Faculty Publications
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Item Synthesis and characterization of temperature sensitive P-NIPAM macro/micro hydrogels(Elsevier B.V., 2011) JagadeeshBabu, P.E.; Suresh Kumar, R.; Maheswari, B.A thermo responsive macro porous poly(N-isopropylacrylamide) hydrogel was synthesized using free radical polymerization. The reaction was optimized by varying the reaction temperature, monomer, cross-linker and initiator based on the strength and swelling characteristics of the hydrogel. The morphology of the macro hydrogel was observed using scanning electron microscope (SEM). The swelling behavior of the macro hydrogel was performed gravimetrically and found that the gel synthesized at 36 °C had maximum deswelling ratio of 34.5 (-). These optimized values were further used to synthesis micro hydrogels using water-oil (w/o) emulsion technique. The morphology of the micro hydrogels were observed through SEM. Effect of water-oil ratio and stirrer speed on the mean particle size of the micro hydrogels were studied. Micro hydrogels synthesized at 1:1.5. w/o ratio and at 800. rpm had perfect spherical shape and had least particle mean diameter of 0.74 ?m, with SD of 0.5. Dye release kinetics with respect to temperature and time were studied using methylene blue solution. The release kinetic studies of micro hydrogel showed higher sustained release for 56. h compared to the macro hydrogel. © 2011 Elsevier B.V.Item Rapid removal of cobalt (II) from aqueous solution using cuttlefish bones; Equilibrium, kinetics, and thermodynamic study(2013) Sandesh, K.; Suresh Kumar, R.; JagadeeshBabu, P.E.The objective of this study is to assess the adsorption potential of cobalt (II) using cuttlefish bones. The bones were treated with 0.01 N HCl to enhance the heavy metal uptake. The adsorbent was characterized using scanning electron microscope and energy dispersive X-ray spectrometer. An adsorption study was conducted in a batch system to optimize process variables such as initial concentration of cobalt (II), pH, sorbent loading, particle size, process temperature, and contact time. The optimal pH was found to be 9. The kinetic data followed the pseudosecond-order kinetic model, and the equilibrium time was found to be 20 min. In the first minute of the adsorption process, 50% of the cobalt (II) was adsorbed by the cuttle bones. Adsorption isotherms were expressed by the Langmuir and Freundlich adsorption models. The Langmuir adsorption model fits the experimental data reasonably well compared with the Freundlich model. The maximum adsorption capacity of this new sorbent was found to be 76.6 mg g-1 at 40 °C. Thermodynamic parameters, including the Gibbs free energy (?Go), enthalpy (?Ho), and entropy (?So), indicated that the adsorption of cobalt (II) by cuttlefish bones was feasible and endothermic at a temperature range of 20-40 °C. © 2012 Curtin University of Technology and John Wiley & Sons, Ltd.Item Role of N-vinyl-2-pyrrolidinone on the thermoresponsive behavior of PNIPAm hydrogel and its release kinetics using dye and vitamin-B12 as model drug(2014) Maheswari, B.; JagadeeshBabu, P.E.; Agarwal, M.Temperature-sensitive hydrogels hold great promise in biological applications as they can respond to changes in physiological temperature to produce a desired effect like controlled drug delivery. In this study, a series of poly(N-isopropylacrylamide-co-N-vinyl-2-pyrrolidinone) thermosensitive hydrogels were synthesized by radical copolymerization of NIPAm with 1-vinyl-2-pyrrolidinone (NVP). By altering the initial NIPAm/NVP mole ratios, copolymers were synthesized to have their own distinctive lower critical solution temperature which was established using differential scanning calorimetry. The swelling behavior of the hydrogel was analyzed gravimetrically and it was observed that reswelling rate increases with increasing NVP mole ratio. Further characterizations of the hydrogels were performed using Fourier transform infrared spectroscopy and scanning electron microscopy. Release kinetics with respect to temperature was studied using methylene blue dye solution and vitamin B12. Kinetic modeling of the release profile revealed that the release mechanism is a non-Fickian diffusion mechanism. These results suggested that this material has potential application as intelligent drug carriers. The quantities of residual monomers in the PIV4 hydrogel were determined by HPLC method, and the results show almost complete conversion. © 2013 Taylor & Francis.Item Role of graphene quantum dots synthesized through pyrolysis in the release behavior of temperature responsive poly (N,N-diethyl acrylamide) hydrogel loaded with doxorubicin(Taylor and Francis Inc. 325 Chestnut St, Suite 800 Philadelphia PA 19106, 2018) Havanur, S.; JagadeeshBabu, P.E.We have reported the synthesis and characterization of new drug carrier using Poly (N,N-diethyl