- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Micro/nanoscale mesoporous Nb2O5 particles: Effect of synthesis conditions and doping with N, C, or S on their properties
摘要： A simple methodology was designed to obtain mesoporous niobium pentoxide (Nb2O5) solids functionalized with nitrogen, carbon, or sulfur. Dopant precursors were urea (N), citric acid (C) and thiourea (S). The doped solids were characterized using IR, Raman and diffuse reflectance UV–Vis spectroscopies, powder X-ray diffraction, adsorption–desorption isotherms, transmission electron and scanning electron microscopies. Depending on the amount of surfactant (cetyltrimethyl ammonium bromide — CTAB) used during synthesis, the solid presented mainly an orthorhombic crystal structure or an amorphous phase (for the sample with 0.25 mol/L CTAB). The adsorption–desorption isotherms of the synthesized solids showed hysteresis loops ( H1 andH4 types) characteristic of mesoporous solids, while transmission electron micrographs showed a disordered structure of pore channels known as ‘‘wormholes’’. There was considerable interaction between the dopant anion (mainly N and S) and the solid surface, generating new surface chemical species that clogged the pores, reducing specific surface and pore volume. The doped mesoporous Nb2O5 materials were polycrystalline, formed by primary monocrystalline particles of nanometric size (10–20 nm). Doping with N, C and S caused an important effect on the absorption of visible light, reducing the band gap energy value to 2.95 eV when doped with N, and to ～2.8 eV with S, relative to that of the undoped sample (3.03 eV). This result is important considering the potential use of mesoporous Nb2O5 materials in photocatalytic processes.
关键词： N, C and S dopants,Synthesis,Nanomaterials,Characterization,Mesoporous Nb2O5
更新于2025-09-10 09:29:36
-
Aptamers Improving Fluorescence Anisotropy and Fluorescence Polarization Assays for Small Molecules
摘要： Nucleic acid affinity probes, such as aptamers, have been combined with fluorescence anisotropy (FA) / fluorescence polarization (FP) technology for the development of a diverse range of assays. Formation of a complex between a small fluorescent molecule and its binding partner usually increases the overall size of the fluorescent molecule and decreases its rate of rotation, resulting in increases in fluorescence anisotropy/polarization. Structure-switching of the fluorescently labeled aptamers arising from target binding can also affect molecular volume, local rotation of the fluorophore, and/or fluorescence lifetime, causing changes in anisotropy/polarization. Incorporation of the unique adsorptive properties of single-stranded nucleic acid aptamers on nanomaterials, hybridization of aptamers with complementary sequences, and the amplifiable ability of nucleic acid aptamers have broadened the applications of fluorescence anisotropy assays and enhanced their sensitivity. This review focuses on aptamer-based fluorescence anisotropy assays for the detection of small molecules, such as therapeutic drugs, environmental contaminants, natural toxins, and metabolites.
关键词： aptamer,adenosine triphosphate (ATP),nanomaterials,anisotropy,cocaine,nucleic acids,toxins,DNAzyme,polarization,aflatoxin B1,ochratoxin A (OTA),tyrosinamide
更新于2025-09-10 09:29:36
-
Large-scale uniform fabrication and morphology control of ultrafine perovskite nanocrystals
摘要： Nanomaterials are playing more and more important roles in modern industry, while the large-scale fabrication and dispersibility still need to be addressed. This report explores the uniform fabrication and morphology control of ultrafine BaTiO3 (BT) nanocrystals using a "TEG-sol" method. By varying the reactant concentration, the obtained product sols, Ba/Ti ratios, structure and morphology of the nanocrystals are investigated. The results reveal that under low concentrations (0.4 - 0.8 mol/L), transparent sols with uniform BT nanocrystals are obtained. Increasing the concentration to higher than 1.0 mol/L, BT precipitates with abnormal large crystals are obtained. Moreover, the Ba/Ti ratio variation further reveals that the surface organics are critical to the control of crystal size and morphology. This investigation is potential to be extended to the synthesis of various perovskite nanocrystals.
关键词： morphology control,Nanomaterials,BaTiO3,TEG-sol method,perovskite nanocrystals
更新于2025-09-10 09:29:36
-
Bandgap Engineered Polypyrrole-Polydopamine Hybrid with Intrinsic Raman and Photoacoustic Imaging Contrasts
摘要： Intrinsically multimodal nanomaterials have revealed their great potential as a new class of contrast agents. We herein report a bandgap engineering strategy to develop an intrinsically Raman-photoacoustic (PA) active probe that is based on semiconducting conjugated polymers. This dual modal probe is prepared by doping a semiconducting conjugated polymer with polydopamine (PDA) through a one-pot reaction. When applied in the polypyrrole (PPy), this strategy can enhance Raman scattering and the PA amplitude of PPy-PDA hybrid by 3.2 and 2.4 times, respectively, so that both signals can be further applied in bioimaging. In the hybrid, such a dual-enhancement effect is achieved by infusing these two macromolecules at the nanoscale to reduce the optical bandgap energy. This work not only introduces a dual modal contrast agent but also provides a new method of manipulating semiconducting polymer’s inherent optical features for bioimaging.
