Conducting Polymer with Improved Long-Time Stability: Polyaniline-Polyelectrolyte Complex

1993 ◽  
Vol 328 ◽  
Author(s):  
Linfeng Sun ◽  
Sze C. Yang ◽  
Jia-Ming Liu
Keyword(s):  
Thermal Stability ◽  
Conducting Polymers ◽  
Charge Density ◽  
Polyelectrolyte Complex ◽  
Polymeric Complex ◽  
Time Stability ◽  
Weak Base ◽  
Electrically Conductive ◽  
Long Time ◽  
Heat And Moisture

ABSTRACTConducting polymers, e.g. polyaniline, generally lack stability in their electrically conductive form due to heat and moisture induced loss of dopant. Using a template-guided synthesis scheme, we synthesized a polymeric complex of polyaniline and polyelectrolyte that showed stability against dedoping by moisture and heat. The polymeric complex consists of a strand of polyaniline twisted tightly with a strand of polyelectrolyte. The polyelectrolyte in the complex serves as a macromolecular dopant for polyaniline. These two components of the complex are tightly bound so that the dopant is not lost during tests for thermal stability and stability in water and Moisture. Since the dopant is a polyelectrolyte with high linear anion charge density, the complex resists deprotonation by water or weak base (pH < 10).

Long-time stability of metals after severe plastic deformation: Softening and hardening by self-annealing versus thermal stability

2018 ◽  
Vol 729 ◽  
pp. 340-348 ◽  
Author(s):  
Kaveh Edalati ◽  
Yuki Hashiguchi ◽  
Hideaki Iwaoka ◽  
Hirotaka Matsunaga ◽  
Ruslan Z. Valiev ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Plastic Deformation ◽  
Severe Plastic Deformation ◽  
Time Stability ◽  
Long Time ◽  
Long Time Stability

scholarly journals Seawater Absorption and Adhesion Properties of Hydrophobic and Superhydrophobic Thermoset Epoxy Nanocomposite Coatings

Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 272
Author(s):  
Ayman M. Atta ◽  
Mohamed H. El-Newehy ◽  
Meera Moydeen Abdulhameed ◽  
Mohamed H. Wahby ◽  
Ahmed I. Hashem
Keyword(s):  
Thermal Stability ◽  
Oleic Acid ◽  
Salt Spray ◽  
Adhesion Properties ◽  
In Situ Modification ◽  
Long Time ◽  
Seawater Environment ◽  
Thermoset Epoxy ◽  
The Cost

The enhancement of both thermal and mechanical properties of epoxy materials using nanomaterials becomes a target in coating of the steel to protect it from aggressive environmental conditions for a long time, with reducing the cost. In this respect, the adhesion properties of the epoxy with the steel surfaces, and its proper superhyrophobicity to repel the seawater humidity, can be optimized via addition of green nanoparticles (NPs). In-situ modification of silver (Ag) and calcium carbonate (CaCO3) NPs with oleic acid (OA) was carried out during the formation of Ag−OA and CaCO3−OA, respectively. The epoxide oleic acid (EOA) was also used as capping for Ca−O3 NPs by in-situ method and epoxidation of Ag−OA NPs, too. The morphology, thermal stability, and the diameters of NPs, as well as their dispersion in organic solvent, were investigated. The effects of the prepared NPs on the exothermic curing of the epoxy resins in the presence of polyamines, flexibility or rigidity of epoxy coatings, wettability, and coatings durability in aggressive seawater environment were studied. The obtained results confirmed that the proper superhyrophobicity, coating adhesion, and thermal stability of the epoxy were improved after exposure to salt spray fog for 2000 h at 36 °C.

Density and sound velocity measurement by an Anton Paar DSA 5000 density meter: Precision and long-time stability

2021 ◽  
Vol 329 ◽  
pp. 115547
Author(s):  
Zdeněk Wagner ◽  
Magdalena Bendová ◽  
Jan Rotrekl ◽  
Adéla Sýkorová ◽  
Maja Čanji ◽  
...  
Keyword(s):  
Sound Velocity ◽  
Velocity Measurement ◽  
Time Stability ◽  
Long Time ◽  
Long Time Stability

scholarly journals Improvement of the thermal stability of dendritic silver-coated copper microparticles by surface modification based on molecular self-assembly

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Tae Hyeong Kim ◽  
Hyeji Kim ◽  
Hyo Jun Jang ◽  
Nara Lee ◽  
Kwang Hyun Nam ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Photoelectron Spectroscopy ◽  
Self Assembly ◽  
Electrically Conductive ◽  
X Ray ◽  
Alkyl Chains ◽  
Conductive Film ◽  
Initial Resistance ◽  
Thermal Stability Of ◽  
Scanning Electron

AbstractIn the study reported herein, silver-coated copper (Ag/Cu) powder was modified with alkanethiols featuring alkyl chains of different lengths, namely butyl, octyl, and dodecyl, to improve its thermal stability. The modification of the Ag/Cu powders with adsorbed alkanethiols was confirmed by scanning electron microscopy with energy dispersive spectroscopy, X-ray photoelectron spectroscopy, and thermogravimetric analysis. Each powder was combined with an epoxy resin to prepare an electrically conductive film. The results confirmed that the thermal stability of the films containing alkanethiol-modified Ag/Cu powders is superior to that of the film containing untreated Ag/Cu powder. The longer the alkyl group in the alkanethiol-modified Ag/Cu powder, the higher the initial resistance of the corresponding electrically conductive film and the lower the increase in resistance induced by heat treatment.

Influence of Oligonucleotide-Stopper on Size and Thermal Stability of Concatemer DNA Compexes

2011 ◽  
Vol 6 (4) ◽  
pp. 115-124
Author(s):  
Nikolay Filippov ◽  
Aleksandr Lomzov ◽  
Dmitriy Pyshnyi
Keyword(s):  
Thermal Stability ◽  
Gene Delivery ◽  
Thermodynamic Model ◽  
Length Distribution ◽  
Polymeric Complex ◽  
Multicomponent Complex ◽  
Maximum Contribution ◽  
Polymeric Complexes ◽  
Thermal Stability Of ◽  
Drug And Gene Delivery

Multicomponent polymeric associates based on nucleic acids are well used in drug and gene delivery into cells, in DNA fragments manipulations, in amplifying of the molecular hybridization signal, etc. Nevertheless, the formation of these systems is not well studied. In this paper, influence of a component that terminates concatemer elongation on a length and thermal stability of the multicomponent complex was studied. We have shown that addition of a oligonucleotide-stopper to the polymeric complex consisting of two oligonucleotide species decreases the length of concatemer complexes proportionally to the stopper concentration. Effect of the stopper on melting temperature was shown to be concentration dependent. We have proposed a thermodynamic model, which allows one to predict the thermal stability and the length distribution of the concatemeric complex consisting of two types of oligonucleotides in the presence of the stopper. We have also determined the length of polymeric complexes, which makes the maximum contribution to the intensity of the analyzed signal

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