Electrical and Humidity-Sensing Properties of EuCl2, Eu2O3 and EuCl2/Eu2O3 Blend Films

Chemosensors ◽  
2021 ◽  
Vol 9 (10) ◽  
pp. 288
Author(s):  
Pi-Guey Su ◽  
Nok-Him Choy
Keyword(s):  
Complex Impedance ◽  
Fast Response ◽  
Humidity Sensing ◽  
Sensing Properties ◽  
Blend Film ◽  
Blend Films ◽  
Long Term Stability ◽  
Humidity Sensing Properties

Impedance-type humidity sensors based on EuCl2, Eu2O3 and EuCl2/Eu2O3 blend films were fabricated. The electrical properties of the pure EuCl2 and Eu2O3 films and EuCl2/Eu2O3 blend film that was blended with different amounts of EuCl2 were investigated as functions of relative humidity. The influences of the EuCl2 to the humidity-sensing properties (sensitivity and linearity) of the EuCl2/Eu2O3 blend film were thus elucidated. The impedance-type humidity sensor that was made of a 7 wt% EuCl2/Eu2O3 blend film exhibited the highest sensitivity, best linearity, a small hysteresis, a fast response time, a small temperature coefficient and long-term stability. The complex impedance plots were used to elucidate the role of ions in the humidity-sensing behavior of the EuCl2/Eu2O3 blend film.

Investigations of the humidity sensing properties of side-chain-type sulfonated poly (arylene ether ketone)s

2019 ◽  
Vol 31 (9-10) ◽  
pp. 1248-1258
Author(s):  
Fanting Meng ◽  
Zhuang Zhuang ◽  
Yurong Zhang ◽  
Hui Na
Keyword(s):  
Complex Impedance ◽  
Fast Response ◽  
Side Chain ◽  
Humidity Sensing ◽  
Sensing Properties ◽  
Arylene Ether ◽  
Ether Ketone ◽  
Chain Type ◽  
Humidity Sensing Properties ◽  
Sulfonated Poly

Side-chain-type sulfonated poly (arylene ether ketone)s containing naphthalene moieties with a degree of sulfonation (Ds) from 0.2 to 1.9 were synthesized. Humidity sensors were fabricated by cast coating on silver–palladium interdigital microelectrodes. The properties of this series of materials in terms of water absorption, glass transition temperature, and humidity sensing were characterized in detail. The investigations on the humidity sensing performance showed that with the increase in the Ds, the hysteresis of our materials exhibits an increasing trend first, followed by a decrease. This special phenomenon has not been reported before and caught our attention. From the results of humidity sensing properties, among the materials, the one with 0.2 Ds is promising for applications in humidity sensing due to its small hysteresis and fast response to varied relative humidity (RH). For a better understanding of the humidity sensing behavior of the sensor, complex impedance spectra were also measured. In the long-term stability measurement, the deviation of the measured impedance of the sensor at 97% RH is not obvious, proving good stability in a humid environment.

scholarly journals Synthesis of a Flower-Like g-C3N4/ZnO Hierarchical Structure with Improved CH4 Sensing Properties

Nanomaterials ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 724 ◽  
Author(s):  
Xiaojie Li ◽  
Yanwei Li ◽  
Guang Sun ◽  
Na Luo ◽  
Bo Zhang ◽  
...  
Keyword(s):  
Hierarchical Structure ◽  
Carbon Nitride ◽  
Fast Response ◽  
Optimum Operating ◽  
Optimum Operating Temperature ◽  
Sensing Properties ◽  
Long Term Stability ◽  
Response Recovery ◽  
Calcination Method

