Surface functionalised silica materials have been prepared, followed by the extensive testing of their ability to remove metal ions from aqueous solutions. Modifications include ligand attachment and polymer grafting from the silica surface whilst the metals tested range from first row transition metals right through to the lanthanides and actinides. Characterisation of the materials produced has been of paramount importance for the understanding of the modification process and this is also extensively discussed. Atom transfer radical polymerisation (ATRP) has been used as the primary polymerisation method. Following polymerisation of 2-hydroxyethyl methacrylate (HEMA), post functionalisation was attempted. However, this was found to cause severe cross-linking and all attempts to attach ligands to this failed. Nonetheless, this process was transferred to grafting from silica surfaces and a novel approach to the characterisation of this material was implemented. (3-aminopropyl) triethoxysilane (APTES) was reacted with multiple forms of silica, primarily ZEOprep silica (average particle size 71.48 πm) and fumed silica (0.007 μm). This produced an amine coated surface to which 2-bromoisobutyryl bromide (BIBB) was attached, providing the required surface for radical polymerisation to proceed with a selected monomer. Solid State Nuclear Magnetic Resonance (SSNMR) has been utilised as the major characterisation technique for each step, leading to significant understanding of how this occurs. Thermogravimetric Analysis (TGA) and elemental analysis has supported this method at each stage whilst also enabling one to calculate the moles of APTES present, per gram of APTES-functionalised silica. For the ZEOprep silica this was calculated to be at up to 1.51 x 10-3 mol g-1 and for the fumed silica 1.63 x 10-3 mol g-1. As well as testing the selective nature of these materials, solutions of individual ions and radionuclides were used to measure the effectiveness of the materials for a specific ion. Rd values for these metals ions including solutions of Co(II), Ni(II), Cu(II), Cd2+, Eu(III) and [UO2]2+ have reached values ranging from 7.49 x 104 mL g-1 to as high as 2.17 x 109 mL g-1. These values are regarded as outstanding by other groups that have reported similar results and these are discussed in the report. This range includes values that were observed when competing Na+ and Ca2+ ions were present at 0.5 % and 1 % (w/w). pH testing was also investigated with the materials using a solution of europium ions to determine the most effective range and this was found to fall between pH 4 and 5. X-ray Photoelectron Spectroscopy (XPS) has been utilised to help gain an understanding of the binding between Cu(II) ions and APTES, suggesting that copper ions bind with oxygen atoms closer to the silica surface as well as the nitrogen atoms at the end of the ligand. Meanwhile STEM (Scanning Transmission Electron Microscope) has been used to show how effectively the surface area of the material is used by imaging the europium ions over a sample of APTES-functionalised fumed silica. Ligands and polymers have been focussed on to build a catalogue of functional materials and this has been achieved in collaboration with PhosphonicS Ltd. The most significant finding from these selective investigations was that uranyl ions were found to be the most readily removed. Cu(II) and Eu(III) ions were also removed relatively effectively whilst Co(II), Ni(II), Zn2+ and Cd2+ proved the most challenging but certainly not impossible. [UO2]2+ concentrations were reduced from 17.1 ppm to 1.6 ppm after 4 weeks with use of the ligand SEA (2-aminoethyl sulfide ethyl silica), even with six other metal ions present at similar initial concentrations and a starting pH of 4.67 by adding just 50 mg of the material to a 45 mL solution.

Le but du travail est d'étudier la structure supramoléculaire de mélanges de tensioactif hydrophile, n-octyl-beta-glucoside (C8G1), et d'un extractant d'ions métalliques hydrophobe, le tributyl-n-phosphate (TBP), en présence d'eau, d'huile et de sels. Les systèmes classiques d'extraction ionique (composés d'une phase aqueuse, d'huile et d'extractant dont le but est d'extraire un soluté de la phase polaire sont passés en revue. L'aspect colloïdal et les transitions de phases que l'on retrouve dans ces systèmes sont souvent décrits singulièrement. Nous avons transposé l'approche « diagramme de phases » issue de la physico-chimie des systèmes moléculaires organisés à ces systèmes d'extractant afin d'orienter globalement l'analyse de ces systèmes complexes. La discussion est basée sur des considérations géométriques. Un modèle thermodynamique a été développé en considérant les contraintes d'empilement des ces extractants