Department of Chemistry
Permanent URI for this communityhttps://repository.cuilahore.edu.pk/handle/123456789/14
Browse
21 results
Search Results
Item Synthesis and Characterization of PANI@cellulose Nanocomposite based Electrochemical Sensor for Environmental Remediation(Library Information Services COMSATS University Islamabad Lahore Campus, 2021-02-26) Nageen Shoukat; SP20-R06-010; Dr. Lubna Sherin; LHR TP 7564In this work, porous CuO-NiO/CA/PANI@Ni-foam sensor electrode has been designed using electospinning of CA/PANI composite on Ni-foam and then drop casting of CuO-NiO nanoparticles for detection of bisphenol A (BPA). 3D nickel foam has been chosen as electrode substrate for the direct growth of CA/PANI since Ni-foam has the advantages of excellent electrical conductivity, low cost, commercial availability, and porous structure, which provides large surface area for synthesis of nanofibers. This direct grown structure of CuO-NiO/CA/PANI@Ni-foam provides exceptional properties, such as reduced resistance, good electron transport, better adhesion stability and the excellent electrical conductivity as compared with non-direct synthesized electrode. Furthermore, a synergetic effect between CuO-NiO/CA/PANI and Ni-foam substrate enables the electrode for excellent sensing behavior towards BPA. The resultant CuO-NiO/CA/PANI@Ni-foam was analyzed using Fourier transform infrared spectroscopy, X-ray diffraction, Raman spectroscopy and scanning electron microscopy. Different electrochemical methods such as cyclic voltammetry, electrochemical impedance and differential pulse voltammetry were used for evaluation of synthesized sensor’s performance against BPA. Under optimal conditions, a linear response was observed against BPA and very low limit of detection as well (LOD=0.6uM). The CuO-NiO/CA/PANI@Ni-foam electrode demonstrated high reproducibility, consistency, and stability when used to detect BPA in water. The synthesized sensor's results demonstrated that it was extremely selective for the detection of BPA, suggesting that it could be useful in environmental based surveillances.Item Study of Cellulose-Based Nanocomposite Sheets for Potential Application in Flexible Electronics(Library Information Services COMSATS University Islamabad Lahore Campus, 2021-02-26) MUHAMMAD HABIB UR REHMAN; SP20-R06-017; Dr. Lubna Sherin; LHR TP 7571Cellulose, an abundant, cheap and bio-compatible polymer have been widely used in writing and packaging for decades. In modern world it has found a vast range of high tech applications such as flexible electronics. It is anticipated that use of cellulose substrate in flexible electronics can reduced millions tons of electronic waste. In this work lemongrass leaves were used as cellulose source to prepare cellulose sheets. The characterization techniques such as FTIR and XRD were used to confirm that fabrication of cellulose substrate. The analysis on cellulose substrate was performed by using two conventionally used methods in electronics e.g., electro spraying of conductive ink and adhesive copper tape. Poly 3, 4-ethylenedioxythiophene: Poly styrene sulfonic acid (PSS: PEDOT) was used as conducting ink for electro-spraying. The substrate, electro-sprayed for 6 minutes and curred at 80 °C for 40 minutes, showed remarkable results. Comparison of substrate behavior was made between synthesized cellulose substrate and commercially used reference PET substrate by using adhesive copper tape. Current-voltage measurement were recorded for the conductance study. Results of cellulose substrates behavior similar to that of reference substrate show that it can be a potential candidate of eco-friendly substrate for electronics; addressing the need for biodegradable, cost-effective and environment friendly green electronics especially in the fabrication of recyclable microwave components and antennas.Item Nanomaterials based Enzyme mimetic detection assay for the easy, early, sensitive, and selective detection of Tuberculosis(Library Information Services COMSATS University Islamabad Lahore Campus, 2021-02-26) Misbah Javid; SP20-R06-022; LHR TP 7576Sensors are very important devices for the early detection and monitoring of diseases during their progression and treatments. A long story short, technologies are moving towards optical biosensors as novel sensing devices considering its major advantages as a quick response, high sensitivity, and less complexity. Fluorescence based sensors are one which are 100 to 1000 times more sensitive than any other technique. Fluorescence mechanism is based on measurement of excitation and emission wavelength of absorbed and emitted radiations. Tuberculosis is a lung infection caused by bacteria named as mycobacterium tuberculosis. It is the second most common cause of death with 2 million annual global death rates estimated worldwide. As Tuberculosis doesn’t show any symptom at its latent stage and Enzyme based detection test such as PCR, ELISA tests