scholarly journals Synthesis and Ethanol Sensing Properties of Novel Hierarchical Sn3O4Nanoflowers

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Xingyang Li ◽  
Fengping Wang ◽  
Jianhai Tu ◽  
Hidayat Ullah Shah ◽  
Jianling Hu ◽  
...  
Keyword(s):  
Gas Sensing ◽  
Chemical Properties ◽  
Hierarchical Structures ◽  
Hydrothermal Time ◽  
Hydrothermal Route ◽  
One Pot ◽  
Practical Applications ◽  
Lower Temperature ◽  
Ethanol Sensing ◽  
Physical And Chemical

Due to the metastable property and arduous preparation, to control the size and shape of intermediate Sn3O4nanocrystals to tune functional properties still poses great challenge, and the physical and chemical properties are not fully investigated. Here, we report a simple one-pot template-free hydrothermal route to fabricate Sn3O4flower-like hierarchical structures self-assembled by aligned high-density nanoslices. In order to explore the growth mechanism, a series of samples with various hydrothermal time were prepared and examined by FESEM and Raman. Results show that the hydrothermal time influences the phases and morphology of the final products. Particularly, a sensor based on these Sn3O4was implemented to investigate the potential of Sn3O4for the ethanol detection, revealing that this material reacts to ethanol in a linear way with high response yet at lower temperature (190°C) than that of the well-known SnO2. Also, this intermediate tin oxide with rational control over dimension and morphology provides new opportunities for practical applications in gas sensing towards other reducing gases.

scholarly journals Bimetallic Nanocrystals: Structure, Controllable Synthesis and Applications in Catalysis, Energy and Sensing

Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1926
Author(s):  
Gaojie Li ◽  
Wenshuang Zhang ◽  
Na Luo ◽  
Zhenggang Xue ◽  
Qingmin Hu ◽  
...  
Keyword(s):  
Gas Sensing ◽  
Chemical Properties ◽  
Research Progress ◽  
Synthesis Methods ◽  
Controlled Synthesis ◽  
Controllable Synthesis ◽  
Composition And Structure ◽  
Bimetallic Nanocrystals ◽  
Physical And Chemical ◽  
And Chemical Properties

In recent years, bimetallic nanocrystals have attracted great interest from many researchers. Bimetallic nanocrystals are expected to exhibit improved physical and chemical properties due to the synergistic effect between the two metals, not just a combination of two monometallic properties. More importantly, the properties of bimetallic nanocrystals are significantly affected by their morphology, structure, and atomic arrangement. Reasonable regulation of these parameters of nanocrystals can effectively control their properties and enhance their practicality in a given application. This review summarizes some recent research progress in the controlled synthesis of shape, composition and structure, as well as some important applications of bimetallic nanocrystals. We first give a brief introduction to the development of bimetals, followed by the architectural diversity of bimetallic nanocrystals. The most commonly used and typical synthesis methods are also summarized, and the possible morphologies under different conditions are also discussed. Finally, we discuss the composition-dependent and shape-dependent properties of bimetals in terms of highlighting applications such as catalysis, energy conversion, gas sensing and bio-detection applications.

scholarly journals Proanthocyanidins: Oligomeric Structures with Unique Biochemical Properties and Great Therapeutic Promise

2012 ◽  
Vol 7 (3) ◽  
pp. 1934578X1200700 ◽  
Author(s):  
Zhanjie Xu ◽  
Peng Du ◽  
Peter Meiser ◽  
Claus Jacob
Keyword(s):  
Protein Interactions ◽  
Biological Activities ◽  
Antioxidant Properties ◽  
Chemical Properties ◽  
Cancer Chemoprevention ◽  
Biochemical Properties ◽  
Synthetic Methods ◽  
Practical Applications ◽  
Wide Range ◽  
Physical And Chemical

Proanthocyanidins represent a unique class of oligomeric and polymeric secondary metabolites found ubiquitously and in considerable amounts in plants and some algae. These substances exhibit a range of rather surprising physical and chemical properties which, once applied to living organisms, are translated into a multitude of biological activities. The latter include antioxidant properties, cancer chemoprevention, anti-inflammatory and anti-diabetic effects as well as some exceptional, yet highly interesting activities, such as anti-nutritional and antimicrobial activity. Despite the wide range of activities and possible medical/agricultural applications of proanthocyanidins, many questions still remain, including issues related to bioavailability, metabolism and the precise biochemical, extra- and intracellular targets and mode(s) of action of these highly potent materials. Among the various physical and chemical interactions of such substances, strong binding to proteins appears to form the basis of many of their biological activities. Once easy-to-use synthetic methods to produce appropriate quantities of pure proanthocyanidins are available, it will be possible to identify the prime biological targets of these oligomers, study oligomer-protein interactions in more detail and develop possible practical applications in medicine and agriculture.

