Faculty Publications
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Item Influence of Aquaculture Sludge on Volume Change Behavior of Expansive Clays(Springer Science and Business Media Deutschland GmbH, 2023) Thotakura, T.V.; Sunil, B.M.; Chaudhary, B.Aquaculture waste sludge (AWS) from the aquaculture ponds in the delta region of Andhra Pradesh is most popular. Intensive aquaculture practice involves usage of higher dosages of minerals and chemicals in the aquaculture ponds. Further, due to the intensive activity, there is a formation of AWS at the bottom of the ponds. In this study, experimental investigation was carried with various concentrations of ASW sludge was blended with the expansive clays. A summary of one-dimensional swell-consolidation studies on expansive clays blended with AWS is presented. Rate of heave, swell potential, and swelling pressure significantly decreased with the increase in ASW content. The paper also explores microstructural behavior of the expansive clays blended with AWS. © 2023, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.Item Thermoplastic vulcanizates from post consumer computer plastics/nitrile rubber blends by dynamic vulcanization(Springer Japan, 2013) Anandhan, S.; Bhowmick, A.K.Due to depletion of natural resources and increasing greenhouse emissions, new technologies for the transformation of waste polymers into valuable materials represent one of our greatest current needs. Acrylonitrile-butadiene-styrene terpolymer (ABS) is one of the most widely used engineering plastics and is used as outer casing for electronic equipment. Nitrile rubber (NBR) is used in many applications that demand oil resistance. In an attempt to explore whether these materials can be successfully recycled, we prepared blends of scrap computer plastics (SCP) based on ABS with NBR and waste NBR powder (w-NBR), and investigated their mechanical properties and recyclability. Specifically, we assessed the effect of dynamic vulcanization and replacement of virgin NBR with w-NBR on the properties of 60/40, 70/30, and 80/20 NBR/SCP blends. These blends exhibited thermoplastic elastomeric behavior. The thermoplastic elastomeric blends showed excellent swelling resistance to standard lubricant oil (namely, IRM 903 oil). © 2013 Springer Japan.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 In situ vanadophosphomolybdate impregnated into conducting polypyrrole for supercapacitor(Elsevier Ltd, 2020) Anandan Vannathan, A.A.; Maity, S.; Kella, T.; Shee, D.; Das, P.P.; Mal, S.S.The fast modernization and advancement in lifestyle increase the consumption of power daily due to all innovative technologies, e.g., hybrid vehicles, solar cells, smart power grid, communication devices, artificial hearts, etc. Conducting organic polymer-based energy storage devices had attracted much attention due to the conductive nature for a long time. However, its application has been restricted because of swelling and shrinking capability during the charge and discharge cycle. The combination of redox-active inorganic metal oxides, such as polyoxometalates (multi-metal oxide cluster) with conduction polymers, could enhance the material's stability due to its fast multi-electron redox property. Here, we report the two polypyrroles combined vanadophosphomolybdates, namely PPy-H4[PVMo11O40] and PPy-H5[PV2Mo10O40] nanohybrid electrode materials. The PPy-H5[PV2Mo10O40] electrode material behaves as pseudocapacitance and can deliver an excellent capacitance of 561.1 F/g in 0.1 M H2SO4 electrolyte solution at a 0.2 A/g current density, indicating capacitive composite material. The electrochemical impedance spectroscopy (EIS) reveals that PPy-H5[PV2Mo10O40] is more capacitive than PPy-H4[PVMo11O40] and PPy with equivalent series resistance (ESR) of 5.74 ?. The cell capacitance of PPy-H5[PV2Mo10O40] and PPy-H4[PVMo11O40] are found to be 5.38 and 9.15 mF, stipulating in small SC cell application. Likewise, the PPy-H5[PV2Mo10O40] nanohybrid electrode shows better responsive behavior with a relaxation time of 0.16 ms. Furthermore, the PPy-H5[PV2Mo10O40] electrode exhibits outstanding cycle stability, retaining ~95% of its capacitance after 4500 cycles as compare to PPy-H4[PVMo11O40] (~91%) electrode. © 2020Item High-performance electrochemical supercapacitors based on polyoxometalate integrated into polyaniline and activated