Department of Chemistry
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Item Metal Nanoparticles Decorated Carbon Materials for Estimation of Meat Spoilage(Library Information Services COMSATS University Lahore Campus, 2023-03-13) Javaria Ashiq; SP22-R06-007; Dr Mian Hasnain Nawaz; LHR TP 8646The health and food security of humans are greatly threatened by spoiled meat, which is why early detection and alerts regarding the freshness of the meat are necessary. Here, we used an easy, fast, and direct approach to create a fluorescent probe that uses silver nanoparticles (AgNP) as recognition site and Perylene (PER) as a fluorophore to provide easy and effective meat freshness monitoring. The selective interaction of Histamine (His) causes this probe to exhibit a clear fluorescence quenching phenomenon. The change from the non-aggregated form of PER/AgNP to its aggregated form upon binding of the biomarker (His) is responsible for the fluorescent quenching phenomenon. With a low detection limit of 16.74 µM and a wide linear range of 25-3200 µM, the proposed sensing array made it possible to monitor Histamine (His), a component of spoiled Meat. Fluorescence behavior, surface chemistry, and chemical content were all examined using a variety of characterization techniques, including XRD, FTIR, UV-Vis, Zeta potential, DLS, and Fluorescence Spectrophotometry. The selectivity and sensitivity of the sensor have been confirmed using different molar concentrations of histamine and other analytes. Consequently, our results indicate that the proposed sensor has a high degree of discernment and sensitivity in its fluorescence quenching efficacy in response to histamine. The sensing probe was used to determine the freshness of real chicken samples, and it showed strong and non-destructive screening capabilities for on-site meat freshness assessment which was also captured by Confocal Microscope.Item Synthesis and Electrochemical Characterization of Nanocomposite with Graphene Enforcement for the Detection of Heavy Metal Ion in Water(Library Information Services COMSATS University Lahore Campus, 2023-03-13) Muhadsa Zahra; SP22-R06-001; Dr. Lubna Sherin; LHR TP 8640Arsenic, one of nature's most prevalent environmental toxins, was found to be exceedingly abundant in the Earth's mantle during this thesis. Arsenic can manifest in various oxidation states (-3, 0, +3, and +5), with arsenite (As3+) being particularly toxic in natural water and surface soil. The extended presence of arsenic in these environments posed a significant risk to human well-being. Recognizing the critical importance of an effective sensing technique for the detection of As3+ ions, this study aimed to safeguard human health and well-being while preserving a beautiful and healthy biosphere. The advantages of electrochemical sensing, such as easy instrumentation, high sensitivity, strong selectivity, mobility, and on-site analysis capability, were considered. A Nanocomposite Cu-Fe/GA@NS-rGO was synthesized to detect very low levels of As3+ in water and achieve sensitivity up to 0.7 nM. The morphological and physicochemical characteristics of the synthesized material were investigated through Fourier-transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). The electrochemical behavior of the Pencil graphite electrode (PGE) modified with Cu-Fe/GA@NS-rGO was examined using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). It was demonstrated that, with the Cu-Fe/GA@NS-rGO/PGE, As3+ could be sensed via differential pulse voltammetry (DPV). As the concentration increased from 10 to 80 nM, a substantial linear response was achieved, with a limit of detection of 0.7 nM. The remarkable sensitivity of the Cu-Fe/GA@NS-rGO-modified PGE underscored its electroanalytical capabilities, suggesting its practical applicability in its as-prepared state for real-world scenariosItem Desulphurization of Fuel Oil with Tubular-Polyoxometalates based Catalyst: Optimization Using Response Surface Methodology(Library Information Services COMSATS University Islamabad Lahore Campus, 2023-02-27) Hamna Khalid; SP22-R06-004; Dr. Sadaf Ul Hassan; LHR TP 8643A facile catalyst termed H4SiW12O40@fHNTs was synthesized and optimized for the oxidative desulphurization of model fuel oil. Halloysite nanotubes (HNTs) were subject to functionalization with 3-aminopropyltriethoxysilane (APTES) and subsequently utilized as a substrate to immobilize H4SiW12O40. The electrostatic interaction between H4SiW12O40 and the functionalized halloysite nanotubes was characterized using UV, FTIR, XRD, and Raman spectroscopy. The oxidative desulphurization process was conducted using an oxidant i.e., hydrogen peroxide and acetonitrile as the extractant. The optimization of process variables, including reaction temperature, catalyst amount, and oxidant concentration, using the Box-Behnken method. The optimal conditions were determined to be 70°C, 70 mg, and 8 ml oxidant concentration, resulting in a desulfurization efficiency of 92.17%. Furthermore, the effectiveness of H4SiW12O40@fHNTs was demonstrated in real fuel