scholarly journals Agroforestry and the Improvement of Soil Fertility: A View from Amazonia

2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
Rachel C. Pinho ◽  
Robert P. Miller ◽  
Sonia S. Alfaia
Keyword(s):  
Soil Fertility ◽  
Management Practices ◽  
Relevant Literature ◽  
Chemical Properties ◽  
Tropical Soils ◽  
Agroforestry Systems ◽  
Natural Ecosystems ◽  
Practical Applications ◽  
Northern Brazil ◽  
Physical And Chemical

This paper discusses the effects of trees on soil fertility, with a focus on agricultural systems in Amazonia. Relevant literature concerning the effects of trees on soil physical and chemical properties in tropical, subtropical, and temperate regions is reviewed, covering both natural ecosystems and agroecosystems. Soil carbon, in the form of organic matter, is considered as an indicator of biological activity as well as in relation to policy issues such as carbon sequestration and climate change. In the case of tropical soils and Amazonia, information on the effects of trees on soils is discussed in the context of traditional agriculture systems, as well as in regard to the development of more sustainable agricultural alternatives for the region. Lastly, attention is given to a case study in the savanna region of Roraima, northern Brazil, where a chronosequence of indigenous homegarden agroforestry systems showed clear effects of management practices involving trees on soil fertility. The use of diverse tree species and other practices employed in agroforestry systems can represent alternative forms of increasing soil fertility and maintaining agricultural production, with important practical applications for the sustainability of tropical agriculture.

Salting-out and salting-in experiments with lignosulfonates (LSs)

Holzforschung ◽  
2013 ◽  
Vol 67 (5) ◽  
pp. 549-557 ◽  
Author(s):  
Bernt O. Myrvold
Keyword(s):  
Chemical Properties ◽  
Physical And Chemical Properties ◽  
Salting Out ◽  
Practical Applications ◽  
Common Ion ◽  
The Common ◽  
Common Ion Effect ◽  
The Stability ◽  
Physical And Chemical ◽  
And Chemical Properties

Abstract The solubility of lignosulfonates (LSs) in water is strongly dependent on other ions present in the water phase. The differences in the solubility might strongly influence the measurements of the physical and chemical properties of the LS molecules. A reduced solubility of the LS might also affect its utility in many practical applications. The understanding of the interaction between LSs and various salts is important for both practical and theoretical reasons. Therefore, the effect of salt concentrations on the LS has been investigated for 41 different salts with 14 different cations and 16 different anions. The observations cannot be explained by the common ion effect or the screening effects. On the contrary, it was found that the stability of LS solutions follows the Hofmeister series, with the exception of those ions that will chemically interact with the LS molecule. Moreover, the positions of phosphate (HPO42-) and sulfate (SO42-) ions were reversed.

Synthesis and Gas Sensing Properties of Urchin-Like CuO Self-Assembled by Nanorods through a Poly(ethylene glycol)-Assisted Hydrothermal Process

2009 ◽  
Vol 79-82 ◽  
pp. 1059-1062 ◽  
Author(s):  
Jiang Ying Li ◽  
Bao Juan Xi ◽  
Jun Pan ◽  
Yi Tai Qian
Keyword(s):  
Ethylene Glycol ◽  
Gas Sensing ◽  
Hydrothermal Process ◽  
Poly Ethylene Glycol ◽  
High Concentration ◽  
Hydrothermal Route ◽  
Xrd Pattern ◽  
Sensing Properties ◽  
Poly Ethylene ◽  
Ethanol Sensing