are time taking with low sensitivity of detection. Our approach is to design the cost-effective nanomaterial-based assay which can monitor the presence of Tuberculosis by the indication of volatile markers of Tb in exhaled breath. Nanotechnology could play a key role in the detection of Tb due to the added advantages it offers such as an easy and cost-effective synthesis with improved morphologies which include high surface area, pore size, better stability as compared to enzymes. So, the nanomaterial-based detection assays are more preferred over enzymes for remote sensing. Therefore, novel graphene oxide based nanocomposites modified with Fe3O4-Co3O4-ZnO nanoparticles, are synthesized using hydrothermal method. The average crystallite size and planes were calculated by XRD, and functional group identification was done using FTIR analysis. Different concentrations of analyte (Mm-M) were observed using fluorescence spectrophotometer to check sensitivity and selectivity of the assay. Hence, the synthesized nanocomposite are shown with high sensitivity and selectivity towards methyl nicotinate volatile organic marker for Tb.Item Synthesis and Characterization of Cellulose based MOF for Photo-Catalytic Application(Library Information Services COMSATS University Islamabad Lahore Campus, 2021-02-26) Zarmina Ali; SP20-R06-015; Dr. M. Shahid Nazir; LHR TP 7569Metal organic frameworks are porous materials which are formed by the combination of organic and inorganic substances joined together by coordinate covalent bonds. This class of compounds possess many unique characteristic features. Such as high porosity, large surface area, stability and ability to modify their properties. MOFs are widely used for water treatment, sensing applications, in catalysis, removal of contaminants from air, and in targeted drug delivery applications. The Bio–MOFs with polysaccharides functionalities have gained a lot of importance due to their biocompatible nature and strengthened structures, without affecting internal properties of MOFs. Cellulose is a biodegradable, cost effective natural material which can be used to enhance the porosity, crystallinity & surface area of MOFs .However, Cellulose based MOFs show poor aqueous stability because cellulose swells in water due to its hydrophilic nature. In this work, hydrophobic composite of cellulose based Ni MOF composite is synthesized and has been explored for photocatalytic dye degradation. Aqueous stability of novel composite was achieved by its modification through adipic acid. After synthesizing cellulose from cotton stalk, it has been converted into nanocrystals to get versatile properties that is higher crystallinity. Ni MOF possesses excellent feature of narrow Band gap region (2.3 eV approximately).Narrow regions cause to improve the absorption of light rays, thereby facilitating dye degradation through photocatalysis. Two different combinations of MOFs that is CNCs @ Ni-MOF & CNCs @ AP@ Ni-MOF are synthesized. Kappa no. of extracted cellulose was found to be 30.5, which showed effective removal of lignin content from it.These novel composites are characterized via FTIR at each step during their preparation to confirm the successful modification. For CNCs @AP @ Ni MOF, the characteristic peak at 712cm-1 shows O-Ni-O bonding. The major peaks present in the regions of 3339 and 1102 cm−1, corresponding to the stretching vibrations of -OH functionality and glycosidic linkage (C-O-C) respectively. One of the major peak which proves the modification by adipic acid, was appeared at 1440 cm−1, ascribed the bendingItem Use of Plant Biomass to Reduce Peroxide Value and Free Fatty Acids of Used Cooking Oil(Library Information Services COMSATS University Islamabad Lahore Campus, 2026-02-26) Kalsoom Fatima; SP20-R06-004; Dr. Muhammad Javid Iqbal; LHR TP 7559The refining of used cooking oil (UCO) and its conversion into useful product is the need of the time. Degradation and spoiling of cooking oil due to oxidation, hydrolysis and polymerization which depends upon frying cycles, frying time and high temperature. Use of damaged cooking oil is dangerous for human consumption and causes various health issues like heart problem, renal and liver disorders in the long run. Different synthetic inorganic adsorbent such as silica gel, magnesium oxide, aluminum hydroxide and activated clay are used in recycling of UCOs. Bio-adsorbents are fresh idea to prepare adsorbents from different biomass like bagasse, coconut husk, rice husk, pineapple dregs, soft wood, and corncob. The treatment of UCOs with biomass bagasse gives better results and a cheap source adsorbent. Sugarcane bagasse is used because of its low cost, quick growth, broad cultivation. Easy availability of Bagasse made from sugarcane includes 50% cellulose, 25% hemicelluloses, and 25% lignin. High carbon content is present in the bagasse, which is one of the key reasons for its effectiveness as an adsorbent. The FFAs and