Product analysis, electrical and dielectric properties depending on thermal influence of poly(N-isopropyl acrylamide)/graphite-filled composite

Biryan, Fatih; Abubakar, Abdullahi Musa; Demirelli, Kadir

doi:10.1016/j.tca.2018.09.009

Cited by 14 publications

(10 citation statements)

References 20 publications

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“…The main reason for this discrepancy is that these studies investigate aqueous solution or suspension of Poly(NIPAM) whereas the samples are dried and pelleted in this study. Biryan et al 53 also reported dielectric properties of dried Poly(NIPAM) and found ε' value slightly less than 4 at 1 kHz and this can be considered as comparable with ε' value of this study. They also found that addition of graphite increased the value of ε' significantly.…”

Section: Analysis Of Dielectric and Electrical Characteristicssupporting

confidence: 90%

“…Linear fit reveals σ dc values as 3.74 × 10 −11 S/cm for hydrogel sample and 1.02 × 10 −8 S/cm for composite sample thanks to Pyrrole incorporation to hydrogel. In the literature, one can encounter studies on Poly(NIPAM) that show much higher σ dc values 47–53 , but as mentioned earlier these studies focus on aqueous solution or suspension of Poly(NIPAM) whereas our study focuses on pelleted sample. On the other hand, σ ac values of this study are compatible with those of, 53 which investigates dried poly(NIPAM) sample, so it is estimated that σ dc values would be comparable as well.…”

Section: Resultsmentioning

confidence: 99%

“…Analogous representation of σ ac is given by; 56 σ ac = σ dc + 1 s dσ ac dlnω ð8Þ σ ac -dσ ac /dlnω curves of the samples drawn for the low frequency region are given in Figure 9. According to [47][48][49][50][51][52][53] , but as mentioned earlier these studies focus on aqueous solution or suspension of Poly(NIPAM) whereas our study focuses on pelleted sample. On the other hand, σ ac values of this study are compatible with those of, 53 which investigates dried poly(NIPAM) sample, so it is estimated that σ dc values would be comparable as well.…”

Section: Analysis Of Dielectric and Electrical Characteristicsmentioning

confidence: 99%

“…According to [47][48][49][50][51][52][53] , but as mentioned earlier these studies focus on aqueous solution or suspension of Poly(NIPAM) whereas our study focuses on pelleted sample. On the other hand, σ ac values of this study are compatible with those of, 53 which investigates dried poly(NIPAM) sample, so it is estimated that σ dc values would be comparable as well. As to s values of the samples for low frequency region, s value was obtained as 0.83 for hydrogel sample so the conductivity mechanism is quantum mechanical tunneling (QMT) 59 indicating that the carrier transport in hydrogel sample is governed by tunneling of charge carriers between spatially localized states near Fermi level.…”

Section: Analysis Of Dielectric and Electrical Characteristicsmentioning

confidence: 99%

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One‐step preparation of poly(NIPAM‐pyrrole) electroconductive composite hydrogel and its dielectric properties

Şarkaya

Yıldırım

Allı

2021

J of Applied Polymer Sci

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Conductive polymers and hydrogels are two of the hot prospect polymer types that are used for new stimuli responsive materials. In this study, one‐step preparation of electroconductive composite hydrogels containing polypyrrole (PPy) and N‐isopropylacrylamide (NIPAM) using free radical polymerization technique was achieved with N,N‐methylenebisacrylamide as a crosslinker and ammonium peroxy disulphate (APS) as initiator, in mixture of water/isopropyl alcohol. The equilibrium swelling degree of the poly(NIPAM)‐pyrrole) electroconductive composite hydrogel was 9.88 g of H2O/g dry polymer. According to TGA results, the thermal stability of the prepared composite poly(NIPAM‐PPy) conductive hydrogel (700°C) hydrogel is higher than that of pure poly(NIPAM) hydrogel (600°C). Furthermore, prepared samples were characterized by FTIR, and SEM analyzes. Later, the samples were pressured into pellets so that electrical impedance spectroscopy (EIS) measurements were taken between 10 and 10 MHz at room temperature. The dielectric constant value of composite poly(NIPAM‐PPy) hydrogel at 10 Hz is almost 10 times higher than that of poly(NIPAM) hydrogel. Both samples' real and imaginary parts of dielectric constant decreased with increased frequency. Samples exhibited non‐Debye relaxation since experimental data fit into dielectric model of Havriliak‐Negami. Moreover, low frequency data yielded d.c. conductivity of the pure and composite samples as 3.74 × 10−11 and 1.02 × 10−8 S/cm, respectively. Real part of impedance at low frequencies also points out ~103 times lower resistance values at 10 Hz for composite poly(NIPAM‐PPy) hydrogel. Therefore, EIS results support that electroconductive composite hydrogel fabrication was achieved using free radical polymerization technique.

