Electron Microscopy (TEM). The SEM analysis confirmed the existence of a spherical structure, smooth and agglomerated white particle in between the wrinkled GO sheet, demonstrating a successful synthesis of SGO/ZnO composite. The EDX analysis revealed the presence of carbon, zinc, and oxygen with no impurities. The successful incorporation of ZnO on SGO yielded a BET surface of 123 m²/g for SGO/ZnO, which is far greater than that of the separate SGO and ZnO with surface areas of 19 m²/g and 76 m²/g respectively. The batch studies revealed that the removal of fluoride ion by CGO, SGO, and SGO/ZnO was 89.4 %, 94.8 %, and 99.2 %. Also, the jovanovic isotherm model fitted well to the fluoride ion adsorption onto CGO, SGO, and SGO/ZnO suggesting a monolayer adsorption with mechanical contact possibility. The estimated adsorption capacities (Q_max) were 105.64, 116.37, and 188.60 mg/g for CGO, SGO, and SGO/ZnO, respectively. In addition, the adsorption kinetics study showed that the pseudo-second-order kinetic model suits the adsorption model, indicating the presence of an ionic interaction between the adsorbent functional groups and the fluoride ion. The adsorption thermodynamic analysis indicates that the adsorption process was spontaneous, endothermic, with strong affinity between the adsorbate and adsorbents. Furthermore, the regenerability and reusability analysis showed that about 39.5 %, 49.9 %, and 70.6 % of fluoride ion on CGO, SGO, and SGO/ZnO was removed after fifth desorption-adsorption cycles, suggesting that the SGO/ZnO was more stable. The interaction mechanism between SGO/ZnO and fluoride ion was governed primarily by pore-filling, hydrogen bonding, electrostatic attraction, and physical adsorption.

In line with the UN Sustainable Development Goals 3 and 12 which are focused on good health and sustainable production respectively, we report the green synthesis of silver nanoparticles using Beauveria bassiana extracts and their role as active nanocosmeceutical ingredients. In this study, optimal conditions for B. bassiana-mediated nanoparticle (BbAgNP) synthesis were evaluated, and the functional properties of the materials were characterised via UV-Vis, Fourier transform infrared spectroscopy, Particle size analyser, Electron microscopy, Thermogravimetric analysis, Differential scanning calorimetry, etc. Subsequently, the antioxidant (DPPH assay), antimicrobial activities (broth microdilution method) as well as toxicity (brine shrimp lethality) were investigated. Furthermore, the effect of BbAgNPs on the sun protection and stability of cosmetic formulation was also studied. Results indicate that the highest efficiency of BbAgNP synthesis was achieved with the extracellular extract at pH 10.0, 60°C and 3 h. BbAgNP was also recorded to have an average size of 41 nm, zeta potential of −23.2 ±1.1 mV and face-centred crystalline structure. Furthermore, thermal analysis showed that it was stable between 25°C and 100°C. Similarly, BbAgNP was recorded to have an IC₅₀ of 400.22 μg/mL against DPPH radicals, remarkable broad antimicrobial spectrum (Gram -positive, Gram-negative bacteria, and yeasts), low toxicity on brine shrimps and low photocatalytic activity. The addition of BbAgNP to the cream formulation was observed to increase the sun protection ability of the cream by 2.6-fold without any detrimental effect on its short-term stability. These findings support the potential of fungi-mediated nanoparticles as valuable ingredients in the cosmeceutical industries.

The altered riboflavin (RF) level is considered a biomarker for early diagnosis of human ailments and also serves as an internal marker for tracing food quality and adulteration. This necessitates the need for a sensitive, selective, and affordable method for RF estimation in real samples. RF, a biological chelating ligand, is known to have an affinity for complex formation with Cu(II) by coordinating through the electron-rich nitrogen and oxygen atoms on its structure. Motivated by this, CuO nanoflakes grown over graphitic carbon nitride (gCN) support is presented as an electroactive interface (gCN.CuNF|GCE) for electrochemical RF detection. A systematic analysis of the tailored electroactive interface is presented using HR-SEM, XRD, FT-IR, and XPS. The electrochemical analysis reveals the electro-oxidation of RF at gCN.CuNF|GCE with a 4.6 times higher current and a ∼13 mV potential shift, outlining the electro-catalytic activity of the composite material towards RF. The developed sensor exhibited a discernible peak even for 25 nM RF, showcasing an LOD of 6 nM. Furthermore, excellent selectivity for RF was observed even with potential interfering species, including cyanocobalamin. Besides detectability at the nanomolar range, excellent performance was verified for repeatability and RF analysis in food and pharmaceutical samples.

This study aims to develop fly ash (FA) modified with melamine (M) and polyacrylic acid (PAA) for strong adsorption of Sudan II dye from aquatic media. Surface functionality and morphological characteristics of the prepared FA/PAA/M composite were characterized using Fourier transform infrared (FTIR) and scanning electron microscopy (SEM) techniques. A factorial design model was applied to estimate the influence of adsorption and interactions of adsorption parameters such as contact time, pH, adsorbent dose, and initial dye solution. The significant interactions among these factors were investigated by analysis of variance (ANOVA). The isotherm modeling data indicated the Langmuir adsorption capacity for raw FA and FA/PAA/M composite as 57.4 and 142.3 mg/ g, respectively. This means that the Sudan II dye adsorption capacity of FA was boosted more than one time after modification with PAA/M polymer due to increased affinity towards the dye molecules by amide and hydroxyl groups onto the surface of the composite adsorbent. The adsorption kinetic evaluation revealed that the Sudan II dye adsorption by the composite was well-defined by the pseudo-second-order model. The produced FA/PAA/M showed a reasonable regeneration performance of 72/66 % after the adsorption/desorption processes were repeated four times. The adsorption mechanism between dye molecules and surface functional groups of the composite was described by hydrogen bonding interactions, π- π interactions, metal-π interaction and electrostatic attractions. The results indicated that the composite could be a promising adsorbent for dye removal from industrial wastewater due to its strong adsorption capacity, easy preparation, and good reusability performance.

Graphene oxide (GO) is a unique and versatile material derived from graphene, which is a single layer of carbon atoms arranged in a hexagonal lattice. Functionalized graphene oxide refers to GO that has undergone further chemical modifications by attaching specific functional groups or molecules to its surface. This process imparts exceptional optical, electronic, thermal, magnetic, and mechanical characteristics, in addition to a substantial specific surface area and various functionalities to the material broadening its scope for potential applications. With an eye on the evolving demands of future materials, this review comprehensively outlines the synthesis of GO through diverse techniques, encompassing mechanical, chemical, and electrochemical exfoliation along with reduced GO and chemical vapour deposition approaches. Additionally, we delve into the synthesis of GO functionalized (fGO) with diverse functional groups using various methods, including chemical and covalent modification; addition, cycloaddition, electrophilic, nucleophilic and esterification; and condensation. fGO finds applications in diverse areas, all of which are explored in this work, including energy storage, sensors, catalysis, drug delivery, nanocomposites, biosensors, and environmental remediation. These findings undoubtedly pave the path for the creation of innovative synthetic nanocomposites through surface modification, expanding their potential for versatile applications.