peroxide values has been reduced by applying bio adsorbent obtained from the bagasse. The adsorption potential of AC derived from bagasse for FFAs and PV in WCOs was examined using an adsorption process with various operational parameters such as pH, adsorbent masses, and agitation time. To assess the structural examination of the material and functional groups, AC was analyzed using XRD and FTIR, respectively. For adsorbent synthesis bagasse was heated with 0.1N solution of NaOH at 250℃ and 500RPM. Then for oil treatment used cooking oil (50 mL) was heated at 110°C for 10 minutes then added different adsorbent masses such as 2,3 and 4g and set on stirring top at 500 RPM for 30 minutes for FFA. After that same process is followed by using different agitation time like 250, 500 and 750 RPM instead of adsorbent mass. At 750 rpm and 4g adsorbent mass, the best results were obtained.Item Hydrogels with Antibacterial Properties for Potential Treatment of Periodontitis(Library Information Services COMSATS University Islamabad Lahore Campus, 2021-02-26) Saira Sajjad; SP20-R06-012; Dr. Asma Tufail Shah; LHR TP 7566Periodontitis is a severe inflammation of specialized tissues that support and surround the teeth called periodontium. Periodontal tissues weaken over the passage of time due to the persistent bacterial attack and are difficult to recover once they are lost and damaged. For tissue repair or wound healing, it is important to develop a biomaterial which would have such qualities that make it most suitable for the regeneration of bone tissues along with antibacterial properties. Bioactive glasses (BG) have been studied for their biocompatibility and ability of bone regeneration and hydroxyapatite formation in the body. Moreover, Acetanilide (Drug) has been found to possess analgesic, anti-pyretic as well as anti-bacterial properties and was expected to be better choice for developing a hydrogel in combination with bioactive glass that heals or repair the bone tissue. In this study a thermo-sensitive, anti-bacterial and biodegradable chitosan-based hydrogel was developed by Sol-Gel method using different concentrations of bioactive glass in combination with chitosan and acetanilide. Physiochemical properties of hydrogel were studied through various analytical techniques such as FTIR, XRD and contact angle. Gelation and setting time of bioactive glass based hydrogels were studied and it was observed that gelation and setting time were affected by the different concentrations of bioactive glass. The injectability and flowabililty of hydrogel was also investigated using needles of different gauges. Anti-bacterial potential was analyzed against two bacterial strains, E.coli and S.aureus, in which chitosan based hydrogel with bioactive glass and Acetanilide (CS-BG-Aa) showed effective anti-bacterial activity.Item Design of Novel Alkali Metals (Li, Na, K) Doped [6] Cycloparaphenylenes with High Nonlinear Optical Response(Library Information Services COMSATS University Islamabad Lahore Campus, 2021-02-26) Ruqiya Rasul; SP20/R06/011; Dr. Mazhar Amjad Gilani; LHR TP 7565Nonlinear optical (NLO) materials have gained tremendous attention because of their vast applications in different fields such as optoelectronics, telecommunication and data storage etc. In this work, geometric, electronic, linear and nonlinear optical properties of alkali metals (Li, Na and K) doped cyclic organic systems i.e., [6] cycloparaphenylene ([6]CPP) and methylene bridged [6] cycloparaphenylene (MB[6]CPP) are investigated via density functional theory (DFT). The diffuse excess electrons generated by alkali metals have significantly tuned their electro-optical properties. The alkali metals doped CPP based complexes have exhibited a large thermodynamic stability up to -32.1 kcal/mol. Moreover, reduction in HOMO-LUMO (H-L) energy gap has been observed up to 2.92 eV because of the generation of new HOMO which is further confirmed by density of state (DOS) analysis. The NBO analysis has revealed the charge transfer from metals to the CPPs. In addition, NCI and QTAIM analyses have exploited the nature of intramolecular interactions. Doping of alkali metal atoms significantly has increased the first hyperpolarizability (βₒ) of all the complexes. The K@r6-[6]CPP has exhibited the highest hyperpolarizability value of 1.10 x 107 au. Moreover, the absorption spectra have revealed the bathochromic shift for the alkali metals doped complexes. Furthermore, the frequency dependent first hyperpolarizability calculations have been done for M@r6 doped [6]CPP and MB[6]CPP at two routinely used frequencies (532 nm and 1064 nm). The results have shown that the highest response of both SHG (2.25 × 107 au) and EOPE (2.81 × 106 au) are obtained for K@r6-[6]CPP at 1064 nm. These fascinating results will be helpful to utilize the designed [6]CPP and MB[6]CPP based complexes for the generation of advanced optoelectronic devices and high performance NLO