Faculty Publications
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Item Microscopic and spectroscopic characterization of elastomer for microfluidics application(Optica Publishing Group (formerly OSA), 2020) Banik, S.; Pooja, N.; Chakraborty, I.; Mal, S.S.; Mahato, K.K.; Srisungsitthisunti, P.; Mazumder, N.We have developed elastomers using potato and corn starch with various concentration and characterised them using microscopic and spectroscopic techniques. © OSA 2020 © 2020 The Author(s)Item Advanced Microscopic Visualization for Structural Characterization of Cellulose Extracted from Saccharum Spontaneum (Kohua Bon) of Assam, India(Optica Publishing Group (formerly OSA), 2021) Chakraborty, I.; Kalita, R.D.; Singh, P.; Banik, S.; Govindaraju, I.; Mal, S.S.; Zhuo, G.-Y.; Mahato, K.K.; Mazumder, N.Alpha, microcrystalline and nanocrystalline cellulose were sequentially extracted from stems and leaves of Saccharum spontaneum and were subjected to morphological and structural characterization using advanced microscopy techniques, including Scanning electron microscopy and nonlinear optical microscopy. © Optica Publishing Group 2021, © 2021 The Author (s)Item Morphological and Thermal Characterization of Starch-Based Elastomers(Optica Publishing Group (formerly OSA), 2021) Pooja, N.; Banik, S.; Chakraborty, I.; Mal, S.S.; Mahato, K.K.; Srisungsitthisunti, P.; Mazumder, N.Novel elastomers are synthesized from corn and potato starch with potential application in the fabrication of biodegradable microfluidic devices. The developed elastomers were subjected to morphological and thermal characterization. © Optica Publishing Group 2021, © 2021 The Author (s)Item Microscopic and Thermal Characterization of Starch-Silicon Dioxide Elastomers(Optica Publishing Group (formerly OSA), 2022) Pooja, N.; Banik, S.; Chakraborty, I.; Mal, S.S.; Mahato, K.K.; Srisungsitthisunti, P.; Mazumder, N.Elastomers were synthesized from potato starch with silicon dioxide as a reinforcement filler. The films were further subjected to microscopic and thermal characterization. © 2022 The Author(s)Item Microscopic and spectroscopic characterization of rice and corn starch(Wiley-Liss Inc., 2020) Govindaraju, I.; Pallen, S.; Umashankar, S.; Mal, S.S.; Kaniyala Melanthota, S.; Mahato, D.R.; Zhuo, G.-Y.; Mahato, K.K.; Mazumder, N.Starch granules from rice and corn were isolated, and their molecular mechanism on interaction with ?-amylase was characterized through biochemical test, microscopic imaging, and spectroscopic measurements. The micro-scale structure of starch granules were observed under an optical microscope and their average size was in the range 1–100 ?m. The surface topological structures of starch with micro-holes due to the effect of ?- amylase were also visualized under scanning electron microscope. The crystallinity was confirmed by X-ray diffraction patterns as well as second-harmonic generation microscopy. The change in chemical bonds before and after hydrolysis of the starch granules by ?- amylase was determined by Fourier transform infrared spectroscopy. Combination of microscopy and spectroscopy techniques relates structural and chemical features that explain starch enzymatic hydrolysis which will provide a valid basis for future studies in food science and insights into the energy transformation dynamics. © 2020 Wiley Periodicals, Inc.Item Investigation of structural and physico-chemical properties of rice starch with varied amylose content: A combined microscopy, spectroscopy, and thermal study(Elsevier B.V., 2022) Govindaraju, I.; Zhuo, G.-Y.; Chakraborty, I.; Melanthota, S.K.; Mal, S.; Sarmah, B.; Baruah, V.J.; Mahato, K.K.; Mazumder, N.Starch from a given botanical source can vary considerably in terms of physicochemical properties in its native and hydrolyzed forms. The current study investigated the structural and functional characteristics of starch from ten indigenous rice varieties endemic to Northeast India. In vitro enzymatic hydrolysis was used to reveal the dextrose equivalent profile of each type of starch. Gezep Sali and Betguti Sali respectively exhibited the highest and lowest starch hydrolysis. Among the ten rice varieties, amylose content varied between 7.50 and 28.58%. Optical and scanning electron microscopy (SEM) revealed