PhD Theses (Chemical Engineering)

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Amine Functionalized and Cation-Exchanged Zeolites for Selective Adsorption of Carbon Dioxide over Nitrogen and Methane
(2025) Bhati, Geetanjali
This Ph.D. research works addressed enhanced CO₂ capture through the adsorption-based processes and with Zeolite-Y as the primary support material. To assess alternate commercial as well as synthesized sorbents, single gas sorption experiments with CO2, N2 and CH4 were conducted. Among alternate sorbents, Zeolite-Y was selected after comparing its CO₂ adsorption capacity (highest of 1.89 mmol g-1 at 303K and 1bar) with respect to other commercial zeolites (Beta and ZSM-5 commercial sorbents). After selecting Zeolite Y as the primary support material, the study followed a three-phase approach. Among these, firstly, Zeolite-Y was functionalized with mono-, di-, and triethanolamine. Thereby, the monoethanolamine-loaded samples exhibited the highest CO₂ uptake (up to 2.26 mmol/g at 303 K and 1 bar). The adsorption behavior was modeled with the Langmuir and Virial isotherm, and selectivity was assessed via IAST. In the second phase, cation-loaded Zeolite-Y (Li⁺, Na⁺, K⁺ at 5 wt.%) were prepared and the sorbents exhibited enhanced CO₂ selectivity and for the loading order of K⁺ > Na⁺ > Li⁺. Among all, potassium loaded Zeolite Y sorbent exhibited highest CO2 uptake (2.89 mmol g-1 at 303K and 1bar). The third phase examined K₂CO₃-impregnated Zeolite-Y. Accordingly, the variant carbonate loadings affirmed optimal CO₂ capacity at 10 wt.% loading of the carbonate (3.61 mmol g-1 at 303K and 1bar). Also, the synthesized functional materials exhibited excellent cyclic stability and selectivity. In summary, the Ph.D. thesis research works novelty can be mentioned in terms of cation-carbonate loading for cost-effective, stable and high-performance zeolite-based adsorbents and for the proximity towards industrial-scale CO₂ capture.
Theoretical and Electrochemical Investigation on Controlling Metal (carbon steel/ruthenium) Dissolution in Corrosive Environments
(2025) Dhongde, Nikhil Rahul
Bioglass and glass-ceramics play a crucial role in regenerative medicine by facilitating bone regeneration and tissue engineering applications. Despite its invention over 50 years ago, 45S5 bioglass remains the benchmark for bioactive materials. However, maintaining its vitreous state in sol-gel-derived nanopowders remains a challenge. This work systematically investigates the effect of Na₂O content on the vitreous state and bioactivity of sol-gel-derived 45S5 compositions. The findings confirm that complete retention of the vitreous state is not feasible through the sol-gel route, shifting the focus to glass-ceramics while preserving high bioactivity. To develop an efficient thermoseed for magnetic hyperthermia, iron oxide and magnetic nanoparticles (MNPs) were incorporated into 45S5 glass-ceramics. While direct iron oxide substitution was cytotoxic above 10 wt.%, MNP-substituted glass-ceramics exhibited improved magnetic properties without compromising bioactivity. The optimal combination of bioactivity and induction heating performance was achieved when MNPs substituted CaO. A systematic heat treatment further optimized the material’s properties, yielding a thermoseed with superior performance compared to FluidMag-CT. This study provides new insights into sol-gel-derived 45S5 ceramics, including phase evolution, bioactivity, and magnetism, offering a significant advancement in bioactive and magnetic glass-ceramics.
Process-Product Characteristics of Refractance Window Dried Turmeric Powder and Golden Milk Products
(2023) Talukdar, Preetisagar
The Ph.D. thesis targets the sensitivity and optimality of the novel refractance window drying (RWD) process for the drying of Curcuma longa and associated product development. The conducted research work has been addressed in the five phases of research namely comparative efficacy of RWD, tray and oven drying process for the drying of paste and sliced Curcuma longa samples; sensitivity and optimality of mylar film thickness, water bath temperature and drying time during RWD of Curcuma longa sliced sample; RSM based optimization of bath temperature, drying time and air velocity; NaFeEDTA and folic acid fortification of RW dried Curcuma longa powder and associated characterization and analysis; storage and sensory studies of fortified and non-fortified RW dried Curcuma longa powder and golden milk product system and nutritional and sensory analysis of RW dried Lakadong turmeric variety powder and golden milk product system.