dans le film moléculaire formant les micelles inverses d'extractant dans l'huile. Ce modèle a permis de prédire la solubilité de l'eau au sein de ces micelles inverses ainsi que leurs tailles obtenues expérimentalement. Dans une deuxième partie, le comportement physico-chimique des phases aqueuses et organiques composées respectivement d'eau/C8G1 et de TBP/huile/eau ont été étudiées, en s'intéressant particulièrement aux effets de sels, par des techniques de diffusion de rayons X aux petits angles, diffusion dynamique de la lumière et de spectroscopie UV-visible. Dans la dernière partie la description complète de la microémulsion en faisant varier la balance hydrophile-hydrophobe du mélange C8G1 et TBP a été obtenue en combinant des mesures de diffusion de neutrons aux petits angles et d'analyse chimique (Karl-Fischer, Carbone Organique Total, ICP-OES…). Le comportement co-surfactant du TBP a été déterminé par comparaison aux co-surfactants classiques que sont les n-alcools (4<n<8). Les compositions de films moléculaires mixtes de C8G1/TBP et de C8G1/n-hexanol, obtenues expérimentalement, ont été confirmées par un modèle basé sur des paramètres géométriques moléculaires. Nous avons tenté d'exploiter les propriétés interfaciales de ces molécules pour le contrôle des cinétiques d'extraction liquide-liquide d'ion et la séparation d'ion « sans solvant » par flottation. / The presented work describes the supramolecular structure of mixtures of a hydrophilic surfactant n-octyl-beta-glucoside (C8G1), and the hydrophobic metal ion extractant tributylphosphate (TBP) in n-dodecane/water as well as in the presence of salts.In the first part, basic solvent extraction system, composed of water, oil and extractant, will be introduced. The focus, however, lies on the extraction of multivalent metal ions from the aqueous phase. During this extraction process and in the following thermodynamic equilibrium, aggregation and phase transition in supramolecular assemblies occur, which are already described in literature. Notably, these reports rest on individual studies and specific conclusions, while a general concept is still missing. We therefore suggest the use of generalized phase diagrams to present the physico-chemical behaviour of (amphiphilic) extractant systems. These phase diagrams facilitated the development of a thermodynamic model based on molecular geometry and packing of the extractant molecules in the oil phase. As a result, we are now in the position to predict size and water content of extractant aggregates and, thus, verify the experimental results by calculation.Consequently, the second part presents a systematic study of the aqueous and organic phase of water/C8G1 and water/oil/TBP mixtures. The focus lies on understanding the interaction between metal ions and both amphiphilic molecules by means of small angle x-ray scattering (SAXS), dynamic light scattering (DLS) and UV-Vis spectroscopy. We confirmed the assumption that extraction of metal ions is driven by TBP, while C8G1 remains passive. In the third and last part, microemulsions of C8G1, TBP, water (and salt) and n-dodecane are characterized by small angle neutron scattering (SANS), and chemical analytics (Karl Fischer, total organic carbon, ICP-OES,...). The co-surfactant behaviour of TBP was highlighted by comparison to the classical n-alcohol (4<n<8) co-surfactants. The compositions of the C8G1/TBP and C8G1/n-hexanol interfacial mixed films obtained experimentally were confirmed by the prediction of a model based on the molecular geometrical parameters. We furthermore exploit the interfacial properties of these molecules to control the kinetics of liquid-liquid extraction and attempt a “solvent free” ion separation using flotation.

Among the various heterogeneous catalytic reactions three way catalysis (TWC), catalytic combustion of hydrogen, water gas shift reaction (WGS) and preferential oxidation of CO (PROX) in the hydrogen rich stream are some of the important reactions receiving the attention presently. Three-way catalysis (TWC) involves simultaneous removal of the three pollutants (i.e., CO, NOx, and HCs) from the automobile exhaust. Catalytic combustion of hydrogen by oxygen or hydrogen-oxygen recombination reaction is an industrially important reaction. It has variety of application such as in sealed lead acid batteries and nuclear reactors. Water gas shift (WGS) reaction is of specific importance to produce hydrogen from carbonaceous material. PROX is an important step to further purify hydrogen produced form WGS. Hydrogen purified using PROX can be directly fed to polymer electrolyte membrane fuel cells. By and large, noble metals Pt, Pd, Rh, Ru and some of their alloys are dispersed on oxide or high surface area carbon