"Preparation and Study the Electrical Properties of Chitosan, Hydroxyethylcellulose, and Polyvinyl Alcohol polymer Blend Doped with Different ratios of 4-(2-Pyridylazo)Resorcinol Monosodium Salt Hydrate "

2020 ◽  
Vol 8 (1) ◽  
pp. 49-55
Author(s):  
Zainab J. Sweah ◽  
Fatima H. Malik
Keyword(s):  
Polyvinyl Alcohol ◽  
Polymer Blend ◽  
Young Modulus ◽  
Weight Percent ◽  
Hydroxyethyl Cellulose ◽  
Salt Hydrate ◽  
Ohmic Behavior ◽  
Current Voltage ◽  
Semiconductor Behavior ◽  
Monosodium Salt

"The polymer blend of Chitosan: polyvinyl alcohol (PVA) (1:1) weight percent and hydroxyethyl cellulose (HEC) (0.5%) was prepared. The profile of the sample and its properties were measured by Fourier transfer Infrared spectroscopy (FTIR). The Scanning Electron Microscopy (FESEM) was used to describe the morphology of the polymer blend with two magnifications without any ratio of 4- (2-Pyridylazo) resorcinol monosodium salt hydrate and with 0.15 % of a 4-(2-Pyridylazo) resorcinol monosodium salt hydrate. The mechanical properties were demonstrated and characterized by Elongation and Young modulus. The polymer blend was incorporated with different weight ratios of 4-(2-Pyridylazo) of resorcinol monosodium salt hydrate, (0.03, 0.05, 0.07, 0.09, 0.15) gm of weight %. The current-voltage (I-V) characterization of prepared thin films showed ohmic behavior and the electrical conductivity was improved by increasing the ratio of dopant that leads all samples to reflect a semiconductor behavior.

scholarly journals Mori-Tanaka-based statistical methodology to compute the effective Young modulus of polymer matrix nano-composites considering the experimental quantification of nanotubes dispersion and alignment degree

2022 ◽  
Vol 10 (1) ◽  
pp. 79-98 ◽  
Author(s):  
Iván David Patiño ◽  
Cesar Augusto Isaza
Keyword(s):  
Polyvinyl Alcohol ◽  
Free Path ◽  
Orientation Angle ◽  
Young Modulus ◽  
Distribution Functions ◽  
Reinforced Composites ◽  
Statistical Methodology ◽  
Weight Content ◽  
Path Distance ◽  
Walled Cnts

This paper presents a Mori-Tanaka-based statistical methodology to predict the effective Young modulus of carbon nanotubes (CNTs)-reinforced composites considering three variables: weight content, reinforcement dispersion and orientation. Last two variables are quantified by two parameters, namely, free-path distance between nano-reinforcements and orientation angle regarding the loading direction. To validate the present methodology, samples of multi-walled CNTs (MWCNTs)-reinforced polyvinyl alcohol (PVA)-matrix composite were manufactured by mixing solution. The MWCNT/PVA Young modulus was measured by nano-indentation, while the MWCNTs Young modulus was quantified by micro-Raman spectroscopy. Both stretched and unstretched composite specimens were fabricated. Transmission electron microscopy (TEM) and in-plane image analysis were used to obtain fitting coefficients of log-normal frequency distribution functions for the free-path distance and orientation angle. It was evidenced that numerical results fit well to measured values of effective Young modulus of MWCNTs and MWCNT/PVA, with exception of some particular cases where significant differences were found. Microstructural heterogeneities, cluster formation, polymer chains alignment, errors associated with the dispersion, orientation and mechanical characterization procedures, as well as idealization and statistical errors, were identified as possible causes of these differences. Finally, using the proposed methodology and the dispersion and orientation distribution functions experimentally obtained, the effective Young modulus is estimated for three kinds of thermoplastic matrices (polyvinyl alcohol, polyethylene ketone, and ultra-high molecular weight polyethylene) with different kinds of nanotubes (single wall, double wall, and multi-walled), at different weight contents, finding the superior mechanical performance for double-walled CNTs-reinforced composites and the lower one for multi-walled CNTs-reinforced ones.