Optimization of Renewable Energy Systems
(2024) Maharana,Debasis
The transition to carbon-neutral energy sources like solar, wind, biofuels etc., reduces dependence on fossil fuels. Biofuels offer a practical alternative, while solar energy is popular for its low cost and abundance. This thesis explores optimization methodologies for developing renewable energy systems, focusing on biorefinery supply chains and solar energy systems, ensuring technical and economic feasibility. The biofuel supply chain requires complex, multi-stage optimization, particularly in biorefinery capacity planning, where design constraints limit economic processing options leading to suboptimal results. MILP models can optimize supply chain decisions; however, they are computationally intensive. Metaheuristic methods provide near-optimal solutions but face challenges with feasibility due to complex mass balance constraints.
Computational Experiments on Metaheuristic Techniques for Combinatorial Problems
(2024) Kommadath, Remya
This thesis investigates the application of metaheuristic techniques in addressing single and multi-objective combinatorial optimization problems, focusing on the essential role of efficient solution strategies. Firstly, this thesis underscores the importance of meticulously designed solution frameworks through an in-depth analysis of three specific combinatorial optimization problems: production planning of a petrochemical industry, scheduling jobs on dissimilar parallel machines, and optimization of a compression-absorption cascaded refrigeration system. The thesis also addresses the limitations of metaheuristic techniques in solving computationally expensive problems by proposing variants that leverage parallel computing architectures. Additionally, this work emphasizes the necessity of precise implementations of metaheuristic techniques to ensure optimal effectiveness in their application.
Ultrasound-Assisted Extraction of Bioactives from Horticultural Produces and their Encapsulation with Ion Gelation Method
(2023) Wani, Khalid Mehmood
Till date, various extraction and purification processes have been deployed to obtain liquid extraction of bioactive constituents from plants and their by-products. Traditional techniques such as maceration, hydro-distillation, soxhlet extraction, and hot water extraction have been deployed to extract valuable bioactive compounds from plant sources. These techniques suffer with the basic limitations of long extraction time, use of expensive and toxic solvents and degradation of heat sensitive compounds. On the other hand, the application of ultrasound assisted extraction (UAE) has been mostly explored in food and pharmaceutical processing schemes for the needful extraction of bioactive components. This is due to its simplicity, lower cost, lower processing time, lower solvent requirements, effective extraction efficiency, lower energy, higher reproducibility, scalability, and environmentally friendly nature.
Development of Kaolin-based Microporous Membrane for Energy Efficient Microalgal Harvesting and Effluent Recycle Under Circular Bioeconomic Approach
(2024) Agarwalla, Ankit
Biodiesel as a renewable energy source can provide an alternative to the alarmingly depleting energy from fossil fuels. Microalgae is an encouraging third-generation feedstock for the production of biodiesel as it has the capability of oil production throughout the year. Besides several advantages, commercial production of microalgal biomass feedstock is not considered sustainable due to its high production cost. In this context, recycling the culture media carry significant potential to reduce the overall cost for the long-term growth of microalgal industry. In this work, indigenous low-cost disc and tubular membranes were fabricated using naturally available kaolin as the key precursor. Different composition of kaolin (80-92 wt.%) and binder (8-20 wt.%) was used to optimize the raw material and binder composition. The optimized binder concentration in disc membrane was used to further fabricate tubular membranes. With increase in binder percentage from 8% to 20% in disc membranes, the percentage porosity, average pore size and water permeability decreased from 34.52% to 21.5%, 2.28 μm to 0.195 μm and 6.12×10-9 to 1.69×10-9 m Pa-1 s-1 respectively while flexural strength increased slightly from 7.1 MPa to 9.4 MPa. Hence, binder percentage of 8% i.e., 2% boric acid, 2% sodium metasilicate and 4% sodium carbonate was found to be optimum. Thereafter, tubular membranes will be fabricated using this binder concentration. The fabricated tubular membranes had porosity of ~26% - 47%, a pore diameter of 0.123-0.182 μm, water permeability of 4.2×10-8 – 17.1×10-8 m3 m-2 s-1 kPa-1, along with good mechanical and chemical strength.
