Department of Chemistry
Permanent URI for this communityhttps://repository.cuilahore.edu.pk/handle/123456789/14
Browse
32 results
Search Results
Item Synthesis of Polymeric Membranes to Achieve High Gas-Liquid Mass Transfer(Library Information Services COMSATS University Islamabad Lahore Campus, 2021-02-26) Muhammad Tayyab Khalid; FA19-R06-021; Dr. Muhammad Yasin; LHR TP 7555The world is meeting its energy requirements through fossil fuels. However, the environmental consequences caused by the utilization of fossil fuels and their expected depletion are the big concerns. These issues can be resolved by environmentally friendly utilization of coal and by exploring renewable alternatives to fossil fuels. One option is to produce biofuels such as bioethanol, biobutanol and biohydrogen by the biological conversion of syngas produced by the gasification of coal and biomass. Syngas is a mixture of CO, CO2, and H2 and can be converted into biofuels by using microorganisms. The scale up of syngas fermentation is limited by several issues, mainly the gas-liquid mass transfer (GL-MT). The GL-MT in syngas fermentation can be assessed by measuring the overall volumetric mass transfer coefficient (kLa). One of the potential ways to achieve high GL-MT in syngas fermentation is by employing membrane-bioreactors (MBRs). All the published studies on MBRs have used membranes that were synthesized for water purification. Hence, there was a need to synthesize membranes targeted for high GL-MT applications. In this study, the polyimide (P84) membranes were synthesized by varying the concentration of polymer, adding different concentrations of polyvinyl pyrrolidone (PVP), and impregnating the metal-organic framework (MOF) ZIF8 to get low pore size, high porosity, and high hydrophobicity. The highest values of porosity were achieved for membranes M-8 having 12% polyimide and 2% PVP. The GL-MT of O2 was investigated in a bubble column reactor (BCR) employing membrane spargers made of pure PI (P84), additive incorporated PI, and MOF incorporated mixed matrix membrane (MMM). The average values of the obtained kLa were 136.8 h-1 (for pure PI), 212.4 h-1 (for additive incorporated membrane), and 241.2 h-1 (for MMM). For the MOF-based membranes, 78% saturation was achieved in 60 seconds with the highest kLa at a low value of AS/VL (10.7 m-1).Item In-Situ Fabrication of Metal Organic Frameworks Nanocomposite for Oxygen Reduction Reaction(Library Information Services COMSATS University Islamabad Lahore Campus, 2021-02-25) Farhan Zafar; FA19-R06-009; Dr. Naeem Akhtar Khan; LHR TP 7344The purpose of this research project is to fabricate carbon and nitrogen coated zeolite imidazole framework-8 (CN coated ZIF-8) nanoparticles and to evaluate their oxygen reduction capability. CN coated ZIF-8 has been synthesized through solvothermal method, in which zinc nitrate hexahydrate is mixed with 2-methylimidazole to form ZIF-8 which is further wrapped with dopamine and calcined to form CN-coated ZIF- 8. Fourier transform (FT-IR) studies confirmed the presence of functional groups in the synthesized nanocomposites, and X-ray diffraction (XRD) confirmed the CN- coated ZIF-8 nanocomposite. CN-coated ZIF-8 interacts with the oxygen through electrostatic force (van der Waals force) and results in the transformation of O2 into H2O. Glassy carbon electrode (GCE) was modified with CN-coated ZIF-8 and was applied for oxygen reduction reaction by using 0.1 M potassium hydroxide (0.1 M KOH) as an electrolyte. The synthesized electrode is cheap, robust, and has shown good electrocatalytic activity for ORR.Item 2 Deoxy-D-ribose Releasing Sodium Alginate Based Hydrogels for Burn Wounds and Diabetic Ulcers(Library Information Services COMSATS University Islamabad Lahore Campus, 2021-02-25) SAFINA ABID; CIIT/FA19-R06-004/LHR; Dr. Muhammad Yar; LHR TP 73312 Deoxy-D-Ribose has important biomedical applications due to its ability to stimulate angiogenesis, particularly in chronic and diabetic wound healing. The goal of this study was to see if manufactured tube hydrogel accelerates wound healing by stimulating angiogenesis in rats. 2 Deoxy-D-Ribose (2dDR), a small sugar, was loaded into sodium-alginate to produce a tube hydrogel. FTIR analysis confirmed the presence of sodium-alginate functional groups in freeze dried membranes. Drug release studied indicated that that approximately 98% of 2dDR was released between 1-7 days, that is beneficial for