Faculty Publications
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Item Solution electrospinning of styrene-acrylonitrile random copolymer from dimethyl sulfoxide(Springer India sanjiv.goswami@springer.co.in, 2013) Senthil, T.; Anandhan, S.Electrospinning is an efficient and versatile technique for the fabrication of ultrafine fibers having diameters ranging from nano to sub-micron level for various potential applications. In this study, we have investigated the influence of process and solution parameters, such as solution concentration, flow rate and applied voltage, on the morphology of electrospun poly(styrene-co-acrylonitrile) (SAN) fibers. Morphology and average diameter (Davg.) of the electrospun SAN fibers were characterized by scanning electron microscopy (SEM). The SEM results reveal that concentration, applied voltage and flow rate of solution are strongly associated with formation of defects, such as beads, in the fibers. Ultrafine SAN fibers with Davg. in the range of 96-872 nm were obtained by controlling the experimental parameters. The Davg. of electrospun fibers increased with increasing solution concentration, applied voltage and flow rate. Also, the Davg. exhibits a power law relationship with the solution concentration. © 2013 Central Institute of Plastics Engineering & Technology.Item Chemical-resistant Ultrafine Poly(styrene-co-acrylonitrile) Fibers by Electrospinning: Process Optimization by Design of Experiment(2013) Senthil, T.; George, G.; Anandhan, S.The effects of solution and processing parameters on the morphology and diameter of electrospun poly(styrene-co-acrylonitrile) fibers were investigated by design of experiment. Morphology of the electrospun fiber mats were investigated by scanning electron microscopy. With increasing solution concentration, fiber morphology changed from that of a spindle-like beaded one to smooth, and the average fiber diameter increased from 96 to 876 nm. Average fiber diameter gradually increased with applied voltage; however, fiber morphology was only slightly influenced by flow rate. Regression analysis results reveal that solution concentration has the most significant impact on the average and standard deviation of fiber diameter. © 2013 Copyright Taylor and Francis Group, LLC.Item Structure-property relationship of sol-gel electrospun ZnO nanofibers developed for ammonia gas sensing(Academic Press Inc. apjcs@harcourt.com, 2014) Senthil, T.; Anandhan, S.Zinc oxide (ZnO) based nanomaterials have been used in various gas sensors due to the wide band gap (3.37. eV), large exciton binding energy and high mobility of charge carriers of ZnO. In this work, nanocrystalline ZnO nanofiber mats were synthesized through combined sol-gel electrospinning techniques followed by calcination, in which poly(styrene- co-acrylonitrile) and zinc acetate were used as the binder and precursor, respectively. Average diameter of the ZnO nanofibers decreased from 400 to 60. nm, while their grain size and crystallinity were enhanced by increasing the calcination temperature. Morphology and structure of the ZnO nanofiber mats were characterized by high resolution transmission electron microscopy, scanning electron microscopy, Fourier transform infrared spectroscopy and X-ray diffraction. ZnO nanofiber mats were found to be superhydrophilic (contact angle was close to 0°) by contact angle measurements. The sensitivity of these ZnO nanofibers in detecting gaseous ammonia was tested using an indigenous set up. Due to their high surface area and superhydrophility, these ZnO nanofiber mats were highly sensitive in sensing gaseous ammonia and the sensitivity of these mats increased as a function of their calcination temperatures. © 2014 Elsevier Inc.Item Electrospinning of non-woven poly(styrene-co-acrylonitrile) nanofibrous webs for corrosive chemical filtration: Process evaluation and optimization by Taguchi and multiple regression analyses(Elsevier, 2015) Senthil, T.; Anandhan, S.Nano-fibrous ultra-filtration membranes of poly(styrene- co-acrylonitrile) were produced from n-butanone solution by electrospinning. Effects of governing parameters on morphology and variation in diameter of the electrospun fibers were experimentally investigated by orthogonal experimental design. The process parameters were selected by Taguchi's method. Multiple regression analysis was used to obtain a quantitative relationship between selected electrospinning parameters and average fiber diameter and ANOVA was used to identify the statistically significant parameters and set the optimal level for each parameter. Confirmation experiment revealed a good agreement between the predicted values of the response obtained from optimum level parameters and the observed experimental values. © 2014 Elsevier B.V.Item Fabrication of styrene-acrylonitrile random copolymer nanofiber membranes from N,N-dimethyl formamide by electrospinning(SAGE Publications Ltd info@sagepub.co.uk, 2015) Senthil, T.; Anandhan, S.Ultrafine styrene-acrylonitrile random copolymer (SAN) nanofiber-based membranes were produced from N,N-dimethyl formamide solution by electrospinning. The purpose of this study was to find the optimum values of the electrospinning parameters and the influence of major significant parameters on the electrospun fiber morphology and the average fiber diameter (Davg) and its standard deviation using design of experiment. A backward elimination model for multiple regression analysis was employed to obtain quantitative interactions among selected electrospinning parameters and the final fiber diameter. The dependence of the Davg and morphology on the critical entanglement concentration was also studied. Morphology of the electrospun nanofiber mats were examined by scanning electron microscopy. Davg of electrospun SAN fibers increased considerably with increasing solution concentration. Fibers with diameters ranging from 40 to 650 nm were obtained. Analysis of variance was utilized to identify the statistically significant parameters (p < 0.05) and error variance. © The Author(s) 2013.Item Sol–gel electrospun mesoporous ZnMn2O4 nanofibers with superior specific surface area(Springer New York LLC barbara.b.bertram@gsk.com, 2017) Shamitha, C.; Senthil, T.; Wu, L.; Kumar, B.; Anandhan, S.ZnMn2O4 has application potential in lithium ion batteries, supercapacitors, sensors, and thermistors. In this study, mesoporous spinel ZnMn2O4 nanofibers were synthesized by sol–gel assisted electrospinning combined with calcination, using poly(styrene-co-acrylonitrile) as sacrificial polymeric binder. Structural, morphological and optical properties of these ceramic nanofibers were characterized. X-ray diffraction and X-ray photoelectron spectroscopy results revealed the presence of hexagonal ZnMnO3 and MnO phases in the ZnMn2O4 nanofibers produced. Based on these observations we propose a plausible mechanism of formation of ZnMn2O4 nanofibers. The nanofibers calcined at 773 K exhibit a specific surface area of 79.5 m2 g?1, which is higher than that of the zinc manganite nanofibers synthesized hitherto by sol–gel electrospinning. Moreover, this material exhibits four bandgaps, which is believed to be the first observation in ZnMn2O4 nanofibers. © 2017, Springer Science+Business Media, LLC.
