@article { ISI:000278744500055, title = {Synthesis and characterization of nanocrystalline zinc substituted nickel ferrites}, journal = {Journal of Alloys and Compounds}, volume = {496}, number = {1-2}, year = {2010}, month = {APR}, pages = {256-260}, publisher = {ELSEVIER SCIENCE SA}, address = {PO BOX 564, 1001 LAUSANNE, SWITZERLAND}, abstract = {

Nanocrystalline zinc substituted nickel ferrites, Ni(1-x)Zn(x)Fe(2)O(4) (0.0 \<= x \<= 1.0) have been prepared by citrate gel auto-combustion method. The effect of zinc ion content on structural, electrical transport and magnetic properties has been studied. The X-ray diffraction (XRD) pattern revealed that, all the compositions possess single-phase spinel structure. The nano-sized grain structure formation was confirmed by transmission electron microscopy (TEM). The dc electrical resistivity shows the samples are semiconducting in nature. The magnetic measurements showed that the composition Ni(0.6)Zn(0.4)Fe(2)O(4) has maximum saturation magnetization (M(s)) while high coersivity (Hc) for ZnFe(2)O(4). Thermoelectric power measurement study showed that the compounds, with x \<= 0.4 are p-type and for x \> 0.4 behaves n-type conduction mechanism. (C) 2010 Published by Elsevier B.V.

}, keywords = {Electron microscopy, Magnetic, Sintering, X-ray diffraction}, issn = {0925-8388}, doi = {10.1016/j.jallcom.2010.01.009}, author = {Hankare, P. P. and Sankpal, U. B. and Patil, R. P. and Mulla, Imtiaz S. and Sasikala, R. and Tripathi, A. K. and Garadkar, K. M.} } @article {45644, title = {Application of glucose derived magnetic solid acid for etherification of 5-HMF to 5-EMF, dehydration of sorbitol to isosorbide, and esterification of fatty acids}, journal = {Tetrahedron Letters}, volume = {57}, year = {2016}, month = {SEP }, pages = {4398-4400}, type = {Article}, abstract = {

In this study, the catalytic activity of Glu-Fe3O4-SO3H was evaluated for three acid catalyzed reactions: etherification of 5-hydroxymethylfurfural (5-HMF) to 5-ethoxymethylfurfural (5-EMF) in ethanol, dehydration of sorbitol to isosorbide, and esterification of fatty acids with good yields and selectivity. Moreover, the catalyst can be easily separated from the reaction with an external magnetic force and reused at least five times without a significant decrease in catalytic activity. (C) 2016 Elsevier Ltd. All rights reserved.

}, keywords = {dehydration, Esterification, etherification, Magnetic}, issn = {0040-4039}, doi = {10.1016/j.tetlet.2016.08.061}, author = {Thombal, Raju S. and Jadhav, Vrushali H.} } @article {46887, title = {Dual responsive cellulose microspheres with high solid-state fluorescence emission}, journal = {Colloids and Surfaces A-Physicochemical and Engineering Aspects}, volume = {591}, year = {2020}, month = {APR}, pages = {124510}, type = {Article}, abstract = {

Materials that respond to multiple stimuli such as magnetic field and light are attractive for security and medical diagnostic applications. One of the major challenges in dual functional microspheres is that the presence of magnetic nanoparticles can quench fluorescence emission. Also, there is a probability of solid-state quenching due to the proximity of the fluorophore. We report here a facile approach to prepare cellulose microspheres with high solid-state fluorescence using 40 \% tetrabutylammonium hydroxide (TBAH). The fluorescence quenching effect due to the presence of Fe3O4 nanoparticles and solid-state quenching due to aggregation of fluorophore was systematically investigated. Microspheres with the detectable magnetic response and fluorescence quantum yield as high as 0.57 (FMB 414) was obtained by optimizing the reaction conditions. Such a high quantum yield has not been reported before for dual stimuli-responsive fluorescent microspheres. The magnetic and fluorescent properties were found to be durable even after multiple washing cycles. These dual responsive cellulose microspheres can be added as security features to authenticate documents such as passports, degree certificates, currency notes, financial documents etc.

}, keywords = {Fluorescent, Magnetic, Microcrystalline cellulose, microspheres, Stimuli responsive microspheres, Tetrabutylammonium hydroxide}, issn = {0927-7757}, doi = {10.1016/j.colsurfa.2020.124510}, author = {Yadav, Prashant and Prajitha, K. P. and Dhaware, Vinita and Subramani, Mohan and Joy, Pattayil and Asha, S. K. and Shanmuganathan, Kadhiravan} }