scholarly journals Fundamental study of colloidal stability and dispersion of novel nanosized conductive polyaniline (PANI)/prevulcanised latex (PVL) film for antimicrobial applications

2021 ◽  
Vol 1195 (1) ◽  
pp. 012055
Author(s):  
M F Banjar ◽  
H D Suphi ◽  
M I Sarizan ◽  
A N A Yahaya ◽  
N A Khalil ◽  
...  
Keyword(s):  
Colloidal Stability ◽  
Mechanical Performance ◽  
Oxidative Polymerization ◽  
Sodium Dodecyl ◽  
Testing Machine ◽  
Fundamental Study ◽  
Ammonium Persulphate ◽  
Effective Dispersion ◽  
Conductive Polyaniline ◽  
Enhanced Conductivity

Abstract A smart material possessed enhanced conductivity integrated in prevulcanized latex (PVL) film produced throughout this work. Also recognizing the synthesis route of PANI was vast and vary, choosing suitable method was great importance corresponding to the aim of study. PANI was prepared through chemical oxidative polymerization of aniline carried out in aqueous solution which aniline dissolved in strong acidic solution (1 M HCl) with the presence of Ammonium Persulphate (APS) as the oxidizing agent and Sodium Dodecyl Sulphate (SDS) as surfactant. However, PANI was readily in acidic condition while PVL in basic and consequently causes a state of immiscibility upon mixing. Hence, PANI formed then mixed with 0.1 – 0.5 % KOH via homogenizer to increase the pH and maintain the homogeneity as well as dispersion to be combined with PVL. Various studies on PANI synthesis and incorporation with latex had been reported but very limited in focusing the colloidal and dispersion stability of the mixture. Zeta potential measurements revealed an effective dispersion and the colloidal stability as the pH of PANI increases. Analysis of mechanical performance using Universal testing Machine revealed that addition of PANI improves greatly in novel film tensile strength and Young’s Modulus by 109 % and 230 %, respectively.

Fabrication of Conductive Textile via Chemical Oxidative Polymerization of Aniline on Polyester Cloth

2018 ◽  
Author(s):  
alireza razaghi
Keyword(s):  
Acidic Solution ◽  
Oxidative Polymerization ◽  
Morphological Structure ◽  
Infrared Spectrometry ◽  
Aniline Monomer ◽  
Polyester Textile ◽  
Conductive Polyaniline ◽  
Conductive Textile ◽  
Polymerization Conditions ◽  
Aniline Polymerization

In this research aniline polymerization conditions were optimized in presence of pre-treated polyester textile to achieve as high electrical conductivity as 100 S/Cm. Alkaline activation of the polyester textile was followed by immersion in to aqueous acidic solution of aniline monomer. Then the oxidant solution was used to initiate the polymerization. Finally, the prepared product was washed and dried prior to ant test. Functional groups were studied by Fourie-transformed infrared spectrometry (FTIR) from the surface of the polyaniline coated textile. Also, morphological structure of synthesized conductive polyaniline was studied by scanning electron microscopy (SEM). The synthesized cloth was used in a closed circuit in order to light up alight emitting diode to emphasis the conductivity of the textile and fibres that synthesised by this method.

Fabrication of Conductive Textile via Chemical Oxidative Polymerization of Aniline on Polyester Cloth

2018 ◽  
Author(s):  
alireza razaghi
Keyword(s):  
Acidic Solution ◽  
Oxidative Polymerization ◽  
Morphological Structure ◽  
Infrared Spectrometry ◽  
Aniline Monomer ◽  
Polyester Textile ◽  
Conductive Polyaniline ◽  
Conductive Textile ◽  
Polymerization Conditions ◽  
Aniline Polymerization

In this research aniline polymerization conditions were optimized in presence of pre-treated polyester textile to achieve as high electrical conductivity as 100 S/Cm. Alkaline activation of the polyester textile was followed by immersion in to aqueous acidic solution of aniline monomer. Then the oxidant solution was used to initiate the polymerization. Finally, the prepared product was washed and dried prior to ant test. Functional groups were studied by Fourie-transformed infrared spectrometry (FTIR) from the surface of the polyaniline coated textile. Also, morphological structure of synthesized conductive polyaniline was studied by scanning electron microscopy (SEM). The synthesized cloth was used in a closed circuit in order to light up alight emitting diode to emphasis the conductivity of the textile and fibres that synthesised by this method.