关键词： intrinsically multimodal nanomaterials,semiconducting polymers,polydopamine,intermolecular electron transfer
更新于2025-09-10 09:29:36
-
Carbon Nanomaterials for Bioimaging, Bioanalysis, and Therapy || Carbon Nanomaterials for Photothermal Therapies
摘要： Photothermal cancer therapy, also called photothermal therapy (PTT), uses light‐induced heat to treat cancer cells. PTT has attracted attention owing to its advantages over traditional cancer therapies such as chemotherapy, radiation therapy (RT), and surgery. Thermal therapy was discovered during the nineteenth century when cancer patients were administered living bacteria to cause inflammation and subsequent fever. The use of circulating heated water to treat uterine cervical cancer was also reported during that era. Owing to the rudimentary technology of that age, neither clinical applications nor further studies of thermal therapy were explored. Interest in PTT was revived in the 1980s, and owing to the fast development of optical and nanomaterial technology during recent decades, thermal therapy, particularly PTT has become a fast‐growing field of study.
关键词： Carbon nanomaterials,Theranostics,Nanocomposites,Cancer therapy,Photothermal therapy
更新于2025-09-10 09:29:36
-
Thermophysical properties of methacrylic polymer films with guest-host and side-chain azobenzene
摘要： The methacrylic polymer films containing azobenzenes with different peripheral substituents in the form of side-chain (P) and guest-host (A) systems were thermally investigated. The azo polymers with thicknesses below 1 μm were deposited on glass substrates using spin coating method. Photothermal radiometry (PTR) and scanning thermal microscopy (SThM) were used for determination of thermophysical properties of polymer samples. The topography of studied compounds was examined by atomic force microscopy (AFM). The results showed the influence of peripheral substituents as well as that of the polymer system on the thermophysical properties of studied azo polymers. Thermal diffusivity (α) extracted from PTR measurements is between 5.56 10-8 m2s-1 and 11.3?10-8 m2s-1 for A samples, 2.76 10-8 m2s-1 and 7.62?10-8 m2s-1 for P samples depending on the substituent. Likewise, thermal effusivity (ε) changes from 474 Ws1/2m-2K-1 to 532 Ws1/2m-2K-1 for A, and from 473 Ws1/2m-2K-1 to 564 Ws1/2m-2K-1 for P samples. The volumetric heat capacity (Cv) and in-depth thermal conductivity (κ) were calculated on the base of PTR results. Local κ obtained from SThM measurements is between 0.15 Wm-1K-1 and 0.22 Wm-1K-1 due to different substituents and polymer system. Thermal studies performed in this work provide valuable information for engineers designing azobenzene polymer thin films based devices and supplement the knowledge of their thermal behavior in the system.
关键词： polymer,nanomaterials,thermophysical properties,thin films,azobenzenes
更新于2025-09-09 09:28:46
-
Big Potential From Silicon-Based Porous Nanomaterials: In Field of Energy Storage and Sensors
摘要： Silicon nanoparticles (SiNPs) are the promising materials in the various applications due to their unique properties like large surface area, biocompatibility, stability, excellent optical and electrical properties. Surface, optical and electrical properties are highly dependent on particle size, doping of different materials and so on. Porous structures in silicon nanomaterials not only improve the specific surface area, adsorption, and photoluminescence efficiency but also provide numbers of voids as well as the high surface to volume ratio and enhance the adsorption ability. In this review, we focus on the significance of porous silicon/mesoporous silicon nanoparticles (pSiNPs/mSiNPs) in the applications of energy storage, sensors and bioscience. Silicon as anode material in the lithium-ion batteries (LIBs) faces a huge change in volume during charging/discharging which leads to cracking, electrical contact loss and unstable solid electrolyte interphase. To overcome challenges of Si anode in the LIBs, mSiNPs are the promising candidates with different structures and coating of different materials to enhance electrochemical properties. On the basis of optical properties with tunable wavelength, pSiNPs are catching good results in biosensors and gas sensors. The mSiNPs with different structures and modified surfaces are playing an important role in the detection of biomarkers, drug delivery and diagnosis of cancer and tumors.
