Electrically conductive epoxy/polyaniline composite fabrication and characterization for electronic applications

2021 ◽  
pp. 073168442110239
Author(s):  
Iqra A Rashid ◽  
Asra Tariq ◽  
HM Fayzan Shakir ◽  
Ayesha Afzal ◽  
Fahad Ali ◽  
...  

This study reports on the electrical conductivity, dielectric, and electromagnetic interferenc (EMI) shielding properties of conductive epoxy/PAni blend containing various concentrations. Polyaniline (PAni) was synthesized using oxidative chemical polymerization technique and then dispersed into epoxy resin using a sonication bath. Infrared spectra confirm the curing of composites. Increasing the aspect ratio of PAni in epoxy increased the electrical conductivity and improves the microwave absorption properties of composites in the microwave range (0.1 GHz–20 GHz). Electrical conductivity was measured by using the four-probe method, and the maximum conductivity of the composite was achieved 3.51 × 10−13 Scm−1 with 30 wt% of PAni. The maximum porosity of the composite with 30 wt% of PAni was 15.5%. EMI shielding was measured by a vector network analyzer (VNA) in the microwave region (0.1 GHz–20 GHz), which gives the maximum value of 63 dB. IR shielding was measured by IR spectroscopy and less than 0.5% transmission was observed in NIR (700 nm–2500 nm) region. The average particle size of PAni is found to be 113 nm. These composites were used as a potential candidate for conductive coatings, EMI shielding purposes, and electronic applications.

Fractals ◽  
2011 ◽  
Vol 19 (03) ◽  
pp. 317-328 ◽  
Author(s):  
ISHWAR DAS ◽  
NAMITA R. AGRAWAL ◽  
RINKI CHOUDHARY ◽  
SANJEEV KUMAR GUPTA

Fractal growth patterns of polyaniline were developed during electropolymerization of aniline using the surfactants sodium dodecyl sulphate (NaDS) and NaDS containing cetyl trimethyl ammonium bromide (CTAB). Growth kinetics was studied and electric potential oscillations were monitored as a function of time. On addition of CTAB polymer growth was inhibited due to coordination of CTAB with the growing polyaniline chain. The average particle size of the polymer aggregate obtained from aniline- NaDS-H2O system was ~150 nm as evident by Transmission Electron Microscopy (TEM) results. Polymer aggregates were characterized by electrical conductivity measurements, X-ray diffraction (XRD) and Thermogravimetric (TG) studies. An interaction between NaDS and aniline was observed in the absence of electric field as evident by (i) electrical conductivity of aqueous solution of NaDS in the absence and presence of aniline, and (ii) their crystallization patterns on microslides. A mechanism for the development of fractal patterns and electrical potential oscillations is proposed on the basis of diffusion limited aggregation process.


2005 ◽  
Vol 475-479 ◽  
pp. 1763-1766 ◽  
Author(s):  
Yan Wang ◽  
Yang Liu ◽  
Ju Sheng Ma ◽  
Zhaowen Dong ◽  
Mingli Yin

Fine Au powders with spherical morphology and good dispersivity were produced. The average particle size is 1~2m. The influences of constituents on the rheology of organic vehicles were investigated by orthogonal design method. Consequently, the compatible Au thick film pastes for LTCC substrate have been prepared. SEM was carried out to study the sintering behaviors and microstructures of the buried pastes with LTCC substrate. These pastes have high electrical conductivity (less than 3m/sq.), reliable wire bond strength (greater than 9 grams, 25m Au wire) and fine line printability (as small as 80m). The via filling technology was also discussed in this paper.


2021 ◽  
Author(s):  
Aishwarya Nadgir ◽  
Ashok H Sidarai

Abstract The fluorescence based applications such as chemosensing of Fe3+ ion, temperature sensing, NOR-gate molecular logic operations, and fluorescent ink were achieved using an expired medicine namely Pantoprazole (sensor1) which is a derivative of benzimidazole class. The phenomenon of quenching was a basic principle used in sensing Fe3+. We found that there was a combined effect of dynamic and static processes in quenching of fluorescence of sensor1. To confirm the selectiveness of sensor1, we performed interference experiments with other metal ions. There was no interference between these metal ions and Fe3+. The low LOD value of 1.032µM suggested that the molecule is highly sensitive towards Fe3+. A high quantum yield of 8.087% increased the possibility of using sensor1 for light applications. There was a 2:1 stoichiometric ratio between sensor1 and Fe3+. The FTIR data analysis confirmed the presence of functional groups S = O, C-O-C, etc. The average particle size found with the DLS method was 130.5nm. The zeta potential of -12.7mV indicated that sensor1 is quite stable in solution form. For logic gate application EDTA (Ethylenediaminetetraaceticacid) and Fe3+ were considered as inputs and fluorescence intensity was taken as an output. In thermal sensing application, the high value of activation energy i.e 908meV and relative sensitivity of 1.2% 0C−1 affirmed that sensor1 can be used for thermal applications. The sensor1 was also apt for fluorescent ink application. Hence this investigation deduced that sensor1 can be a potential candidate for such applications over other conventional synthesized fluorescent probes.


