M.Phil / MS
Permanent URI for this collectionhttps://repository.cuilahore.edu.pk/handle/123456789/30
This collection archives the complete set of theses produced by students of the COMSATS University Islamabad, Lahore Campus.
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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 Synthesis and Characterization of Polysaccharide-MOF Composites for Environmental Remediation(Library Information Services COMSATS University Islamabad Lahore Campus, 2021-02-25) Osama Kokab; SP20-R06-002; Dr. M. Shahid Nazir; LHR TP 7557MOFs are porous co-ordination networks/polymers which are highly crystalline substances with enhanced porosity, large surface area and improved overall attributes. These cages comprise of metal ion clusters which serve as the secondary building units (SBUs). Based on the coordination geometry of the organic linkers with metal ions; their structure and unique attributes can vary accordingly. Zeolitic Imidazole Framework-8 (ZIF-8) have improved structural porosity, flexibility, surface functionality and crystalline nature making it feasible to be utilized in various applications including the gas storage, CO2 adsorption, alkane/alkene separation and the catalysis. The biodegradability, higher surface area, and flexible binding interaction between the cellulose and ZIF-8 have made it an ideal choice for the various water remediation applications. The poor wet chemistry of the ZIF8-Cellulose composite is reported previously as the cellulose swells and loose dimensional stability in aqueous media. To overcome this problem, the ZIF8-APTES-Cellulose composite is synthesized which have high hydrophobicity and aqueous stability. The wet chemistry is tested by measuring the water contact angle which is 139.5°. The FTIR analysis shows a significant peak at 450cm-1 confirming the Zn-N bond along with peaks at 1550cm-1, 1480 cm-1, 1080cm-1, and 1020 cm-1 confirming the N-H bending of APTES, C=N vibration, C-N vibration of imidazole and C-O vibration of the composite respectively. Moreover, XRD analysis of the composite shows characteristic peak positions at 7.3°, 10.3°, 12.7°, 18°, 22.7° and 35.02° confirming the presence of ZIF8, APTES and cellulose. The dye degradation efficiency for the composite is explored at different conditions such as pH, dose of adsorbent, and concentration of dyes to achieve the optimized results. The maximum efficiency for the degradation of Congo Red dye is achieved 95% with 4mg dose of adsorbent at pH 4.0. This study opens up avenue for the dye remediation of wastewater.