are the active catalysts. An alternative approach can be to make Pt2+, Pd2+, Rh3+, Ru4+ ions substituted in reducible support such as CeO2, Ce1-xTixO2-δ and TiO2 to increase the dispersion and bring down the cost. In this thesis we have followed this new approach and show that noble metal ionic catalysts are superior to noble metal nano particles. In the 1st chapter we present an overview of heterogeneous catalysis and important heterogeneous catalytic reactions. Monolithic catalyst and various ways to coat catalysts for application have been reviewed. Metal-support interaction till date is also reviewed. In the 2nd chapter, synthesis of noble metal ionic catalysts by solution combustion method is described. Coating of washcoat and active catalyst phase over ceramic honeycomb by a new combustion method is described. Solution combustion reaction and characterization of the catalyst by x-ray diffraction, x-ray photoelectron spectroscopy, temperature programmed reduction and reaction is given. We have fabricated experimental systems to carryout catalytic reaction and in this chapter they have been presented. In the 3rd chapter, we report a new process of coating of active exhaust catalyst over -Al2O3 coated cordierite honeycomb. The process consists of (a) growing  -Al2O3 on cordierite by solution combustion of Al(NO3)3 and oxylyldihydrazide (ODH) at 600 0C. Active catalyst phase, Ce0.98Pd0.02O2- is coated on - Al2O3 coated cordierite again by combustion of ceric ammonium nitrate and ODH with 1.2  10-3 M PdCl2 solution at 500 0C. In this way a coat layer over cordierite ceramic has been achieved and catalyst has the active sites in the form of Pd2+ ions rather than Pd metal. Weight of the active catalyst can be varied from 0.02 to 2 wt% which is sufficient but can be loaded even up to 12 wt% by repeating dip dry combustion [1]. Adhesion of catalyst to cordierite surface is via oxide growth on oxide ceramic which is very strong. 100 % conversion of CO is achieved below 80 oC at a space velocity of 880 h-1. At much higher space velocity of 21000h-1, 100 % conversion is obtained below 245 oC. Activation energy for CO oxidation is 8.4 kcal/mol. At a space velocity of 880 h-1 100% NO conversion is attained below 185 oC and 100 % conversion of ‘HC’(C2H2) below 220 oC. At the same space velocity 3-way catalytic performance over Ce0.98Pd0.02O2- coated monolith shows 100% conversion of all the pollutants below 220 o C with 15% excess oxygen. Catalytic activity of cordierite honeycomb coated by this new coating method for the oxidation of major hydrocarbons in exhaust gas is discussed further in this chapter. ‘HC’ oxidation over the monolith catalyst is carried out with a mixture having the composition, 470 ppm of both propene and propane and 870 ppm of both ethylene and acetylene with the varying amount of O2. 3-way catalytic test is done by putting hydrocarbon mixture along with CO (10000ppm), NO (2000ppm) and O2 (15000ppm). Below 350 oC full conversion is achieved [2]. A comparison of the results shows that Ce1-xPdxO2-δ far superior to other catalysts. In this method, handling of nano material powder is avoided. In the 4th chapter we present a detailed study on the catalytic combustion of hydrogen by oxygen (hydrogen oxygen recombination reaction). Ever since Michel Faraday showed H2 + O2 recombination reaction over platinum metal plates, Pt metal has remained the only room temperature recombination catalyst. In search of an alternative catalyst, we discovered a new Pt free Ti0.99Pd0.01O2- compound which shows high rates of this reaction above 45 oC compared to Ce0.98Pt0.02O2-, Pt/Al2O3 and Pd/Al2O3. High rates of H2+O2 recombination over Pt and Pd ion respectively in CeO2 and TiO2 is due to the protonic type H2+ adsorption on Pt2+ or Pd2+ and dissociative chemisorption of O2 on the electron rich oxide ion vacancies [3]. In the case of Ce0.98Pt0.02O2-, H2/Pt ratio in a TPR experiment is ~2.3 at 0 oC. In the case of Ti0.99Pd0.01O2- also, H2 adsorption occurs below 0 oC and H2 / Pd ratio is ~2.2. Thus, more than 4-5 H atoms are adsorbed per metal ion. This is attributed to hydrogen spillover. H2 is known to be adsorbed as hydride ion (H-) over Pt, Pd, Rh, Ru, Os and Ir metals. Proton NMR studies of H2 adsorbed on Pd metal have shown upfield i.e. negative shift of 12 ppm with respect to TMS. We have studied proton NMR of Ti0.99Pd0.01O2- + H2 which show a downfield shift of 11.35 ppm confirming H+ or H2+ kind of species over Pd2+ ion in Ti0.99Pd0.01O2-. In Ce0.98Pt0.02O2- also H2 adsorption led to H2+ like species observed at 8 ppm and DFT calculations indeed showed H2+ kind species. H2+ is a precursor for dissociation and can readily induce O2 dissociation leading to high rates of recombination. In the 