the polyhedral shape of the native starch granules and deformation of the shape upon enzymatic hydrolysis. Second harmonic generation (SHG) microscopy and X-ray diffraction (XRD) analysis confirmed the presence of and variations in starch crystallinity. XRD revealed spectral peaks characteristic of A-type starch crystals in the native form. The elevated intensity of XRD peaks in hydrolyzed starch granules confirmed the occurrence of amylose hydrolysis rather than hydrolysis in amylopectin regions. Fourier transform infrared (FTIR) spectra revealed the common stretching and bending of bonds in all native starches; however, changes were observed in the fingerprint region (1080, 1000, 926 cm−1) of hydrolyzed starch granules, which indicates the amylolysis of the amylose region and disturbances in the ordered arrangement in the crystalline part. Differential scanning calorimeter (DSC) endotherms revealed the highest and lowest gelatinization peak temperatures in Harfoni (78 °C) and Tulosi Sali (41 °C) rice cultivars, respectively. The findings in this study can help to optimize the usage of rice starch in food and non-food industries. Furthermore, understanding the control points of starch digestion and genetically tailoring rice grains with different digestibility could be beneficial for nutraceutical applications. © 2021 Elsevier LtdItem Spectroscopic methods for assessment of hand sanitizers(Springer Science and Business Media Deutschland GmbH, 2022) Banik, S.; Melanthota, S.K.; Anandan Vannathan, A.; Mahato, K.K.; Mal, S.S.; Mazumder, N.Sanitization of inanimate objects or body surfaces using disinfectant is essential for eliminating disease-causing pathogens and maintaining personal hygiene. With the advent of health emergencies, the importance and high demand for hand sanitizers (HS) are observed in everyday life. It is also important to know the constituent added to formulate HS, as the presence of harsh chemicals can cause skin irritation. In this study, different spectroscopic techniques were used to assess several commercially available HS along with the in-house prepared HS as per the WHO protocol. Fourier transform infrared spectroscopy and Raman spectroscopy identified the different HS chemical bonds and quantified the amount of alcohol and water in the HS. Varying amount of alcohols in HS, calibration profile was generated to identify its amount in commercial samples. Further, the commercial samples were also checked for contaminants whose presence in the HS might bring down its sanitization efficacy. © 2022, The Author(s).Item Synthesis and detailed characterization of sustainable starch-based bioplastic(John Wiley and Sons Inc, 2022) Chakraborty, I.; Pooja, N.; Banik, S.; Govindaraju, I.; Das, K.; Mal, S.S.; Zhuo, G.-Y.; Rather, M.A.; Mandal, M.; Neog, A.; Biswas, R.; Managuli, V.; Datta, A.; Mahato, K.K.; Mazumder, N.There is an urgent requirement of replacing the environmentally hazardous petroleum-based plastics with sustainable and efficient starch-based bioplastics. Development and detailed characterization of the biodegradable bioplastics from plant-based polysaccharides such as starch is essential to reduce plastic pollution in the environment. In this research, bioplastics were developed from an equivalent blend of starch from two different sources namely rice and potato (1:1, w/w), crosslinked with different concentrations of citric acid (CA). The effect of CA cross-linking of starch-based bioplastics was investigated on its physicochemical and functional properties. The X-ray diffraction (XRD) spectra revealed that the synthesized bioplastics were amorphous in nature with broad diffraction peaks. Further, the peak at 1716 cm−1 in Fourier transform infrared (FTIR) spectra indicated the formation of ester bonds in CA cross-linked bioplastics. Atomic force microscopy (AFM) revealed the surface roughness of the bioplastics decreased with increasing concentration of CA. Mechanical and thermal properties of bioplastics were characterized using universal testing machine, differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA), respectively. © 2022 Wiley Periodicals LLC.Item Evaluation of physicochemical properties of citric acid crosslinked starch elastomers reinforced with silicon dioxide(Royal Society of