Solvato-Controlled Doping of Conducting Polymers: Enhanced Stabilty in Silver-Triflate Doped Films

1997 ◽  
Vol 488 ◽  
Author(s):  
Michael V. Lauritzen ◽  
Steven Holdcroft
Keyword(s):  
Conducting Polymers ◽  
Ferric Chloride ◽  
Metallic Silver ◽  
Silver Triflate ◽  
Conductive Films ◽  
Conductive Film ◽  
Oxidative Doping ◽  
The Stability ◽  
Controlled Doping ◽  
Enhanced Stability

AbstractStable, conductive films of poly(3-alkylthiophenes) (P3ATs) can be obtained from a single chloroform based solution containing polymer, oxidant (silver triflate), and an oxidantcoordinating ligand (pyridine). Casting of this solution, followed by evaporation of the ligand, results in an electronically conductive film which is more stable and, notably, in the case of thick films, is free of the cracking which often results from swelling of the films during the doping process. This technique, coined solvato-controlled oxidative doping, results in films possessing enhanced stability compared to those oxidized by conventional dopants such as ferric chloride. Also, these silver-containing films are much more stable than those electrochemically doped with the triflate anion. Thus, the presence of metallic silver in the doped film has a profound effect on the stability of the conducting form.

scholarly journals Formation of a conductive overcoating layer based on hybrid composites to improve the stability of flexible transparent conductive films

RSC Advances ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 4428-4434 ◽  
Author(s):  
Jin-geun Lee ◽  
Wonseok Cho ◽  
Youngno Kim ◽  
Hangyeol Cho ◽  
Hongjoo Lee ◽  
...  
Keyword(s):  
Hybrid Composites ◽  
Protective Layer ◽  
Silica Sol ◽  
Organic Polymer ◽  
Transparent Conductive Film ◽  
Transparent Conductive Films ◽  
Conductive Films ◽  
Conductive Film ◽  
The Stability

A protective layer that can be applied on a flat flexible transparent conductive film was prepared by combining silica sol and organic polymer.

Optical and electrical properties and simulation curves of NiO/Al/NiO transparent conductive film

2019 ◽  
Vol 33 (01) ◽  
pp. 1850417 ◽  
Author(s):  
Shuyun Wang ◽  
Kailin Wen ◽  
Yang Sun ◽  
Xianwu Xiu ◽  
Shuyun Teng ◽  
...  
Keyword(s):  
Electrical Properties ◽  
Metal Film ◽  
Room Temperature ◽  
Optical And Electrical Properties ◽  
Light Wavelength ◽  
Conductive Films ◽  
Conductive Film ◽  
Average Transmittance ◽  
Interface Characteristics ◽  
Experimental Data Analysis

In this paper, NiO/Al/NiO transparent conductive films were prepared by magnetron sputtering at the room temperature. Effects of the NiO and Al layers thicknesses on the optical and electrical properties of the NiO/Al/NiO laminated films were analyzed. When the light wavelength falls in range 300–900 nm, with the increase of the NiO and Al layers thicknesses, the transmittance of the laminated film first increases significantly and then decreases slightly, finally tends to be stable. The laminated film obtained the best optical and electrical properties when the NiO layer is 40 nm and the Al layer is 12 nm. The maximum transmittance is 83%, the average transmittance is 77.3%, the film resistivity is [Formula: see text] and the carrier concentration is [Formula: see text]. At the same time, the transmittance of laminated film is simulated by FDTD software. But the simulation curve is different from the experimental data. Analysis results show that, with the NiO dielectric is added on both sides of the metal Al film, the light reflection characteristic of laminated film has been completely different from that of the single Al metal film because of the change of interface characteristics between Al film and NiO film, and the actual luminous transmittance greatly increases.

scholarly journals Swine-Origin H1 Influenza Viruses Isolated from Humans Exhibit Sustained Infectivity in an Aerosol State

