scholarly journals Facile and Scalable Synthesis and Self-Assembly of Chitosan Tartaric Sodium

Polymers ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 69
Author(s):  
Sixuan Wei ◽  
Rujie Peng ◽  
Shilong Bian ◽  
Wei Han ◽  
Biao Xiao ◽  
...  
Keyword(s):  
Self Assembly ◽  
Optical Microscope ◽  
Solvent Evaporation ◽  
Resonance Spectroscopy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Evaporation Temperature ◽  
Transmission Electron ◽  
Naoh Solution ◽  
Scalable Synthesis

Chitosan-based nanostructures have been widely applied in biomineralization and biosensors owing to its polycationic properties. The creation of chitosan nanostructures with controllable morphology is highly desirable, but has met with limited success yet. Here, we report that nanostructured chitosan tartaric sodium (CS-TA-Na) is simply synthesized in large amounts from chitosan tartaric ester (CS-TA) hydrolyzed by NaOH solution, while the CS-TA is obtained by dehydration-caused crystallization. The structures and self-assembly properties of CS-TA-Na are carefully characterized by Fourier-transform infrared spectroscopy (FTIR), nuclear magnetic resonance spectroscopy (1H-NMR), X-ray diffraction (XRD), differential scanning calorimeter (DSC), transmission electron microscopy (TEM), a scanning electron microscope (SEM) and a polarizing optical microscope (POM). As a result, the acquired nanostructured CS-TA-Na, which is dispersed in an aqueous solution 20–50 nm in length and 10–15 nm in width, shows both the features of carboxyl and amino functional groups. Moreover, morphology regulation of the CS-TA-Na nanostructures can be easily achieved by adjusting the solvent evaporation temperature. When the evaporation temperature is increased from 4 °C to 60 °C, CS-TA-Na nanorods and nanosheets are obtained on the substrates, respectively. As far as we know, this is the first report on using a simple solvent evaporation method to prepare CS-TA-Na nanocrystals with controllable morphologies.

scholarly journals Low-temperature hydrothermal synthesis of hierarchical flower-like CuB2O4 superstructures

2020 ◽  
Vol 14 (2) ◽  
pp. 113-118
Author(s):  
Daniel Ursu ◽  
Anamaria Dabici ◽  
Marinela Miclau ◽  
Nicolae Miclau
Keyword(s):  
Thermal Stability ◽  
Low Temperature ◽  
Self Assembly ◽  
Hydrothermal Solution ◽  
Optical Measurements ◽  
Oriented Attachment ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
One Step

We report for the first time the fabrication of hierarchical ordered superstructure CuB2O4 with flower-like morphology via a one-step, low temperature hydrothermal method. The tetragonal structure of CuB2O4 was determined by X-ray diffraction and high-resolution transmission electron microscopy. Optical measurements attested of the quality of the fabricated CuB2O4 and high temperature X-ray diffraction confirmed its thermal stability up to 600 ?C. The oriented attachment growth and the hierarchical self-assembly of micrometer-sized platelets producing hierarchical superstructures with flower-like morphology are designed by pH of the hydrothermal solution. The excellent band gap, high thermal stability and hierarchical structure of the CuB2O4 are promising for the photovoltaic and photocatalytic applications.

scholarly journals Structural Characterization of Graphene Oxide: Surface Functional Groups and Fractionated Oxidative Debris

Nanomaterials ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 1180 ◽  
Author(s):  
Elvin Aliyev ◽  
Volkan Filiz ◽  
Muntazim M. Khan ◽  
Young Joo Lee ◽  
Clarissa Abetz ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Graphene Oxide ◽  
Functional Groups ◽  
Structural Model ◽  
Oxide Surface ◽  
Resonance Spectroscopy ◽  
X Ray Diffraction ◽  
Surface Functional Groups ◽  
X Ray ◽  
Transmission Electron

The purpose of this work is the structural analysis of graphene oxide (GO) and by means of a new structural model to answer the questions arising from the Lerf–Klinowski and the Lee structural models. Surface functional groups of GO layers and the oxidative debris (OD) stacked on them were investigated after OD was extracted. Analysis was performed successfully using Fourier transform infrared spectroscopy (FTIR), ultraviolet-visible spectroscopy (UV-Vis), X-ray photoemission spectroscopy (XPS), energy-dispersive X-ray spectroscopy (EDX), Raman spectroscopy, solid-state nuclear magnetic resonance spectroscopy (SSNMR), standardized Boehm potentiometric titration analysis, elemental analysis, X-ray diffraction (XRD), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The analysis showed that graphene oxide layers, as well as oxidative debris contain different functional groups such as phenolic –OH, ketone, lactone, carboxyl, quinone and epoxy. Based on these results, a new structural model for GO layers is proposed, which covers all spectroscopic data and explains the presence of the other oxygen functionalities besides carboxyl, phenolic –OH and epoxy groups.