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Section: Analysis Of Dielectric and Electrical Characteristicssupporting

confidence: 90%

Section: Resultsmentioning

confidence: 99%

Section: Analysis Of Dielectric and Electrical Characteristicsmentioning

confidence: 99%

Section: Analysis Of Dielectric and Electrical Characteristicsmentioning

confidence: 99%

See 2 more Smart Citations

One‐step preparation of poly(NIPAM‐pyrrole) electroconductive composite hydrogel and its dielectric properties

Şarkaya

Yıldırım

Allı

2021

J of Applied Polymer Sci

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“…The thermal degradation of PNiPAM showed a single-step degradation over the temperature range from 320 to 430 °C. The thermal degradation was initiated by the thermal cleavage of C-N, C-C, and C-O bonds in the polymer chain, and these cleavages gave rise to chain free radicals, which would then become involved in further complicated reaction processes at elevated temperatures, including chain transfer, rearrangement, isomerization, cyclizations, etc., resulting the formation of six-and four-membered amide ring compounds 43,44 .…”

mentioning

confidence: 99%

Properties enhancement of carboxymethyl cellulose with thermo-responsive polymer as solid polymer electrolyte for zinc ion battery

Dueramae

Okhawilai

Kasemsiri

et al. 2020

Sci Rep

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A novel polymer host from carboxymethyl cellulose (cMc)/poly(N-isopropylacrylamide) (pnipAM) was developed for a high safety solid polymer electrolyte (SPE) in a zinc ion battery. Effects of the PNiPAM loading level in the range of 0-40% by weight (wt%) on the chemical, mechanical, thermal, and morphological properties of the CMC/PNiPAMx films (where x is the wt% of PNiPAM) were symmetrically investigated. The obtained CMC/PNiPAMx films showed a high compatibility between the polymers. The CMC/PNiPAM20 blend showed the greatest tensile strength and modulus at 37.9 MPa and 2.1 GPa, respectively. Moreover, the thermal degradation of CMC was retarded by the addition of PNiPAM. Scanning electron microscopy images of CMC/PNiPAM20 revealed a porous structure that likely supported Zn 2+ movement in the SPEs containing zinc triflate, resulting in the high Zn 2+ ion transference number (0.56) and ionic conductivity (1.68 × 10-4 S cm −1). interestingly, the presence of PNiPAM in the CMC/PNiPAMx blends showed a greater stability during charge-discharge cyclic tests, indicating the ability of pnipAM to suppress dendrite formation from causing a short circuit. The developed CMC/PNiPAM20 based SPE is a promising material for high ionic conductivity and stability in a Zn ion battery. With the environmental concerns and the limitation of fossil fuels as well as the growing energy demands, the rechargeable battery is one kind of renewable energy sources which is consecutively developed for a sustainable energy supply. In spite of the most promising technology of lithium-ion batteries (LIBs), the zinc ion battery is used as a compelling alternative battery chemistry to LIBs for energy storage system 1-3 owing to its low cost, abundance, inflammability, low toxicity, promising energy density and environmental friendlier 4,5. The utilization of metal-ion batteries as power sources has led to exhaustive research on electrolyte systems with high electrochemical performance. It plays a significant role in battery electrochemistry that is the medium for the movement of ions within the batteries. Recently, solid polymer electrolytes (SPEs) have interested raised attention and enhanced research efforts as a fascinating alternative electrolyte bridge to liquid polymer electrolyte (LPEs) due to a lot of benefits, i.e., high durability, high energy density, lightweight, great flexibility for cell design, inert towards the electrodes, overcome the limitation of solvent leakage and low volatility, reduce the cell assembly cost, and great electrochemical and thermal stability 6. Fundamentally, SPEs consist of a dissolution of metal salts, e. g. lithium and zinc salt, in a host polymer, which the hopping process is used to describe the metal ions movement along the amorphous phase of polymer after the salts dissociate by interaction with the polar group of polymer 7. To coordinate with ions, therefore, the host polymer must contain electron donor groups such as O, N, and S. Moreover, it should