In this paper, a hierarchical structure of graphite carbon nitride (g-C3N4) modified ZnO (g-C3N4/ZnO) was synthesized using a simple precipitation-calcination method. Through this method, g-C3N4 nanosheets with a controlled content were successfully decorated on the petals of flower-like ZnO. Various techniques were used to confirm the successful formation of the g-C3N4/ZnO hierarchical structure. The methane (CH4) sensing properties of g-C3N4/ZnO sensor were investigated. The result exhibited that after decorating ZnO with g-C3N4, the CH4 sensing performances of the fabricated sensor were remarkably improved. At the optimum operating temperature of 320 °C, the response of the sensor fabricated with CNZ-3 (the sample with an optimum content of g-C3N4) towards 1000 ppm CH4 was as high as 11.9 (Ra/Rg), which was about 2.2 times higher than that of the pure ZnO sensor (5.3). In addition, the CNZ-3 sensor also exhibited a fast response/recovery speed (15/28 s) and outstanding long-term stability. The enhancing CH4 sensing mechanism may be contributed to enlarged surface area, pore structure, and g-C3N4-ZnO n-n junction.

scholarly journals Complex Impedance Analysis of the Humidity Sensing Properties of Polypyrrole

2009 ◽  
Vol 25 (02) ◽  
pp. 327-330 ◽  
Author(s):  
WANG Rui ◽  
◽  
ZHANG Tong ◽  
HE Yuan ◽  
GENG Wang-Chang ◽  
...  
Keyword(s):  
Complex Impedance ◽  
Impedance Analysis ◽  
Humidity Sensing ◽  
Sensing Properties ◽  
Complex Impedance Analysis ◽  
Humidity Sensing Properties

scholarly journals AC Humidity Sensing Properties of Mesoporous K2CO3-SiO2Composite Materials

2016 ◽  
Vol 2016 ◽  
pp. 1-6
Author(s):  
Liang Guo ◽  
Xuefeng Chu ◽  
Xiaohong Gao ◽  
Chao Wang ◽  
Yaodan Chi ◽  
...  
Keyword(s):  
Composite Material ◽  
Mesoporous Silica ◽  
Complex Impedance ◽  
Ion Transfer ◽  
Humidity Sensing ◽  
Sensing Properties ◽  
Response And Recovery ◽  
Humidity Range ◽  
Humidity Sensing Properties

The mesoporous silica SBA-15 and mesoporous K2CO3-SiO2composite material were synthesized. Characterization of microstructure and morphology of materials indicated that the composite material had saved the porous framework of mesoporous silica SBA-15. Humidity sensing properties of different inverse proportion K2CO3-SiO2composite material were studied and we found that the sample with 0.16 g/g K2CO3exhibited excellent linearity in the wide humidity range. The complex impedance changed five orders of magnitude from 11% RH to 95% RH. The rapid response and recovery time were 10 s and 38 s, respectively. Finally a feasible ion transfer mechanism was brought forward to explain the sensing mechanism.

scholarly journals Electrical and Humidity-Sensing Properties of Impedance-Type Humidity Sensors that Were Made of Ag Microwires/PPy/SnO2 Ternary Composites

Chemosensors ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 92
Author(s):  
Pi-Guey Su ◽  
Ping-Hsiang Lu
Keyword(s):  
Composite Film ◽  
Humidity Sensor ◽  
Composite Films ◽  
Complex Impedance ◽  
Humidity Sensors ◽  
Ternary Composite ◽  
Humidity Sensing ◽  
X Ray ◽  
Sensing Properties ◽  
Humidity Sensing Properties

Impedance-type humidity sensors were fabricated via one-step UV-irradiation photopolymerization of Ag microwires (Ag MWs), polypyrrole (PPy) and SnO2 ternary composite (Ag MWs/PPy/SnO2) films on an alumina substrate. X-ray diffractometry (XRD), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM) coupled with an energy dispersive X-ray (EDX) elemental mapping were used to analyze the morphology, structure, and composition of Ag MWs/PPy/SnO2 ternary composite films. Microstructural observations revealed that the Ag MWs were embedded, and PPy formed on the surface of the Ag MWs/PPy/SnO2 ternary composite film. The effects of the addition amounts of loading of Ag and PPy on the electrical and humidity-sensing properties of the Ag MWs/PPy/SnO2 ternary composite films were investigated. The impedance-type humidity sensor based on Ag MWs/PPy/SnO2 ternary composite film containing 6 mg of Ag and 0.1 g of PPy had the highest sensitivity and an acceptable linearity over the RH ranged from 10% to 90% RH, a low hysteresis, a fast response time, and long-term stability. This technique is useful for practical application because its fast and ease of fabrication. The ions (H3O+) that dominate the impedance changed with relative humidity (RH) for the humidity sensor that based on Ag MWs/PPy/SnO2 ternary composite film was analyzed using complex impedance spectra.