angiogenesis and wound healing. Antibacterial test revealed indicate that the sugar could not be metabolized by strains of E. Coli and Staphylococcus aureus. The rat models treated with alginate blank-Gel significantly promote wound healing and the 5% of 2 Deoxy-D-Ribose further significantly showed a rapid full thickness wound healing up to day 14 in contrast to untreated rat. Hair regeneration in rat model showed extensive hair follicle regrowth in 5% of 2 Deoxy-D-Ribose treated portion as compared to other groups. All these experiments confirm that these 2 Deoxy-D-Ribose (2dDR) tube hydrogel is suitable to use for stimulating angiogenesis and maintaining moist environment to accelerate wound healing applicationsItem Synthesis and Characterization of Metal Substituted Bioactive Glass for Treatment of Periodontal Disease(Library Information Services COMSATS University Islamabad Lahore Campus, 2021-02-25) Samreen Ashraf; FA19-R06-001; Dr. Asma Tufail Shah; LHR TP 7322Periodontitis is a serious gum infection that damages soft tissue and if not treated well can destroy bone resulting in tooth loss and is caused by different bacteria such as Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis and Tannerella forsythia. Roughly 50% world population is affected with it and 750 million people suffer from its severe form. The damaged bone can be regenerated in different ways, including using one’s own bone, or using donor’s bone and third way by using different synthetic bone fillers including bioactive glasses. Bioactive glasses (BGs) are non-crystalline biomaterials that are able to bond soft and hard living tissues and dissolve over time to stimulate growth of new tissues. In this research, an effective approach of periodontal treatment is to treat it with nano-sized bioactive glass prepared by co-precipitation method in which metal copper and fluoride ions are doped to increase its antimicrobial properties as well as strength. Different concentrations of copper-fluoride (Cu-F) doped bioactive glass have been prepared and characterized by different analytical techniques including FTIR, XRD and SEM-EDX to confirm the successful incorporation of copper and fluoride ions. The results showed that metal doped bioactive glasses were successfully prepared.Item Synthesis and Characterization of Al-Based Metal Organic Framework for Environmental Application(Library Information Services COMSATS University Islamabad Lahore Campus, 2021-02-25) Maria Shamim; FA19-R06-003; Dr. M. Shahid Nazir; LHR TP 7325Metal organic framework, also called porous co-ordination networks are highly advanced class of crystalline materials with high porosity. MOFs synthesis is influenced via various factors such as solvent, pH and temperature of the system and can be synthesized via various routes. MOFs functionalization can be carried out pre-synthetically or via post-synthetic mode while there are various methods for the activation of MOFs out of which thermal activation is immensely in practice. Synthesis of environment friendly and water stable MOFs is the need of the hour, to be used in environmental applications. Aluminium being the light metal with smaller ionic radius and higher charge makes hydrothermally stable MOFs; a distinguished feature fit to carry out environmental applications such as dye adsorption and heavy metal remediation. Among variously synthesized MOFs, MIL-96(Al) stands out significantly in terms of stability. Three different combinations of MOFs 1) CTAB Modified MIL-96(Al) 2) CTAB-Fe3O4@MIL-96(Al) 3) Fe3O4@MIL-96(Al)/Ag-CTAB, are prepared using MIL-96(Al). These MOFs are characterized via FTIR at each step of their synthesis to confirm the synthesis. XRD has been carried out to confirm the crystallinity of the synthesized materials. MIL-96(Al) is a microcrystalline structure, as proved from 2Ө using XRD studies; characteristics peaks appearing at 9.2o and 11.2o. Average crystal size is determined to be 30.84nm for CTAB Modified MIL-96(Al), 30.95nm for CTAB-Fe3O4@MIL-96(Al) and 16.98nm for Fe3O4@MIL-96(Al)/Ag-CTAB. These synthesized MOFs have turned out be efficient adsorbent for dye removal such as methylene blue. Adsorption efficiencies of CTAB Modified MIL-96(Al), CTAB-Fe3O4@MIL-96(Al) and Fe3O4@MIL-96(Al)/Ag-CTAB are found to be 71.16%, 83.04% and 63.28%, respectively. Further, presence of certain functional groups in these MOFs can be suggestive of their use to be explored in heavy metal remediation