Air-Water Interfacial Film of Zirconia and its Heat-Treatment

2011 ◽  
Vol 295-297 ◽  
pp. 1095-1098
Author(s):  
Chun Kan
Keyword(s):  
Electron Microscopy ◽  
Heat Treatment ◽  
Self Assembly ◽  
Energy Dispersive Spectrum ◽  
X Ray Diffraction ◽  
X Ray ◽  
Zirconia Film ◽  
Transmission Electron ◽  
Assembly Structure ◽  
Calcined Temperature

The air-water interfacial zirconia film composed of nanodisks with self-assembly structure is prepared. Scanning electron microscopy (SEM), Energy Dispersive Spectrum (EDS), X-ray diffraction (XRD) and Transmission electron microscopy (TEM) are used to characterize the film. Furthermore, the heat-treatment of this film is studied by thermogravimetry and differential thermal analysis (TG-DTA), XRD, and Raman spectroscopy (Raman). The results suggest that the zirconia of the samples changes from amorphous phase to t-ZrO2phase then m-ZrO2phase with the rise of calcined temperature.

Study of Antioxidant Property of the Endosperm Extract of Borassus flabellifer (Taal) and its use in the green synthesis of Gold nanoparticles

2017 ◽  
Vol 1 (2) ◽  
Author(s):  
Sk Nurul Hasan ◽  
Braja Gopal Bag
Keyword(s):  
Gold Nanoparticles ◽  
Room Temperature ◽  
Antioxidant Property ◽  
Resonance Spectroscopy ◽  
Surface Plasmon Resonance Spectroscopy ◽  
Dpph Radical ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ftir Studies ◽  
Transmission Electron

The antioxidant activity of the endosperm extract of Borassus flabellifer (commonly known as Taal) has been studied against a long lived 2,2-diphenylpicrylhydrazyl (DPPH) radical at room temperature. The phytochemicals present in the endosperm extract have been utilized for the synthesis of stable gold nanoparticles at room temperature under very mild conditions. The synthesized gold nanoparticles were characterized by Surface Plasmon Resonance spectroscopy, High resolution transmission electron microscopy, X-Ray diffraction and FTIR studies and a mechanism for the synthesis of stabilized gold nanoparticles has been proposed.

Preparation, Characterization, and Photocatalytic Performance of Bismuth and Boron Co-Doped Mesporous TiO2 by EISA Method

2014 ◽  
Vol 953-954 ◽  
pp. 1003-1007
Author(s):  
Yu Xiu Zhang ◽  
Li Yang ◽  
Dai Mei Chen ◽  
Shuang Deng ◽  
Ying Jie Shi
Keyword(s):  
Visible Light ◽  
Self Assembly ◽  
Photocatalytic Performance ◽  
X Ray Diffraction ◽  
X Ray ◽  
Assembly Method ◽  
Transmission Electron ◽  
Evaporation Induced Self Assembly ◽  
Crystallite Sizes ◽  
Mesoporous Structures

Abstract. The large-pore mesoporous Bi-B-TiO2 nanoparticles with the different Bi/Ti rations were prepared by EISA(evaporation-induced self-assembly) method. The prepared catalysts were characterized by X-ray diffraction, transmission electron microscopy, N2 absorption-desorption, ultraviolet visible light spectroscopy and photoluminescence spectroscopy technologies. The results revealed that all the samples are large aperture mesoporous structures. The crystallite sizes were in the range7-11nm, as confirmed by the results obtained from TEM images. The photodecomposition experiments showed that the photodegradation activity of Bi-B-doped TiO2 was higher than that of undoped TiO2 in degradation of 2, 4–dichlorophenol under visible light irradiation.

Fabrication of Nanosheets and Micro-Spheres from the Self-Assembly and Polymerization of N-Octadecyltrichlorosilane

2011 ◽  
Vol 311-313 ◽  
pp. 485-488 ◽  
Author(s):  
Shuai Zhang ◽  
Qing Ping Ke ◽  
Lei Zhang ◽  
Tian Di Tang
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Self Assembly ◽  
Micelle Formation ◽  
The Self ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Hydrolysis Process ◽  
Scanning Electron

Formation of layered nanosheets and micro-spheres from a simple self-assembly and polycondensation of n-octadecylsilane (PODS) in water and toluene is demonstrated, respectively. The structure of the micro-spheres was characterized by Scanning Electron Microscope (SEM), Transmission Electron Microscopy (TEM) and X-ray Diffraction (XRD). According to the TEM images, it was firstly confirmed that the micro-spheres consist of stacks of bilayered polymerized n-octadecylsilane with head-to-head arrangements. The co-effects of water and solvent were proposed to control the octadecyltrichlsilane hydrolysis process and eventually the morphology of the micro-spheres. A micelle formation mechanism for the formation of the PODS micro-spheres under the co-effects of water and solvent were firstly proposed.

scholarly journals Influence of temperature on the magnetic properties of Mn3O4 nanowires

2021 ◽  
pp. 203-208
Author(s):  
Sangaraju Sambasivam ◽  
Yedluri Anil Kumar ◽  
Chandu V.V. Muralee Gopi ◽  
Venkatesha Narayanaswamy ◽  
Ihab M. Obaidat
Keyword(s):  
Morphological Evolution ◽  
Synthesis Temperature ◽  
Resonance Spectroscopy ◽  
X Ray Diffraction ◽  
Weiss Temperature ◽  
X Ray ◽  
Transmission Electron ◽  
Spin Resonance ◽  
Influence Of Temperature On ◽  
Intense Electron

