scholarly journals Electrochemical Synthesis of Polypyrrole and Polypyrrole-Indomethacin Coatings on NiCr Alloys Involving Deep Eutectic Solvents

Metals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1130
Author(s):  
Florentina Golgovici ◽  
Maria-Steliana Cârlan ◽  
Andreea-Gabriela Popescu ◽  
Liana Anicai
Keyword(s):  
Electrochemical Synthesis ◽  
Choline Chloride ◽  
Deep Eutectic Solvents ◽  
Polymeric Coatings ◽  
Nicr Alloy ◽  
Drug Molecules ◽  
Enhanced Dissolution ◽  
Nickel Chromium ◽  
Angle Measurements ◽  
Contact Angle Measurements

There is an increased interest in the use of the deep eutectic solvents (DESs) as electrolytic media for electrochemical synthesis of conducting polymers, which could influence their characteristics. Moreover, the polypyrrole layers represent an attractive route for pharmaceutical drug release. The paper presents several experimental results regarding the electrodeposition of polypyrrole and of polypyrrole-indomethacin coatings on nickel-chromium NiCr alloy substrates widely used in dentistry, involving DES-based electrolytes, namely eutectic mixtures of choline chloride and malonic acid. This type of electrolyte also allowed an enhanced dissolution of indomethacin as compared to aqueous ones. The electropolymerization process has been investigated by cyclic voltammetry and chronoamperometry. The obtained indomethacin containing polymeric coatings have been thoroughly characterized involving scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, contact angle measurements in simulated body fluid (SBF) and indomethacin release studies. Adherent and uniform polypyrrole-indomethacin layers have been obtained on NiCr alloy substrates. The release tests showed that the polypyrrole coatings containing indomethacin may deliver the drug molecules for longer periods of at least 17 days. The maximum released amount was around 99.6% suggesting these layers may act as an active reservoir for indomethacin. Kinetics analysis based on the Korsmeyer–Peppas model suggested the diffusion of the drug out of the polymer layer as the most probable mechanism governing the release.

Electrochemical Synthesis of Conducting Polymers Involving Deep Eutectic Solvents

2020 ◽  
Vol 16 (4) ◽  
pp. 478-494 ◽  
Author(s):  
Florentina Golgovici ◽  
Liana Anicai ◽  
Andreea Florea ◽  
Teodor Visan
Keyword(s):  
Ionic Liquids ◽  
Conducting Polymers ◽  
Electrochemical Synthesis ◽  
Conductive Polymers ◽  
Electrochemical Polymerization ◽  
Choline Chloride ◽  
Deep Eutectic Solvents ◽  
Widespread Application ◽  
Eutectic Mixtures ◽  
New Findings

Background: Deep eutectic solvents (DESs) represent a new generation of ionic liquids which are widely promoted as “green solvents”. They are gaining widespread application in materials chemistry and electrochemistry. DESs are defined as eutectic mixtures of quaternary ammonium salt with a hydrogen bond donor in certain molar ratios. Their use as solvents for electrochemical synthesis of conducting polymers could influence the polymer properties and reduce their economic cost. Objective: This review presents the most recent results regarding the electropolymerization of common conductive polymers involving choline chloride based ionic liquids. New findings from our laboratory on the electrochemical growth of conductive polymers are also discussed. Methods: The electrochemical polymerization mechanisms during synthesis of polypyrrole (PPy), polyaniline (PANI) and poly(3,4-ethylenedioxythiophene) (PEDOT) using various formulations of DESs are reviewed, as well as their characteristics, mainly from surface morphology view point. Results: Some general information related to the preparation and characterization of DESs is also presented, followed by an overview of the recent advances in the field of electropolymerization using DESs. Conclusion: Electropolymerization of conducting polymers involving DESs represents an attractive route of synthesis due to their compositional flexibility which makes possible the preparation of unlimited formulations further influencing the polymer morphology and properties. The use of these inexpensive eutectic mixtures has a large potential to contribute to the development of more sustainable technological processes meeting many of the required features characteristic to the green chemistry.

scholarly journals Nanostructured Tin-based Alloys Composites using Deep Eutectic Solvents as Electrolytes