Numerical Study on Droplet Breakup Dynamics in Microchannels
(2023) Biswas, Saikat
Droplets can be used as mini-reactors. They provide precise control over any reagent amount, which improves reaction repeatability and uniformity. The small droplets decrease exposure to potentially hazardous chemicals. The food industry, diagnostic testing, cosmetics, supra-magnetic nanoparticle production, medication delivery, and drug discovery all use homogeneous droplets. Droplets are often formed by mechanical agitation. However, mechanical mixing produces droplets of varying sizes. This might jeopardize process controllability. Microfluidics, the study of fluid dynamics at the micro to the nanoscale, enables the control of droplet size and quantity. With hundreds to thousands of droplets formed each second, the throughput of droplet formation rises. Droplets can be formed using i) Active method ii) Passive method. The passive method includes various ways, such as T-junction, co-flow, flow-focusing, and some variants. On the other hand, additional energy such as alternating or direct current is applied in the case of active splitting. In this work, an interest was felt in doing the numerical study on droplet breakup dynamics in microchannels using the passive method with the help of CFD. The objectives of the present work are as follows:
Xylitol from low-cost substrate and process optimization
(2023) Vardhan, Harsh
Xylitol is a high-quality polyalcohol, mainly used in pharmaceuticals, hygiene products, and food due to its functional properties such as anticarcinogenic, antibacterial, low-calorie, and hypoglycemic properties. At present, xylitol is primarily produced through chemical hydrogenation of xylose at high temperatures (150 °C) and pressure (5.5 MPa) on the reaction with metal catalysts such as Pl, Ru, Pt and Raney nickel. Separation and purification of xylitol is very expensive through this process. However, compared to this method, xylitol production through bioconversion of hemicellulosic hydrolysate by micro-organisms is an environment friendly, less energy-intensive, renewable, and overall economical process. This process ensures high safety, low production cost and high product selectivity. The primary objective of this research is to utilize the agricultural bio-waste (such as areca nut husk) as a feedstock for the production of xylitol, preferably in a repetitive batch fermentation process, with C. tropicalis as the fermentative microorganism. Primary processes include, biomass characterization and pretreatment (Mainly dilute acid hydrolysis and lime treatment), Acidic and Enzymatic hydrolysis of biomass, detoxification of acidic hydrolysate by using activated charcoal and cation-anion exchange resins, detoxified hydrolysate was fermented by C. tropicalis for xylitol production and finally downstream process was performed for product purification. Lignocellulosic materials are inexpensive and readily available biomass in the form of either agricultural wastes or forest residues. These materials can be used as energy producer sources for solids (xylitol, etc.) liquids (ethanol, butanol, etc.) and gaseous (CO, H2, etc.) as energy to meet increasing energy demands. Biomass pretreatment is a predetermined step to fragment lignocellulosic biomass into its basic components such as lignin and carbohydrate molecules. The first objective of present study is the pretreatment and characterization of lignocellulosic biomass namely Areca nut husk (Arecan catechu), which is widely available in the region of North-Eastern part of India. The study includes several physical characterizations like ultimate and proximate analysis, thermogravimetric analysis, crystallinity and chemical characterization that embraced Raman spectroscopy and FTIR. This study revealed that the Areca husk fiber contained 29.17% hemicellulose. Combination of all these properties revealed that Areca nut husk can be explored as the impending potential for low-cost source of xylose.
