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Dose-dependent enhancement of bioactivity by surface ZnO nanostructures on acid-etched pure titanium
摘要： Zinc (Zn) is found to be essential in biologic osseous functions, and deficiency of Zn may cause delayed skeletal growth and osteoporosis. Additionally, Zn-based coatings are reported to be effective to promote the bioactivity of implants. In this study, we employed the hydrothermal treatment to incorporate Zn into the surface of acid-etched pure Ti. The process was conducted in ammonia solution with an increased Zn precursor concentration (0.0002 M, 0.002 M and 0.02 M, respectively). XPS analysis demonstrated that the nanostructures were composed of ZnO. Proliferation and alkaline phosphatase (ALP) activity of osteoblast-like SaOS-2 cells were enhanced dose-dependently, compared to those on the acid-etched pure Ti without ZnO nanostructures. This study addresses a favourable surface modification method to improve the bioactivity of implants.
关键词： nanostructure,titanium,bone regeneration,hydrothermal treatment,ZnO
更新于2025-09-23 15:23:52
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Fabrication and photoluminescent properties of Tb3+ doped carbon nanodots
摘要： Carbon nanodots (CNDs) doped with Tb ions were synthesized using different synthetic routes: hydrothermal treatment of a solution containing carbon source (sodium dextran sulfate) and TbCl3; mixing of CNDs and TbCl3 solutions; freezing-induced loading of Tb and carbon-containing source into pores of CaCO3 microparticles followed by hydrothermal treatment. Binding of Tb ions to CNDs (Tb-CND coupling) was confirmed using size-exclusion chromatography and manifested itself through a decrease of the Tb photoluminescence lifetime signal. The shortest Tb photoluminescence lifetime was observed for samples obtained by hydrothermal synthesis of CaCO3 microparticles where Tb and carbon source were loaded into pores via the freezing-induced process. The same system displays an increase of Tb photoluminescence via energy transfer with excitation at 320–340 nm. Based on the obtained results, freezing-induced loading of cations into CNDs using porous CaCO3 microparticles as reactors is proposed to be a versatile route for the introduction of active components into CNDs. The obtained CNDs with long-lived emission may be used for time-resolved imaging and visualization in living biological samples where time-resolved and long-lived luminescence microscopy is required.
关键词： freezing-induced loading,Tb3+ doping,photoluminescence,hydrothermal treatment,Carbon nanodots,CaCO3 microparticles
更新于2025-09-23 15:21:01
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Fluorescent emission from a natural carbon matrix incorporating sodium
摘要： The process of functionalization of metals in natural carbon matrices has become an important area of research due to its improved properties and applications. Carbon materials possessing photoluminescence (PL) properties find a wide range of applications in photonics. Among the various carbon materials available in nature, cellulose has critical importance since it is the most abundant and wide-spread biopolymer on Earth, and also, the important component in plants’ skeleton. In the present work, the functionalized carbonaceous material is prepared by the hydrothermal treatment of natural cellulosic source Aloe Vera and the metallic element sodium is properly incorporated into it by adding sodium borohydride to observe the fluorescence emission changes. The incorporation of metal ions in the carbon matrix leads to structural modifications and properties as evidenced by field emission scanning electron microscopy, Energy dispersive spectroscopy, X-ray dot mapping, X-ray Photoelectron spectroscopy, and X-ray diffraction analysis. The optical emission characteristics are studied using Photoluminescence spectroscopy, CIE plot, power spectrum, color purity, and quantum yield. The excitation wavelength dependent photoluminescence emission mechanism shown by the carbon–metal incorporated products obtained from the cellulosic raw materials makes them suitable for biomedical and biosensing applications because of the non-toxic and eco-friendly nature.
关键词： Photoluminescence,Hydrothermal treatment,Sodium incorporation,Carbon matrix,Aloe Vera
更新于2025-09-23 15:21:01
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Formation of carbon quantum dots and graphene nanosheets from different abundant carbonaceous materials
摘要： Carbon quantum dots (CQDs) and graphene nanosheets (GNs) are one of the most attractive fluorescent carbon nano-sized materials with unique features of optical and physico-chemical properties having various applications in chemical sensing, biomedicine, semiconductor devices, photo-catalyzing, and electrocatalysis. The primary purpose of this preliminary work is the feasibility study for synthesis of nano-structured value-added carbon products i.e., CQDs and GNs from cheap and abundant carbon sources, such as coal, petroleum coke, graphite, and coal-based humic acid by hydrothermal techniques. The physico-chemical properties of the raw precursors were evaluated by proximate and ultimate analysis. High resolution-transmission electron microscopy (HR-TEM), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), Fourier transforms infrared (FT-IR) spectroscopy, X-ray powder diffractometer (XRD), UV-visible (UV-vis), and fluorescence (FL) spectrophotometer were used to achieve physico-chemical parameters of carbon nanostructures, to better comprehend the development of carbon quantum dots and graphene nanosheets. HR-TEM analysis indicates that the dimensions of the synthesized CQDs from different carbon sources exist in the range of 3-6.5 nm. The approximate quantum yields (QY) of the synthesized carbon nanomaterials were found to be about 2-22%. The synthesised carbon based nanomaterials (i.e. CQDs and GNs) have been efficiently used in the photo-degradation of harmful 2-nitrophenols (2-NP) with the efficiency of 80.79% for CQDs and 82.53% for GNs, respectively. The present study provides a simple and environmentally-sound technique for large-scale fabrication of typical CQDs and GNs from abundantly available low-grade coal and other carbonaceous materials for photo-catalysis application.