5th chapter we report water gas shift reaction (WGS) and preferential oxidation of CO (PROX) over Ti0.99Pt0.01O2-, Ce0.83Ti0.15Pt0.02O2- and Ce0.98Pt0.02O2-δ. The water gas shift reaction (WGS) is an important reaction to produce hydrogen. In this study, we have synthesized nano crystalline catalysts where Pt ion is substituted in the +2 state in TiO2, CeO2 and Ce1-xTixO2-δ. The catalysts have been characterized by X-ray diffraction and X-ray photoelectron spectroscopy (XPS) and it has been shown that Pt2+ ions in these reducible oxides of the form Ti0.99Pt0.01O2-, Ce0.83Ti0.15Pt0.02O2- and Ce0.98Pt0.02O2-δ are highly active. These catalysts were tested for the water gas shift reaction both in presence and absence of hydrogen. It is shown that Ti0.99Pt0.01O2- exhibits higher catalytic activity than Ce0.83Ti0.15Pt0.02O2- and Ce0.98Pt0.02O2-δ [4]. Further, experiments were conducted to determine the deactivation of these catalysts by performing the daily startup and shutdown of the reactor for over 24 hours. There was no sintering of Pt and no carbonate formation and, therefore, the catalyst did not deactivate even after prolonged reaction. There was no carbonate formation because of the highly acidic nature of Ce4+, Ti4+ ions in the catalysts. Further, PROX activity of these catalysts has been studied. Ce0.83Ti0.15Pt0.02O2- and Ce0.98Pt0.02O2-δ showed high activity, large operating temperature window and low working temperature proving them to be highly effective PROX catalysts. In the 6th chapter we study the electrocatalysis of formic acid electro-oxidation and simultaneously mapping the electronic states of the electrodes by X-ray photoelectron spectroscopy (XPS). Ionically dispersed platinum in Ce1-xPtxO2-δ and Ce1-x-yTiyPtxO2-δ is very active towards oxygen evolution and formic acid oxidation. Higher electro-catalytic activity of Pt2+ ions in CeO2 and Ce1-xTixO2 compared to Pt0 in Pt/C is due to Pt2+ ion interaction with the supports, CeO2 and Ce1-xTixO2 respectively [5]. Further, ionic platinum does not suffer from CO poisoning effect unlike Pt0 in Pt/C. Utilization of lattice oxygen from the electrodes during the reaction has been demonstrated. This lattice oxygen exchange is responsible to convert CO to CO2 in the lower potential region to remove CO poisoning effect. In 7th chapter we repeat our study on the noble metal ion reducible oxide interaction in Ce1-xPtxO2- and Ce1-xPdxO2- (x= 0.02) system by a novel electrochemical method combined with XPS. Working electrodes made of CeO2 and Ce0.98Pt0.02O2- mixed with 30% carbon are cycled between 0.0-1.2 V in potentio-static (chronoamperometry) and potentio-dynamic (cyclic voltametry) mode with reference to saturated calomel electrode (SCE). Reversible oxidation of Pt0 to Pt2+ and Pt4+ state due to the applied positive potential is coupled to simultaneous reversible reduction of Ce4+ to Ce3+ state. CeO2 reduces to CeO2-y (y= 0.35) after applying +1.2 V which is not reversible. But Ce0.98Pt0.02O2- reaches a steady state with Pt2+: Pt4+ in the ratio of 0.60: 0.40 and Ce4+: Ce3+ in the ratio of 0.55: 0.45 giving a composition Ce0.98Pt0.02O1.74 at 1.2 V which is reversible [6]. Composition of Pt ion substituted compound is reversible between Ce0.98Pt0.02O1.95 to Ce0.98Pt0.02O1.74 within the potential range of 0.0-1.2 V. Thus, Ce0.98Pt0.02O2- forms a stable electrode for oxidation of H2O to O2 unlike CeO2. A linear relation between oxidation of Pt2+ to Pt4+ with simultaneous reduction of Ce4+ to Ce3+ is observed demonstrating Pt-CeO2 metal support interaction is due to reversible Pt0/Pt2+/Pt4+ interaction with Ce4+/Ce3+ redox couple. Similar studies have been performed with Ce0.98Pd0.02O2- catalyst to show the redox coupling between Pd2+/Pd0 and Ce4+/Ce3+ redox couples. We expect similar redox coupling for Pd, Pt ions substituted TiO2, and Ce1-xTixO2. In the final chapter 8, a critical review and conclusion on the results presented in the thesis is presented. The combustion synthesized catalysts reported in this thesis stabilizes the Pt and Pd metals in their ionic state rather than zero valent metallic state. Thus, the catalysts are uniform solid catalysts. High activity and stability of these catalysts are shown to be due to the electronic interaction between noble metal ions and the reducible oxide. Redox couples Pt0/Pt2+, Pt2+/Pt4+ and Pd0/Pd2+ interact with Ce4+/Ce3+, Ti4+/Ti3+ couples such that metal is oxidized and the support is reduced. This has been established in the thesis by a combined use of electrochemistry and XPS thus solving a long standing problem of metal support interaction in catalysis. We hope that the results presented in the thesis is a worthwhile contribution to catalysis. (For mathematical equations pl refer pdf file.)