Urchin-like CuO, consisting of closely packed nanorods with a diameter of 10nm, have been successfully synthesized by a poly(ethylene glycol) (PEG)-assisted hydrothermal route at low temperature of 100°C. The as-obtained Urchin-like CuO were thoroughly characterized by X-ray diffraction (XRD) study, Field emission scanning electron microscope (FESEM), High-resolution transmission electron microscopy (HRTEM) and Gas sensor measurements. From the XRD pattern, all the peaks detected can be assigned to CuO in a monoclinic structure with lattice parameters a=4.662, b=3.416 and c=5.118 (JCPDS card no. 65-2309). The FESEM and TEM showed that the diameter of the urchin-like CuO sphere is about 1µm. Further investigation of the formation mechanism reveals that the PEG-assisted hydrothermal process is vital to the formation of 3D structures. Besides the template function, PEG often plays as a reductant while reacting with Cu(+2). In our case, no impurity peaks of Cu2O were observed in the XRD pattern, implying that PEG did not reduce Cu(+2) to Cu(+1). We attribute this to the high concentration of PEG. The sensor based on the urchin-like CuO nanostructures exhibit excellent ethanol-sensing properties at reduced working temperature (200°C), which shows a sensitivity two times higher than that of CuO particles(about 100nm, made from calcinations of Cu(NO3)2 at 400°C). The enhancement in sensitivity of the as-prepared CuO may be contributed to the fancy 3D nanostructures.

scholarly journals CuFe2O4@CuO: A Magnetic Composite Synthesized by Ultrasound Irradiation and Degradation of Methylene Blue on Its Surface in the Presence of Sunlight

Proceedings ◽  
2019 ◽  
Vol 48 (1) ◽  
pp. 17 ◽  
Author(s):  
Ahmad Massoud-Sharifi ◽  
Gheffar K. Kara ◽  
Mahboubeh Rabbani
Keyword(s):  
Methylene Blue ◽  
Environmental Remediation ◽  
Spinel Ferrite ◽  
Sol Gel ◽  
Chemical Properties ◽  
Pollutant Removal ◽  
Magnetic Composite ◽  
Hydrothermal Route ◽  
X Ray ◽  
Practical Applications

Spinel ferrite MFe2O4 (M = Cu, Ca, Mg, Ni, etc.) nanoparticles and their composites are a new promising materialbecause they have shown great interest in the field of sensing, optoelectronics, catalysis, and solar cells due to their unique physical and chemical properties that differ from their bulk structures. Today, lots of CuFe2O4 nanomaterials have been synthesized by different methods, such as hydrothermal route and sol-gel combustion methods. Nevertheless, there are hardly any results about photocatalytic activity. For this reason, we tried to increase optical properties by preparing a composite of CuFe2O4 nanomaterials with other oxides. In this paper, a CuFe2O4@CuO magnetic composite was synthesized via an ultrasound method. The samples prepared were characterized by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), diffuse reflectance spectrpscopy (DRS), field emission scanning electron microscopy (FESEM) images, vibrating sample magnetometer (VSM), and elemental analysis (energy-dispersive X-ray (EDX)). The catalytic activity of as-synthesized CuFe2O4@CuO was evaluated using the degradation of methylene blue. Furthermore, a possible reaction mechanism was discussed. Finally, the catalyst was used for effective degradation of methylene blue (MB) in its solution, which indicated a potential for practical applications in water pollutant removal and environmental remediation.

scholarly journals Investigation of the Reactivity of 1-Azido-3-Iodobicyclo[1.1.1]pentane under “Click” Reaction Conditions

2020 ◽  
Author(s):  
Elisabeth Sitte ◽  
Brendan Twamley ◽  
nitika grover ◽  
Mathias Senge
Keyword(s):  
Click Reaction ◽  
Chemical Properties ◽  
Building Blocks ◽  
Dipolar Cycloaddition ◽  
Coupling Reactions ◽  
Reaction Conditions ◽  
One Pot ◽  
Click Reactions ◽  
Drug Molecules ◽  
Physical And Chemical

The bicyclo[1.1.1]pentane (BCP) unit exhibits special physical and chemical properties and is under scrutiny as a bioisostere in drug molecules. We employed methodologies for the synthesis of different BCP triazole building blocks from one precursor, 1-azido-3-iodobicyclo[1.1.1]pentane, by Cu(I)-catalyzed 1,3-dipolar cycloaddition (“click”) reactions and integrated cycloaddition-Sonogashira coupling reactions. Thereby, we accessed three classes of substituted BCP derivatives: 1,4-disubstituted triazoles, 5-iodo-1,4,5-trisubstituted triazoles and 5-alkynylated 1,4,5-trisubstituted triazoles. This gives entry to the synthesis of multiply substituted BCP triazoles either on a modular or a one-pot basis. These methodologies were further utilized for appending large chromophoric porphyrin moieties onto the BCP core.