as well.Item Fabrication of the Sensor Device for the Detection of Cancer Biomarker(Library Information Services COMSATS University Islamabad Lahore Campus, 2021-02-25) Shaista Ahmed; FA19-R06-005; Dr. Usman Latif; LHR TP 7327Cancer is one of the leading cause of death worldwide and delay in diagnosis is one of the major reason of high mortality rate. Among different cancer biomarkers interleukin-8 (IL-8) is considered as useful biomarker for the purpose of quick and accurate diagnosis. A sensitive and selective interdigital transducer based sensor have been fabricated by using molecular imprinted polymer (MIP) technique for the detection of biomarker IL-8. Detection sites synthesized by using functional monomer Methylmethacrylate (MMA), Graphene Oxide GO, cross linker Ethylene glycol dimethacrylate (EGDMA) and IRGACURE blend as a photo initiator. The synthesized sensor showed a high sensitive response for a linear range of IL-8 concentration 1ng/ml to 500ng/ml and coefficient of determination of R2 = 0.954 confirm the linear detection behavior with 239 pg/ml limit of detection. It also showed high selectivity Ribonuclease, IL-6, Lysozyme, Chymotrypsin and Glycoprotein used as control proteins. This sensor showed a unique strategy for detection of IL-8 in buffer as well as in saliva. Scanning electron microscopy (SEM) has been used to analyze the morphology of the fabricated sensor surfaceItem Synthesis and Characterization of rGO-coated PMMA Beads Based TPU Nanocomposites for Gas Sensing Application(Library Information Services COMSATS University Islamabad Lahore Campus, 2021-02-25) FA19-R06-029; Muhammad Saqlain Iqbal; Dr. S. M. Imran Hassan; LHR TP 7323Nanocomposites of polymers have recently gotten a lot of interest in the materials world since they often have more advanced properties than their counterpart polymer micro-composites. A novel reduced graphene oxide (rGO)coated poly (methyl methacrylate) (PMMA) beads based thermoplastic polyurethane (TPU) nanocomposites were prepared by the melt mixing method. Graphene oxide was synthesized by following improved hummer’s method and reduce it thermally at 300 oC. The PMMA beads were coated with reduced graphene oxide by the solution mixing method and then this synthesized rGO coated PMMA beads were introduced in TPU matrix in 1, 2, 5, and 8 % wt. of TPU along with 1% carbon nanotubes (CNTs) by following melt mixing method in an internal mixer. Scanning electron microscopy (SEM) was performed to examine the dispersion of fillers in the nanocomposites. Fourier transform infrared spectroscopy (FTIR) was applied for functional groups analysis. X-ray diffraction analysis results were obtained to know about the crystal structure of the GO, rGO and rGO coated PMMA beads. Raman spectrum was obtained to know the defects after oxidation and reduction of graphite and GO, respectively. The effect of rGO coated PMMA and CNTs was observed on the conductivity properties of the synthesized polymer nanocomposites. Electrical conductivity values were obtained using four probe for these nanocomposites and the data showed that the synthesized polymer nanocomposites were conductive. Gas sensing application of these composites could be possible.Item Synthesis and Characterization of Nitrogen Base Covalent Organic Framework for Environmental Application(Library Information Services COMSATS University Islamabad Lahore Campus, 2021-02-25) Malka Shahid; A19-R06-027; Dr. M. Shahid Nazir; LHR TP 7319Covalent organic frameworks (COFs) are porous two-dimensional and three-dimensional structures due to their large structural diversity, inherent porosity, and excellent stability has been acknowledged as an excellent and versatile platform for gas adsorption, gas, and energy storage, as the heterogenous catalyst, in optoelectronic devices, in chemical sensing, treatment of wastewater, pollutants detection and their removal, photoconductivity, biomedical applications and for dye adsorption. Several different dyes are used for different applications to overcome the environmental parameters suitable dye storage, dye release, and dye removal method is required. So our main objective was to figure a desirable COF of resplendent porosity and stability with a less heat-intensive method for dye application. These days, there has been a major sake given to the development of the nanocomposites by employing the nanoscale panorama in one of two constituents. To produce nanocomposites