Mechanical Properties Comparison of Different La Content in AZ91

2014 ◽  
Vol 620 ◽  
pp. 67-72 ◽  
Author(s):  
Yan Yan Zhang ◽  
Chun Xia He ◽  
Hang Song Yang ◽  
Jian Xiu Liu
Keyword(s):  
Magnesium Alloy ◽  
Mechanical Performance ◽  
Testing Machine ◽  
Powder Metallurgy Method ◽  
Az91 Magnesium Alloy ◽  
Compression Performance ◽  
Hardness Tester ◽  
Mechanics Performance ◽  
Tension And Compression ◽  
Az91 Magnesium

In order to improve the comprehensive mechanics performance of AZ91 magnesium alloy which is used as car's material, the La element was added in AZ91 magnesium alloy and specimens was prepared by powder metallurgy method. The influence of La on microstructure, hardness and compression performance of AZ91 a magnesium alloy specimen was studied using metallographic electronic microscope, hardness tester, universal tension and compression testing machine. The experimental results show that when amount of La's addition is 1.2%, its mechanical performance is best, hardness is 67.1 HV, compressive strength is 115.8 MPa, increased respectively by 20.0% and 29.5% compared the AZ91 magnesium alloy substrate, and the grain refinement effect of AZ91 magnesium alloy is the best at this time.

A model study on the impact of metal ions on pre-vulcanization of concentrated natural rubber latex and dipped-products

2021 ◽  
pp. 147776062110629
Author(s):  
Porntip Rojruthai ◽  
Narueporn Payungwong ◽  
Jitladda T Sakdapipanich
Keyword(s):  
Natural Rubber ◽  
Metal Ions ◽  
Colloidal Stability ◽  
Mechanical Stability ◽  
Testing Machine ◽  
Natural Rubber Latex ◽  
Tensile Testing Machine ◽  
Model Study ◽  
Stability Time ◽  
The Impact

A model study on the influence of some heavy metal ions on the stability and vulcanization efficiency of uncompounded and compounded high-ammonia natural rubber (HANR) latex was carried out by an exogenous addition and then determined by Brookfield viscometer, mechanical stability time (MST) tester, and tensile testing machine. The case of pre-vulcanized HANR latex with different aging times was determined by the change in the volatile fatty acid (VFA) number, MST, and viscosity. The compounded HANR latex was coagulated by adding Mn2+and Mg2+ while it was unaltered by adding Zn2+, Fe2+, and Cu2+ ions, leading to their colloidal stability. Therefore, these metal ions were chosen further to study the pre-vulcanization of compounded HANR latex. The presence of Zn2+, Fe2+, and Cu2+ in the latex is responsible for the delay in the vulcanization process and changes the appearance of compounded latex. Before compounding, the addition of such metal ions led to the reduction in tensile strength of the obtained gloves. At the same time, there was no effect on the tensile properties of the gloves made from the compounded HANR latex containing the metal ions.

Electrochemical Studies on Corrosion Resistance of Coatings Based on Polyaniline and Silica Gel

2021 ◽  
Vol 1167 ◽  
pp. 13-22
Author(s):  
C.C. Soumya ◽  
K.E. George ◽  
Sunil K. Narayanankutty
Keyword(s):  
Silica Gel ◽  
Electrochemical Impedance ◽  
Oxidative Polymerization ◽  
Corrosion Current ◽  
Nacl Solution ◽  
Chemical Oxidative Polymerization ◽  
Ammonium Persulphate ◽  
Protection Efficiency ◽  
Corrosion Studies ◽  
Doped Polyaniline

Organic acid doped polyaniline (PANI), hybrid with silica gel (SiG) and composites with metal primer have been prepared by chemical oxidative polymerization of double-distilled aniline in an acidic medium at 0-5 °C in an ice bath using ammonium persulphate as oxidant and p-toluene sulphonic acid (p-TSA) as the dopant. The anticorrosive property of PANI coatings containing alkyd primer, zinc chromate and silica gel was investigated. The coatings were characterized by FTIR spectroscopy, scanning electron microscopy and electrochemical impedance spectroscopy. The corrosion studies were carried out in a 3.5 wt% NaCl solution. On introduction of SiG, PANI, and PANI-SiG hybrid, the corrosion current decreased from 0.03626 μA to 0.007856 μA, 0.02042 μA, and 0.011 μA, respectively. The penetration rates calculated in mm/yr. for the composites: SiG/Primer, PANI/Primer and PANI-SiG/Primer were 0.430× 10-4, 1.110× 10-4, and 0.599 × 10-4, respectively and that of neat primer was 1.977 × 10-4. The corrosion protection efficiency of the primer was improved up to 7% on introduction of the PANI-based fillers. The 5 wt% of 1:1 PANI-SiG/primer composite, which contains 2.5wt% of PANI, showed better results than that of 5wt% PANI in Primer and these results are very close to that of 5wt% SiG/Primer composites.