acrylamide) (PDEA) and graphene quantum dots (GQDs). PDEA is a stimuli-responsive, macroporous polymer which has the ability to respond to change in surrounding temperature and addition of GQDs will help in improving the inherent characteristics of PDEA. In this research work, PDEA hydrogels along with GQDs have been synthesized by free radical polymerization. The effect of various concentrations of GQDs on the property of PDEA hydrogel was studied. The structural analysis of synthesized hydrogels was done using Fourier transform infrared spectroscopy (FT–IR). The internal surface morphology of porous hydrogels was observed using scanning electron microscope (SEM) micrographs. From the analysis, it has been observed that the equilibrium swelling ratio (ESR) and reswelling kinetics of the hydrogel significantly increased as the GQDs content was varied. The cancer drug (an anthracycline that is used for cancer chemotherapy) Doxorubicin (DOX) release behavior was studied and found that the performance of hydrogel is dependent on hydrogel composition, time, and surrounding temperature. The cytotoxicity of GQDs incorporated PDEA hydrogels gave a significant report which supports the potential application of hydrogel as an intelligent drug carrier. © 2018, © 2018 Taylor & Francis Group, LLC.Item Synthesis and optimization of poly (N,N-diethylacrylamide) hydrogel and evaluation of its anticancer drug doxorubicin’s release behavior(Springer London, 2019) Havanur, S.; Farheenand, V.; JagadeeshBabu, P.E.A macroporous temperature-responsive poly(N,N-diethylacrylamide) (PDEA) hydrogel was synthesized and optimized through free radical polymerization. The optimized hydrogel was achieved by evaluating the swelling characteristics, physical stability and mechanical strength through altering the components namely concentration of N,N-diethylacrylamide (monomer), ammonium peroxodisulfate (initiator), N,N?-methylbisacrylamide (cross-linker) and N,N,N?,N?-tetramethylethylenediamine (accelerator). The equilibrium swelling behavior was performed gravimetrically, and the PDEA hydrogel synthesized at 36 °C exhibited a maximum swelling of 18.332 g.g ?1 . Also, the LCST of the prepared PDEA hydrogel was found to be around 29 °C. However, the results of time-controlled swelling and deswelling kinetics indicated that hydrogels are temperature sensitive. Further, characterization of the hydrogel was performed using scanning electron microscopy, differential scanning calorimetry, thermal gravimetric analysis, and Fourier transform infrared spectroscopy. The hydrogel was assessed for its cytotoxicity in MDA-MB-231 cell line by MTT assay. The release behavior of anticancer drug doxorubicin (DOX), a hydroxyl derivative of anthracycline, was studied at above and below the LCST temperature. It was found that the DOX release from the DOX-loaded hydrogels was significantly improved when the surrounding temperature of the release media was increased near to physiological temperature. The cumulative release profile of hydrogel at different temperatures was fitted to different kinetic model equations and non-Fickian diffusion release mechanism was revealed. These results suggest that PDEA has a potential application as an intelligent drug carrier. © 2018, Iran Polymer and Petrochemical Institute.Item One step synthesis of silver nanowires using fructose as a reducing agent and its antibacterial and antioxidant analysis(Institute of Physics Publishing helen.craven@iop.org, 2019) Sharma, D.; Rakshana, D.A.; Mohan Balakrishnan, R.M.; JagadeeshBabu, P.E.Silver nanowires were synthesised using hydrothermal method by reducing silver nitrate (AgNO3) using fructose in the presence of poly-vinylpyrrolidone (PVP). The parameters such as the effect of process temperature, AgNO3 molarity, PVP and fructose (C6H12O6) concentration influencing the synthesis of silver nanowires (Ag NWs) were investigated. The scanning electron microscope (SEM) images showed that ultra-long, uniform and thin silver nanowires were obtained under optimized conditions; 0.02 M AgNO3, 0.016 g ml-1 of fructose, 0.16 g ml-1 of PVP at 160 °C within 22 h. The dynamic light scattering (DLS) analysis revealed that the silver nanowires obtained have an average diameter of 77 nm possessing high level of crystallinity with face centered cubic (fcc) phase that is evident from the x-ray diffraction (XRD) patterns peaked at (111), (200), (220), (311) and (222) planes. FT-IR (Fourier transform infrared spectroscopy) results suggested that there is adsorption of PVP molecules on the silver atoms. Ag NWs exhibited better antibacterial activity against Escherichia coli and high antioxidant activity against 2,2-diphenyl-1- picrylhydrazyl (DPPH) free radical scavenger. This work gives a green approach to the hydrothermal synthesis of Ag NWs using fructose with a promising antibacterial and antioxidant properties. © 2019 IOP Publishing Ltd.