samples, reducing dibenzothiophene content from 354 ppm to 224 ppm. The catalyst exhibited excellent recyclability, maintaining a stable desulphurization rate over five consecutive cycles. This research underscores the potential of H4SiW12O40@fHNTs as an effective and reproducible catalyst for the process of oxidative elimination of sulphur, offering promise for the development of cleaner and more sustainable fuel technologies. ixItem Natural Polymer based Biocompatible Hemodialysis Membrane(Library Information Services COMSATS University Islamabad Lahore Campus, 2023-02-27) Tahira Nasir; SP22-R06-020; Dr. Muhammad Irfan; LHR TP 8659With 850 million affected people globally, ESRD is expected to rank as the fifth leading cause of death globally by 2040. Of all kidney replacement therapies, hemodialysis is the most widely used kind in the world, serving approximately 2 million patients. Different synthetic polymeric membranes are used for HD treatment and natural polymer based membranes were not evaluated in hemodialysis research. Current dialysis systems frequently deal with problems like hemocompatibility and dialysis performance or vice versa and high death ratio suggests the improvement in this field. In current research work, silk fibroin (natural polymer) was extracted from silk cocoon and thin film membrane were fabricated and evaluated in hemodialysis application. Different types of membrane were cast based on formulation of variable weight percentage of pure silk (5, 7 and 9 wt.%) and blending of silk with PEG solutions. Polyethylene glycol was added to enhance the hemo-compatibility and wettability of pure silk membranes. FTIR results described that pure silk fibroin was successfully separated from silk cocoon and hydrogen bonding occurred between silk and PEG when blended together. Thermo-rheological analysis illustrates that addition of PEG to silk fibroin decreased the gelling temperature from 46C to 31C. Casting the membrane from its solution in control heating environment developed unique capillary system in all fabricated membranes as shown by FESEM analysis. Contact angle results showed that low molecular weight pure silk (5%) was highly hydrophilic (53.65) and addition of PEG further increased the hydrophilic character (54.07). Density measurements confirmed that with increasing silk weight in cast membranes density were also enhanced and all membrane did not allow the 20kDalton solute molecules to pass through them, thus can forbid the useful albumin loss during dialysis. Alamar Blue Assay and human blood plasma were used to evaluate the x biocompatibility of cast membranes and cytocompatibility and blood clotting experiments illustrate that pure silk and silk-PEG membranes are non-toxic and hemocompatible. Further, the dialysis results showed the 47-49% clearance rate of urea and creatinine in a dialysis cell.Item Effect of Electric Field Variation on Electronic and Nonlinear Optical (NLO) Properties of Ionic Liquids: A DFT Study(Library Information Services COMSATS University Islamabad Lahore Campus, 2023-02-27) Dua Fatima; SP22-R06-018; Dr. Mazhar Amjad Gilani; LHR TP 8657The growing use of nonlinear optical (NLO) materials in various fields has generated interest in designing innovative smart NLO materials. This study focuses on three specific ionic liquids, where the same cation, 1-ethyl-3-methyl imidazolium, is combined with three different anions (Br-, C-, F-). The study explores the effects of External Electric Field (EEFs) on these three ILs using Density Functional Theory (DFT) calculations. The interaction energies calculated confirm the stability of the newly designed ILs. Applying external electric field (EEFs) ranging from 0.001 a.u to 0.006 a.u leads to a significant reduction in the E(H–L) gap, and the lowest energy gap of 4.43 eV is observed in EMIBr at field strength of 0.006 a.u. Natural Bond Orbital (NBO) analysis validates substantial charge transfer from cations to anions, with the highest transfer observed in EMIBr. External Electric field enhances the first hyperpolarizability, and EMIBr exhibits the highest value i.e 1828 a.u at 0.006 a.u. TD-DFT calculations are executed to derive electronic states influenced by an external electric field (EEF), and the highest λmax (nm) i.e. 227 nm, is observed in the case of EMIBr at 0.006 a.u. The study also determines frequency-dependent Second Harmonic Generation (SHG) and Electric-Optical Pockels Effect (EOPE), with noteworthy values observed i.e 2.0×103 and 9.8×103 respectively in case of EMIBr. In conclusion, the study provides guidelines for computationally designing efficient and thermodynamically stable complexes for optical and optoelectronic technologies. The proposed ILs could find potential applications in new electronic devices, contributing to the development of advanced NLO materials.Item Synthesis and Characterization of TiO2/Cellulose@ZIF-8 for the Application of Drug Delivery(Library Information Services COMSATS University Islamabad Lahore Campus, 2023-02-27) Farheen Fatima; SP22-R06-021; Dr. Muhammad Shahid Nazir; LHR TP 