carbon nanohybrid(Springer Science and Business Media Deutschland GmbH, 2023) Anandan Vannathan, A.A.; Kella, T.; Shee, D.; Mal, S.S.Polyaniline (PANI) and carbonaceous materials and metallic compounds have played a significant role in energy storage and conversion devices. PANI has demonstrated tremendous potential in the supercapacitor industry due to its high specific capacitance, high flexibility, and economical price. The CPs damage the hierarchical structure during the charging and discharging process and start swelling. Thus, incorporating polyoxometalates (POMs) into the conducting polymer matrix increases the stability of the electrode material. Here, we have demonstrated a comparative study of two newly synthesized composite materials consisting of K5H2[PV4W8O40] ·11H2O, (PV4W8) POM incorporated into two different supports, such as pseudocapacitive polyaniline (PANI) and EDLC activated carbon (AC) matrix. It was observed that the PANI-PV4W8 composite exhibited excellent capacitance nature at 0.5 M H2SO4 electrolyte solution than AC-PV4W8. The PANI-PV4W8 composite demonstrated the specific capacitance of 584 F g−1 at 0.8 A g−1. The composite also exhibited energy and power density of 81Wh kg−1 and 1598 W kg−1, respectively. Besides, the composite shows 93.13% capacity retention after 4500 cycles by cyclic voltammetry measurement at a 500 mV s−1 scan rate. Furthermore, the AC-PV4W8 showed a specific capacitance of 62 F g−1 at the current density of 0.6 A g−1. Interestingly, The PANI-PV4W8 composite could glow up the red and yellow LED bulb for more than a minute, suggesting a promising electrode material for practical supercapacitor purposes. © 2023, The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.Item Relation between water absorption and mechanical properties of flax 3D braided yarn woven fabric PLA bio-degradable composites(SAGE Publications Inc., 2024) Kanakannavar, S.; Pitchaimani, J.Natural fibre (flax) plain type of woven fabric is developed by using solid braided yarn and is utilised as filler material and PLA (polylactic acid) as a matrix. Solution casting is then used to create sheets of pure PLA and flax fabric–PLA. Composites are manufactured by sheets sequencing technique using the hot compression moulding method. Water absorption, thickness swelling and flexural tests are performed in loading directions of warp and weft of the composites. Results revealed that the absorption of water and swelling of thickness are enriched with an addition of flax fabric. The weft direction loaded composite displayed greater values of water uptake and thickness swelling. The warp direction loaded composites demonstrated the highest flexural strength (92.3 MPa) and modulus (4.5 GPa) compared to weft direction loaded composites. These values are decreased after water absorption. © The Author(s) 2024.Item Exploring the impact of aquaculture sludge on the swell-shrink behavior of expansive clays(Elsevier Ltd, 2024) Thotakura, T.; Sunil, B.M.; Chaudhary, B.; Gobinath, R.; Bala, G.Aquaculture is practiced in many countries including India; coastal region of Andhra Pradesh is known for its intensive aquaculture farming. Sludge obtained from these farms was used to fill low-lying areas during summer. Aquaculture sludge (AS) is an organic material generated at the bottom of the aquaculture pond produced from shrimp effluents, chemical usage, unsustainable feed, minerals, and disinfectants. It is a polluting material that requires care and attention. This work aims to evaluate the effect of the mixing of aquaculture sludge on the geotechnical properties of clay subsoil. Plasticity, compaction characteristics, and one-dimensional swell consolidation tests were performed on expansive blended clays. The results of the swell-shrink behavior of expansive clays mixed with AS show a significant decrease in swelling phenomenon. Microstructural analysis of expansive clay and clay mixed with AS was carried out using scanning electron microscopy (SEM), energy dispersive spectrometry (EDS), and X-ray diffraction (XRD) tests to understand the surface textures, particle sizes, and chemical reactions. Microstructural analysis revealed the development of a crystalline structure with a C-S-H gel and CaCO3. In addition, it also shows the development of flocs and the aggregation of clay particles with AS. © 2024 The Authors