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Phosphorous is an effective and essential mineral nutrient for the growth of biological creatures and it is very necessary for functioning of ecosystems normally. However, the increase in the usage of phosphorous in lots of parts including industry, agricultural and municipalities causes to pollution of water bodies. Additionally, consumption of water which is rich in content of phosphorous can cause to decrease in the levels of calcium amount of blood and that can result in osteoporosis, hyperphosphatemia and hazard public health. For protection of human health and aquatic ecosystems, the amount of phosphorous should be controlled within the limits (<0.5 mg/L as it has been reported by World health organization). The removal of phosphorous from water bodies relies mostly on the adsorbents usage which are effective. In this study, chitosan-alginate hydrogel beads were prepared by mixing chitosan and sodium alginate solution together and dropping them into calcium chloride solution. Sodium alginate and chitosan mixture causing interpenetrated network improves the resistance of the beads in acidic mediums. For characterization of beads SEM and FTIR analysis were conducted to prove the presence of functional groups and calcium ions which has the main effect in phosphate adsorption. Additionally, UV spectroscopy method was used to study adsorption capacity which illustrated that with increasing adsorbent concentration and time, the amount of adsorbed phosphate increase considerably.
In recent years, intensive research efforts have been committed to studying Am-phiphilic polymers, particularly in the pharmaceutical applications. These polymers have ability to form a different macromolecular architecture in the aqueous solution such as polymeric micelles. Novel combshaped, chiral and fluorescent amphiphilic polymers are important for pharmaceutical applications including hydrophobic drug solubilization. In this thesis, four chiral, combshaped and fluorescent novel amphiphilic polymers were synthesized from chitosan and perylene diimide. The compounds were analyzed using FTIR, UV-vis and Emission spectroscopy.
Perylene molecules bearing two aryloxy substituents on bay position (1,7 positions) and two receptor units at the imide positions are most useful fluorescent building blocks for the realization of a broad variety of self-assembly architectures. High absorption of perylene diimides (PDIs) in the visible region offers many advantages for photonic applications, optimum electron transport properties, flexible synthetic potentials to adjust energy levels, solubility, stacking properties, excellent thermal and photo-stability. In this thesis, a novel perylene diimide with tyramine substitution at the bay (1,7-position) and imide position was designed and synthesized successfully. The synthesized product was characterized by FTIR, UV-vis, emission, TGA, DSC techniques and elemental analysis. The photophysical and thermal properties of Ty-B-PDI reveal that it as a good candidate for photovoltaic applications.
Poly(HEMA-co-EGDMA) microparticles were synthesized by using suspension polymerization at different ratios of the monomer, 2-hydroxy ethyl methacrylate (HEMA) and the crosslinker, ethylene glycol dimethacrylate (EGDMA) at 70 °C for 3 hours with stirring at 350 rpm. The redox couple ammonium persulfate (APS) and N,N,N',N-tetramethylene diamine (TEMED) was used as the initiator. Magnesium oxide (MgO) was used as the stabilizer. Ratios of monomer and crosslinkers were altered to synthesise different microbeads of poly(HEMA-co-EGDMA) with different crosslinking ratios. The swelling behaviour of the microparticles was analysed in three different buffer solutions: acetate buffer at pH 2.0, phosphate buffer at pH 7.4 and pH 11 at 37 °C. In addition, loading of flurbiprofen and methylene blue into the microparticles and their release characteristics were investigated. Drug loaded and unloaded samples were analysed by FT-IR spectroscopy and scanning electron microscopy (SEM). Keywords: Poly(HEMA-co-EGDMA), Microbead, Copolymer, Flurbiprofen, Methylene Blue, Controlled Release, HEMA, EGDMA.