Alzheimer’s disease is an incurable neurodegenerative disorder linked to the amyloid β (Aβ) peptide, a 38-43 residue peptide. The detailed molecular disease mechanism(s) is (are) unknown, but oligomeric Aβ structures are proposed to be involved. In common for the papers in this thesis is interactions; interactions between Aβ(1-40) and selected molecules and metal ions. The purpose has been to find out more about the structural states that Aβ can adopt, in particular the β-sheet state, which probably is linked to the oligomeric structures. The methods used have been nuclear magnetic resonance (NMR), circular dichroism (CD) and fluorescence spectroscopy using Thioflavin T (ThT). Upon addition of SDS/LiDS detergent or Congo red (CR) to Aβ(1-40), the initial random coil/PII-helix state was transformed into β-sheet and, in the case of detergent, a final α-helical state. In contrast to SDS/LiDS and CR, the dimeric Affibody molecule locks monomeric Aβ(1-40) in a β-hairpin state. It was found that by truncating the flexible N-terminal end of the Affibody molecule its affinity to Aβ was improved. The aggregation of Aβ(1-40) was further studied in the presence of a β-cyclodextrin dimer by a kinetic assay using ThT. Although having a weak dissociation constant in the millimolar range, the β-cyclodextrin dimer modified the aggregation pathways of Aβ. Finally Aβ(1-40) was studied in presence of Cu2+ and Zn2+ at physiological and low pH. Cu2+ was observed to maintain its specific binding to Aβ when decreasing the pH to 5.5 while Zn2+ behaved differently. This could be of importance in the Alzheimer’s disease brain in which the environment can become acidic due to inflammation.        In conclusion the results show that Aβ(1-40) is very sensitive to its environment, responding by adopting different conformations and aggregating in aqueous solutions. The β-sheet state is induced by varying molecules with different properties, properties that govern the final Aβ state. / At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 4: Manuscript. Paper 5: Manuscript.

La caractérisation des propriétés électriques et diélectriques des membranes d’UF et de NF constitue une étape essentielle pour la compréhension de leurs performances de filtration. Une nouvelle approche a été développée pour déterminer les propriétés diélectriques d’une membrane de NF par spectroscopie d’impédance. Celle-ci repose sur l’isolement de la couche active du support membranaire et sur l’utilisation de mercure comme matériau conducteur, ce qui nous a permis de prouver que la constante diélectrique de la solution à l’intérieur des nanopores est inférieure à celle de la solution externe. Deux configurations de cellule (fibres immergées dans la solution d’étude ou fibres noyées dans un gel isolant) ont été étudiées pour la réalisation de mesures électrocinétiques tangentielles sur fibres creuses et la solution autour des fibres s’est avérée influencer à la fois le courant d’écoulement et la conductance électrique de la cellule. De plus, la contribution importante du corps poreux des fibres au courant d’écoulement ne permet pas de convertir cette grandeur en potentiel zêta luminal. Les propriétés intéressantes de ces membranes ont finalement été mises à profit pour décontaminer des solutions contenant des ions métalliques. Les performances de dépollution, en termes de rétention des polluants et d’impact écotoxicologique, ont été étudiées sur des solutions synthétiques et un rejet issu de l’industrie du traitement de surface. Bien que les performances de rétention aient été remarquables, la toxicité de l’effluent réel n’a pu être totalement annihilée. Une étude approfondie de la rétention des polluants non métalliques s’avère donc nécessaire. / The characterization of electrical and dielectric properties of UF and NF membranes is an essential step to understand their filtration performance. A new approach has been developed to determine the dielectric properties of a NF membrane by impedance spectroscopy. This is based on the isolation of the membrane active layer and the use of mercury as conductive material, which allowed us to prove that the dielectric constant of the solution inside nanopores is lower than that of the external solution. Two cell configurations (fibers immersed in the solution or fibers embedded in an insulating gel) were investigated for the implementation of tangential electrokinetic measurements with hollow fibers and the solution around the fibers was found to influence both streaming current and cell electrical conductance. Moreover, the important contribution of the fiber porous body to the streaming current does not allow the conversion of the latter to luminal zeta potential. The advantageous properties of these membranes were finally used to decontaminate solutions containing metal ions. Decontamination performances in terms of both pollutant retention and ecotoxicological impact were studied on synthetic solutions and a discharge water from surface treatment industry. Although retention performances were remarkable, the toxicity of the real effluent could not be totally annihilated. A thorough study of the retention of non-metallic contaminants is thus required.