2019 ◽  
Vol 85 (10) ◽  
Author(s):  
Joanna A. Pulit-Penaloza ◽  
Jessica A. Belser ◽  
Terrence M. Tumpey ◽  
Taronna R. Maines
Keyword(s):  
Influenza Virus ◽  
Swine Influenza Virus ◽  
Virus Transmission ◽  
Swine Influenza ◽  
Influenza Viruses ◽  
Aerosol State ◽  
The Stability ◽  
Higher Doses ◽  
Enhanced Stability

ABSTRACT The relative importance of influenza virus transmission via aerosols is not fully understood, but experimental data suggest that aerosol transmission may represent a critical mode of influenza virus spread among humans. Decades ago, prototypical laboratory strains of influenza were shown to persist in aerosols; however, there is a paucity of data available covering currently circulating influenza viruses, which differ significantly from their predecessors. In this study, we evaluated the longevity of influenza viruses in aerosols generated in the laboratory. We selected a panel of H1 viruses that exhibit diverse transmission profiles in the ferret model, including four human isolates of swine origin (referred to as variant) and a seasonal strain. By measuring the ratio of viral RNA to infectious virus maintained in aerosols over time, we show that influenza viruses known to transmit efficiently through the air display enhanced stability in an aerosol state for prolonged periods compared to those viruses that do not transmit as efficiently. We then assessed whether H1 influenza virus was still capable of infecting and causing disease in ferrets after being aged in suspended aerosols. Ferrets exposed to very low levels of influenza virus (≤17 PFU) in aerosols aged for 15 or 30 min became infected, with five of six ferrets shedding virus in nasal washes at titers on par with ferrets who inhaled higher doses of unaged influenza virus. We describe here an underreported characteristic of influenza viruses, stability in aerosols, and make a direct connection to the role this characteristic plays in influenza transmission. IMPORTANCE Each time a swine influenza virus transmits to a human, it provides an opportunity for the virus to acquire adaptations needed for sustained human-to-human transmission. Here, we use aerobiology techniques to test the stability of swine-origin H1 subtype viruses in aerosols and evaluate their infectivity in ferrets. Our results show that highly transmissible influenza viruses display enhanced stability in an aerosol state compared to viruses that do not transmit as efficiently. Similar to human-adapted strains, swine-origin influenza viruses are infectious in ferrets at low doses even after prolonged suspension in the air. These data underscore the risk of airborne swine-origin influenza viruses and support the need for continued surveillance and refinement of innovative laboratory methods to investigate mammalian exposure to inhaled pathogens. Determination of the molecular markers that affect the longevity of airborne influenza viruses will improve our ability to quickly identify emerging strains that present the greatest threat to public health.

scholarly journals Numerical Exploration of Kaldorian Interregional Macrodynamics: Enhanced Stability and Predominance of Period Doubling under Flexible Exchange Rates

2010 ◽  
Vol 2010 ◽  
pp. 1-29 ◽  
Author(s):  
Toichiro Asada ◽  
Christos Douskos ◽  
Vassilis Kalantonis ◽  
Panagiotis Markellos
Keyword(s):  
Exchange Rates ◽  
Government Expenditure ◽  
Period Doubling ◽  
Numerical Approach ◽  
Capital Movement ◽  
Dimensional Parameter ◽  
Stability Of Equilibrium ◽  
The Stability ◽  
Flexible Exchange Rates ◽  
Enhanced Stability

We present a discrete two-regional Kaldorian macrodynamic model with flexible exchange rates and explore numerically the stability of equilibrium and the possibility of generation of business cycles. We use a grid search method in two-dimensional parameter subspaces, and coefficient criteria for the flip and Hopf bifurcation curves, to determine the stability region and its boundary curves in several parameter ranges. The model is characterized by enhanced stability of equilibrium, while its predominant asymptotic behavior when equilibrium is unstable is period doubling. Cycles are scarce and short-lived in parameter space, occurring at large values of the degree of capital movementβ. By contrast to the corresponding fixed exchange rates system, for cycles to occur sufficient amount of trade is requiredtogetherwith high levels of capital movement. Rapid changes in exchange rate expectations and decreased government expenditure are factors contributing to the creation of interregional cycles. Examples of bifurcation and Lyapunov exponent diagrams illustrating period doubling or cycles, and their development into chaotic attractors, are given. The paper illustrates the feasibility and effectiveness of the numerical approach for dynamical systems of moderately high dimensionality and several parameters.

