A Novel Sensor Apply in Detection of Indoor Air

2020 ◽  
Vol 12 (2) ◽  
pp. 282-288 ◽  
Author(s):  
Lingling Qi ◽  
Yulun Pan
Keyword(s):  
Hydrothermal Method ◽  
Surface Area ◽  
Indoor Air ◽  
Gas Sensing ◽  
Three Dimensional ◽  
Chemical Properties ◽  
Gas Diffusion ◽  
Directional Transmission ◽  
Sensing Characteristics ◽  
And Chemical Properties

Rutile TiO2 with three dimensional structures displays excellent electrical and chemical properties. In this article, rutile TiO2 nanostructure with flower-like morphology is synthesized via a hydrothermal method without any catalyst, template, surfactant or calcination. Additionally, the effects of the reactants are discussed on the basis of controlled experiment. Interestingly, we found that the rutile TiO2 sensor show excellent gas sensing performances toward VOCs gas, primarily attributed to abundant gas diffusion channels and large gas-sensitive reaction surface area. Meanwhile, these building units promote the directional transmission of electrons, resulting in an improvement of TiO2 gas sensing characteristics.

A Formaldehyde Indoor Gas Sensor Based on Hierarchical α-Molybdenum Trioxide

2021 ◽  
Vol 16 (6) ◽  
pp. 987-992
Author(s):  
Yujun Zhu ◽  
Fan Zhang ◽  
Kaifang Wang ◽  
Yawen Zhang ◽  
Xiuzhi Gu ◽  
...  
Keyword(s):  
Gas Sensor ◽  
Indoor Air ◽  
Gas Sensing ◽  
Molybdenum Trioxide ◽  
Three Dimensional ◽  
Test Results ◽  
Hierarchical Microstructure ◽  
Formaldehyde Sensing ◽  
2D Nanosheets ◽  
Sensing Characteristics

The detection of indoor formaldehyde gas is important because of its highly toxic nature. Herein, the two-dimensional α-MoO3 nanosheets and three-dimensional α-MoO3 hierarchical flowers have been prepared by simple hydrothermal strategy and used as the formaldehyde sensing materials. Their microstructures, morphologies and gas sensing characteristics towards formaldehyde were studied. The test results exhibited that, at the optimal temperature of 250 °C, the sensor performances were enhanced due to the assembly of 2D nanosheets into 3D hierarchical structure. The improved properties were contributed to the formation of the hierarchical microstructure constructed by nanosheets. The hierarchical microstructure based gas sensor has significant potential in indoor air sensing application.

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 Current Progress in Cross-Linked Peptide Self-Assemblies

2020 ◽  
Vol 21 (20) ◽  
pp. 7577
Author(s):  
Noriyuki Uchida ◽  
Takahiro Muraoka
Keyword(s):  
Self Assembly ◽  
Three Dimensional ◽  
Chemical Properties ◽  
Water Soluble ◽  
Cross Linking ◽  
Physical And Chemical Properties ◽  
Cell Scaffold ◽  
Scaffold Materials ◽  
Physical And Chemical ◽  
And Chemical Properties

Peptide-based fibrous supramolecular assemblies represent an emerging class of biomaterials that can realize various bioactivities and structures. Recently, a variety of peptide fibers with attractive functions have been designed together with the discovery of many peptide-based self-assembly units. Cross-linking of the peptide fibers is a key strategy to improve the functions of these materials. The cross-linking of peptide fibers forming three-dimensional networks in a dispersion can lead to changes in physical and chemical properties. Hydrogelation is a typical change caused by cross-linking, which makes it applicable to biomaterials such as cell scaffold materials. Cross-linking methods, which have been conventionally developed using water-soluble covalent polymers, are also useful in supramolecular peptide fibers. In the case of peptide fibers, unique cross-linking strategies can be designed by taking advantage of the functions of amino acids. This review focuses on the current progress in the design of cross-linked peptide fibers and their applications.

Adsorption of CO2 onto Activated Carbons Prepared by Chemical Activation with Metallic Salts

2017 ◽  
Vol 15 (6) ◽  
Author(s):  
Sergio Acevedo ◽  
Liliana Giraldo ◽  
Juan Carlos Moreno-Piraján
Keyword(s):  
Adsorption Capacity ◽  
Surface Area ◽  
Pore Volume ◽  
Activated Carbons ◽  
Elaeis Guineensis ◽  
Chemical Activation ◽  
Chemical Properties ◽  
Metallic Salts ◽  
Adsorption Of Co2 ◽  
And Chemical Properties

Abstract Activated carbons are obtained by chemical activation of African Palm shells (Elaeis guineensis) with different impregnating agents, i. e. magnesium chloride (MgCl2) and calcium chloride (CaCl2) aqueous solutions at different concentrations (3, 5 and 7 % w/v) and temperatures (between 773 and 1073 K), in order to assess their influence on the development of the porosity. The activated carbons prepared are characterized in terms of both textural and chemical properties. The activated carbons have a surface area and a pore volume ranging between 19 and 501 m2.g−1 and 0.03–0.29 cm3.g−1, respectively. Based on the obtained results, the samples with higher surface area and pore volume (i. e. those impregnated with MgCl2 and CaCl2 solutions and thermally treated at 1073 K) are selected to evaluate the adsorption capacity and affinity for CO2. CO2 adsorption capacity varies between 1.78 and 2.95 mmolCO2.g−1 at 273 K and low pressure, and the activated carbon impregnated with the solution of MgCl2 3% and activated at 1073 K (i. e. ACMg3-1073) showed the best performances. Finally, the kinetic results show that adsorption rate for sample ACMg3-1073 is enhanced by its micro-mesoporous nature, being the access routes to the micropores larger.

