Indian Association for the Cultivation of Science

About: Indian Association for the Cultivation of Science is a education organization based out in Kolkata, India. It is known for research contribution in the topics: Catalysis & Excited state. The organization has 3867 authors who have published 10457 publications receiving 220098 citations.

In-situ polymerization of grafted aniline in the channels of mesoporous silica SBA-15

Abstract: Monolayer N-propylaniline functionalized mesoporous silica SBA-15 (MFMS) has been successfully used for the grafting of polyaniline moieties through in-situ polymerization in the presence of ammonium peroxodisulfate (APS) as oxidant. For comparison, siliceous SBA-15 has been used to prepare non-grafted polyaniline (PANI) nanocomposites. The SBA-15, MFMS, and PANI nanocomposites were thoroughly characterized through powder XRD, TEM, SEM, FTIR, TG-DTA and N2 sorption measurements. The powder XRD pattern and TEM image of MFMS show a hexagonal (p6mm) structure. The FTIR, TG-DTA and N2 sorption studies confirm the presence of lattice bound N-propylaniline groups in MFMS material. The decrease in mesopore volume of MFMS from 0.89 to 0.61 ml g−1 after polymerization indicates that the polymers are well packed inside the channels of SBA-15. The thermal analysis further reveals that covalently grafted polyaniline decomposes at much higher temperature than the non-grafted analogue. The increased electrical conductivity of grafted polyaniline compared to non-grafted composites is attributed to the presence of more counter ions and the increased intensity of the “electronic-like absorption’ band at 1155 cm−1 of the former. The grafted PANI exhibits electrorheological effects with an increased shear viscosity under an applied electric field compared with the non-grafted polyaniline nanocomposite.

Structural Variations on Self-Assembly and Macroscopic Properties of 1,4,5,8-Naphthalene-diimide Chromophores

Abstract: Supramolecular assembly and macroscopic properties of a series of bis-(trialkoxybenzamide)-functionalized naphthalene-tetracarboxylicacid-diimide (NDI) chromophores have been studied. The number of methylene units (0, 2, 3, 4; NDI-0, NDI-2, NDI-3, NDI-4, respectively) in between the NDI chromophore and the amide functionalities have been systematically varied to understand the effect of this simple structural variations on the self-assembly. UV−visible spectroscopic studies revealed facile self-assembly in nonpolar medium by synergistic effect of π-stacking, hydrogen-bonding, and hydrophobic interactions. The propensity toward self-assembly was found to follow the order NDI-0 ≫ NDI-2 ≈ NDI-3 > NDI-4 ,which could be attributed to the difference in strength of the H-bonding interaction. Atomic force microscopy (AFM) studies revealed unique morphology for the self-assembled structure in each case such as nanostructure with short-range order (NDI-0), elongated nanowires (NDI-2), relatively flat nanoribbons (N...

Nanoarchitectured Metal Phosphates and Phosphonates: A New Material Horizon toward Emerging Applications

Abstract: Metal phosphate- and phosphonate-based nanoarchitectured materials offer a unique opportunity to design hierarchically porous nanomaterials consisting of interconnected micropores, mesopores, and macropores. Due to their strong affinity toward the metal centers, the phosphate and phosphonate moieties act as ligand sites/linkers to form a wide spectrum of nanoarchitectured materials. In this review, we have summarized the synthetic routes in designing key microporous and mesoporous phosphate and phosphonate molecular sieves. Designing novel nanoarchitectures of metal phosphate- and phosphonate-based microporous and mesoporous materials for catalysis, adsorption, optoelectronics, electrochemical cells, fuel cells, and biomedical applications will further enrich the chemistry of these porous solids in the future.