Applicability of Graphene Oxide-based Membranes in Separation Processes: A Molecular Dynamics Simulation Study
(2024) Reddy, Pilli Rajasekhar
In the past decade, multilayered graphene oxide (GO) membranes have emerged as promising candidates for desalination and wastewater treatment applications. Despite their potential, a comprehensive understanding of separation mechanisms remains elusive due to the intricate morphology and structural arrangement of interlayer galleries. This thesis addresses these challenges by constructing two distinct structural configurations, namely lamellar and non-lamellar, to investigate separation mechanisms at the atomistic level. Moreover, one major issue with layered GO membranes is their tendency to swell in an aqueous environment. Recognizing the tendency of layered GO membranes to swell in aqueous environments, this thesis explores cation intercalation within interlayer galleries as a promising solution to mitigate this problem. The applicability of lamellar, non-lamellar, and cation-intercalated GO membranes as forward osmosis (FO) and reverse osmosis (RO) membranes in separation and purification applications is studied using non-equilibrium molecular dynamics (MD) simulations. Real-life scenarios, including seawater, pharmaceutical industrial wastewater, shale gas wastewater, and human urine are considered to assess the performance of GO membranes. These GO membranes exhibit an improved trade-off between water permeance and selectivity compared to conventional polymeric membranes. This enhanced performance is attributed to the inherent structural characteristics of GO membranes, such as nanosized 2D channels and open edges, which enable the rapid movement of water molecules across membrane layers while efficiently retaining undesired species. Additionally, the nanosized GO nanosheets have abundant oxygen-containing functional groups (OFGs), enhancing their mechanical strength and chemical stability.
Preparation, characterization, and biodegradation studies of novel active poly (3-hydroxybutyrate) nanocomposite films and their application in packaging fresh produce
(2024) Kumari, Satti Venu Gopala
The rising environmental concerns associated with non-biodegradable petrochemical-based food packaging underscore the critical need for sustainable alternatives. Poly (3-hydroxybutyrate) (PHB), a natural polyester of microbial origin has excellent potential for food packaging applications owing to its renewability, high crystallinity, biocompatibility, biodegradability, and physical attributes comparable to conventional plastics. Nonetheless, PHB has certain shortcomings, including low elongation at break, moderate gas barrier properties, and negligible antimicrobial and antioxidant activities for its direct application in food packaging. Observing these facts, our work focused on overcoming the limitations of PHB by combinational loading of essential oil and nanofiller, evaluating the suitability of developed PHB-based nanocomposite films for storing fresh produce and assessing the biodegradability of these films in natural environmental conditions viz. soil and river water. Firstly, five different chemical synthesis routes (precipitation, sonication-precipitation, microwave combustion, conventional combustion, and solvothermal processes) were screened to customize the properties of MgO nanoparticles (NPs) for their reinforcement in PHB. Wherein, the microwave combustion route yielded MgO NPs with higher specific surface area (67.32 m2/g), smaller particle size (5-35 nm), and outstanding antimicrobial and antioxidant activities compared
(A) study on optimal sensor placement strategies for water quality monitoring in water distribution networks
(2024) Gautam, Dinesh Kumar
Ensuring universal access to clean water and sanitation, a key objective of the United Nations Sustainable Development Goal 6, necessitates effective water treatment and distribution. However, the degradation of water quality in common sources like rivers and groundwater has heightened the demand for water treatment, underscoring the significance of water distribution networks (WDNs) in delivering safe water to consumers. This thesis addresses the critical task of optimal sensor placement in WDNs for water quality monitoring, considering challenges such as contamination events, network vulnerabilities and data transmission modes.