Chitin gel beads were prepared, crushed into powder and grafted with poly(4- vinylpyridine) (P4VP) under nitrogen gas by using cerium ammonium nitrate(CAN) as a redox initiator under heterogeneous conditions in toluene. The effect of the amount of chitin, concentration of the monomer (4VP), amount of the initiator (CAN), reaction time and temperature on the grafting percent has been studied. The maximum grafting yield of poly (4-vinylpyridine) on to chitin beads was determined to be 380%. The optimum conditions were 0.10 g of chitin, 10 mL of (4VP) monomer, and 0.50 g of cerium ammonium nitrate (CAN) initiator at 60°C for one hour reaction time. The grafted samples were found to be soluble in aqueous acidic buffer solution (pH=1.2). The grafted and non grafted products were characterized by FTIR spectroscopy, SEM, DSC and C13 NMR analysis. Keywords: 4-vinylpyridine (4VP), chitin gel, redox initiated grafting.
ABSTRACT: Chromophores are responsible for the color of matter. The control of molecular interactions in multichromophores lead to functional dyes with novel properties. Furthermore, tailormade spectroscopic properties could be achieved, which are a prerequisite for applications that require dyes with absorption and emission in a specific region of the visible spectrum. With this special interest, we targeted to synthesize a multichromophoric macromolecule containing two different chromophores – a perylene and naphthalene. We have designed a molecular architecture of, and synthesized a novel multichromphoric macromolecule, N,N’-bis-{N-(3-[4-(3-amino-propyl)-piperazin-1-yl]-propyl)-N’-[1-dehdroabiety]-1,4,5,8-naphthalenetetracarboxydiimidly}-3,4,9,10 perylenebis(dicarboximide)bisimides (NPM) which was carried out in three consecutive steps. Our focus was also to enlarge both the absorption and emission ranges of the macromolecule and to investigate consequent optical properties. The first step includes the synthesis of a perylene dye, N-N’-bis-{3-[4-(3-amino-propyl)- piperazin-1-yl]-propyl}-3,4,9,10-perylenebis(dicarboximide) (PDI) where as in the second step, a naphthalene monoimide, N-(1-dehydroabietyl)-1,4,5,8-naphthalenetetracarboxylic-1,8-anhydride-4,5-imide (NMI) was synthesized. Finally, the designed macromolecule dye (NPM) was synthesized by using the above synthesized compounds, PDI and NMI. All the synthesized compounds were characterized in detail by IR, MS, NMR, UV-vis, DSC and TGA measurements. A much enlarged absorption (325 nm – 550 nm) and emission (375 nm – 700 nm) ranges were achieved by the synthesized macromolecule dye which was appreciably soluble in most of the commercial organic solvents. All the three synthesized compounds were photochemically and thermally stable and found no glass transition temperature in the DSC runs until 300 oC. The fluorescence quantum yields of the compounds were measured and PDI was reported high quantum yield among the three synthesized compounds. Several optical parameters were also calculated and reported. …………………………………………………………………………………………………………………………………………………………………………………………………………
Perylene chromophoric derivatives are versatile compounds for many applications in various fields. Excellent optical properties such as high extinction coefficients and strong fluorescence combined with ease in electron accepting ability are most notable advantages of perylene derivatives. Herein, the project focused on the synthesis of different kinds of perylene dyes, a chiral perylene diimide, a chiral perylene monoimide, and a perylene dicarboxylic acid chiral monoimide, named, N,N′-bis((R)-(+)-1-phenylethyl)-3,4,9,10-perylenebis(dicarboximide) (PDI), N-((R)-(+)-1-phenylethyl)-3,4,9,10-perylenetetracarboxylic-3,4-anhydride-9,10-imide (PMI), chiral perylene-3,4-dicarboxylic -9,10-((R)-1-phenylethyl)carboximide (CPMI), respectively. The final perylene derivative CPMI was synthesized in three consecutive reactions. CPMI was especially designed to be applicable in photovoltaic cells such as dye sensitized solar cells. The synthesized perylene derivatives are characterized in detail by investigating their optical, photophysical, and thermal properties using the techniques FTIR, UV-vis, Fluorescence, DSC, TGA and elemental analysis. They exhibited interesting optical properties, high solubilities, high molar absorption coefficients, and thermal stabilities. Keywords: perylene diimide, perylene monoimide, carboxylic acid monoimde, chiral, extinction coefficient.