关键词： Carbon Dots,Photocatalytic degradation,Carbonaceous materials,Graphene nanosheet,Hydrothermal treatment,Fluorescent materials
更新于2025-09-23 15:19:57
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Blue luminescence carbon quantum dots derived from oil palm empty fruit bunch biomass
摘要： Carbon quantum dots (CQDs) have attracted tremendous attention for their interesting properties such as excellent chemical and photo stability, good water dispersibility, biocompatibility and possessing outstanding photoluminescence (PL) properties. In this study, oil palm biomass is used as the carbon precursor to produce CQDs and exhibit high luminescent properties. However, a large amount of biomass produces by the oil palm industry is either burnt in the open air or disposed in waste ponds and contributes to global climate change via emissions of carbon dioxide and methane. Hence, synthesis the CQDs from oil palm biomass by hydrothermal treatment method has formed excellent properties in optical properties that could be comparable to semiconductor quantum dots. The results have shown the diameter size of CQDs in the range of 2-5 nm. While, the optical properties, UV-vis spectrum of CQDs have given a strong absorption at 282 nm and obtains in brown color under visible light and emitting blue luminescence under 365 nm of UV lamp. Furthermore, PL spectra of CQDs have shown excitation and emission wavelength at 360 nm and 450 nm, respectively. This is attribute to the excitation-wavelength dependent of PL properties. Hence, the spectra from FTIR showed the existence of hydroxyl and carboxyl groups on the CQDs would have originated from lignocellulosic materials, thus resulted in excellent water stability and solubility properties of CQDs. The presented study is the green approached reprocessed biomass from waste to materials with excellent optical properties that could utilize in various field of applications.
关键词： hydrothermal treatment,photoluminescence,optical properties,Carbon quantum dots,oil palm biomass
更新于2025-09-23 15:19:57
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Synthesis of carbon quantum dots in a Nafion matrix: Precursor effect on the ion transport properties
摘要： Carbon quantum dots have been prepared in a Nafion? matrix via the hydrothermal treatment of organic precursors, and the swelling and ion transport properties of the prepared composite materials have been characterized.
关键词： Nafion matrix,ion transport properties,carbon quantum dots,hydrothermal treatment
更新于2025-09-16 10:30:52
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AIP Conference Proceedings [Author(s) 6TH INTERNATIONAL CONFERENCE ON PRODUCTION, ENERGY AND RELIABILITY 2018: World Engineering Science & Technology Congress (ESTCON) - Kuala Lumpur, Malaysia (13–14 August 2018)] - Investigation of optical and electrical properties of nitrogen- and boron-doped carbon dots films
摘要： The optical properties of two types of carbon dots (CDs) doped by nitrogen and boron atoms and the electrical properties of ?lms from the obtained CDs in a polyvinyl alcohol (PVA) matrix were investigated. Synthesis of CDs was carried out using the hydrothermal treatment method. The resulting CDs have a crystalline structure with functional groups on the edges and surface (lateral sizes of CDs is vary in the range of ～7 ?28 nm). The thin ?lms from aqueous suspensions of CDs were obtained by the spin-coating method inside an electrically inert polymer matrix of PVA. The current-voltage characteristics of this obtained ?lms were measured.
关键词： optical properties,polyvinyl alcohol matrix,current-voltage characteristics,carbon dots,electrical properties,spin-coating method,hydrothermal treatment,nitrogen-doped,boron-doped
更新于2025-09-09 09:28:46
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Effect of Different Anions Upon the WO <sub/>3</sub> Morphology and Structure
摘要： In this study the effects of various anions (SO2? 4 , ClO? 4 and PO3? 4 ) were investigated on the hydrothermal treatment of WO3 from Na2WO4 and HCl at 180 and 200 °C. The products were analyzed by XRD and SEM. With the usage of SO2? 4 the obtained product was hexagonal (h-) WO3 in the form of nanorods at both temperatures. Applying ClO? 4 resulted in a mixture of WO3 · 0.33H2O and small amount of m-WO3 at 180 °C and pure WO3 · 0.33H2O at 200 °C. The morphology was consisted of cuboid shapes arranged into spherical structures at 180 °C and longitudinal ones at 200 °C. By the application of PO3? 4 no product formed at either temperature. Using the combination of SO2? 4 and ClO? 4 the product was h-WO3 at both 180 and 200 °C with rod-like crystals; thus, the effect of ClO? 4 was overdominated by the SO2? 4 ions. Utilization of PO3? 4 together with SO2? 4 , and/or ClO? 4 to the reaction mixture completely blocks the hydrothermal formation of solid products by forming water soluble phosphotungstic acids.
关键词： PO3? 4,Hydrothermal Treatment,SO2? 4,ClO? 4,Structure,Morphology,Tungsten Oxides
更新于2025-09-09 09:28:46
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AIP Conference Proceedings [Author(s) 6TH INTERNATIONAL CONFERENCE ON PRODUCTION, ENERGY AND RELIABILITY 2018: World Engineering Science & Technology Congress (ESTCON) - Kuala Lumpur, Malaysia (13–14 August 2018)] - Synthesis of carbon dots and their optical properties
摘要： In this paper, carbon dots were synthesized from glucose, soot and ethylene glycol by hydrothermal treatment. The resulting carbon dots were characterized by luminescent spectrometry and spectrophotometry. The spectra exhibit bright luminescence in the blue region and strong absorption in the ultraviolet region. All samples exhibit typical excitation wavelength-dependent properties.
关键词： optical properties,hydrothermal treatment,luminescence,absorption,carbon dots
更新于2025-09-09 09:28:46