Fine-tuning of conductive and dielectric properties of polypyrrole/TiO2 nanocomposite-coated polyamide fabric

2020 ◽  
pp. 1-14
Author(s):  
Marija Radoičić ◽  
Gordana Ćirić-Marjanović ◽  
Dejan Miličević ◽  
Edin Suljovrujić ◽  
Milica Milošević ◽  
...  
Polymers ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 317
Author(s):  
Sebastian Bonardd ◽  
Cesar Saldías ◽  
Ángel Leiva ◽  
David Díaz Díaz ◽  
Galder Kortaberria

In this work, polymethacrylates containing sulfonyl and nitrile functional groups were successfully prepared by conventional radical polymerization and reversible addition-fragmentation chain-transfer polymerization (RAFT). The thermal and dielectric properties were evaluated, for the first time, considering differences in their molecular weights and dispersity values. Variations of the aforementioned properties do not seem to substantially affect the polarized state of these materials, defined in terms of the parameters ε’r, ε”r and tan (δ). However, the earlier appearance of dissipative phenomena on the temperature scale for materials with lower molecular weights or broader molecular weight distributions, narrows the range of working temperatures in which they exhibit high dielectric constants along with low loss factors. Notwithstanding the above, as all polymers showed, at room temperature, ε’r values above 9 and loss factors below 0.02, presenting higher dielectric performance when compared to conventional polymer materials, they could be considered as good candidates for energy storage applications.


Polymers ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 2044 ◽  
Author(s):  
Povilas Bertasius ◽  
Darya Meisak ◽  
Jan Macutkevic ◽  
Polina Kuzhir ◽  
Algirdas Selskis ◽  
...  

The dielectric properties of epoxy/MWCNT (multi-walled carbon nanotubes)/MgO hybrid composites with a fixed MWCNT amount of 0.12 vol.% (0.2 wt.%) and varying MgO concentrations up to 3 vol.% were investigated in broad frequency (20–40 GHz) and temperature (20–500 K) ranges. The composites with up to 2 vol.% MgO nanoparticles concentration showed a significant increase of DC conductivity in relation to their non MgO-containing counterparts. The optimal content of MgO was found, i.e., 0.46 vol.%, which gave up to 2.5 orders of magnitude larger DC conductivity than those of the samples prepared without MgO additives. Using various amounts of MgO, it is possible to predictably vary the broadband electromagnetic properties of the composites, even entirely eliminating the electrical percolation. Electrical transport at different temperatures can be substantially controlled by the addition of given amounts of MgO. The broadband properties are discussed in terms of the distribution of relaxation times, which are proven to be an effective, noninvasive, and simple tool for checking composite fabrication issues, such as the distribution of MWCNT aggregates within the epoxy matrix.


RSC Advances ◽  
2015 ◽  
Vol 5 (62) ◽  
pp. 50054-50062 ◽  
Author(s):  
Simon J. Dünki ◽  
Martin Tress ◽  
Friedrich Kremer ◽  
Song Yee Ko ◽  
Frank A. Nüesch ◽  
...  

Novel polysiloxanes with dielectric properties which are systematically fine-tuned by utilizing thiol-ene post-polymerization reactions of a polymethylvinylsiloxane with various ratios of 1-butanethiol and 3-mercaptopropionitrile is presented.


ASHA Leader ◽  
2017 ◽  
Vol 22 (6) ◽  
Author(s):  
Christi Miller
Keyword(s):  

2012 ◽  
Vol 82 (3) ◽  
pp. 216-222 ◽  
Author(s):  
Venkatesh Iyengar ◽  
Ibrahim Elmadfa

The food safety security (FSS) concept is perceived as an early warning system for minimizing food safety (FS) breaches, and it functions in conjunction with existing FS measures. Essentially, the function of FS and FSS measures can be visualized in two parts: (i) the FS preventive measures as actions taken at the stem level, and (ii) the FSS interventions as actions taken at the root level, to enhance the impact of the implemented safety steps. In practice, along with FS, FSS also draws its support from (i) legislative directives and regulatory measures for enforcing verifiable, timely, and effective compliance; (ii) measurement systems in place for sustained quality assurance; and (iii) shared responsibility to ensure cohesion among all the stakeholders namely, policy makers, regulators, food producers, processors and distributors, and consumers. However, the functional framework of FSS differs from that of FS by way of: (i) retooling the vulnerable segments of the preventive features of existing FS measures; (ii) fine-tuning response systems to efficiently preempt the FS breaches; (iii) building a long-term nutrient and toxicant surveillance network based on validated measurement systems functioning in real time; (iv) focusing on crisp, clear, and correct communication that resonates among all the stakeholders; and (v) developing inter-disciplinary human resources to meet ever-increasing FS challenges. Important determinants of FSS include: (i) strengthening international dialogue for refining regulatory reforms and addressing emerging risks; (ii) developing innovative and strategic action points for intervention {in addition to Hazard Analysis and Critical Control Points (HACCP) procedures]; and (iii) introducing additional science-based tools such as metrology-based measurement systems.


1979 ◽  
Vol 40 (C3) ◽  
pp. C3-37-C3-40
Author(s):  
L. A. KARAMYSHEVA ◽  
S. I. TORGOVA ◽  
E. I. KOVSHEV ◽  
M. I. BARNIK

2012 ◽  
Vol 03 (1) ◽  
pp. 71-73
Author(s):  
S. Bharadwaj ◽  
◽  
Suman Kumar Burnwal ◽  
T. Ramesh ◽  
S.R. Murthy ◽  
...  

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