Versatile substituents of perylene chrmophores creates higher absorptions in visible region of absorption spectrum and also exhibits higher coefficients of molar extinction. Furthermore, they have the ability to emit light of almost unitary which signifies higher fluorescence quantum yields. Perylene dyes acts a major role in dye sensitized solar cells due to the presence of four carbonyl groups in its core which creates ease of accepting an electron. In this research, N,N′-Bis(3,3,5,5-tetramethyl-4-piperidinyl)-3,4,9,10-perylenebis (dicarboximide) (PPDI) and N-(3,3,5,5-tetramethyl-4-piperidinyl)-3,4,9,10-perylenetetracarboxylic-3,4-anhydride-9,10-imide (PPMI) were sensitized and comparison of their photophysical properties were carried out. FTIR spectroscopy was used to characterize the compounds and their photophysical properties analyzed via absorption and emission spectroscopy. All the perylene dyes synthesized showed very high molar absorptivity with the highest being 152000 M-1cm-1 obtained from PPMI. PPMI absorption spectrum shows a 4 nm blue shift in a polar aprotic solvent as a result of increased level of polarity and the stabilization of PPMI energy levels it induces on the structure. Keywords: Perylene diimide, perylene tetracarboxylic acid, perylene monoimde, perylene carboxylic acid monoimide.
Phytochemical and antioxidant properties of pomegranate juice PJ produced from the Wonderful pomegranate cultivar (Punica granatum L.) grown locally in North Cyprus was undertaken. The objective of this research study was to determine the biologically active components present, antioxidant activity, total anthocyanin content etc. of PJ and compare it with the unprocessed Pomegranate fruit juice PF. Antioxidant activity of both samples was determined using the DPPH (2,2-diphenyl-1-picrylhydrazyl) assay while pH differential method was used to determine the anthocyanin content. Results obtained from the qualitative phytochemical screening of locally manufactured PJ confirmed the presence of several phytochemicals such as; tannin, phenol, saponin, flavonoids, in our sample. The pH of the juice increased only slightly when compared to the unprocessed juice with both samples having similar results for titratable acid. Antioxidant activity of PJ was high (94.60%) though slightly lower than that of the PF (95.20%) which shows that PJ possess good antioxidant activity. Total anthocyanin content (10.12 mg cyanidin-3-glucoside / 100 g), flavonoid (58.52 mg quercetin/ 100 g) and calcium (27.81 mg/kg) content was found to be higher in the PJ than the fruit (2.46 mg cyanidin-3-glucoside/ 100 g; 53.44 mg quercetin/ 100 g and 12.46 mg/kg) while the Vitamin C (67.30 mg/kg), total sugar (148.46 g/kg) and potassium (250.04 mg/100g) content was higher in the fruit than the juice (18.70 mg/kg; 139.24 g/kg and 236.14 mg/100g). Keywords: antioxidant activity, pomegranate, phytochemical screening, colour, anthocyanins
π-Conjugated light emitting polymers are having very wide applications in many areas, especially in optoelectronic, photonic and renewable energy systems. 2,7-substituted polycarbazoles are excellent p-type candidates with great potential toward these applications. However, very few reports were published in literature about the applicability of poly(2,7-carbazoles) which is attributed to the difficulties in direct functionality at 2,7-positions (meta-). In the present work, we report the synthesis of a 2,7-dibromo-substituted polycarbazole (poly(N-dodecylcarbazole)-2,7-diyl) material via four different consecutive steps. In first two steps, the basic 2,7-substitution was made by using commercial dibromobiphenyl and then the monomeric dodecylcarbazole was synthesized by nucleophilic substitution in the third step. Finally, the titled polymer was synthesized by Yamamoto polymerization. The structures of the intermediate products are confirmed by FTIR. The monomer and polymer were characterized by FTIR, UV-vis, emission and NMR techniques. The polymer has shown broad absorption comparing to the parent 2,7-dibromo-substituted-carbazole and monomeric dodecylcarbazole. Similarly, PCbz has exhibited strong excimer emission in all of the most commonly used organic solvents. Nevertheless, owing to the attractive tunable optical properties poly(2,7-carbazoles) and derivatives, they could be used as smart materials for electroactive and photonic device architectures. Keywords: Carbazole, Dodecylcarbazole, Poly(dodecylcarbazole), Excimer