Structural, Functional and Morphological Modifications of Graphene Oxide-based Nanocarriers for Anticancer Drug Delivery
(2024) Sonatakke, Ankush Dasharath
Chemotherapy has continued to be the most frequently utilized therapy for cancer treatment. Despite the abundance of chemical chemotherapeutic agents and anticancer medications, their unregulated administration and inability to distinguish between rapidly proliferating healthy cells and cancer cells lead to adverse impacts on cancer therapeutics. Moreover, due to the diversity of cancer cells, the emergence of drug resistance, and the undesirable effects induced by high and/or repetitive drug doses, the administration of a solitary chemotherapeutic agent frequently fails to accomplish a comprehensive cancer regression. The major challenges related to effective and sustainable consumption of chemotherapeutic agents can be subsided with targeted drug delivery systems (DDS) directed by the advanced nanomaterials (nanocarriers), natural chemotherapeutic agents such as gallic acid (GA), caffeic acid (CA), targeting ligands such as folic acid (FA) and employing co-delivery systems for chemotherapeutic agents. Previous studies related to anticancer DDS have demonstrated the therapeutic potential of graphene-based nanocarriers due to their distinct surface characteristics.
Solvothermal Liquefaction of Peel and Pulp of Citrus limetta Fruits and Analysis of Products
(2024) Acharya, Sneha
The contemporary need for clean and sustainable renewable energy demands a shift towards harnessing diverse biomass resources for thermochemical conversion. Citrus fruits, particularly sweet lime scientifically recognized as Citrus limetta (CL), generates substantial waste in the form of peel and pulp after juice extraction. This dissertation addresses the disposal challenge by focusing on the liquefaction of these fruit wastes under less severe conditions of temperature (240-280 °C) and pressure (90-130 bar). Methanol, a high-polarity hydrogen-donor solvent, was chosen for its efficacy in biomass hydrogenation, yielding biocrude and biochar with properties akin to traditional fossil fuels. Varied biomass-to-solvent ratios resulted in a 12.5 wt. % biocrude yield from Citrus limetta peel at 240 °C, showing an increase compared to similar citrus fruit wastes. The generated biocrude from Citrus limetta pulp achieved a notable energy density of 26.76 MJ kg-1 at a constant temperature of 260 °C and a 1:4 biomass-to-solvent ratio. GC-MS analysis revealed a higher area percentage of phenol derivatives in the biocrude, indicating the decomposition of the thermally stable lignin biopolymer during liquefaction. Co-liquefaction of Citrus limetta peel and pulp co-feed exhibited synergy, enhancing the biocrude yield to 13.47 wt. % at 240 °C and a 1:2 biomass-to-solvent ratio. The rise in temperature during co-liquefaction yielded a maximum higher heating value (HHV) of 27.6 MJ kg-1 at 280 °C, surpassing single-feed liquefaction. GC-MS and proton nuclear magnetic resonance (1H NMR) results confirmed a biocrude rich in aromatics, alkanes and aliphatics. Biochar energy densities in the range of 14.45 MJ kg-1 to 20.62 MJ kg-1 suggested its application as a source for thermochemical conversion. Additionally, Brunauer Emmett Teller (BET) results underscored the porous nature of solid biochar and its utility as low-cost adsorbents in soil remediation and catalysts for thermochemical conversion. Finally, in evaluating biocrude energy density, Citrus limetta pulp demonstrated higher efficiency than the peel under conditions of 280 °C and a biomass-to-solvent ratio of 1:4. In situations where separating pulp and peel would be impractical, co-liquefaction of Citrus limetta peel and pulp could possibly be recommended for optimal biofuel production.
Identification, Quantification and Removal of Microplastics from Various Sources
(2023) Yaranal, Naveenkumar Ashok
Microplastics in the environment pose a significant threat to the entire ecosystem. The frequent utility of plastic in daily life, inadequate disposal, and improper waste management leads to a wide distribution of microplastic in atmospheric, terrestrial, and aquatic environments. Household, industrial, tyre wear and tear, construction, incineration, plastic litter, landfill, and agricultural activities are the major sources of microplastics in the environment. Microplastics are associated with various monomers and plastic additives. On the other hand, it becomes the carrier of toxic and hazardous chemicals from the surrounding environment. Microplastics enter the human body through the air, food, and drinking water (tap and bottled water). Taking all these issues into consideration, the main objectives of this work are divided into four sections. The first section deals with microplastics in Brahmaputra River water, tap water, and household purified water. The second section deals with the identification of microplastics in sea water and beach sediments. The third section deals with the identification of microplastics in Indian edible salts and the removal of microplastics to produce microplastic-free salt. The fourth section deals with the quantification of microplastics and removal from the laundry outlets using the electrocoagulation method.