Molecules ◽  
2019 ◽  
Vol 24 (16) ◽  
pp. 2996 ◽  
Author(s):  
Jing He ◽  
Yi-en Du ◽  
Yang Bai ◽  
Jing An ◽  
Xuemei Cai ◽  
...  

Anatase/rutile mixed-phase TiO2 nanoparticles were synthesized through a simple sol-gel route with further calcination using inexpensive titanium tetrachloride as a titanium source, which effectively reduces the production cost. The structural and optical properties of the prepared materials were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), and UV-vis adsorption. The specific surface area was also analyzed by Brunauer–Emmett–Teller (BET) method. The anatase/rutile mixed-phase TiO2 nanocomposites containing of rod-like, cuboid, and some irregularly shaped anatase nanoparticles (exposed {101} facets) with sizes ranging from tens to more than 100 nanometers, and rod-like rutile nanoparticles (exposed {110} facets) with sizes ranging from tens to more than 100 nanometers. The photocatalytic activities of the obtained anatase/rutile mixed-phase TiO2 nanoparticles were investigated and compared by evaluating the degradation of hazardous dye methylene blue (MB) under ultraviolet light illumination. Compared to the commercial Degussa P25-TiO2, the mixed-phase TiO2 nanocomposites show better photocatalytic activity, which can be attributed to the optimal anatase to rutile ratio and the specific exposed crystal surface on the surface. The anatase/rutile TiO2 nanocomposites obtained at pH 1.0 (pH1.0-TiO2) show the best photocatalytic activity, which can be attributed to the optimal heterojunction structure, the smaller average particle size, and the presence of a specific exposed crystal surface. The enhanced photocatalytic activity makes the prepared anatase/rutile TiO2 photocatalysts a potential candidate in the removal of the organic dyes from colored wastewater.


2006 ◽  
Vol 317-318 ◽  
pp. 917-920
Author(s):  
Jae Kwang Kim ◽  
Kyung Hun Kim ◽  
Yong Ho Choa ◽  
Jong Won Yoon ◽  
Kwang Bo Shim

Dense 8mol% yttria-stabilized zirconia (8YSZ) consisting of submicrometer-sized grains was prepared using spark plasma sintering (SPS) along with Al2O3 additives. The starting powder with average particle size of 50nm was densified to 98% of the relative density with short sintering time (5min) at 1200 while preserving a submicrometer grain size. The fracture toughness and bending strength showed maximum values of 2.54MPam1/2 and 380MPa at 2vol% alumina-added 8YSZ, due mainly to the higher relative density and small grain size. The electrical conductivity of 2vol% alumina-added 8YSZ was 0.0278 S/cm at 700 in airThus, alumina additions in 8YSZ using the SPS method are an effective process to improve the mechanical strength and electrical conductivity.


2021 ◽  
Vol 22 (4) ◽  
pp. 664-686
Author(s):  
M.B. Khanvilkar ◽  
A.K. Nikumbh ◽  
R.A. Pawar ◽  
N.J. Karale ◽  
D.V. Nighot ◽  
...  

In this work, five substituted perovskite such as (Gd0.9Sr0.1) Mn0.8Co0.2O3, Tb0.8Sr0.2FeO3, Gd0.6Sr0.4RuO3, SrCe0.95Y0.05O3, and Mn0.6Co0.4SnO3 were synthesized by tartrate and hydroxide precursor method. The resulting samples were characterized by inductively coupled plasma spectroscopy, energy dispersive X-ray analysis, infrared spectroscopy, thermal analysis, X-ray powder diffraction, transmission electron microscope (TEM), selected field of electron diffraction (SAED), d.c. electrical conductivity, Hall effect, dielectric measurements, and low-temperature magnetization measurements. The X-ray diffraction pattern for all compounds was indicated the formation of single-phase perovskite with orthorhombic structure except Tb0.8Sr0.2FeO3 and Mn0.6Co0.4SnO3 perovskite. These compounds showed a cubic and rhombohedral structure, respectively. The lattice parameter and the unit cell volume slightly decreased as ionic radii decrease in agreement with the lanthanide contraction. The average size of cation ˂ RA ˃, mismatch factor (σ2), and tolerance factor (t) gives the combined effects of disorder and inhomogeneity in these compounds. The average particle size determined from TEM was in the range of 22 to 77 nm for all compounds. The temperature dependence of electrical conductivity for all compounds showed a definite break in 500 K to 610 K. except the Gd0.6Sr0.4RuO3 compound, which corresponds to semiconducting behavior. While the Gd0.6Sr0.4RuO3 sample shows a metallic-like semiconductor. The thermoelectric power and Hall effect measurements for all compounds were n-type semiconductivity except the SrCe0.95Y0.05O3 compound. It showed p-type semiconductivity. The frequency dependence of the dielectric constant and dielectric loss in these substituted perovskites were discussed using the Maxwell-Wagner model. Magnetic studies showed that the thermo-magnetic irreversibility for all compounds.