Comparison between traditional and alternative biocompatible welding techniques used in orthodontic devices

2020 ◽  
pp. 146531252097240
Author(s):  
Fernanda de Souza Henkin ◽  
Luciane Macedo de Menezes ◽  
Berenice Anina Dedavid ◽  
Cátia Abdo Quintão
Keyword(s):  
Tensile Strength ◽  
Laser Welding ◽  
Mechanical Performance ◽  
Steel Wire ◽  
Testing Machine ◽  
Mean Values ◽  
Welding Spot ◽  
Microstructural Morphology ◽  
Orthodontic Devices

Objective: To compare the mechanical strength of joints made by conventional soldering with those made by alternative, more biocompatible, methods (spot, tungsten inert gas [TIG] and laser welding), and to compare the microstructural morphology of wires welded with these techniques. Design: In vitro, laboratory study. Methods: Forty stainless-steel wire segments with 0.8-mm diameter were joined by silver soldering, spot, laser and TIG welding. Ten specimens were produced for each one. Tensile strength test was performed 24 h after welding on the Emic DL2000™ universal testing machine, using a load cell of 1000 N with a crosshead speed of 10 mm/min. Results: The highest tensile strength mean values were obtained with silver soldering (532 N), next were laser (420 N), spot (301 N) and TIG (296 N) welding. Statistically significant differences were observed between the groups; the Dunn post-hoc test revealed differences between laser and spot welding ( p=0.046), laser and TIG ( p = 0.016), spot and silver ( p <0.001), and silver and TIG ( p <0.001). Conclusion: Laser welding strength is high, and comparable to silver welding. Spot and TIG techniques present comparable and significantly lower strengths. The four methods presented resistance values compatible with orthodontic use. The microstructural morphology is different for each technique. The association between the mechanical performance and the microstructure evaluation shows that laser presented the highest quality joint.

Acoustic Emission Characteristics of Rock Failure under Uniaxial Loading

2011 ◽  
Vol 378-379 ◽  
pp. 43-46 ◽  
Author(s):  
Tao Xie ◽  
Qing Hui Jiang ◽  
Rui Chen ◽  
Wei Zhang
Keyword(s):  
Acoustic Emission ◽  
Failure Modes ◽  
Mechanical Performance ◽  
Progressive Failure ◽  
Failure Process ◽  
Testing Machine ◽  
Rock Failure ◽  
Rock Failure Process ◽  
State Variation ◽  
Acoustic Emission Test

With RMT-150C rock testing machine and AEWIN E1.86 DISP acoustic emission system applied, the acoustic emission test was accomplished with two kinds of rock samples including marble and granite under uniaxial compression. Cyclic loading and continuous loading were used through the experiment, and the mechanical performance and acoustic emission (AE) characteristics were obtained during the process of rock progressive failure. Details related to the relationship between amount of AE and stress-strain was given in this paper. A comparison between marble and granite was made as well following the general AE law, on the basis of which, the failure mechanism of rock mass was investigated. Finally, some conclusions can be summarized as follows:(1) AE activity features are different with stress state variation in rock failure process;(2) loading patterns make a direct impact on the failure process thereby affecting AE activities;(3)AE activities are various basing on the different types of rocks, structures and failure modes.

The effect of heat treatment and skimming on precipitate formation in caprine and bovine milks

2014 ◽  
Vol 82 (1) ◽  
pp. 22-28 ◽  
Author(s):  
Zorana N Miloradovic ◽  
Nemanja V Kljajevic ◽  
Snezana T Jovanovic ◽  
Tanja R Vucic ◽  
Ognjen D Macej
Keyword(s):  
Heat Treatment ◽  
Centrifugal Force ◽  
Colloidal Stability ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Bovine Milk ◽  
Protein Composition ◽  
Heat Stability ◽  
Protein Loss ◽  
Caprine Milk

Caprine and bovine milks have a similar overall gross composition, but vary considerably in the ratios of their casein components. These differences in colloidal casein micelles could affect directly or indirectly the heat stability of caprine and bovine milks at their natural pH. In the present work, the differences in colloidal stability of caprine and bovine milk have been studied by analysing the effect of heat treatment and skimming on precipitation of proteins. Raw and heated milk samples (70 °C/5 min, 80°C/5 min and 90°C/5 min) were centrifuged at 600, 2000, and 4500 g. The amount of precipitate formed after skimming was measured and the protein composition of both precipitates and supernatants analysed using the SDS-PAGE (sodium dodecyl sulphate polyacrylamide gel electrophoresis) and densitometry. In caprine milk, the heat treatment prior to skimming had a statistically significant effect on protein precipitation. Centrifugal force had a statistically significant effect on amount of precipitate for both milks, but the amount was 2 to 4 times higher for caprine milk. When defatting the milk for electrophoresis, a centrifugal force of 600 g appeared to be the most appropriate, in order to avoid protein loss and a possible error in the interpretation of results. Results of this study could also serve as the basis for further investigations on adjusting the skimming conditions for caprine milk in industrial dairy processing environment.

Sign in / Sign up

Export Citation Format

Share Document