Chemistry, 2024) Pooja, N.; Chakraborty, I.; Mal, S.S.; Bharath Prasad, A.S.; Mahato, K.K.; Mazumder, N.Thermoplastic starch (TPS), derived from renewable resources, offers advantages such as biodegradability and lower production costs compared to petroleum-based plastics. However, its limited mechanical properties pose a challenge for broader applications. This research aims to explore the potential of enhancing the mechanical and barrier properties of TPS films through the incorporation of silicon dioxide as a reinforcement filler and citric acid as a crosslinking agent. By introducing silicon dioxide as a reinforcement filler, the mechanical strength of the TPS films is expected to be improved. Additionally, the incorporation of citric acid as a crosslinking agent is anticipated to enhance the barrier properties of the films. The combination of these additives holds promise for creating TPS films with improved performance, contributing to the development of sustainable and environmentally friendly materials in various industries. The results reveal that SiO2 improves the stiffness of the films at lower concentrations but causes brittleness at higher concentrations. In contrast, citric acid crosslinked films exhibit improved flexibility and density. Scanning electron microscopy demonstrates the morphological changes in the films, with SiO2 affecting surface roughness and aggregate formation. SiO2 reduces film thickness and transparency, while citric acid enhances water resistance and barrier properties. X-ray diffraction analysis shows a reduction in crystallinity due to the plasticization process. Fourier-transform infrared spectroscopy highlights chemical changes and antimicrobial activity is observed with citric acid against specific bacteria. The soil burial test reveals that citric acid crosslinked films exhibit slower degradation due to antimicrobial properties. The combination of SiO2 reinforcement and citric acid crosslinking enhances the overall performance of the films, promising sustainable and environmentally friendly materials for various applications. © 2024 The Royal Society of Chemistry.Item Comparative analysis of biopolymer films derived from corn and potato starch with insights into morphological, structural and thermal properties(Springer Nature, 2024) Pooja, N.; Banik, S.; Chakraborty, I.; Sudeeksha, H.C.; Mal, S.S.; Srisungsitthisunti, P.; Patil, A.; Mahato, K.K.; Mazumder, N.Starch biopolymer films were prepared using the solvent casting method involving acetic acid hydrolysis and glycerol plasticization. This process facilitated a more uniform distribution of plasticizers within the starch matrix, enhancing the films' flexibility. Fourier-transform infrared (FTIR) and Raman spectroscopy confirmed the formation of ester linkages and structural changes in the biopolymer films, attributed to glycerol integration. The optimal formulation comprised 6% starch, 6.8% acetic acid, and 6.8% glycerol. X-ray diffraction (XRD) analysis revealed a reduction in crystallinity of the starch during film formation, enhancing flexibility. Second harmonic generation (SHG) and coherent anti-Stokes Raman scattering (CARS) microscopy indicated that potato starch films had higher crystallinity compared to corn starch films. Thermal analysis via differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) showed that potato starch films exhibited lower gelatinization temperatures and higher thermal stability compared to corn starch films. Functional characterization demonstrated that higher starch content decreased water solubility and water vapor transmission rate, while increasing starch content improved the film's structural integrity. The films were hydrophilic, with static water contact angles indicating moderate wettability. Degradation studies showed that the films were stable in neutral and basic conditions but degraded under acidic conditions over time. The results suggest that potato starch films, with optimized glycerol and acetic acid content, offer improved flexibility, thermal stability, and structural integrity compared to corn starch films. Their performance in various conditions highlights their potential for specific applications, particularly where moisture and environmental stability are critical. © The Author(s) 2024.