Material Chemistry

Abstract Polyacrylamide zirconium (IV) iodate was synthesized using the sol–gel technique. The
synthesis conditions such as reactant concentrations and temperature were changed to optimize
the ion exchange properties of the hybrid organic–inorganic ion exchange material. Zirconium oxychloride
(0.1 M) was added to 0.1 M potassium iodate in the presence of 0.4 M acrylamide and
heated at 70 C for 6 h to yield the polyacrylamide zirconium (IV) iodate with maximum capacity.
The ion exchange capacity was found to be 3.27 meq/g for Pb(II). The hybrid material has been
characterized on the basis of chemical composition FTIR, XRD, TGA-DTA, SEM and EDX studies.
Sorption studies showed that the hybrid cation exchanger has a high selectivity to Pb(II) in comparison
to other metal ions. Its selectivity was evaluated by performing some important binary
separations like Hg(II)–Pb(II), Cu(II)–Pb(II), Ni(II)–Pb(II), Fe(III)–Pb(II) and Cd(II)–Pb(II). In
addition, the selective separation of Pb(II) was also achieved from a synthetic mixture containing
a large number of metal ions with a recovery of 98.5%. The proposed method was successfully
applied for the selective removal of Pb(II) from wastewater samples.

A theoretical model of shape-anisometric particles embedded in a cubic lattice is formulated for binary mixtures combining rod-like, plate-like and spherical particles. The model aims at providing a tool for the prediction and interpretation of complex phase behavior in a variety of liquid crystalline colloids, biological and macromolecular systems. Introducing just repulsive interactions among the particles, a rich variety of phase structures and multiphasic equilibria is obtained, including isotropic, nematic, lamellar and columnar phases, demixing into phases of the same or different symmetries and structural microsegregation of the different species of the mixture within the same phase.

The synthesis of tetrakis (1,1-dimethyl-2-trimethylammonium) ethylphthalocyaninato Zn(II) tetraiodide 2-a new cationic phthalocyanine -is reported as well as its photophysical properties in water, relevant for the use of this dye as photodynamic sensitizer. The hydrophobicity of the macrocycle leads to strong aggregation which lowers the fluorescence and singlet oxygen quantum yields of aqueous solutions of 2. Photophysical parameters agree with those

A new series of D–A–D molecules (1–3) with carbazole as a donor and 2,5-diaryl-1,3,4-oxadiazole,
dibenzothiophene-S,S-dioxide and benzo[1,2,5]thiadiazole as acceptors have been synthesized. Polyphenylene
dendrons have also been incorporatedtopreventthefacetoface p–p stacking in aggregates. Unlike traditional
D–A systems, which show ACQ problems and large red shifts in the solid state, these derivatives (1–3) exhibit
good solid state luminescence behavior without undergoing a red shift or fluorescence quenching. The present
results indicate that just the combination of a donor–acceptor system with bulkier dendrons is not enough
to generate efficient solid state emissions but the prevention of co-facial interaction between donors and
acceptors in aggregates is more important. In the case of derivative 3, restriction of complete molecular
planarization and steric hindrance near the acceptor can effectively prevent intermolecular donor–acceptor
interactions, thus leading to enhanced emission in aggregates. While in the case of derivative 1, a sterically
unhindered acceptor is easily approached by a donor due to close molecular packing in aggregates
forming weakly luminescent species

A mixed vanadium manganese oxide was synthesized through a chimie douce route. The synthesis proceeds via a cationic exchange reaction occurring between the layers of a synthetic rancieite, a lamellar manganic acid. The vanadium atoms were found to be at a ...

Abstract This study assesses the replacement of low reactive volcanic ash by ashes of an agro-waste matter (cassava peel) within the range of 0–30% by mass in geopolymer synthesis. Gradual replacement of volcanic ash decreases the initial setting time and increases the compressive strength to about 64 and 733% respectively. Also, it turns down the magnitude of efflorescence. After immersion in 5% solution of sulphuric acid, the surface of all specimens remains structurally intact. Cassava peel ash behaves as an additional precursor that brings synergistic effect to volcanic ash during alkaline activation.

... Waldo JE Beek and René AJ Janssen*. Molecular Materials and Nanosystems, Eindhoven University of Technology, PO Box 513, 5600 MB Eindhoven, The Netherlands. E-mail: rajjanssen@tue.nl. Received 14th April 2004, Accepted 7th June 2004. ...

The kinetics and mechanism of the reduction of the iron (III) complex ion,[FeSalen (H 2 O) 2]+, by L-ascorbic acid has been investigated in aqueous perchloric acid medium at 28.5±0.3 o C. The kinetic data was obtained by monitoring the rate of decay of the complex at 515 nm. Under pseudo-first order conditions of concentration of L-ascorbic acid at about 20-fold excess of concentration of complex, the rate of reaction increased with the concentration of ascorbic acid. Least square fits of observed rate against concentration of ...

In the present research, grafting of acrylamide monomer onto a water-soluble food grade polysaccharide, Kundoor mucilage, initiated by ceric ion in aqueous medium has been studied under N2 atmosphere. Ceric ion initiated solution polymerization was found to be satisfactory for the formation of copolymer. The effect of monomer concentration, initiator concentration, reaction time, and temperature, in terms of grafting efficiency (%GE) and percent of grafting (%PG), have been investigated. The graft copolymers were characterized by FTIR, differential scanning calorimetry (DSC), scanning electron microscopy (SEM), and X-ray diffraction (XRD). © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 1186–1191, 2005