8660Metal organic frameworks are a class of porous materials having distinctive features such as large surface area, improved porosity, stability, and tunable structure. They exhibit diverse range of applications. MOFs can be surface engineered with different biomolecules or polymers to enhance stability, functionality, and biocompatibility. Recently, many MOFs have been explored for the application of drug delivery. However, MOFs as drug carriers still have some limitations like uncontrollable release of drug, cytotoxicity, and biocompatibility. To resolve the uncontrolled release problem, MOFs are conjugated with other materials for the fabrication of adsorbent materials, exhibiting desired properties and appropriate application. The aim of this work is to open new avenues for drug control release. Zeolitic Imidazole Framework-8 (ZIF-8) has improved structural porosity, flexibility, surface functionality and crystalline nature making it feasible to be utilized in the field of drug delivery. ZIF-8 is modified with cellulose to make it hydrophobic and to obtain aqueous stability. The biodegradability, higher surface area, and flexible binding interaction between the cellulose and ZIF-8 have made it an ideal choice for drug control studies. In order to enhance the properties ZIF-8 and cellulose is modified with TiO2 for biomedical purposes including biocompatibility, controlled release of drug and targeted drug delivery. The FTIR analysis shows a significant peak at 420cm-1 confirming the Zn-N bond along with peaks at 3648cm-1, 1940cm-1, 1345cm-1, and 1200 cm-1 confirming the O-H of the polymer, C=N vibration, C-N vibration of imidazole and C-O vibration of the composite. Peak at 650cm-1 corresponds to the N-Ti-O bond which confirms the incorporation of TiO2 ix particles inside the MOF structure. Moreover, XRD analysis shows characteristic peak positions at 23.03°, 25.77°, 38.14°, 48.55°, 54.28° and 55.57° confirming the presence of ZIF8, Cellulose and TiO2. Comparative drug release studies of ZIF-8 and modified ZIF-8 were performed at acidic, basic, and neutral pH with respect to time. The maximum release of 91% of cyclophosphamide was obtained under acidic conditions. This is because modified MOF makes strong linkages with the molecules of CP drug and therefore entangle with the molecules of drug owing to the addition of cellulose as well as TiO2.Item Synthesis and Characterization of Conducting Filler-Based Elastomer Composites for Electromagnetic Shielding Applications(Library Information Services COMSATS University Islamabad Lahore Campus, 2023-02-27) Rida Fatima; SP22-R06-013; Prof. Dr. Zulfiqar Ali; LHR TP 8652The evolution of advanced communications systems and other electro-electronic gadgets has led to a type of electromagnetic pollution that has an impact on both the functionality of other equipment and people's health. There is a growing need for effective shielding materials to control EMI and related issues. A variety of composite materials have been developed using various combinations of dissimilar elements because it is widely known that single configuration cannot achieve necessary materials EMI-shielding (EMI-S) efficacy. The most popular materials having EMI shielding materials are made of metals with having inherent flaws including being heavy, more prone to corrosion, expensive, complex to produce, etc. Shields with to overcome these constraints, metal-based structure was modified using a variety of structural types and other materials. Conducting polymer-based composites have distinguished themselves from other classes of materials that form composite produced as Shielding-EMI components due to unique characteristics such as lower weight, environmental stability, long-life, durability, and minimal corrosive tenability. Here, in this work, Conducting Filler-Based Elastomer Composites synthesized and characterized by melt mixing method for electromagnetic shielding applications. The surface modification confirmed by different characterization techniques i.e., Fourier-transform infrared spectroscopy (FTIR), X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM). For the mechanical and EMI Shielding applications composites material characterized by Universal testing machines (UTMs) that test mechanical properties such as tensile, flexural, compressive and shear. Thermogravimetric analysis (TGA) analysis for the measurement of thermal stability of material electrical conductance measurement and use of Vector Network Analyzer by Rhode and Shwarz for EMI Shielding.Item Synthesis and Characterization of Hybrid Mesoporous Silica Based Nanocarriers for Anti-Inflammatory Agents(Library Information Services COMSATS University Islamabad Lahore Campus, 2023-02-27) Husnain Haider; SP22-R06-015; Dr. Fozia Rehman; LHR TP 8654Mesoporous silica MCM-41 was synthesized using sol-gel method and functionalized with 3-aminopropyltriexthoxysilane and -N-(2-Aminoethyl)-3- aminopropyltrimethoxysilane to obtain surface functionalized materials MCM-A! and MCM-A2 respectively. The Fourier-transform infrared spectroscopy, NMR