materials.Item Bilayer Electrospun Membrane Modification with Phytochemicals for Wound Healing / Scar Removal(Library Information Services COMSATS University Islamabad Lahore Campus, 2021-02-26) Ayman Zehra; SP20-R06-005; Dr. Faiza Sharif; LHR TP 7560The main aim of this work was to synthesize bilayer polymeric membranes through electrospinning and then modify the surface of those membranes with phytochemicals by dip coating. These modified membranes are prospective candidates for wound healing and scar removal. Electrospinning is relatively a new technique to produce nano and micro fibrous membranes having nano and microporous morphology for various biomedical applications. Phytochemicals such as Licorice and Bearberry extracts have been used for centuries in Ayurveda and traditional medicine throughout the world, including Persia, China, India and the Pakistan. These extracts have been found effective in the treatment of wounds, hyperpigmentation, melanin reduction, skin aging, freckles and scars for hundreds of years. Many phytochemicals such as alkaloids, flavonoids, tannins, terpenes, arbutin, glyrrhizic acid, volatile oils and organic acids have been found in the chemical composition of the licorice and bearberry extracts. These compounds possess antibacterial, antioxidant, anti-inflammatory, antimicrobial, and in anticancer activitiesItem Covalent Organic Framework Supported Single Atom Catalyst for Hydrogen Evolution Reaction: A Theoretical Investigation(Library Information Services COMSATS University Islamabad Lahore Campus, 2021-02-26) Maria Younas; SP20/R06/025; Dr. Mazhar Amjad Gilani; LHR TP 7579Global environmental considerations are being raised as a result of excessive fossil fuel consumption and excessive carbon dioxide (CO2) emission. Regrettably, fossil fuel reserves are decreasing, and energy generation from them is unsustainable, non-renewable, and unaffordable. Due to these concerns, there is an imperative demand for sustainable and eco-friendly energy conversion electrochemical systems. Hydrogen (H2) is ubiquitously regarded as a future sustainable energy source and an attractive alternative to conventional fossil fuels. Production of hydrogen must be sustainable in order for a hydrogen economy to thrive in the future. Water electrolysis powered by renewable resources is being considered as a sustainable approach to produce hydrogen. In attempt to implement the process of water splitting efficiently, cost-effective, and non-precious metal based electrocatalysts for hydrogen evolution reaction (HER) are required. The development of effective single-atom catalysts (SACs) for electrochemical water splitting is a viable technique. High energy barrier of the HER and a catalyst with low stability continue to pose difficulties for the entire process of water splitting. To address this issue, electrocatalysts with single metal atoms supported on a covalent organic framework (TM@COF SACs) have been proposed for HER. The catalytic performance of these catalysts for HER is determined by the change in the Gibbs free energy of adsorbed atomic hydrogen (ΔGH*) on the catalyst's surface. Density functional theory (DFT) findings suggest that the Zn single atom doped on the surface of the covalent organic framework has a significant impact on the HER performance. This study paves the way for the development and use of highly efficient, stable, and non-precious single atom HER catalysts.Item Fabrication of PET (polyethylene terephthalate) based Thin Film Composite Membranes from Waste Plastic Bottles(Library Information Services COMSATS University Islamabad Lahore Campus, 2021-02-26) Rimsha Yasin; SP20-R06-027; Dr. Muhammad Yasin; LHR TP 7581Fresh water scarcity and pollution are the major issues all over the world and millions of people do not have access to clean water. Plastic waste is also a major pollutant of fresh water. In this study, PET is recycled and extracted from waste PET bottles. Forward osmosis (FO) is an efficient technique employed to treat water pollution by converting wastewater into clean water. The TFC membranes have shown great potential for high performance water purification, while the FO process has proved to be an energy efficient process compared with the RO process. This study employed a unique approach where the support layer of the TFC membranes was prepared using waste PET bottles. The support was optimized to give additional separation efficiency by incorporating MOF, i.e., MIL-100, into the support layer. MM supports with different loadings of MIL-100 (0wt%, 1wt%, 3wt%, 6wt% and 12wt%) were fabricated. Then TFC membranes were fabricated via Interfacial polymerization to produce top active polyamide layer. Finally, the performance of TFC membranes for desalination was assessed in the FO process. It was estimated that TFC membrane with 3wt% loading of MIL-100 showed high water flux and rejection as compared to other TFC membranes
- «
- 1 (current)
- 2
- 3
- »