Metal ion contamination in surface and ground water is a major threat as it has a direct implication on the health of terrestrial and aquatic flora and fauna. Lead (Pb2+), mercury (Hg2+), cadmium (Cd2+), nickel (Ni2+), copper (Cu2+) and cobalt (Co2+) are few of these metal ions which are classified under the high risk category. Of these, lead and mercury are of greater concern, as even nanomolar concentrations can be lethal, as they can be bio-accumulated and result in physiological as well as neurological disorders. In Asian countries like India and China, heavy metal pollution is more prevalent, as a consequence of poor governmental policies or ineffective or inadequate measures to combat this problem. In recent times, the monitoring and assessment of water pollution is a critical area of study, as it has a direct implication for its prevention and control. The major techniques used for metal ion detection are atomic absorption spectroscopy (AAS), X-ray fluorescence, ion chromatography, neutron activation, etc. Alternatively, the electrochemical, optical and electrical methods provide a platform for the fabrication of portable devices, which can facilitate the on-site analysis of samples in a rapid and cost-effective manner. This has led to a new field of research called chemical sensors or chemo sensory devices. The main aim of this study is to develop various chemosensory materials and test their response towards metal ion sensing. In this study, electroactive polymers have been synthesized for various sensor applications. The focus has been to design synthesize and test various functionalized electroactive polymers (FEAP) for the development of electrochemical, optical and chemoresistive sensors. Electroactive polymers like polyaniline, polypyrrole, polypyrrole grafted to exfoliated graphite oxide and dipyrromethene conjugated with p-(phenylene vinylene) have been synthesized and evaluated after functionalizing with metal coordinating ligands. These metal coordinating ligands were selected, in order to enhance their metal uptake capacity. Various metal ligands like imidazole, tertiary amine group, iminodiacetic acid, and dipyrromethene incorporated either in the polymer backbone or as a part of the backbone have been chosen for the metal binding. These functionalized electroactive polymers (FEAP) served as active material for metal ion sensing. The present investigation is subdivided into three sections. The first part includes design and chemical synthesis of the functionalized polymers by a series of organic reactions. The synthesis has been followed up by characterization using spectroscopic methods including NMR, FTIR, GCMS and Mass spectrometry. In the second part of the investigation, the synthesized polymer has been characterized for the changes in electronic, electric and optical properties after interaction with the selected metal ions. For this, the FEAP is allowed to interact with various metal ions and the changes in the relevant properties have been measured. This includes the study of changes in the conductivity, electronic properties like absorption or emission of the polymer, changes in the redox properties, etc. The third phase of investigation deals with the fabrication of the devices using the active FEAP. The sensor devices comprised of either films, or electrode modified with FEAP or solution of the FEAP, in combination with an appropriate technique has been used for the sensing. The major objectives are enumerated below 1. Functionalzation of polyaniline with imidazole functional group to get imidazole functionalized polyaniline (IMPANI) and study of the electronic, electrical and optical properties of the same. 2. Preparation of films of IMPANI and study of the change in conductivity of the film upon interaction with various metal ions, namely Cu2+, Co2+ and Ni2+ in their chloride form. 3. Synthesis of amine functionalized aniline monomer and chemical graft polymerization onto exfoliated graphite oxide as a substrate to synthesise the amine funtionalised polyaniline grafted to exfoliated graphite oxide (EGAMPANI). Modification of the carbon paste electrode (CPE) with EGAMPANI and study of the electrode characteristic. 4. Study of the electrode properties of EGAMPANI modified carbon paste electrode. 5. Evaluation of the EGAMPANI modified carbon paste electrode as a multi-elemental voltammetric sensor for Pb2+, Hg2+ and Cd2+ in aqueous system. 6. Functionalization of polypyrrole with iminodiacetic acid and characterization of the polymer to synthesis iminodiacetic acid functionalized polypyrrole (IDA-PPy). 7. Modification of the CPE with IDA-PPy by drop casting method and evaluation of the Pb2+ sensing properties. 8. Study of the effect of other metal ions say Hg2+, Co2+, Ni2+, Zn2+, Cu2+ and Cd2+ on the anodic stripping current of Pb2+ using EGAMPANI modified CPE. 9. Synthesis of dipyrromethene-p-(phenylene vinylene) conjugated polymer for heavy metal ion sensing. 10. Study of the changes in the optical absorption and emission properties of the polymer in THF and evaluation of the change in these optical properties upon interaction with the metal ions as analyte. The salient findings of the research work are highlighted as follows, In the first synthesis, aniline has been functionalized with imidazole group and this monomer has been chemical oxidatively polymerized to obtain imidazole functionalized polyaniline (IMPANI). The synthesized polymer possesses a nano-spherical structure, as confirmed from the morphological characterisation using scanning electron microscopy. The IMPANI has been interacted with a representative metal ion, copper (II) chloride, and the copper complexed polymer (Cu-IMPANI) has been subjected to various studies. The coordination of copper with IMPANI results in an increase of molecular weight of the polymer as a result of aggregation, as observed from dynamic light scattering measurements. Apart from