scholarly journals Dendrimers: A New Race of Pharmaceutical Nanocarriers

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Pooja Mittal ◽  
Anjali Saharan ◽  
Ravinder Verma ◽  
Farag M. A. Altalbawy ◽  
Mohammed A. Alfaidi ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Chemical Properties ◽  
Biologically Active ◽  
Dimensional Structure ◽  
Synthesis Mechanism ◽  
Drug Conjugates ◽  
Wide Range ◽  
New Race ◽  
Physical And Chemical ◽  
And Chemical Properties

Dendrimers are nanosized, symmetrical molecules in which a small atom or group of atoms is surrounded by the symmetric branches known as dendrons. The structure of dendrimers possesses the greatest impact on their physical and chemical properties. They grow outwards from the core-shell which further reacts with monomers having one reactive or two dormant molecules. Dendrimers’ unique characteristics such as hyperbranching, well-defined spherical structure, and high compatibility with the biological systems are responsible for their wide range of applications including medical and biomedical areas. Particularly, the dendrimers’ three-dimensional structure can incorporate a wide variety of drugs to form biologically active drug conjugates. In this review, we focus on the synthesis, mechanism of drug encapsulations in dendrimers, and their wide applications in drug delivery.

BIOMEDICAL APPLICATIONS OF ELECTROSPUN NANOFIBERS

2020 ◽  
Vol 27 (11) ◽  
pp. 2030001
Author(s):  
ZHANG YANCONG ◽  
DOU LINBO ◽  
MA NING ◽  
WU FUHUA ◽  
NIU JINCHENG
Keyword(s):  
Biomedical Applications ◽  
Three Dimensional ◽  
Chemical Properties ◽  
Electrospun Nanofibers ◽  
High Porosity ◽  
Nanofiber Diameter ◽  
Surface Microscopy ◽  
Different Shapes ◽  
Physical And Chemical ◽  
And Chemical Properties

Electrospun technology is a simple and flexible method for preparation of nanofiber materials with unique physical and chemical properties. The nanofiber diameter is adjustable from several nanometers to few microns during the preparation. Electrospun nanofiber materials are easy to be assembled into different shapes of three-dimensional structures. These materials exhibit high porosity and surface area and can simulate the network structures of collagen fibers in a natural extracellular matrix, thereby providing a growth microenvironment for tissue cells. Electrospun nanofibers therefore have extensive application prospects in the biomedicine field, including in aerospace, filtration, biomedical applications, and biotechnology. Nanotechnology has the potential to revolutionize many fields, such as surface microscopy, silicon fabrication, biochemistry, molecular biology, physical chemistry, and computational engineering, while the advent of nanofibers has increased the understanding of nanotechnology among academia, industry, and the general public. This paper mainly introduces the application of nanofiber materials in tissue engineering, drug release, wound dressing, and other biomedicine fields.

Defects in Intermetallic Compounds: How Do They Differ From Those in Ordinary Metals?

MRS Bulletin ◽  
1995 ◽  
Vol 20 (7) ◽  
pp. 29-36 ◽  
Author(s):  
Y.Q. Sun
Keyword(s):  
Intermetallic Compounds ◽  
Elastic Stress ◽  
Three Dimensional ◽  
Chemical Properties ◽  
Three Dimensions ◽  
Superlattice Structure ◽  
Unit Cells ◽  
Line Defects ◽  
Physical And Chemical ◽  
And Chemical Properties

Just as in ordinary metals, defects in intermetallic compounds fall into three basic categories: point defects (vacancies, substitutional and interstitial atoms), line defects (dislocations), and planar defects (stacking faults, interfaces, grain boundaries). Also like ordinary metals, many important physical and chemical properties of intermetallic compounds are governed by the presence of these defects and the effects on them from temperature, composition, chemical environment, elastic stress state, and so on.What ultimately distinguishes an intermetallic compound from ordinary metals is its superlattice crystal structure. A two-dimensional analogue of the actual three-dimensional superlattice structure is shown in Figure 1a where the superlattice (unit cell marked by full lines) is made up of two identical sublat-tices (unit cells marked by dotted lines). A property of the sublattice is that it is exclusively occupied by one atom species, and accordingly sublattices are named after the atoms that occupy them, for example, the A and B sublattices in Figure 1a. In three dimensions, a super-lattice may consist of several sublattices. For example, the L12 superlattice of Ni3Al consists of four interpenetrating cubic sublattices, one occupied by Al atoms (Al sublattice), the other three by Ni atoms (Ni sublattices). When the sub-lattices are occupied exclusively by their designated atoms, the crystal is said to be fully ordered. The crystal will be partially ordered if a certain fraction of the sublattice sites is taken up by atoms that would otherwise sit at other sublattices; this fraction is used to describe the degree of long-range order.

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