2020 ◽  
Vol 6 (2) ◽  
pp. 70-85
Author(s):  
Ana Teresa Silva Cardoso Brandão ◽  
Renata Costa ◽  
António Fernando Silva ◽  
Carlos Manuel De Melo Pereira
Keyword(s):  
Morphological Changes ◽  
Choline Chloride ◽  
Lithium Ion ◽  
Deep Eutectic Solvents ◽  
Carbon Composites ◽  
The Past ◽  
Nickel Chromium ◽  
Electrochemical Window ◽  
Copper Zinc ◽  
Metal And Alloys

Metal and alloys electrodeposition from aqueous electrolytes is restricted due to the narrow electrochemical window and hydrogen evolution. To overcome these disadvantages, over the past years, ionic liquids (ILs) and deep eutectic solvents (DES) based on choline chloride have been successfully applied for the electrodeposition of different metals.Tin (Sn) layers applied to automotive or decorative plating are thought of as ecological alternatives to exchange lead and nickel/chromium coatings. Over the past few years, the attention drawn by metallic alloys and composites, namely Sn alloys (nickel, indium, copper, zinc…) and Sn-carbon materials composites, has increased due to the possibility of applying these materials as anodes for lithium-ion batteries.This review will highlight the leading research regarding the electrodeposition of Sn and several alloys and carbon composites, emphasizing the morphological changes of the alloy combinations using DESs as electrolytes.

Nanostructured Polymer Brushes With Reversibly Changing Properties

2002 ◽  
Vol 727 ◽  
Author(s):  
Denys Usov ◽  
Manfred Stamm ◽  
Sergiy Minko ◽  
Christian Froeck ◽  
Andreas Scholl ◽  
...  
Keyword(s):  
Polymer Brushes ◽  
Phase Segregation ◽  
Water Contact ◽  
Angle Measurements ◽  
Nanostructured Polymer ◽  
Contact Angle Measurements ◽  
Vertical Segregation ◽  
Oxygen Plasma Etching ◽  
Grafting From ◽  
Photoemission Electron

AbstractWe investigated the interplay between different mechanisms of the lateral and vertical segregation in the synthesized via “grafting from” approach symmetric A/B (where A and B are poly(styrene-co-2,3,4,5,6-pentafluorostyrene) and poly(methylmethacrylate), respectively) polymer brushes upon exposure to different solvents. We used X-ray photoemission electron spectroscopy and microscopy (X-PEEM), AFM, water contact angle measurements, and oxygen plasma etching to study morphology of the brushes. The ripple morphology after toluene (nonselective solvent) revealed elongated lamellar-like domains of A and B polymers alternating across the surface. The dimple-A morphology consisting of round clusters of the polymer A was observed after acetone (selective solvent for B). The top layer was enriched with the polymer B showing that the brush underwent both the lateral and vertical phase segregation. A qualitative agreement with predictions of SCF theory was found.

Wrinkling Poly(trimethylene 2,5-Furanoate) Free-standing Films: Nanostructure Formation and Physical Properties

2020 ◽  
Author(s):  
Michelina Soccio ◽  
Nadia Lotti ◽  
Andrea Munari ◽  
Esther Rebollar ◽  
Daniel E Martínez-Tong
Keyword(s):  
Irradiation Time ◽  
Polymer Surface ◽  
Laser Source ◽  
Free Standing ◽  
Force Microscopy ◽  
Nanostructure Formation ◽  
Physicochemical Changes ◽  
Angle Measurements ◽  
Atomic Force ◽  
Contact Angle Measurements

<p>Nanostructured wrinkles were developed on fully bio-based poly(trimethylene furanoate) (PTF) films by using the technique of Laser Induced Periodic Surface Structures (LIPSS). We investigated the effect of irradiation time on wrinkle formation using an UV pulsed laser source, at a fluence of 8 mJ/cm2. It was found that the pulse range between 600 and 4800 pulses allowed formation of periodic nanometric ripples. The nanostructured surface was studied using a combined macro- and nanoscale approach. We evaluated possible physicochemical changes taking place on the polymer surface after irradiation by infrared spectroscopy, contact angle measurements and atomic force microscopy. The macroscopic physicochemical properties of PTF showed almost no changes after nanostructure formation, differently from the results previously found for the terephthalic counterparts, as poly(ethyleneterephthalate), PET, and poly(trimethyleneterephthalate), PTT. The surface mechanical properties of the nanostructured PTF were found to be improved, as evidenced by nanomechanical force spectroscopy measurements. In particular, an increased Young’s modulus and higher stiffness for the nanostructured sample were measured. <br></p>

scholarly journals Adhesion Studies during Generative Hybridization of Textile-Reinforced Thermoplastic Composites via Additive Manufacturing

