Iron-based catalytic systems in atom-transfer controlled-radical-polymerization processes

Abstract

The literature data about the use of catalytic systems and compositions based on iron and its com plexes for the controlled synthesis of polymers via the atom transfer mechanism are generalized and ana lyzed. The effects of the oxidation number of a metal atom, the ligand environment, the structure of a radical initiator, the activating additives, and other factors on the molecular weight characteristics of the polymers and the kinetics of vinyl polymerization are considered.

Bromoalkyl ATRP initiator activation by inorganic salts: experiments and computations

“…The moderating equilibrium is characterized by an equilibrium constant K, which is the ratio between the activation and deactivation rate constants ka and kda, respectively. In most ATRP implementations, a redox-active transition metal complex in its lower oxidation state has been used as activator species, with copper(I) 5,7,10,11 and iron(II) [12][13][14][15][16][17][18] being the most commonly used central metal ions, owing to their considerable versatility. Iron attracts considerable interest because of its lower cost, greater availability, lower toxicity and higher biocompatibility.…”

Comparisons of Fastness of the Coating Processes of Electroless Silver Plating on Polyethylene Membrane Surfaces

“…Considered on the infiltration angle of 102.2 ± 1.1, the pretreated PE membrane surfaces were not soaked. The processes of brush would not firstly cover the silver-amino complex solution enough and evenly to avoid being gathered into drops and lines on PE membrane surfaces [11,20]. It resulted that the amounts of the deposition of the silver element on the PE surfaces were not homogeneous, meaning that the silver-amino complex might be reduced and covered more silver element in the gathered drops and lines where the extra silver element was piled up loosely on the previous matrixes.…”

“…It seemed that the gathered drops and lines of the silver films got more silver element than the maximum amounts of the matrix layers. Moreover, the processes of the brush would scratch the firstly extended silver-amino complex solution to strip the initial attachments of silver element [20,21]. By contrast, the finer vapors of spray (≤ 0.1 μm, 3 MPa) could be dispersed by the processes of spray and absorbed evenly by the PE surfaces.…”

Poly (Ethylene Oxide)-Based Block Copolymer Electrolytes Formed via Ligand-Free Iron-Mediated Atom Transfer Radical Polymerization

“…Among all the catalyst species in the ATRP process, iron attracts great interests thanks to its considerable availability, less toxicity and relatively lower cost [11][12][13][14][15][16][17][18]. Numerous organic complexes, such as phosphines or amines [17,[19][20][21][22], polar solvents [23][24][25] and deep eutectic solvents (DESs) [26][27][28], are employed in order to fulfill the rapid transition of Fe II /Fe III by facilitating the iron dissolution and by tuning the metal redox potential. However, such organic ligands are either relatively expensive or toxic, which is detrimental to the environment and biomedical applications.…”