scholarly journals Highly Sensitive and Selective H2S Chemical Sensor Based on ZnO Nanomaterial

2019 ◽  
Vol 9 (6) ◽  
pp. 1167 ◽  
Author(s):  
Vardan Galstyan ◽  
Nicola Poli ◽  
Elisabetta Comini
Keyword(s):  
Chemical Sensor ◽  
Gas Sensing ◽  
Chemical Properties ◽  
Device Fabrication ◽  
Sensing Systems ◽  
Highly Sensitive ◽  
Prepared Material ◽  
Significant Step ◽  
Reducing Gases ◽  
Physical And Chemical

ZnO is worth evaluating for chemical sensing due to its outstanding physical and chemical properties. We report the fabrication and study of the gas sensing properties of ZnO nanomaterial for the detection of hydrogen sulfide (H2S). This prepared material exhibited a 7400 gas sensing response when exposed to 30 ppm of H2S in air. In addition, the structure showed a high selectivity towards H2S against other reducing gases. The high sensing performance of the structure was attributed to its nanoscale size, morphology and the disparity in the sensing mechanism between the H2S and other reducing gases. We suggest that the work reported here including the simplicity of device fabrication is a significant step toward the application of ZnO nanomaterials in chemical gas sensing systems for the real-time detection of H2S.

scholarly journals Biomimetics: lessons from nature–an overview

2009 ◽  
Vol 367 (1893) ◽  
pp. 1445-1486 ◽  
Author(s):  
Bharat Bhushan
Keyword(s):  
Self Assembly ◽  
Chemical Properties ◽  
Hierarchical Structures ◽  
Self Healing ◽  
Structural Coloration ◽  
High Mechanical Strength ◽  
Flow Energy ◽  
High Adhesion ◽  
Physical And Chemical ◽  
Aerodynamic Lift

Nature has developed materials, objects and processes that function from the macroscale to the nanoscale. These have gone through evolution over 3.8 Gyr. The emerging field of biomimetics allows one to mimic biology or nature to develop nanomaterials, nanodevices and processes. Properties of biological materials and surfaces result from a complex interplay between surface morphology and physical and chemical properties. Hierarchical structures with dimensions of features ranging from the macroscale to the nanoscale are extremely common in nature to provide properties of interest. Molecular-scale devices, superhydrophobicity, self-cleaning, drag reduction in fluid flow, energy conversion and conservation, high adhesion, reversible adhesion, aerodynamic lift, materials and fibres with high mechanical strength, biological self-assembly, antireflection, structural coloration, thermal insulation, self-healing and sensory-aid mechanisms are some of the examples found in nature that are of commercial interest. This paper provides a broad overview of the various objects and processes of interest found in nature and applications under development or available in the marketplace.

scholarly journals Biodiesel Production Using Bauxite in Low-Cost Solid Base Catalyst Precursors

Catalysts ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 1064 ◽  
Author(s):  
Yong-Ming Dai ◽  
Cheng-Hsuan Hsieh ◽  
Jia-Hao Lin ◽  
Fu-Hsuan Chen ◽  
Chiing-Chang Chen
Keyword(s):  
Alkali Metal ◽  
Low Cost ◽  
Chemical Properties ◽  
Acid Methyl Ester ◽  
Biodiesel Production ◽  
Molar Ratio ◽  
Metal Catalyst ◽  
Solid Base ◽  
One Pot ◽  
Physical And Chemical

Investigation was conducted on bauxite mixed with Li2CO3 as alkali metal catalysts for biodiesel production. Bauxite contains a high percentage of Si and Al compounds among products. Because of the high expense of commercial materials (SiO2, Al2O3) that makes them not economical, the method was very recently improved by replacing commercial materials with Si and Al from bauxite. This is one of the easiest methods for preparing heterogeneous transesterification catalysts, through one-pot blending, grinding bauxite with Li2CO3, and heating at 800 °C for 4 h. The prepared solid-base alkali metal catalyst was characterized in terms of its physical and chemical properties using X-ray powder diffraction and field-emission scanning electron microscopy (FE-SEM). The optimal conditions for the transesterification procedure are to mix methanol oil by molar ratio 9:1, under 65 °C, with catalyst amount 3 wt.%. The procedure is suitable for transesterifying oil to fatty acid methyl ester in the 96% range.

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