caa a22 4500 606194932 CHVBK 20210128100916.0 cr unu---uuuuu 210128e20151201xx s 000 0 eng 10.1007/s10934-015-0029-3 doi (NATIONALLICENCE)springer-10.1007/s10934-015-0029-3 Ultrafine nanocrystalline mesoporous NaY zeolites from fly ash and their suitability for eco-friendly corrosion protection [Elektronische Daten] [Rashmi Padhy, Ruchi Shaw, Sangeeta Tiwari, Sandeep Tiwari] Fly ash, an industrial waste from coal based thermal power stations and a vast resource for silica and alumina, remains underutilized. It consists of polycyclic aromatic hydrocarbons, metals, silica etc. which are toxic in nature and silica has also been classified as a carcinogenic material. So a definite need is to make a proper use of the fly ash in order to convert it into useful materials possessing enormous functionality. Preparation of uniform nanocrystalline mesoporous NaY zeolites from fly ash without use of organic structural directing agents is reported for the first time. Different ratios of fumed silica are added to fly ash for preparation of NaY zeolites. The effect of amount of water used during the crystallization process on particle size of the zeolite is reported. Detailed characterization of the prepared zeolites is carried out using XRD, FTIR, SEM EDAX and DLS. Si/Al ratio was calculated using NMR and EDAX data. Porosity, pore size distribution and pore volume were determined using nitrogen adsorption data. The particle size of zeolites was found to be in the range of 400-670nm whereas the crystallite size calculated from the XRD data was in 9-13.4nm range. The synthesized zeolites are found to possess high crystallinity (90-93%). Formation of octahedral crystals is confirmed by SEM observations. BET analysis shows high surface areas and presence of mesopores. IR and NMR spectroscopy confirms the formation of NaY with increased silica content. The prepared zeolites exhibited good ion exchange capacities which were found to decrease with increase in Si/Al ratio. Unlike the common applications of zeolites in catalysis where high purity is desirable, the fly ash based zeolites were exchanged with zinc metal ion and applied as pigment in anticorrosive paint formulations. Corrosion resistance was evaluated using electrochemical impedance spectroscopy measurements. The results indicate that metal exchanged zeolite possesses good anticorrosive property and can be used as an alternate to the conventionally used toxic, lead and chromate based anticorrosive pigments. Springer Science+Business Media New York, 2015 Fly ash nationallicence NaY nationallicence Zeolites nationallicence Corrosion nationallicence Protective coatings nationallicence Padhy Rashmi Amity Institute of Applied Sciences, Amity University Uttar Pradesh, Noida, India aut Shaw Ruchi Amity Institute of Applied Sciences, Amity University Uttar Pradesh, Noida, India aut Tiwari Sangeeta Amity Institute of Applied Sciences, Amity University Uttar Pradesh, Noida, India aut Tiwari Sandeep Council of Scientific and Industrial Research, New Delhi, India aut Journal of Porous Materials Springer US; http://www.springer-ny.com 22/6(2015-12-01), 1483-1494 1380-2224 22:6<1483 2015 22 10934 https://doi.org/10.1007/s10934-015-0029-3 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s10934-015-0029-3 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Padhy Rashmi Amity Institute of Applied Sciences, Amity University Uttar Pradesh, Noida, India aut NATIONALLICENCE 700 1- Shaw Ruchi Amity Institute of Applied Sciences, Amity University Uttar Pradesh, Noida, India aut NATIONALLICENCE 700 1- Tiwari Sangeeta Amity Institute of Applied Sciences, Amity University Uttar Pradesh, Noida, India aut NATIONALLICENCE 700 1- Tiwari Sandeep Council of Scientific and Industrial Research, New Delhi, India aut NATIONALLICENCE 773 0- Journal of Porous Materials Springer US; http://www.springer-ny.com 22/6(2015-12-01), 1483-1494 1380-2224 22:6<1483 2015 22 10934