关键词： lithium ion battery,silicon nanomaterials,bioapplication,porous structures,core shell
更新于2025-09-09 09:28:46
-
Experimental study on microcapsules of Ag doped ZnO nanomaterials enhanced Oleic-Myristic acid eutectic PCM for thermal energy storage
摘要： Novel microcapsules of Ag doped ZnO nanomaterials enhanced Oleic-Myristic acid eutectic phase change materials (PCMs) were synthesized by in-situ polymerization process. X-ray diffraction analysis reveals that Ag doped ZnO nanomaterials has a hexagonal wurtzite structure. Nano enhanced composite PCMs are prepared by mixing different weight percentage of nanomaterials with Oleic-Myristic acid eutectic mixture act as core material. Microscopic analysis reveals the formation of uniform spherical structure of Melamine-Formaldehyde shell over the core material with a perfect core-shell structure. Differential scanning calorimetric analysis showed that microencapsulated PCMs (MEPCMs) melts and freezes in the range of 4.37-5.81 °C and 10.84-11.86 °C with the latent heat of 75.39-79.35 J/g and 74.9-77.95 J/g. MEPCMs have better thermal conductivity, stability and reliability determined by thermal conductivity, thermogravimetric and thermal cycling analysis. Based on the results, MEPCMs with Ag doped ZnO nanomaterials could be suggested as the potential core material for low temperature thermal energy storage applications.
关键词： Thermal stability,Ag doped ZnO nanomaterials,Thermal energy storage,Eutectic mixture,Microcapsules
更新于2025-09-09 09:28:46
-
Nanoscale Materials in Water Purification || Photocatalysis of Graphene and Carbon Nitride-Based Functional Carbon Quantum Dots
摘要： Day by day, global energy demands increase due to the rapid consumption of depleting fossil fuels and environmental pollution. This has led to the search for materials capable of both energy conversion and elimination of environmental pollutants through the aid of renewable solar energy. This is a promising approach for meeting future energy requirements and eliminating environmental pollutants. In this pursuit, semiconductor photocatalysts have immense potential for solving both energy and environmental issues. To date, numerous semiconductor materials have been explored, including those of metal oxides, chalcogenides, borates, titanates, tungstates, vanadates, zirconates, oxyhalides, and metal-based interstitial compounds. However, the majority of these suffer from limitations such as complex synthesis procedures, limited light absorption range due to their wide band gap, high cost, and toxicity-related issues. Over the past decade, carbon-based nanomaterials have gained attention in the field of photocatalysis. Many recent articles have placed emphasis upon metal-free carbon-based photocatalytic systems for degradation of organic pollutants and hydrogen production from water splitting. The prime merit of these nanomaterials is that they originate from naturally abundant constituent elements such as carbon, nitrogen, and oxygen, making them more economical than their metal-based counterparts. Most reported carbon-based photocatalysts have tunable band gap energies, enhancing their optical absorption range. Band gap energy can be tuned by varying synthesis conditions and precursors, resulting in the formation of nanomaterials with different morphologies. The preparation procedures for most carbon-based nanomaterials are less complex than those of metal-based materials.
关键词： water splitting,energy conversion,semiconductor photocatalysts,graphene,carbon nitride,quantum dots,carbon-based nanomaterials,hydrogen production,solar energy,environmental pollutants,photocatalysis
更新于2025-09-09 09:28:46
-
Green and Efficient Production of Boron Nitride Nanosheets via Oxygen Doping-Facilitated Liquid Exfoliation
摘要： As the structural analogue of graphene, boron nitride nanosheets (BNNSs) are anticipated to have a wide range of potential applications. BNNSs exhibit good mechanical properties, outstanding thermal conductivity, oxidation and chemical stability and are excellent electrical insulators. While BNNSs have gained recognition as one of the most versatile 2D materials in recent years, their application in research and industry is still hampered by the lack of methods to produce BNNSs in large quantity and a cost-effective way. In this study, we report highly efficient h-BN exfoliation via the oxygen doping-facilitated liquid exfoliation. Oxygen atoms are introduced into the hexagonal boron nitride (h-BN) structure via a facile thermal treatment. The relationship of thermal treatment, structural changes and h-BN exfoliation are studied to elucidate the key factor for advancing the BNNS production. The optimum concentration of hydroxyl groups and weakening of interlayer interactions have synergistically facilitated the delamination of h-BN in water under mild exfoliation conditions, resulting in up to 1255% yield increment and without noticeable new defects in the BNNS structure as compared with the untreated control. An efficient and environmentally friendly exfoliation process of h-BN is a crucial starting point towards the cost-effective and mass production of BNNSs which is needed for the currently identified and myriad future applications of BNNSs.
关键词： oxygen-doping,nanoplatelets,boron nitride nanosheets,2D nanomaterials
更新于2025-09-09 09:28:46