Dilip Chandra Deb Nath

Application of fly ash as a catalyst for synthesis of carbon nanotube ribbons

The larger diameter-based carbon nanotube (CNT) ropes and ribbons are currently synthesized by catalytic decomposition of hydrocarbons with transition metal-based catalysts e.g., Co, Ni, Fe and Mo at 1100-1200°C, using chemical vapour deposition (CVD) and electric arc methods. We produced CNT ribbons by fly ash (FA) catalyzed pyrolysis of a composite film of poly (vinyl alcohol) (PVA) with FA at 500°C for 10min under a nitrogen flow of 2L/min. Different geometrical structures, e.g.; knotted and twisted, U- and spiral-shaped CNT ribbons were observed in the images of scanning and transmission electron microscopy. The widths of the CNT ribbons measured varied in the ranges 18-80nm. X-ray photoelectron spectroscopy analysis showed five types of carbon binding peaks, C-C/C-H (∼77%), C-O-H (∼9%), -C-O-C (∼5%), C=O (∼5%) and -O-C=O (∼3%). The ratio of intensities of G and D bands, IG/ID was 1.61 analysed by Raman Spectroscopy. CNT ribbons grown on the surface of FA have potential for the fabrication of high-strength composite materials with polymer and metal.

Fabrication of High-Strength Biodegradable Composite Films of Poly (Vinyl Alcohol) and Fly Ash Crosslinked with Glutaraldehyde

A biodegradable composite film of poly (vinyl alcohol) reinforced with fly ash and glutaraldehyde was fabricated using a suspension of these materials in deionized water. The tensile strength and modulus of the films were found to increase proportionally with FA up to 20 wt%, and achieved the maximum 49% and 123% higher, respectively, than that of PVA. The percentage of strain at failure decreased exponentially with FA. The physical and/or chemical bonding in the systems (PVA, FA, and GLA) were directly characterized by the shift of stretching and bending peaks of the structure in the components with FTIR spectra.