this, a significant finding is the decrease of the pH of the system after copper ion coordination attesting to the generation of a secondary hydrochloride ion during the coordination of the copper to the imidazole side chain. This is further confirmed by an increase in conductivity of the Cu-IMPANI compared to IMPANI, measured using the four-probe technique. The increase of conductivity due to copper coordination is one order of magnitude higher. The films which have been prepared from IMPANI and Cu-IMPANI exhibit different morphology. The Cu-IMPANI film prepared by prior co-ordination of Cu ion with IMPANI powder shows a flaky structure, which is not preferable for the conductivity measurements, as a consequence of discontinuity in the medium. To overcome this problem, IMPANI films were initially prepared and then interacted with copper ions for a desired duration, before measurement of the conductivity. This latter procedure enabled the preparation of smooth films for the development of chemoresistive sensors. In continuation of the initial study highlighted above, IMPANI films of thickness 0.02 ± 0.001 mm have been prepared using IMPANI and PANI in DMPU in the ratio of 7:3 by mass. After exposure of the films with respective metal chlorides, such as Ni2+, Co2+ and Cu2+, a change in conductivity is observed in the concentration range of 10-2 to 1 M of metal chlorides. The sensor response may be arranged in the sequence: Ni2+ > Cu2+ > Co2+ at 1M concentration. On the contrary, films prepared from PANI-EB under identical conditions do not exhibit any appreciable change in conductivity. The optimum exposure time is determined to be 10 min for a maximum change in conductivity, after exposure to the chosen metal ions. In the second system taken up for investigation, a tertiary amine containing polyaniline (AMPANI) has been grafted to exfoliated graphite oxide. The amine containing polyaniline grafted to exfoliated graphite oxide (EGAMPANI) has been characterised for structural, morphological and elemental composition. The grafting percentage has been determined to be 7 % by weight of AMPANI on the EGO surface. The synthesized EGAMPANI (5 weight %) has been used to modify carbon paste electrode (CPE) for electrochemical sensor studies. Based on the differential pulse anodic stripping voltammetric studies, the electrochemical response may be arranged in the following sequence: Pb 2+>Cd 2+>Hg 2+ The minimum detection levels obtained are 5×10-6, 5×10-7, and 1.0×10-7 M for Hg2+, Cd2+ and Pb2+ ions respectively. In the next study, an iminodiacetic acid functionalized polypyrrole (IDA-PPy) has been synthesized and characterised for its elemental and structural properties. This has been further used to modify the CPE by drop casting method and used for the specific detection of Pb2+ in acetate buffer. Various parameters governing the electrode performance such as concentration of depositing solution, pH of depositing solution, deposition potential, deposition time, and scan rate, have been optimized to achieve maximum performance and found to be 20 μl, 4.5, -1.3 V, 11 min, 8 mV s-1 respectively for the chosen parameters. Additionally, the influence of other heavy metal ions on the lead response has been studied and it is observed that Co, Cu and Cd ions are found to be interfering. Further, the response of Cd, Co, Cu, Hg, Ni and Zn on IDA-PPy functionalized electrode has been evaluated. The selectivity of IDA-PPy modified electrode for Pb2+ is observed in the concentration range of 1 × 10-7 M and below. The IDA-PPy modified CPE shows a linear correlation for Pb2+ concentration in the range from 1×10-6 to 5×10-9 M and with a lowest limit of detection (LLOD) of 9.6×10-9 M concentration. The efficacy of the electrode for lead sensing has also been evaluated with an industrial effluent sample obtained from a lead battery manufacturing unit. The fourth synthesis pertained to the development of an optical sensor for Fe2+, and Co2+ ions. For this, dipyrromethene as a metal coordinating ligand in conjugation with p-phenylenevinylene has been synthesized and tested for its structural as well as optical properties. It is observed that the polymer shows three absorptions, namely at 294 nm, 357 nm and a major absorption observed as a broad band ranging from 484 to 670 nm. The emission spectrum of the polymer excited at 357 nm shows a characteristic blue emission with a maximum intensity centered at 425 nm. The emission quenching in the presence of various metal ions have been tested and are found to be quenched in presence of Fe2+ and Co2+ ions. All the other metal ions tested namely, Cr3+, Cu2+, and Zn2+ are not found to exhibit any change in the emission spectra below the concentration of 1 × 10-4 M. The linear correlation of the emission intensity with the concentration of the Co2+ and Fe2+ ions has been determined using Stern-Volmer plot. For Co2+ the Stern-Volmer regime is observed from 1×10-4 to 9×10-4 M concentration and the quenching constant Ksv is determined to be 8.67 ×103 M-1. For Fe2+, the linearity is found to be in the regime of 1×10-5 to 9×10-5 M and the quenching constant Ksv is determined to be 7.90 × 103 M-1. In conclusion, different electroactive polymers functionalized with metal coordinating ligands have been synthesized, characterised and evaluated for metal sensing applications. Techniques like electrochemical, optical and conductivity have been used to characterise the response of these FEAP towards metal sensing. It is can be concluded that the electrochemical sensors are more reliable for sensing especially at very low concentrations of metal ions such as Pb, Cd and other techniques like optical and conductimetric are good for detecting metal ions namely Fe, Co, Ni, Cu. The selectivity towards the metal ions is a function of the metal chelating ligand and the extent of sensitivity is dependent upon the technique employed.

No description available.