Single crystalline Mn3O4 nanowires have been synthesized with tetragonal hausmannite structure using a solvothermal method. The structural and morphological evolution of Mn3O4 nanowires have been characterized using powder X-ray diffraction, transmission electron microscopy, and electron resonance spectroscopy. The nanowires were grown uniformly along the (200) direction with a diameter of 5–10 nm range. A relatively broad and intense electron spin resonance (ESR) signal was observed at room temperature, with the g ≈ 2.0. As the synthesis temperature increases from 150 to 250 °C, a decrease in ESR signal intensity and line widths were observed. Mn3O4 displayed a positive Curie-Weiss temperature, θ, which decreases with the increase of synthesis temperature.

scholarly journals Study on Growth Mechanism of Cu Nanowires and Its Application as Transparent Conducting Electrode

2019 ◽  
Vol 19 (1) ◽  
pp. 160
Author(s):  
Dedi Mardiansyah ◽  
Kuwat Triyana ◽  
Harsojo Harsojo
Keyword(s):  
Electron Microscopy ◽  
Growth Mechanism ◽  
Optical Microscope ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cu Nanowires ◽  
Transparent Conducting Electrode ◽  
Transparent Conducting ◽  
Conducting Electrode ◽  
Transmission Electron

Cu nanowires (CuNWs) were synthesized in an aqueous solution at low temperature using ethylenediamine (EDA) as a capping agent and hydrazine as a reducing agent. This study investigated the growth of mechanism CuNWs and fabricated the transparent conducting electrode. For the growth mechanism of CuNWs, the study was conducted with an optical microscope, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD). The performance of the transparent conducting electrode was studied with UV-Vis spectrometer and IV meters. CuNWs growth from Cu nanoparticles (CuNPs) in the solution. Transparent conducting electrode gave a sheet resistance of 48.8 Ohm/sq and the transmittance of 52.63%. The understanding of the growing mechanism of Cu nanowires is important for the development of CuNWs for alternative application as a transparent conducting electrode.

scholarly journals Growth and Characterization of Ni Nano-Micro Structures in the Presence of Ethylenediamine

Crystals ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 397 ◽  
Author(s):  
Lingxiao Chen ◽  
Hang Liu ◽  
Linghao Liu ◽  
Yifan Zheng ◽  
Haodong Tang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Alkaline Conditions ◽  
Naoh Solution ◽  
Micro Structures ◽  
Scanning Electron

Ni nano-micro structures have been synthesized via a solution reduction route in the presence of ethylenediamine (EDA) under strong alkaline conditions. The phase composition, morphology, and microstructure of the resulting products are investigated by X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The presence of EDA plays an important role in the formation of Ni nano-micro structures, and microflowers or microspheres assembled from nanosized horns can be produced by changing the amount of EDA. The size of Ni nano-micro structures is dependent on the NaOH concentration, and long chains assembled from Ni nano-micro structured microspheres can be obtained by reducing the amount of NaOH solution used. The role of both EDA and NaOH in the reduction of Ni (II) to Ni, as well as in the growth of Ni nano-micro structures, has been discussed, and a possible formation mechanism of these Ni nano-micro structures has been proposed based on the experimental results.

scholarly journals The use of zinc metalloporphyrin grafted magnetic nanoparticles for the removal of sulfate ions from wastewaters

2019 ◽  
Vol 2 (2) ◽  
pp. 65-76
Author(s):  
Tahereh Poursaberi ◽  
Ali Akbar Miran Beigi
Keyword(s):  
Electron Microscopy ◽  
Contact Time ◽  
Optimal Conditions ◽  
X Ray Diffraction ◽  
Sulfate Ions ◽  
X Ray ◽  
Transmission Electron ◽  
Naoh Solution ◽  
Ft Ir ◽  
Scanning Electron

This study investigates an application of zinc metalloporphyrin grafted Fe3O4 nanoparticles as a new adsorbent for removal of sulfate ions from wastewaters. The modification of magnetite nanoparticles was conducted by 3-aminopropyltriethoxysilane followed by zinc (II) porphyrin in order to enhance the removal of sulfate ions. Fourier Transform Infrared Spectroscopy (FT-IR), X-ray diffraction (XRD), Transmission Electron Microscopy (TEM) and Scanning Electron Microscopy (SEM) was used to characterize the synthesized nano sorbent. The effect of important experimental factors such as pH, contact time, sorbent dosage and some co-existing anions present in aqueous solutions were investigated. Under optimal conditions (i.e. contact time: 30 min, pH: 6.5 and nanosorbents dosage: 100 mg) for a sulfate sample (50 mL, 50 mgL-1 ) the percentage of the extracted sulfate ions was 94.5%. Regeneration of sulfate adsorbed material could be possible by NaOH solution and the modified magnetic nano sorbent exhibited good reusability.

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