Processes ◽  
2020 ◽  
Vol 8 (9) ◽  
pp. 1176
Author(s):  
Martin Prostredný ◽  
Igor Krupa ◽  
Zdenko Špitalský

The presented paper is focused on studying electrically conductive composites based on an elastomeric matrix and expanded graphite as the filler. A potential application as an environmental remote detector was studied. The influence of filler particle size, film thickness, detector length, temperature, and the amount of oil on the detector response rate were explored. Peel tests were performed in order to investigate the adhesion of prepared detector films to different materials. Expanded graphite with average particle size 5 µm was chosen for the experiments due to its fastest response. Decreasing the detector film thickness has caused an increase in the response rate but also a decrease in the signal measured. The response rate of the detector system was in a practical range even for lower temperatures. From the obtained data, the proposed detector seems to be suitable for a practical application.


Materials ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4138 ◽  
Author(s):  
Israel Ceja ◽  
Karla Josefina González-Íñiguez ◽  
Alejandra Carreón-Álvarez ◽  
Gabriel Landazuri ◽  
Arturo Barrera ◽  
...  

Nanostructured films with electrical conductivity in the semiconductor region were prepared in a polymeric matrix of poly(vinyl alcohol) (PVA) with nanostructures of chitosan-gold nanoparticles (AuNPs)/single-wall carbon nanotubes carboxylic acid functionalized (SWCNT-COOH) (chitosan-AuNPs/SWCNT-COOH) self-assembled. Dispersion light scattering (DLS) was used to determine the average particle sizes of chitosan-AuNPs, z-average particle size (Dz) and number average particle size (Dn), and the formation of crystalline domains of AuNPs was demonstrated by X-ray diffraction (XRD) patterns and observed by means of transmission electron microscopy (TEM). The electrostatic interaction was verified by Fourier transform infrared spectroscopy (FTIR). The electrical conductivity of PVA/chitosan-AuNPs/SWCNT-COOH was determined by the four-point technique and photocurrent. The calculated Dn values of the chitosan-AuNPs decreased as the concentration of gold (III) chloride trihydrate (HAuCl4·3H2O) increased: the concentrations of 0.4 and 1.3 mM were 209 and 90 nm, respectively. Average crystal size (L) and number average size (D) of the AuNPs were calculated in the range of 13 to 24 nm. Electrical conductivity of PVA/chitosan-AuNPs/SWCNT-COOH films was 3.7 × 10−5 σ/cm determined by the four-point technique and 6.5 × 10−4 σ/cm by photocurrent for the SWCNT-COOH concentration of 0.5 wt.% and HAuCl4·3H2O concentration of 0.4 mM. In this investigation, the protonation of the amine group of chitosan is fundamental to prepare PVA films with nanostructures of self-assembled chitosan-AuNPs/SWCNT-COOH.


Author(s):  
A. V. Markov ◽  
A. S. Chizhov

Electrically conductive composites based on high density polyethylene (HDPE) / ultrahigh molecular weight polyethylene (UHMWPE) blends filled with carbon black were studied. The work is a part of the research of electrically conductive materials for the manufacture of self-regulating polymer heaters. In this work, the authors investigated composites based on HDPE/UHMWPE (molecular mass of ~ 7 million) blends filled with carbon black (average particle size ~ 20 nm). The goal of the work was to obtain a self-regulating electrically conductive polymer material with optimal thermoelectric characteristics and high heat resistance. It was shown that the effect of adding UHMWPE to the HDPE/carbon black composites on the thermoelectric behavior of the resulting material was similar to cross-linking. This reduced the undesirable effect of the negative thermal coefficient (NTC) of the electrical resistance. In addition, the heat resistance of the material at elevated temperatures was increased. This makes it possible to exclude the radiation or chemical cross-linking in the manufacture of self-regulating polymer heating elements. The rheological, mechanical and thermoelectric properties of HDPE/carbon black composites modified with UHMWPE were also studied. It was found that a diffusion interphase layer with a reduced fluidity in the melt of HDPE/UHMWPE blends was formed. It was established that self-regulating composites containing 30–40% of UHMWPE had the best operational properties. We can recommend the methods of extrusion and injection molding for the processing of HDPE/carbon black composites mixed with 30% UHMWPE, and the pressing method in case of UHMWPE content of 40%. The ability of the composites to be molded is sharply reduced at higher contents of UHMWPE.


2007 ◽  
Vol 280-283 ◽  
pp. 869-872
Author(s):  
Zhi Ming Du ◽  
Xiao Min Cong ◽  
Peng Wang

Carbonaceous fillers have been widely applied in electrically conductive coatings due to their cheaper, steady electrically conductive capability and other excellent performances. Electrically conductive coatings were synthesized by using graphite and carbon black as fillers in the alkyd resin matrices. Influences of various fillers on electrical conductivity of coatings have been investigated in detail.


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