Molecular Modeling and Experimental Insights in the Application of Hydrophobic Deep Eutectic Solvents for Remediation of Micropollutant from Aqueous Systems
(2023) Paul, Nabendu
Micropollutants have emerged as a new class of pollutants due to their harmful effects on humans and livestock, even at low concentrations. Even if present in low quantities, micropollutants have been associated with a range of detrimental impacts on humans and livestock, including poisoning, neurotoxicity, endocrine-disrupting effects, and microorganism antibiotic resistance. Green solvents, especially hydrophobic DESs (HDESs) through liquid-liquid extraction and microextraction (LLE/LLME) can have a revolutionary impact in achieving the efficient pharmaceutical removal pathway.
Investigation of Multiphase Flow in Porous Micromodels using Micro-PIV Experiments and Numerical Simulations
(2023) Sharma, Vikas Kumar
This study investigated pore-scale flow dynamics and displacement mechanisms in multiphase flow through porous media using experimental and numerical approaches. 2D porous micromodels of various geometries were fabricated to visualize the fluid flow using Micro-Particle Image Velocimetry. Parameters such as displacing phase flow rate, viscosity, heterogeneity of porous medium, interfacial tension, and wettability were found to significantly impact the trapping and mobilization of the non-wetting phase through the porous medium. Chemical slugs (including alkaline solution, polymer solution, and alkali polymer solution) and nanoparticles (silica) improved fluid-fluid and fluid-solid interactions. Silica nanoparticles in an alkaline solution enhanced oil mobilization by reducing the interfacial tension, altering the contact angle, and preparing a stable microemulsion. The parameters such as flow rate and viscosity affected the displacement, showing the shear-induced circulations, viscous instability, droplet breakage, and coalescence, resulting in unsteady flow behavior during immiscible two-phase flow in heterogeneous micromodels. Higher flow rates reduced trapped fluid saturation but intensified shear-induced circulations. Heterogeneous micromodels exhibited more trapping than homogeneous porous medium. Numerical simulations focused on the immiscible two-phase flow in complex pores (such as dead-ends and contraction-expansion pores), highlighting the impact of injection velocity, viscosity ratio, interfacial tension, wettability, trapped oil viscosity, and geometric parameters. Lower contact angles had minimal effect on residual oil saturation until reaching a critical contact angle. Complete displacement from the dead-end occurred when the oil-water interface reached the dead-end bottom before the rupture point. Higher injection velocities improved oil recovery from the dead-ends, while lower velocities enhanced recovery from the contraction-expansion pores. Microscopic studies used 2D micromodels to explore displacement and oil recovery during low-salinity water flooding and subsequent chemical floodings. The observed phenomena included fluctuating flow, flow direction reversal, viscous fingering, film formation, unsteady behavior, and velocity jumps during low salinity water flooding. Polymer flooding had a limited impact on the trapped oil, while the alkali-polymer solution injection enhanced oil recovery through emulsification, interfacial tension reduction, and increased water-wettability. The core flooding experiments demonstrated an overall heavy oil recovery of 75.37% with simultaneous chemical slug injection, whereas individual slug injections resulted in lower oil recovery, particularly for alkali-surfactant-polymer flooding. Porous micromodels elucidated suspension flow dynamics, revealing the influence of initial particle location, concentration, and shear-induced particle migration.
