Othman Charles S. Al Hamouz

Novel cross-linked polymers having pH-responsive amino acid residues for the removal of Cu2+ from aqueous solution at low concentrations.

Two novel cross-linked anionic polyelectrolytes (CAPE) I and II containing pH-responsive amino acid residues have been synthesized via cycloco- and ter-polymerization of a monomer having diallylammonioethanoate motif (90mol%) and a cross-linker 1,1,4,4-tetraallylpiperazinium dichloride (10mol%) in the absence and presence of SO2 (100mol%), respectively. The experimental data for the adsorption of Cu(2+) on the CAPES fitted Lagergren second-order kinetic model thereby indicating the chemical nature of the adsorption process. The fitness order of Freundlich>Langmuir>Temkin for the isotherm models for CAPE I showed the favorability of adsorption on a heterogeneous surface, whereas for CAPE II the fitness order of Langmuir>Freundlich>Temkin certified the favorability toward monolayer adsorption. The adsorption process was spontaneous and endothermic in nature with negative and positive values for ΔG and ΔH, respectively. For the sorbents CAPE I and CAPE II, the efficiency of Cu(2+) removal at an initial metal concentration of 200ppb was found to be 77.5 and 99.4%, respectively. Desorption efficiencies were found to be 88 and 93% for CAPE I and CAPE II, respectively. Treatment of real wastewater samples spiked with Cu(2+) ions showed the excellent ability of the resins to adsorb metal ions.

Novel cross-linked melamine based polyamine/CNT composites for lead ions removal

A novel series of polyamine/CNT composites were synthesized via a single step polycondensation reaction of melamine, paraformaldehyde, various alkyldiamines and chlorinated carbon nanotubes (CNT) at optimized reaction conditions in the presence of N, N-Dimethyl formamide as a solvent. Chlorinated carbon nanotubes synthesized by reacting acidified CNT and thionyl chloride was used. The pure polymer (MFDH) and the functionalized composites (MFDH1, MFDH2, MFDH3 and MFDH4) having 0.01, 0.02, 0.05 and 0.1% weight of the starting precursors were used. The morphology, surface area, molecular structures and overall properties of the new series of polymers were characterized using Raman Spectroscopy, FT-IR, 13C NMR, X-ray diffraction experiments, BET and TGA. A comprehensive design was set up in order to evaluate the effects of pH, temperature, Lead ion initial concentrations and contact time on the ability of the new series of functionalized polymers for Lead (II) ion removal. Wastewater treatment revealed the high efficacy of the synthesized polyamine/CNT composite in the removal of ∼99% of Lead ions in wastewater samples.

Carbon dioxide capture in the presence of water by an amine-based crosslinked porous polymer

An amine-functionalized, crosslinked porous polymer is synthesized by linking 1,4-benzenediamine and pyrrole with p-formaldehyde in the presence of hydrochloric acid catalyst. The resulting polymer was structurally characterized and proven permanently porous with a surface area of 305 m2 g−1. The high concentration of amines (–NH– and –NH2) within the backbone of the polymer result in exceptional selectivity (141) for CO2 over N2 and dynamic capacity (15.1 cm3 g−1) in the presence of water (20 : 80 v/v CO2 : N2, 91% relative humidity, 1 bar, and 298 K). The performance of this polymer is maintained over 45 cycles without loss of selectivity, capacity, nor recyclability at room temperature; making it stand out among all porous organic materials used for carbon capture.

Removal of Zinc and Cadmium Ions Using a Cross-linked Polyaminophosphonate

A cross-linked polyzwitterionic acid (CPZA) containing aminophosphonic acid motifs was synthesized via cyclocopolymerization of diallylaminomethylphosphonic acid and cross-linker 1,1,4,4-tetraallylpiperazinium dichloride (10 mol%) using tert-butylhydroperoxide as the initiator. The CPZA upon treatment with NaOH was converted to a cross-linked anionic polyelectrolyte (CAPE 5). The adsorption of Zn2+ and Cd2+ on CAPE 5 showed that the experimental data fit the Lagergren second-order kinetic model and Langmuir, as well as Freundlich isotherm models. The adsorption capacity of Zn2+ was found to be higher than that of Cd2+, and the adsorption process was spontaneous and endothermic in nature. The low activation energy of 11.3 and 9.3 kJ/mol for Zn2+ and Cd2+, respectively indicated the adsorptions as a favorable process. The resin demonstrated excellent adsorption efficiency in removing the metal ions from aqueous solution.

New Phenol–Glycol Cross-Linked Polymers for Efficient Removal of Mercury from Aqueous Solutions

The study reports the synthesis and characterization of phenol–glycol cross-linked polymers for the removal of mercury ions from aqueous solutions at low pH. The cross-linked polymers were synthesized by one pot in-situ polycondensation reaction of phenol, different glycols and paraformaldehyde used as a linker. The cross-linked polymers were characterized by different spectroscopic techniques (

Removal of mercury (II) via a novel series of cross-linked polydithiocarbamates

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Removal of cadmium ions from wastewater by dithiocarbamate functionalized pyrrole based terpolymers

13C-NMR, FT-IR). Thermal properties were investigated by thermogravimetric analysis and differential scanning calorimetry. The most efficient cross-linked polymer Ph-TETA was investigated under different controlled conditions (pH, initial concentration, time and temperature). The experimental data were subjected to Langmuir and Freundlich isotherm models and found to fit the Freundlich model with a regression value of