SPACE-CHARGE EFFECT IN UNINTENTIONALLY N-DOPED SILICON

2012 ◽  
Vol 26 (08) ◽  
pp. 1250048 ◽  
Author(s):  
KANKAN CONG ◽  
YANG JI
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Space Charge ◽  
Space Charge Effect ◽  
Charge Effect ◽  
Temperature Range ◽  
Ohmic Behavior ◽  
Current Voltage ◽  
Doped Silicon ◽  
High Bias

We report experimental results on current–voltage characteristics of Au-Ti/n-Si/Au-Ti devices made on unintentionally n-doped silicon, which depend dramatically on temperature and external magnetic field. While such devices show Ohmic behavior in the temperature range 154–300 K, space-charge effect dominates at high bias voltages in the temperature range 77–154 K. In the later case, external magnetic field may increase its breakdown voltage, thus inducing large positive magnetoresistance similar to those reported by other groups.

Kaolin-loaded chitosan/polyvinyl alcohol electrospun scaffold as a wound dressing material: in vitro and in vivo studies

2020 ◽  
Vol 29 (5) ◽  
pp. 270-280
Author(s):  
Majid Salehi ◽  
Saeed Farzamfar ◽  
Arian Ehterami ◽  
Zahrasadat Paknejad ◽  
Farshid Bastami ◽  
...  
Keyword(s):  
Polyvinyl Alcohol ◽  
Polymer Blend ◽  
Cellular Response ◽  
Blood Compatibility ◽  
Transmission Rate ◽  
Weight Ratio ◽  
In Vivo Studies ◽  
Collagen Fibres ◽  
Uptake Capacity ◽  
Sterile Gauze

Objective: To evaluate the application of a fabricated dressing containing kaolin for skin regeneration in a rat model of excisional wounds. Method: In the present study, kaolin was loaded into electrospun polyvinyl alcohol (PVA)/chitosan polymer blend to develop a composite nanofibrous dressing. To make the yarns, kaolin with weight ratio of 5% was added to PVA/chitosan polymer blend and subsequently formed into nanofibres using the electrospinning method. Scaffolds were evaluated for to their microstructure, mechanical properties, surface wettability, water vapour transmission rate, water-uptake capacity, blood uptake capacity, blood compatibility, microbial penetration test, the number of colonies, and cellular response with the L929 cell line. Rats with full-thickness excisional wounds were treated with kaolin-containing and kaolin-free dressings. Results: The study showed that rats treated with the kaolin-incorporated mats demonstrated a significant closure to nearly 97.62±4.81% after 14 days compared with PVA/chitosan and the sterile gauze, which showed 86.15±8.11% and 78.50±4.22% of wound closure, respectively. The histopathological studies showed that in the PVA/chitosan/kaolin group, dense and regular collagen fibres were formed, while wounds treated with sterile gauze or PVA/chitosan scaffolds had random and loose collagen fibres. Conclusion: Our results show the potential applicability of PVA/chitosan/kaolin scaffolds as a wound care material.

scholarly journals Ultrathin Electrolyte Membranes with PFSA-Vinylon Intermediate Layers for PEM Fuel Cells

Polymers ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 1730
Author(s):  
Jedeok KIM ◽  
Kazuya Yamasaki ◽  
Hitoshi Ishimoto ◽  
Yusuke Takata
Keyword(s):  
Fuel Cells ◽  
Polyvinyl Alcohol ◽  
High Current Density ◽  
Pem Fuel Cells ◽  
High Humidity ◽  
High Current ◽  
Intermediate Layers ◽  
Current Voltage ◽  
Electrolyte Membranes ◽  
Reinforcing Material

We prepared ultrathin PFSA/PFSA-vinylon/PFSA laminated electrolyte membranes (thickness = 10 μm) for fuel cells without using a reinforcing material. Nafion and Aquivion solutions were used as PFSA polymers. Vinylon was synthesized by formalizing polyvinyl alcohol. From the current-voltage measurements using ultrathin PFSA/PFSA-vinylon/PFSA membranes; the cell resistances are significantly lower than that using a 50 μm Nafion membrane. A high current density was obtained under both low- and high-humidity conditions. Ultrathin PFSA/PFSA-vinylon/PFSA laminated membranes will help to further improve the performance of PEMFCs.

Bio-nanocomposite films based on cellulose nanocrystals filled polyvinyl alcohol/chitosan polymer blend

2015 ◽  
Vol 132 (22) ◽  
pp. n/a-n/a ◽  
Author(s):  
Nassima El Miri ◽  
Karima Abdelouahdi ◽  
Mohamed Zahouily ◽  
Aziz Fihri ◽  
Abdellatif Barakat ◽  
...  
Keyword(s):  
Polyvinyl Alcohol ◽  
Polymer Blend ◽  
Cellulose Nanocrystals ◽  
Nanocomposite Films
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