I värme- och kraftvärmeverk förbränns olika typer av bränslen för produktion av el och fjärrvärme. Vid förbränningen bildas rökgaser som innehåller föroreningar, till exempel tungmetaller, från bränslet. Anläggningarna har ofta krav på utsläpp både via rökgaserna och avloppsvatten. Rökgaserna renas därmed genom olika tekniker var av en vanlig teknik är rökgaskondensering. Vid rökgaskondenseringen bildas en vätska, kallad rökgaskondensat, som delvis innehåller tungmetaller från bränslet. Rökgaskondensatet måste renas innan det kan lämna anläggningen och det görs bland annat med tungmetalljonbytare. Jonbytarmassan i tungmetalljonbytarkolonnerna behöver bytas ungefär två gånger per driftsäsong då den inte längre kan binda mer tungmetaller. Detta är en kostnad för värme- och kraftvärmeverken som de vill minimera. I denna studie undersöktes om lokal provtagning och analys på ett kraftvärmeverk av ett antal utvalda tungmetaller i rökgaskondensat är en bra metod för att optimering av reningssteget med tungmetalljonbytare. Samt om detta kan säkerställa att miljökraven för tungmetaller i det renade rökgaskondensatet uppfylls. Med optimering avses att jonbytarmassornas fulla kapacitet utnyttjas, d.v.s. att byten av jonbytarmassor kan reduceras utan att riskera otillåtna halter av tungmetaller i de renade rökgaskondensatet till följd av att jonbytarmassorna använts för länge. Även tiden som behöver avsättas för lokal provtagning och analys dokumenterades. I dagsläget sker analyser hos ackrediterade laboratorium där det tar drygt två veckor att få resultatet och under väntetiden kan mycket på anläggningen förändras. En verifiering av resultaten från studien gjordes mot resultat från ett sådant. I denna studie undersöktes lokal provtagning och analys med mätinstrumentet FREEDD som bygger på tekniken kvartskristall mikrobalans (QCM-teknik). Andra alternativ för lokal analys har inte undersökts här.  Resultatet visade att det i dagsläget är svårt att med lokal provtagning optimera reningssteget med jonbytarmassor samt kontrollera utsläppen av tungmetaller via det renade rökgaskondensatet. Korrigeringar hos mätinstrumentet och provpunkterna behöver göras för att få pålitligt resultat. Tiden som behöver avsättas för provtagning och analys beror på vilken metall som ska analyseras då tiden för preparering av prov varierar. Men om det kan möjliggöra att anläggningarna kan använda jonbytarmassorna längre samt får kontroll på utsläppen via det renade rökgaskondensatet kan det vara lönsamt att avvara den tiden. / In heating and combined heat and power plants, different types of fuels are burned to produce electricity and district heating. During the combustion flue gases containing pollutants, such as heavy metals, are formed from the flue. The plants have requirements for low emissions, both from the flue gases and the wastewater. The flue gases are purified by various techniques and a common technique is flue gas condensation. During the flue gas condensation, a liquid called flue gas condensate, is formed, which partly contains heavy metals from the flue. The flue gas condensate must be cleaned before it can leave the plant. A step in the purification of the flue gas condensate is usually heavy metal ion-exchanger. The ion-exchange mass in the heavy metal ion-exchange columns needs to be changed approximately twice per operating season as it no longer has room to bind more heavy metals. This is an expensive cost for the heating and combined heat and power plants that they want to minimize. This study investigated whether local sampling and analysis at a cogeneration plant of a number selected heavy metals in flue gas condensate is a good method for optimizing the purifications step with heavy metal ion-exchangers. And if this can ensure that the environmental requirements for the heavy metals in the purified flue gas condensate are met. Optimization means that the full capacity of the ion-exchange masses is utilized, i.e. that the exchange of ion-exchange masses can be reduced without risking unauthorized levels of heavy metals in the purified flue gas condensate as a result of the ion exchange masses being used for too long.  The time needed for local sampling and analysis was also documented. At present, analyzes are done at accredited laboratories where it takes over two weeks to get the result and during that time much can be changes at the plant. A verification of the result of the study was also made against the result of an accredited laboratory. In this study, local analysis was made with the measuring instrument FREEDD which is based on quartz crystal microbalance (QCM-technology). Other options for local sampling and analysis have not been investigated. The result showed that, in the present, it is difficult to optimize the purification step with ion-exchange masses and check emissions of heavy metals with the purified flue gas condensate. To obtain reliable result, corrections to the measuring instrument and test points need to be made. The time that needs to be set aside for sampling and analysis depends on the metal, as the time for sample preparation varies.  But if it can enable the plants to use the ion-exchange masses longer and gain control of the emissions of heavy metals with the purified flue gas condensate, it can be profitable to save that time.

No description available.

This report summarizes the work on the cloning, expression, and purification of PerR, a metal sensing regulator from Saccharopolyspora erythraea and the subsequent characterization using small angle X-ray scattering and other biochemical methods. The report aims to provide an insight into prokaryotic metal homeostasis, provide a better understanding of how PerR works and provide valuable information for the continued work on the crystallization of PerR.