DETERMINATION OF THE STABILITY OF COMPLEX COMPOUNDS OF COPPER (II), ZINC (II), CADMIUM (II) AND SILVER (I) WITH COVALENTLY IMMOBILIZED SULFUR CONTAIN LIGANDS

"The purpose of this study is to determine the stability of the obtained coordination compounds of some d-metals with covalent immobilized sulfur-containing ligands. To achieve this goal, coordination compounds of copper (II), zinc (II), cadmium (II) and silver (I) ions with covalent immobilized sulfur-containing ligands - О,О-di- (2-aminoethyl) -dithiophosphate potassium - polyester matrix (KD2AEDTP-PEM), O,O-di- (2-aminoethyl) -dithiophosphate potassium - carbamide-formaldehyde matrix (KD2AEDTP-KFM). Studies were carried out to determine the acid-base properties of covalent-immobilized sulfur-containing ligands - KD2AEDTP-PEM, KD2AEDTP-KFM and the concentration stability of the obtained coordination compounds with ions of copper (II), zinc (II), cadmium (II), and silver (I). Based on the results of integral and differential potentiometric titrations, it was established that the ionization constants (pK) of the dithiophosphoric group in KD2AEDTP-PEM and KD2AEDTP-KFM are 3.23 and 3.35, and the ionization constants of the amino group are 9.76 and 9.63, respectively. As a result of studies of polymer ligands by potentiometric titration via the method of individual weighed portions, it was shown that polyfunctional polymer ligands have the ability to form stable coordination compounds with metal ions of copper (II), zinc (II), cadmium (II) and silver (I). "

Polymer Ligands Derived from Jute Fiber for Heavy Metal Removal from Electroplating Wastewater

Industrial operations, domestic and agricultural activities worldwide have had major problems with various contaminants caused by environmental pollution. Heavy metal pollution in wastewater also a prominent issue; therefore, a well built and economical treatment technology is demanded for pollution-free wastewater. The present work emphasized pure cellulose extracted from jute fiber and further modification was performed by a free radical grafting reaction, which resulted in poly(methyl acrylate) (PMA)-grafted cellulose and poly(acrylonitrile)-grafted cellulose. Subsequently, poly(hydroxamic acid) and poly(amidoxime) ligands were prepared from the PMA-grafted cellulose and PAN-grafted cellulose, respectively. An adsorption study was performed using the desired ligands with heavy metals such as copper, cobalt, chromium and nickel ions. The binding capacity (qe) with copper ions for poly(hydroxamic acid) is 352 mg g−1 whereas qe for poly(amidoxime) ligand it was exhibited as 310 mg g−1. Other metal ions (chromium, cobalt and nickel) show significance binding properties at pH 6. The Langmuir and Freundlich isotherm study was also performed. The Freundlich isotherm model showed good correlation coefficients for all metal ions, indicating that multiple-layers adsorption was occurred by the polymer ligands. The reusability was evaluated and the adsorbents can be reused for 7 cycles without significant loss of removal performance. Both ligands showed outstanding metals removal capacity from the industrial wastewater as such 98% of copper can be removed from electroplating wastewater and other metals (cobalt, chromium, nickel and lead) can also be removed up to 90%.

Do polymer ligands block the catalysis of metal nanoparticles? Unexpected importance of binding motifs in improving catalytic activity

Polymer NHC ligands enhance the catalytic activity of metal nanoparticles despite the increase of surface crowdedness.

Colloidal stability of nanoparticles stabilized with mixed ligands in solvents with varying polarity

For gold nanoparticles stabilized with cetyl trimethylammonium bromide (CTAB) and polymer ligands, increase in solvent polarity leads to stabilization–aggregation–stabilization–aggregation transitions.