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3888
Author(s):  
Johanna Maier ◽  
Christian Vogel ◽  
Tobias Lebelt ◽  
Vinzenz Geske ◽  
Thomas Behnisch ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Polyamide 6 ◽  
Thermoplastic Composites ◽  
Efficient Production ◽  
Angle Measurements ◽  
Small Series ◽  
Contact Angle Measurements ◽  
Static Tensile ◽  
Pre Treatment ◽  
Manufacturing Technologies

Generative hybridization enables the efficient production of lightweight structures by combining classic manufacturing processes with additive manufacturing technologies. This type of functionalization process allows components with high geometric complexity and high mechanical properties to be produced efficiently in small series without the need for additional molds. In this study, hybrid specimens were generated by additively depositing PA6 (polyamide 6) via fused layer modeling (FLM) onto continuous woven fiber GF/PA6 (glass fiber/polyamide 6) flat preforms. Specifically, the effects of surface pre-treatment and process-induced surface interactions were investigated using optical microscopy for contact angle measurements as well as laser profilometry and thermal analytics. The bonding characteristic at the interface was evaluated via quasi-static tensile pull-off tests. Results indicate that both the bond strength and corresponding failure type vary with pre-treatment settings and process parameters during generative hybridization. It is shown that both the base substrate temperature and the FLM nozzle distance have a significant influence on the adhesive tensile strength. In particular, it can be seen that surface activation by plasma can significantly improve the specific adhesion in generative hybridization.

Self-assembled luminescent cholate gels induced by a europium ion in deep eutectic solvents

Soft Matter ◽  
2021 ◽  
Author(s):  
Meng Sun ◽  
Qintang Li ◽  
Xiao Chen
Keyword(s):  
Self Assembly ◽  
Choline Chloride ◽  
Deep Eutectic Solvents ◽  
Sodium Cholate ◽  
The Self ◽  
Europium Ion ◽  
Self Assembled

Luminescent gels have been successfully fabricated through the self-assembly of sodium cholate and a europium ion in choline chloride-based deep eutectic solvents.

scholarly journals Epoxy/alumina composite coating on welded steel 316L with excellent wear and anticorrosion properties

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Maryama Hammi ◽  
Younes Ziat ◽  
Zakaryaa Zarhri ◽  
Charaf Laghlimi ◽  
Abdelaziz Moutcine
Keyword(s):  
Electrochemical Behaviour ◽  
Sem Analysis ◽  
Water Contact ◽  
Welded Steel ◽  
Melted Zone ◽  
Angle Measurements ◽  
Contact Angle Measurements ◽  
Alumina Composite ◽  
The Cost ◽  
Good Contrast

AbstractThe main purpose of this study is to elaborate anticorrosive coatings for the welded steel 316L, since this later is widely used in industrial field. Hence, within this work we have studied the electrochemical behaviour of different zones of the welded steel 316 in 1 M HCl media. The macrography study of the welded steel has revealed the different areas with a good contrast. We have stated three different zones, namely; melted zone (MZ), heat affected zone (HAZ) and base metal zone (BM). Impedance studies on welded steel 316L were conducted in 1 M HCl solution, coating of Epoxy/Alumina composite was applied on different zones, in order to reveal the anti-corrosion efficiency in each zone. Scanning electron microscopy (SEM) analysis was undertaken in order to check how far the used coating in such aggressive media protects the studied zones and these findings were assessed by water contact angle measurements. The choice of this coating is based on the cost and the safety. We concluded that the Epoxy/Alumina composite has a good protecting effect regarding welded steel in aggressive media.

Toxico-metabolomics study of a deep eutectic solvent comprising choline chloride and urea suggests in vivo toxicity involving oxidative stress and ammonia stress

2021 ◽  
Vol 23 (3) ◽  
pp. 1300-1311 ◽  
Author(s):  
Dasom Jung ◽  
Jae Back Jung ◽  
Seulgi Kang ◽  
Ke Li ◽  
Inseon Hwang ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Choline Chloride ◽  
Deep Eutectic Solvent ◽  
Deep Eutectic Solvents ◽  
In Vivo Toxicity ◽  
Metabolomics Study ◽  
Ammonia Stress

The in vitro and in vivo studies suggest that choline chloride-based deep eutectic solvents may not be considered as pure, safe mixtures even if they consist of safe compounds.

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