Studies on Utilization of Algal Biomass for Food Packaging
(2023) Mondal, Kona
The increasing demands for safe and healthier food products have led to the development of novel packaging technologies that protect the globe from hazards arising from fossil-based non-biodegradable food packaging material. In this regard, renewable bio-based and biodegradable plastics produced by economically viable industrial processes can be considered and utilized as sustainable plastic food packaging material. Besides, the whole world is combating the crucial problem of post-harvest losses of fresh produces, wherein India is facing a 30-40% loss due to post-harvest. In this context, novel packaging technologies in the form of edible film and coating as a preservation technique can provide an alternative solution to protect post-harvest fresh produce. In the present work, the development of sustainable primary food packaging material in the form of edible films and coating is studied and characterized for various physicochemical, biochemical, and microbial properties. Also, the developed edible coating formulation is applied to food systems (green chili, tomato, onion, and potato) to check the effectiveness of the coating. The storage study of the coated fresh produce has been conducted at room temperature to determine the effectiveness of coating on the quality and shelf-life extension of the produce and to draw a comparison against the uncoated. Among the variety of edible biopolymers, chitosan, and guar gum have been utilized in this work. Further, targeting to develop active edible packaging and tuning the inherent properties of these edible biopolymers for obtaining better effectiveness, natural food additives such as green algae extract, and essential oil is added. Algae is an emerging biomaterial, predominantly used for biodiesel production by utilizing its oil. It is used in the pharmaceuticals and food industry. However, the residue of algae biomass after oil extraction is treated as waste either used as cattle and aqua feed or dumped as waste. Interestingly, this industrial bio-based waste can be utilized as a whole or by extracting its bioactive compounds and can be incorporated into the biopolymer to obtain effective properties. The green algae biomass residue has been utilized and the extract is added to the edible packaging formulation for enhancement of barrier, physicochemical, antioxidant, antimicrobial, and other characteristics properties which are necessary for food packaging. Besides, sustainable bio-composites have been fabricated with the incorporation of cellulose nanocrystal biomaterials extracted from algae biomass residue for the development of secondary packaging material. In this context, Poly(lactic acid) (PLA), and Poly(ε-caprolactone) (PCL) have been utilized in order to develop secondary packaging, which is one of the most widely studied sustainable polymers that possess several properties that are comparable to conventional polymers. The developed biodegradable bio-composites are studied in detail for crystalline behavior and migration properties. Active agent curcumin is deliberately added to the bio-composites to study the effect of nanostructured material on the migration behavior of active compounds. The active secondary food packaging material is further applied to food systems to understand the effect of packaging material. Further, a cytotoxicity test has been performed on all the developed packaging materials for understanding the non-toxicity and biocompatible nature. Overall, in this thesis, an alternative pathway for extending the shelf-life of perishables using edible coating technology has been reported and it has also demonstrated the capability of utilizing algae biomass waste for the fabrication of primary and secondary food packaging material. Also, this thesis work provides the first step in the utilization of algae biomass for the development of primary active packaging material.
Solvation and Extraction Mechanism of Aromatic Solutes and Asphaltene utilizing Deep Eutectic Solvents: Experimental and Atomistic Simulation Studies
(2023) Kumar, Nikhil
Deep eutectic solvents (DES) have emerged over the last two decades as a novel class of ionic liquids (ILs). In their broadest sense, DESs are usually formed by mixing a quaternary ammonium salt (typically choline chloride and derivatives) with hydrogen bond donor molecules such as amines, amides, alcohols, carboxylic acids, sugars, or polyols. The mixing of these two components upon gentle heating and in a specific molar ratio leads to a depression of the melting point, resulting in most of the cases in a liquid at room temperature, where no waste is produced, and no further purification steps are needed. Furthermore, DES's components are often biodegradable and non-toxic.
Bioinspired Synthesis of Metal Oxides and Sulphide Electrocatalysts for CO2 and N2 Conversion to Formate and Ammonia
(2023) Chowdhury, Anirban
This doctoral work focuses on the development of environmentally friendly processes for the synthesis of metal oxides and metal sulphide (nano)electrocatalysts. These catalysts are then utilized for the electrochemical reduction of CO2 and N2 to produce value-added chemicals in a semi-batch laboratory electrolyzer.

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