Complexation, Stability and Behavior of L-Cysteine and L-Lysine with Different Iron Sources

1984 ◽  
Vol 47 (1) ◽  
pp. 36-40 ◽  
Author(s):  
S. M. FLYNN ◽  
F. M. CLYDESDALE ◽  
O. T. ZAJICEK
Keyword(s):  
Ferric Chloride ◽  
Ferrous Sulfate ◽  
Mixed Valence ◽  
Qualitative Evaluation ◽  
Low Ph ◽  
Iron Hydroxides ◽  
The Stability ◽  
Ph Range ◽  
Effective Stability ◽  
And Behavior

Effective stability constants for cysteine and lysine with five different iron sources were evaluated along with their behavior in solution. The values obtained for ferric chloride-cysteine, ferrous sulfate-cysteine, ferric chloride-lysine, ferrous sulfate-lysine, hydrogen-reduced lysine, and electrolytic-reduced lysine were 6.81 × 102 to 2.78 × 103, 1.33 × 105 to 1.36 × 105, 6.00 × 10−4 to 7.64 × 10−3, 6.37 ×10−4 to 4.82× 10−3, 9.34 × 10−2 to 1.38 × 10−1, and 4.18 × 10−4 to 7.27 × 10−4, respectively. No measurable complexation occurred with hydrogen- and electrolytic-reduced iron with cysteine nor with ferric orthophosphate and cysteine or lysine. The stability of soluble ferric cysteine over the pH range 2.0 to 7.4 indicates that this complex has the potential to be used as an iron additive in food. Approximately half of the hydrogen and electrolytic reduced iron and only 0.11% of ferric orthophosphate were soluble in acid, whereas ferric chloride and ferrous sulfate were completely soluble. Qualitative evaluation of the iron-amino acid systems over a range of pH from 2.0 to 12.0 indicated that there was a mixed valence state of free iron in most cases with low pH favoring reduction and high pH oxidation, until precipitation of iron hydroxides occurred.

Novel Magnesium Aminoclay-Vitamin C Hybrid for Enhanced Stability and Bioactivity in Cosmeceutical Applications

2020 ◽  
Vol 20 (7) ◽  
pp. 4257-4262 ◽  
Author(s):  
Vinh Van Tran ◽  
Ju-Young Moon ◽  
Young-Chul Lee
Keyword(s):  
Vitamin C ◽  
Synthesis Method ◽  
Vital Role ◽  
Promising Candidate ◽  
Controllable Release ◽  
Lipid Particles ◽  
The Stability ◽  
Double Hydroxide ◽  
Enhanced Stability

Vitamin C (VC) is a hydrophilic antioxidant that plays a vital role in the protection of health and is also an integral ingredient in beauty formulations due to its numerous distinct and necessary properties. However, its application in the area of cosmeceuticals still confronts huge challenges relating to its instability and low bioactivity. Therefore, it is necessary to prevent its degradation by utilizing microencapsulation techniques, many and various of which, entailing the use of liposomes, nanoemulsions, lipid particles, and layered double hydroxide, have already been introduced. Nevertheless, such techniques still have several disadvantages in terms of either their difficult preparation or toxicity to skin. Recently, aminoclay (AC), a synthetic organic-nanoclay comprising 3-aminopropyl-functionalized magnesium phyllosilicate, has been proposed as a promising candidate for encapsulation and delivery of active agents in cosmeceuticals. In the present work, a novel magnesium aminoclay/vitamin C (MgAC-VC) hybrid was successfully fabricated by a simple onepot synthesis method via the in situ loading of VC into MgAC. The resultant hybrid was found to highly improve the stability and controllable release of VC. Compared with free VC, the MgAC-VC hybrid exhibited significantly enhanced stability of VC under high temperature (60 °C) as well as slow and controllable release of VC from MgAC-VC hybrids over 24 h. Our results suggest that such MgAC-VC hybrids can potentially be utilized in cosmeceutical applications for delivery of VC and other antioxidants.