THE ROLE OF POLYETHYLENIMINE IN ENHANCING PERFORMANCE OF GLUTAMATE BIOSENSORS

2018 ◽  
Vol 8 (3) ◽  
pp. 36-41
Author(s):  
Diep Do Thi Hong ◽  
Duong Le Phuoc ◽  
Hoai Nguyen Thi ◽  
Serra Pier Andrea ◽  
Rocchitta Gaia
Keyword(s):  
First Generation ◽  
Good Reproducibility ◽  
Complex Matrices ◽  
Long Term Stability ◽  
In Vitro Characterization ◽  
Glutamate Oxidase

Background: The first biosensor was constructed more than fifty years ago. It was composed of the biorecognition element and transducer. The first-generation enzyme biosensors play important role in monitoring neurotransmitter and determine small quantities of substances in complex matrices of the samples Glutamate is important biochemicals involved in energetic metabolism and neurotransmission. Therefore, biosensors requires the development a new approach exhibiting high sensibility, good reproducibility and longterm stability. The first-generation enzyme biosensors play important role in monitoring neurotransmitter and determine small quantities of substances in complex matrices of the samples. The aims of this work: To find out which concentration of polyethylenimine (PEI) exhibiting the most high sensibility, good reproducibility and long-term stability. Methods: We designed and developed glutamate biosensor using different concentration of PEI ranging from 0% to 5% at Day 1 and Day 8. Results: After Glutamate biosensors in-vitro characterization, several PEI concentrations, ranging from 0.5% to 1% seem to be the best in terms of VMAX, the KM; while PEI content ranging from 0.5% to 1% resulted stable, PEI 1% displayed an excellent stability. Conclusions: In the result, PEI 1% perfomed high sensibility, good stability and blocking interference. Furthermore, we expect to develop and characterize an implantable biosensor capable of detecting glutamate, glucose in vivo. Key words: Glutamate biosensors, PEi (Polyethylenimine) enhances glutamate oxidase, glutamate oxidase biosensors

Nanostructured Lipid Carriers (NLCs) for drug delivery: Role of Liquid lipid (oil)

2020 ◽  
Vol 17 ◽  
Author(s):  
Anisha D’Souza ◽  
Ranjita Shegokar
Keyword(s):  
Drug Delivery ◽  
Essential Oils ◽  
Drug Carrier ◽  
Drug Loading ◽  
Performance Criteria ◽  
Long Term Stability ◽  
Natural Oils ◽  
Optimal Drug

: In recent years, SLNs and NLCs are among the popular drug delivery systems studied for delivery of lipophilic drugs. Both systems have demonstrated several beneficial properties as an ideal drug-carrier, optimal drug-loading and good long-term stability. NLCs are getting popular due to their stability advantages and possibility to load various oil components either as an active or as a matrix. This review screens types of oils used till date in combination with solid lipid to form NLCs. These oils are broadly classified in two categories: Natural oils and Essential oils. NLCs offer range advantages in drug delivery due to the formation of imperfect matrix owing to the presence of oil. The type and percentage of oil used determines optimal drug loading and stability. Literature shows that variety of oils is used in NLCs mainly as matrix, which is from natural origin, triglycerides class. On the other hand, essential oils not only serve as a matrix but as an active. In short, oil is the key ingredient in formation of NLCs, hence needs to be selected wisely as per the performance criteria expected.

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