Uptake of divalent metal ions (Cu2+, Zn2+, and Cd2+) by polysiloxane immobilized diamine ligand system

Porous solid siloxane polymers carrying diamine functional group of formula P–(CH2)3NH–CH2CH2NH2 (where P–represents a silica-like siloxane framework) have been prepared by replacement of the iodine in iodopolysiloxane with ethylenediamine. The iodofunctionalized polysiloxane was prepared by polycondensation of Si(OEt)4 and (MeO)3Si(CH2)I. The polysiloxane diamine ligand system exhibits high potential for preconcentration of divalent metal ions (Cu2+, Zn2+, and Cd2+). The tendency to chemisorb these divalent metal ions by the diamine ligand system at the optimum conditions was found in the order: Cu2+ > Zn2+ > Cd2+. Diamine ligand system suffers from leaching of ligand containing groups upon treatment with acidic solutions

Synthesis of Nanometal Oxide–Coated Cotton Composites

Several selected studies dealing with the development of novel antimicrobial metal oxide–coated cotton nanocomposites and their antimicrobial applications have been reviewed in this chapter. Synthesis of metal oxide nanoparticles (NPs) and its deposition onto cotton fibers were conducted using various methods. These include the high energy γ-radiation, thermal treatment-assisted impregnation, “pad-dry-cure” of the impregnated fabric in the colloid formulation of metal oxide soluble, and ultrasonic radiation methods. The coated metal oxide nanoparticles have shown an effective enhancement for antimicrobial activity. They reduce the chance of diseases originating from hospital infections. The antimicrobial properties of cotton fabrics finished with metal oxide NPs against a variety of bacterial strains commonly associated with nosocomial infections, caused by Staphylococcus aureus and Escherichia coli, have been investigated by four different methods. The morphology of the cotton-coated metal oxide nanoparticles and their chemical structure have been analyzed by UV-vis, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), X-ray diffraction (XRD) and X-ray photoelectron spectra (XPS). SEM and XRD analyses revealed that the shape and size of the coated nanoparticles are dependent on the nature of the metal oxide and its preparation conditions

Synthesis and structural characterization of a new macrocyclic polysiloxane-immobilized ligand system

A new porous solid macrocyclic 1,4,7,11,14-pentaazapentadecane-3,15-dione polysiloxane ligand system of the general formula P–(CH2)3–C11H22O2N5 (where P represents [Si–O] n siloxane network) has been prepared by the reaction of polysiloxane-immobilized iminobis(N-(2-aminoethyl)acetamide) with 1,3-dibromopropane. The FTIR and XPS results confirm the introduction of the macrocyclic functional ligand group into the polysiloxane network. The new macrocyclic polysiloxane ligand system exhibits high potential for the uptake of metal ions (Fe3+, Co2+, Ni2+, Cu2+ and Zn2+)

Preconcentration and separation of copper (II) by 3-aminopropylpolysiloxane immobilized ligand system

Porous solid insoluble polysiloxane-immobilized ligand system bearing propylamine of the general formula P-(CH2)3-NH2 (where P represents [Si–O] n siloxane network) was prepared and evaluated for the separation and preconcentration of copper(II) from aqueous solution. The ligand system retained Cu(II) effectively when used as a metal ion extractant. The ligand system also showed high selectivity to separate copper(II) from a mixture of metal ions (Co(II), Ni(II), Cu(II)) when used as chromatographic stationary phase. The optimum pH appeared to be pH = 5.5 using acetate buffer as an eluent. Thermal analysis showed that the ligand system is very stable at relatively high temperatures

A review on polysiloxane-immobilized ligand systems: synthesis, characterization and applications

The immobilized silica gel ligand systems made by modification of silica surfaces have been briefly summarized. Short background was described based on the synthesis methods and their applications. In this review more attention towards the functionalized polysiloxane xerogels and their postmodification has been given. Polysiloxane-immobilized ligand systems bearing organofunctionalized ligand groups of general formula P–(CH2)3–X (where P represents a three-dimensional silica like network-matrix and X is an organofunctional group) were prepared through the sol–gel process by hydrolytic polycondensation of Si(OR)4 and the appropriate silane coupling agent (RO)3Si(CH2)3X (where R is an alkyl group, e.g CH3 or C2H5). There are many other immobilized ligand systems, which were prepared by treatment of post-polysiloxane precursors with an appropriate organofunctional ligand. Variety of