spectroscopy, XRD, nitrogen adsorption and desorption analysis and scanning electron microscopy were done for characterization of materials. The prepared materials were loaded with the anti-inflammatory drug Diclofenac (water soluble). The drug loading capacity of MCM-A1 and MCM-A2 were found as 21.6% and 26% respectively. The drug release profiles were constructed up to 75 hours. The results indicated that drug loaded materials showed distinct profiles and slow and controlled drug release was observed from these materials. The MCM-A1 showed a faster rate of drug release compared to MCM-A2, which is attributed to N-(2- Aminoethyl)-3-aminopropyltrimethoxysilane moieties attached to MCM-A2 surface resulting strong bonding interactions between the amine groups and drug molecules. By incorporating organic groups onto silica, the drug release rates could be tailored by varying the content of functional groups. The obtained results suggest that such extended drug delivery system may be used as controlled release cargos for water soluble anti-inflammatory drugs such as diclofenac sodium to enhance the drug safety and efficacy.Item N/S co-doped Reduced Graphene Oxide Fabricated Carbon Cloth Electrode for Flexible Supercapacitor(Library Information Services COMSATS University Islamabad Lahore Campus, 2023-02-27) Nimra Pervaiz; SP22-R06-012; Dr. Sara Riaz; LHR TP 8651Flexible supercapacitor have gained much attention as energy saving devices to power up portable and wearable electronics. The basic principles recognized for traditional capacitor are also applicable to flexible supercapacitors. Nevertheless, flexible supercapacitors have improved charge storage, exceptional flexibility and less resistance, leading to high capacitive performance than traditional capacitors. As compared with batteries, supercapacitors possess very high power density. Therefore, electrode material owing improved power density and energy density with outstanding cycling stability is fabricated. In this research, graphene oxide doping with nitrogen and sulphur was performed. The synthesized material was characterized using Raman spectroscopy, X-rays diffraction, Fourier transformed infrared spectroscopy, scanning electron microscopy and X-ray photoelectron microscopy. Electrochemical activity was studied by galvanostatic charge-discharge, electrochemical impedance spectroscopy and cyclic voltammetry employing carbon cloth as substrate for electrode substance. The specific capacitance of N/S-rGO obtained from electrochemical experiment is 290 Fg-1 at current density of 1 Ag-1. The energy density was calculated to be 40 Wkg-1 at power density of 500 Wh kg-1. These outcomes suggest N/S-rGO is potential electrode material to be employed in the high performance supercapaitors.Item Nutritional Evaluation of Fresh Vegetables as a Source of Water-Soluble Vitamins(Library Information Services COMSATS University Islamabad Lahore Campus, 2023-02-27) Wishah Mahmood; SP22-R06-006; Dr. Muhammad Javid Iqbal; LHR TP 8645Water-soluble vitamins are imperative for good health because they work as cofactors and coenzymes in numerous metabolic processes. Long recognised as rich suppliers of these essential elements, fresh veggies are. With a focus on vitamin C (ascorbic acid), vitamin B1 (thiamine), vitamin B2 (riboflavin), vitamin B3 (niacin), vitamin B5 (pantothenic acid), vitamin B6 (pyridoxine), vitamin B7 (biotin), vitamin B9 (folate), and vitamin B12 (cobalamin), this study presents a thorough evaluation of fresh vegetables as a source of water-soluble vitamins. The study uses a multimodal strategy to examine the vitamin content in a variety of frequently consumed fresh vegetables, like Potato, Tomato and Cucumber. The Study includes laboratory studies, literature reviews, and dietary assessments. High-performance liquid chromatography (HPLC) is a methodology used to precisely measure vitamin amounts. The findings show that water-soluble vitamins are certainly abundant in fresh vegetables, with notable differences in content between different vegetable types and species. Additionally, the influence of elements like climate, soil quality, and agricultural techniques on vitamin content is explored. This study emphasizes how crucial it is to include a variety of fresh vegetables in daily diets in order to maintain an appropriate intake of water-soluble vitamins, which are crucial for overall health and well-being. For nutritionists, dietitians, and consumers looking to maximize their vitamin intake through natural and sustainable food sources, it offers helpful insights. As a result of our research, it was noticed that the overall amount of WSVs in fresh vegetables available in Pakistan having satisfactory levels of these vitamins and met the prescribed values of FDA and WHO. Overall, it is reasonable to infer that ingesting a wide range of locally available fresh vegetables in different combinations might help in nutrient acquisition, perhaps reducing the need for food fortification and other forms of supplementation.
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