of amended structure and corporeal features, the maintenance of nanoparticles and agglomeration is necessary for technological application. In this sense, Iron and Iron oxide nanoparticles have been considered as an efficient material for dye removal but iron-based magnetic nanoparticles (such as Fe3O4 and γ-Fe2O) have very low stability in harsh conditions, and decomposition of material result in loss of their magnetic properties. In this study, the modification of COFs is done by the preparation of Iron-based magnetic COFs (Fe3O4@LZU-1) which also ensue the stabilization of magnetic nanoparticles. For the preparation of Fe3O4 @LZU-1, a very facile approach is utilized which shows excellent chemical stability. Synthesis of Fe3O4 and Fe3O4@LZU1 was confirmed by FTIR and XRD. In FTIR spectra of Fe3O4@LZU-1, C=N appears at 1622 cm-1 that confirms the condensation reaction between two selected monomers. In XRD all the characteristics peaks were observed in the sample of Fe3O4 NPs and Fe3O4@LZU-1 fitted well with the JCPDS database (Card no. 075-1609) indicating that the formation of shell on the surface of NPs does not cause any evident change in diffraction peaks. According to the previous studies in Fe3O4 NPs for achieving the superparamagnetism, the estimated particles size is considered to be below 20 nm, and here in our reported work particle size for both magnetic nanoparticles and COF x magnetic nanocomposite is 11.93 and 10.58 nm which shows high magnetization saturationItem Fabrication of a Suitable Visible Light Driven Photocatalyst for Sustainable Production of Hydrogen from Water Splitting(Library Information Services COMSATS University Islamabad Lahore Campus, 2021-02-24) Ayesha Nawaz; FA19-R06-038; Dr. Sara Riaz; LHR TP 7326Excessive use of fossil fuels has caused a lot of environmental damage so they must be replaced with sustainable energy resources. Hydrogen has clean and renewable properties so it can be used as a sustainable energy resource. Photocatalytic water splitting is an efficient way of producing hydrogen but it requires an efficient photocatalyst having high photochemical stability, efficient charge separation capability, good light harvesting properties and suitable band gap. Tungsten oxide has suitable properties for photocatalytic water splitting but it suffers from recombination of photogenerated charge carriers. Herein, different composites of tungsten with transition metal borides and oxides of copper and nickel have been successfully synthesized by precipitation method. FTIR studies, XRD analysis and SEM of the prepared composites, WO3-NiCoB, WO3-CuO-NiO, WO3-NiB and WO3-CuO-NiB have been done for detection of functional group, investigation of crystalline and structural properties, and study of the surface morphology of prepared composites. The photocatalytic activity of WO3, WO3-CuO-NiO and WO3-NiCoB has measured by photodegradation of AO-II. The results of activity showed that WO3-NiCoB worked better in photodegradation of AO-II in comparison to its other counterparts, WO3 and WO3-CuO-NiO.Item Synthesis of Platinum Based Catalyst and Evaluation of its Catalytic Properties(Library Information Services COMSATS University Islamabad Lahore Campus, 2021-02-24) Sabiqa Inam; FA19-R06-032; Dr. Um-e-Salma Amjad; LHR TP 7343The niobium pentaoxide supported platinum (Pt/Nb2O5) catalyst was successfully synthesized by using a conventional wet impregnation method. The catalytic activity of synthesized catalyst was evaluated for the model reaction of dehydrogenation of methylcyclohexane to toluene and hydrogen. The catalyst was first reduced with hydrogen and then used for experiment. The experiment was performed in the fixed bed reactor within a temperature range of 300°C to 500°C for 3hours. Under the experimental conditions, dehydrogenation of methylcyclohexane was successfully carried out over Pt/Nb2O5 catalyst. Various concentrations of Pt loading on supports have been employed to determine which concentration give better results. A mechanistic study based on thorough description was done by Raman and XRD characterization techniques to determine the structure and elemental composition of the catalyst. Catalytic activity was monitored by the condensate volume and the fractions of gasses produced during reaction. The percentages of gaseous products were analyzed with the help of gas analyzer. The greater volume of condensate was recorded at temperature of 400oC.