π-Conjugated polymer with Alloxazine-6,9-diyl unit in the Main chain: Synthesis, chemical properties, and sensing ability for metal ions and nucleosides

2020 ◽  
Vol 155 ◽  
pp. 104691
Author(s):  
Isao Yamaguchi ◽  
Nanami Fujii ◽  
Aohan Wang
Keyword(s):  
Metal Ions ◽  
Conjugated Polymer ◽  
Main Chain ◽  
Chemical Properties ◽  
Chain Synthesis

Chitosan-based Magnetic Composites - Efficient Adsorbents for Removal of Pb(II) and Cu(II) from Aqueous Mono and Bicomponent Solutions

2018 ◽  
Vol 69 (9) ◽  
pp. 2323-2330 ◽  
Author(s):  
Daniela C. Culita ◽  
Claudia Maria Simonescu ◽  
Rodica Elena Patescu ◽  
Nicolae Stanica
Keyword(s):  
Aqueous Solutions ◽  
Metal Ions ◽  
Chemical Properties ◽  
Order Kinetic ◽  
Mass Ratio ◽  
Magnetic Adsorbent ◽  
Magnetic Composites ◽  
Initial Ph ◽  
Order Kinetic Model ◽  
Physical And Chemical

A series of three chitosan-based magnetic composites was prepared through a simple coprecipitation method. It was investigated the influence of mass ratio between chitosan and magnetite on the physical and chemical properties of the composites in order to establish the optimum conditions for obtaining a composite with good adsorption capacity for Pb(II) and Cu(II) from mono and bicomponent aqueous solutions. It was found that the microspheres prepared using mass ratio chitosan / magnetite 1.25/1, having a saturation magnetization of 15 emu g--1, are the best to be used as adsorbent for the metal ions. The influence of different parameters such as initial pH values, contact time, initial concentration of metal ions, on the adsorption of Pb(II) and Cu(II) onto the chitosan-based magnetic adsorbent was investigated in details. The adsorption process fits the pseudo-second-order kinetic model in both mono and bicomponent systems, and the maximum adsorption capacities calculated on the basis of the Langmuir model were 79.4 mg g--1 for Pb(II) and 48.5 mg g--1 for Cu(II) in monocomponent systems, while in bicomponent systems were 88.3 and 49.5 mg g--1, respectively. The results revealed that the as prepared chitosan-based magnetic adsorbent can be an effective and promising adsorbent for Pb(II) and Cu(II) from mono and bicomponent aqueous solutions.

scholarly journals Conjugated Polymer Films Having a Uniaxial Molecular Orientation and Network Structure Prepared by Electrochemical Polymerization in Liquid Crystals

Polymers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2425
Author(s):  
Jiuchao Dong ◽  
Shigeki Nimori ◽  
Hiromasa Goto
Keyword(s):  
Liquid Crystals ◽  
Network Structure ◽  
Polymer Films ◽  
Conjugated Polymer ◽  
Main Chain ◽  
Electrochemical Polymerization ◽  
Electronic Devices ◽  
New Method ◽  
Magnetic Orientation ◽  
Organic Electronic Devices

A new method for fabricating conjugated polymer films was developed using electrochemical polymerization in liquid crystals and magnetic orientation. A uniaxial main chain orientation and a crosslinked network structure were achieved with this method. By employing eight types of monomers, the influence of the crosslinking for the film was investigated. The crosslinking was found to improve the solvent resistance of the conjugated polymer films. This new method is expected to be useful in various applications, such as high-powered organic electronic devices with durability.

scholarly journals ZnO-nanostructure-based electrochemical sensor: Effect of nanostructure morphology on the sensing of heavy metal ions

2018 ◽  
Vol 9 ◽  
pp. 2421-2431 ◽  
Author(s):  
Marina Krasovska ◽  
Vjaceslavs Gerbreders ◽  
Irena Mihailova ◽  
Andrejs Ogurcovs ◽  
Eriks Sledevskis ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Metal Ions ◽  
Heavy Metal Ions ◽  
Electrochemical Sensors ◽  
Zno Nanorods ◽  
Large Diameter ◽  
Chemical Properties ◽  
Volume Ratio ◽  
Zno Nanostructures ◽  
Zno Nanostructure

ZnO nanostructures are promising candidates for use in sensors, especially in electrochemical sensors and biosensors, due to their unique physical and chemical properties, as well as sensitivity and selectivity to several types of contamination, including heavy metal ions. In this work, using the hydrothermal method, nanostructures of ZnO were synthesized in four different morphologies: nanorods, nanoneedles, nanotubes and nanoplates. To determine the peculiarities of adsorption for each morphology, a series of electrochemical measurements were carried out using these nanostructured ZnO coatings on the working electrodes, using aqueous solutions of Pb(NO3)2 and Cd(NO3)2 as analytes with different concentrations. It was found that the sensitivity of the resulting electrochemical sensors depends on the morphology of the ZnO nanostructures: the best results were achieved in the case of porous nanostructures (nanotubes and nanoplates), whereas the lowest sensitivity corresponded to ZnO nanorods with a large diameter (i.e., low surface-to-volume ratio). The efficiency of sedimentation is also related to the electronegativity of adsorbate: it has been shown that all observed ZnO morphologies exhibited significantly higher sensitivity in detecting lead ions compared to cadmium ions.

scholarly journals Elucidating the role of metal ions in carbonic anhydrase catalysis

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Jin Kyun Kim ◽  
Cheol Lee ◽  
Seon Woo Lim ◽  
Aniruddha Adhikari ◽  
Jacob T. Andring ◽  
...  
Keyword(s):  
Carbonic Anhydrase ◽  
Metal Ions ◽  
Metal Ion ◽  
Catalytic Mechanism ◽  
Chemical Properties ◽  
Water Network ◽  
Native Metal ◽  
Trigonal Bipyramidal ◽  
Electrostatic Effect

Abstract Why metalloenzymes often show dramatic changes in their catalytic activity when subjected to chemically similar but non-native metal substitutions is a long-standing puzzle. Here, we report on the catalytic roles of metal ions in a model metalloenzyme system, human carbonic anhydrase II (CA II). Through a comparative study on the intermediate states of the zinc-bound native CA II and non-native metal-substituted CA IIs, we demonstrate that the characteristic metal ion coordination geometries (tetrahedral for Zn2+, tetrahedral to octahedral conversion for Co2+, octahedral for Ni2+, and trigonal bipyramidal for Cu2+) directly modulate the catalytic efficacy. In addition, we reveal that the metal ions have a long-range (~10 Å) electrostatic effect on restructuring water network in the active site. Our study provides evidence that the metal ions in metalloenzymes have a crucial impact on the catalytic mechanism beyond their primary chemical properties.

Polyazomethine with vinylene and phenantridine moieties in the main chain: Synthesis, characterization, opto(electrical) properties and theoretical calculations

2012 ◽  
Vol 24 (4) ◽  
pp. 319-330 ◽  
Author(s):  
Agnieszka Iwan ◽  
Jeconias Rocha Guimarães ◽  
Maria Cristina dos Santos ◽  
Ewa Schab-Balcerzak ◽  
Michal Krompiec ◽  
...  
Keyword(s):  
Electrical Properties ◽  
Main Chain ◽  
Theoretical Calculations ◽  
Chain Synthesis
Sign in / Sign up

Export Citation Format

Share Document