scholarly journals Numerical Exploration of Kaldorian Macrodynamics: Enhanced Stability and Predominance of Period Doubling and Chaos with Flexible Exchange Rates

2008 ◽  
Vol 2008 ◽  
pp. 1-23 ◽  
Author(s):  
Toichiro Asada ◽  
Christos Douskos ◽  
Panagiotis Markellos
Keyword(s):  
Exchange Rates ◽  
Stability Region ◽  
Extreme Values ◽  
Period Doubling ◽  
Model Parameters ◽  
Flip Bifurcation ◽  
Bifurcation Curve ◽  
The Stability ◽  
Flexible Exchange Rates ◽  
Enhanced Stability

We explore a discrete Kaldorian macrodynamic model of an open economy with flexible exchange rates, focusing on the effects of variation of the model parameters, the speed of adjustment of the goods marketα, and the degree of capital mobilityβ. We determine by a numerical grid search method the stability region in parameter space and find that flexible rates cause enhanced stability of equilibrium with respect to variations of the parameters. We identify the Hopf-Neimark bifurcation curve and the flip bifurcation curve, and find that the period doubling cascades which leads to chaos is the dominant behavior of the system outside the stability region, persisting to large values ofβ. Cyclical behavior of noticeable presence is detected for some extreme values of a state parameter. Bifurcation and Lyapunov exponent diagrams are computed illustrating the complex dynamics involved. Examples of attractors and trajectories are presented. The effect of the speed of adaptation of the expected rate is also briefly discussed. Finally, we explore a special model variation incorporating the “wealth effect” which is found to behave similarly to the basic model, contrary to the model of fixed exchange rates in which incorporation of this effect causes an entirely different behavior.

scholarly journals Dispersing hydrophobic natural colourant β-carotene in shellac particles for enhanced stability and tunable colour

2017 ◽  
Vol 4 (12) ◽  
pp. 170919 ◽  
Author(s):  
Dong Chen ◽  
Chun-Xia Zhao ◽  
Camille Lagoin ◽  
Mingtan Hai ◽  
Laura R. Arriaga ◽  
...  
Keyword(s):  
Research And Development ◽  
Polymer Matrix ◽  
Food Quality ◽  
Great Promise ◽  
Natural Food ◽  
Visual Attributes ◽  
Emulsion Droplets ◽  
The Stability ◽  
Β Carotene ◽  
Enhanced Stability

Colour is one of the most important visual attributes of food and is directly related to the perception of food quality. The interest in natural colourants, especially β-carotene that not only imparts colour but also has well-documented health benefits, has triggered the research and development of different protocols designed to entrap these hydrophobic natural molecules to improve their stability against oxidation. Here, we report a versatile microfluidic approach that uses single emulsion droplets as templates to prepare microparticles loaded with natural colourants. The solution of β-carotene and shellac in the solvent is emulsified by microfluidics into droplets. Upon solvent diffusion, β-carotene and shellac co-precipitates, forming solid microparticles of β-carotene dispersed in the shellac polymer matrix. We substantially improve the stability of β-carotene that is protected from oxidation by the polymer matrix and achieve different colour appearances by loading particles with different β-carotene concentrations. These particles demonstrate great promise for practical use in natural food colouring.

A low-cost, highly-conductive polyvinyl alcohol flexible film with Ag-microsheets and AgNWs as fillers

RSC Advances ◽  
2016 ◽  
Vol 6 (84) ◽  
pp. 80905-80909 ◽  
Author(s):  
Yongyun Mao ◽  
Junmei Guo ◽  
Changyi Hu ◽  
Hongwei Yang ◽  
Yuwen Yang ◽  
...  
Keyword(s):  
Polyvinyl Alcohol ◽  
Low Cost ◽  
High Conductivity ◽  
Conductive Films ◽  
Flexible Film ◽  
Conductive Film ◽  
Ag Nanowires

Low-cost, high-conductivity flexible conductive films were fabricated using Ag-microsheets, Ag-nanowires (AgNWs) and polyvinyl alcohol (PVA) as conducting agents. The flexible conductive film shows good conductivity under stretching.

Sign in / Sign up

Export Citation Format

Share Document