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Smart Core‐Shell Nanostructures for Force, Humidity, and Temperature Multi‐Stimuli Responsiveness

Ali

Schäffner

Belegratis

et al. 2022

Adv Materials Technologies

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stimuli and transmits the information to the brain. [1] In the last decade, a substantial understanding of how this complex system behaves has been gained. [2][3][4] Nevertheless, its replication to form artificial skins is still a relatively new field with massive potential. Relying on advancements in functional materials, structural design, and state-of-art production/deposition techniques, a wide variety of single/ multi-stimuli responsive sensory systems, suitable for electronic skin (e-skin) applications, have been reported. [5][6][7][8] An efficient e-skin design requires a combination of functional materials with suitable mechanical and electrical properties, [9] in addition to the micro/nanoscale control of the layer's thickness and dimensions, which is optimized by the choice of suitable fabrication techniques.For pressure and force detection, the most common methods exploit piezoelectric, piezoresistive, or capacitive sensing. [10][11][12][13] Bao's group investigated an e-skin design based on flexible pressure-sensitive organic thinfilm transistors deploying a force-sensitive gate dielectric capacitance. The sensor has a maximum sensitivity of 8.4 kPa −1 and a fast response time of 10 ms. This was realized with a combination of microstructured polydimethylsiloxane (PDMS) gate dielectric and a high-mobility semiconducting polymer in a transistor design. The sensor relies on capacitance change due to mechanical excitations. [14] Another pressure-sensitive e-skin design, investigated by Bao's group, is realized by a composite piezoresistive material consisting of an organic polymer and nickel nanostructured microparticles. [15] Park and Jang investigated hybrid piezoelectric/piezoresistive pressure sensors based on a nanohybrid material from graphene with free-standing nanofibers of PEDOT/P(VDF-HFP). Their e-skin device impresses with a gauge factor as high as 320 under tensile strain thus showing high sensitivity to pressure with a low limit of detection of 0.5 Pa only. [16] Humidity sensors for e-skin applications have also been investigated. [17,18] Guo et al. demonstrated that a tungsten sulfite (WS 2 ) film combined with graphene electrodes and PDMS substrate exhibits a high humidity response (up to 90% relative humidity or RH) due to the change in the WS 2 conductivity. [19] Similarly, e-skin sensitivity to changes in surrounding temperature is desired and has been investigated. [20][21][22] Chen et al.A force, humidity, and temperature-responsive electronic skin is presented by combining piezoelectric zinc oxide (ZnO) and poly-N-vinylcaprolactamco-di(ethylene glycol) divinyl ether hydrogel into core-shell nanostructures using state-of-the-art dry vapor-based techniques. The proposed concept is realized with biocompatible materials in a simplified design that delivers multi-stimuli sensitivity with high spatial resolution, all of which are prerequisites for an efficient electronic skin. While the piezoelectricity of ZnO provides sensitivity to external force, the thermoresponsiveness of the hydrogel...

show abstract

Product analysis, electrical and dielectric properties depending on thermal influence of poly(N-isopropyl acrylamide)/graphite-filled composite

Cited by 14 publications

References 20 publications

One‐step preparation of poly(NIPAM‐pyrrole) electroconductive composite hydrogel and its dielectric properties

One‐step preparation of poly(NIPAM‐pyrrole) electroconductive composite hydrogel and its dielectric properties

Properties enhancement of carboxymethyl cellulose with thermo-responsive polymer as solid polymer electrolyte for zinc ion battery

Smart Core‐Shell Nanostructures for Force, Humidity, and Temperature Multi‐Stimuli Responsiveness

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