Separation of Cu (II), Ni (II), and Co (II) Ions Using Iminobis (N‐2‐Aminoethylacetamide) Polysiloxane‐Immobilized Ligand System

Extraction of Cu(II), Ni(II), and Co(II) metal ions from aqueous solutions was investigated using iminobis(N‐2‐aminoethylacetamide) polysiloxane‐immobilized ligand system of the general formula P‐(CH2)3‐N(CH2CONHCH2CH2NH2)2, where P represents [Si‐O]n siloxane network. The immobilized ligand system also showed high selectivity to separate copper(II) from a mixture of metal ions (Co(II), Ni(II), Cu(II)) when used as chromatographic stationary phase. The ligand system preconcentrated Cu(II) effectively at different concentrations when used as a stationary phase extractant. The optimum pH for maximum metal uptake appeared to be pH 5.0 using acetate buffer solution. The preconcentated chemisorbed metal ions were regenerated from the solid extractant using 0.5 M HCl

Synthesis of new polysiloxane-immobilized ligand system di (amidomethyl) aminetetraacetic acid

A new chelating porous polysiloxane-immobilized tetraacetic acid ligand system has been prepared. This material was made by chemical modification of the iminodiacetic acid polysiloxane with thionyl chloride and diethyliminodiacetate, respectively. The polysiloxane functionalized with di(amidomethyl)aminetetraacetic acid of the general formula P-(CH 2 ) 3 N(CH 2 C(O)N) 2 (CH 2 COOH) 4 [where P represents the polysiloxane backbones (Si‒O‒Si) n ] was characterized by Thermogravimetric Analysis (TGA) and FTIR spectra. The FTIR results proved that tetraacetic acid groups are successfully grafted onto the polysiloxane surface. This ligand system exhibits high potential for extraction of divalent metal ions (Co+2, Ni+2, Cu+2, and Zn+2) from aqueous solution

Masanobu Wakasa, Yuya Takamori, Toshiyuki Takayanagi, Masayuki Orihara

The photochemistry of octaisopropylcyclotetragermane was studied by laser flash photolysis and trapping experiments. Upon irradiation of the cyclotetragermane, the main reaction was a ring opening to form octaisopropyltetragermane-1, 4-diyl biradical (kmax= 310 and 550 nm), but generations of diisopropylgermylene and tetraisopropyldigermene are negligible

Uptake of divalent metal ions (Cu2+, Zn2+ and Cd2+) by polysiloxane immobilized glycinate ligand system

Porous solid siloxane polymer carrying glycinate functional group of formula –(CH2)3NHCH2COOH has been prepared by the sol-gel process. Treatment of aqueous solutions of divalent metal ions with the polysiloxane glycinate ligand system demonstrates that this material exhibits high potential for preconcentration of metal ions (Cu2+, Zn2+ and Cd2+). The ligand system chemisorbs these divalent metal ions, at optimum conditions, in the order: Cd2+ < Zn2+ < Cu2+. The uptake of copper ions is concentration dependent but it is independent on the presence of other competing ions. Treatment of the glycinate ligand system with acidic solution results in leaching of bound ligands. The highest leaching occurs in presence of copper ions at low p

SYNTHESIS OF POLYSILOXANE-IMMOBILIZED MONOAMINE, DIAMINE, AND TRIAMINE LIGAND SYSTEMS IN THE PRESENCE OF CTAB AND THEIR APPLICATIONS

International audiencePolysiloxane-immobilized monoamine, diamine, and triamine ligand systems of the general formula P-(CH2)(3)-X [where P represents a polysiloxane three-dimension silica like network, and X represents monoamine(-NH2), diamine (-NH(CH2)(2)NH2), or triamine (-NH(CH2)(2)NH(CH2)(2)NH2) functional ligand groups] were prepared by hydrolytic polycondensation of the tetraethylorthosilicate (TEOS) and the appropriate amine silane coupling agent (RO)(3)Si-(CH2)(3)X in the presence of cetyltrimethylammonium bromide (CTAB) as surfactant using the sol-gel method. The polysiloxane-immobilized amine ligand systems exhibit a higher potential for divalent metal ions (Cu2+, Ni2+, Co2+) when CTAB was used as surfactant than those of the corresponding polysiloxane ligand systems prepared without CTAB. X-ray Photoelectron Spectroscopy (XPS) analyses show a significant change in the surface composition as resulting from the incorporation of CTAB, which can be related to the increase in the uptake of metal ions