Faculty Publications

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    Supramolecular synthons in noncovalent synthesis of a class of gelators derived from simple organic salts: Instant gelation of organic fluids at room temperature via in situ synthesis of the gelators
    (2009) Das, U.K.; Trivedi, D.R.; Adarsh, N.N.; Dastidar, P.
    (Chemical Equation Presented) The supramolecular synthon approach has been employed to synthesize noncovalently a series of low molecular mass organic gelators (LMOGs) derived from benzylammonium salts of variously substituted benzoic acids. The majority of the salts (75%) prepared showed interesting gelation properties. Instant gelation of an organic fluid, namely methyl salicylate, was achieved at room temperature by using most of the gelator salts by in situ synthesis of the gelators. Table top rheology and scanning electron microscopy (SEM) were used to characterize the gels. Single crystal X-ray diffraction studies revealed the presence of both 1D and 2D supramolecular synthons. X-ray powder diffraction (XRPD) studies indicated the presence of various crystalline phases in the fibers of the xerogels. By using these data, a structure-property correlation has been attempted and the working hypothesis for designing the gelator has been reinforced. © 2009 American Chemical Society.
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    Defluoridation of fresh water using the process of Electrocoagulation combined with Adsorption
    (2013) Wali, A.; Saidutta, M.B.
    In India, fluoride is the major inorganic pollutant of natural origin found in groundwater. Fluoride pollution occurs due to natural and manmade reasons and high concentrations have a detrimental effect on health. Electrochemical techniques like Electrocoagulation(EC) appears to be one of the most effective approaches for treatment of water and wastewater because of its versatility, safety, selectivity, amenability to automation and environmental compatibility. Results show that the percentage removal of fluoride was around 94 to 96% for monopolar and bipolar electrodes. Adsorbents like tricalcium phosphate and activated alumina used along with electrocoagulation process also gave promising results. © 2013 CAFET-INNOVA TECHNICAL SOCIETY.
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    Effect of Surface Chemistry on Hemolysis, Thrombogenicity, and Toxicity of Carbon Nanotube Doped Thermally Sprayed Hydroxyapatite Implants
    (American Chemical Society, 2024) Shankar, D.; Jambagi, S.C.; Gowda, N.; Lakshmi, K.S.; Jayanthi, K.J.; Chaudhary, V.K.
    Assessing blood compatibility is crucial before in vivo procedures and is considered more reliable than many in vitro tests. This study examines the physiochemical properties and blood compatibility of bioactive powders ((0.5-2 wt % carbon nanotube (CNT)/alumina)-20 wt %)) produced through a heterocoagulation colloidal technique followed by ball milling with hydroxyapatite (HAp). The 1 wt % CNT composite demonstrated a surface charge ∼5 times higher than HAp at pH 7.4, with a value of −11 mV compared to −2 mV. This increase in electrostatic charge is desirable for achieving hemocompatibility, as evidenced by a range of blood compatibility assessments, including hemolysis, blood clotting, platelet adhesion, platelet activation, and coagulation assays (prothrombin time (PT) and activated partial thrombin time (aPTT)). The 1 wt % CNT composite exhibited hemolysis ranging from 2 to 7%, indicating its hemocompatibility. In the blood clot investigation, the absorbance values for 1-2 wt % CNT samples were 0.927 ± 0.038 and 1.184 ± 0.128, respectively, indicating their nonthrombogenicity. Additionally, the percentage of platelet adhered on the 1 wt % CNT sample (∼5.67%) showed a ∼2.5-fold decrement compared to the clinically used negative control, polypropylene (∼13.73%). The PT and aPTT experiments showed no difference in the coagulation time for CNT samples even at higher concentrations, unlike HAC2 (80 mg). In conclusion, the 1 wt % CNT sample was nontoxic to human blood, making it more hemocompatible, nonhemolytic, and nonthrombogenic than other samples. This reliable study reduces the need for additional in vitro and in vivo studies before clinical trials, saving time and cost. © 2024 American Chemical Society.
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    Abating cationic dye in wastewater using natural coagulants
    (John Wiley and Sons Inc, 2025) Varala, S.; Kumari, A.; Buruga, K.; Bhargava, S.K.; Parthasarathy, R.
    Natural coagulants are a biodegradable and potential alternative to chemical coagulants. Cassia fistula seeds and Cactus opuntia f-indica are employed herein to reduce the concentration of methylene blue dye in aqueous solutions. Maximum removal efficiency was obtained by optimizing the process parameters by the Taguchi method in the design of experiments (DOE). At optimum conditions, the removal efficiencies of C. fistula seeds and Cactus opuntia f-indica were 98.27% and 92.75%, respectively. The adsorption kinetics data were fitted to pseudo-first-order, pseudo-second-order, Elovich, intra-particle diffusion, and Boyd kinetic models. Accordingly, intra-particle diffusion and pseudo-second-order kinetics suggested the coagulation process to be an adsorption process controlled by the solid-phase sorption with intra-particle diffusion as the rate-limiting step. A comparative study was also conducted using alum to determine its effectiveness in reducing dye concentration. Results suggested biocoagulants are appropriate alternatives for reducing dye concentrations in wastewater and treating textile and dye industrial effluents. © 2024 American Institute of Chemical Engineers.
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    Synthesis, characterization of graft copolymers and their application in treatment of refinery wastewater
    (Springer, 2025) Chandan, K.K.; Chauhan, V.K.S.
    This article presents the synthesis, characterisation, and application of graft copolymers for coagulation-flocculation for cleaning refinery wastewater. The grafted copolymer is prepared using potassium persulfate as an initiator under a nitrogen atmosphere, and polysaccharides (Starch, amylose, and guar gum) as backbone polymers and acrylamide as the monomer. The synthesised grafted copolymer is characterised using standard techniques, and the molecular weight is estimated using the Mark-Houwink equation. The coagulation-flocculation experiments were conducted using alum as a coagulant and the synthesised graft copolymers as flocculants. The efficiency of turbidity removal was evaluated by adjusting the pH during synthesis and measuring the supernatant turbidity values. Results showed that the grafted copolymer St-g-PAM-II exhibited turbidity removal efficiency of 92.19% at pH 10. These findings demonstrate the potential of the grafted copolymer as an effective flocculant in refinery wastewater treatment. The synthesis process and characterisation techniques provided valuable insights into the structural and morphological properties of the graft copolymers. The estimated molecular weights provided approximate values for their molecular size. Present study highlighted the importance of pH adjustment and the role of graft copolymers in turbidity removal. This research contributes to developing sustainable and efficient wastewater treatment methods with potential applications in the petroleum industry. © Indian Academy of Sciences 2025.