Polypyrrole modified with sulfated β-cyclodextrin: characterization and application in the sensing of viologens

In this thesis a conducting polypyrrole (ppy) matrix doped with the anionic sulfated β-cyclodextrin (sβ-CD) was electrosynthesized and characterized. This modified polymer, ppysβ-CD, was used as a sensor for the detection of three compounds, methyl, ethyl and benzyl viologen. Methyl viologen is commonly known as paraquat and it is one of the most commonly used herbicides worldwide. The sβ-CD was permanently immobilized within the ppy backbone during the potentiostatic growth of the polymer. The incorporation of the macrocycle was confirmed by means of cyclic voltammetry (CV), quartz crystal microbalance (QCM) and differential scanning calorimetry (DSC). The large dopant was found not to significantly alter certain properties of the polymer such as diffusion of a probe analyte to the surface and charge transfer rate constant. The cyclodextrin modified polymer was shown to have cation exchange properties and this characteristic was used towards the sensing of the three electroactive viologen compounds. The three viologens were detected by means of differential pulse voltammetry (DPV), while for methyl viologen constant potential amperometry (CPA) experiments were also performed. These techniques gave a good linear response for the current measured at the polymer surface, as a function of the viologen concentration. Detection limits of 1.00 x 10-4 M for ethyl viologen (DPV), 2.50 x 10-5 M for benzyl viologen (DPV) and 1.56 x 10-5 M for methyl viologen (CPA) were measured experimentally. A detailed analysis was performed on the interaction of the sβ-CD with methyl, ethyl and benzyl viologen, using both electrochemistry (CV and RDV) and spectroscopy (UV-Vis, 1H NMR). It was established that a 1:1 interaction occurs between the sβ-CD and each of the viologens. The formation of inclusion complexes was verified not to occur. The generation of association complexes was instead suggested. These complexes result from an ion pairing interaction between the sβ-CD and the viologens, either in their dication state or in their radical state

Economic and environmental assessment of thermal insulation. A case study in the Italian context

Abstract An analysis of the state of the art has shown how current European policy underpins the importance of assessing the impact of different energy efficiency strategies during the life cycle of buildings. In this study a framework is developed for the identification of the optimal material to be used to achieve the highest level of energy efficiency in building retrofits, taking into account environmental and economic elements and comparing different scenarios. For each of these scenarios the Life Cycle Cost Analysis was applied together with related environmental analysis in terms of the production of CO2. The research was applied to an industrial factory in Italy. Results showed that, among ten material with different origin, namely plant, animal, mineral and fossil origin, the optimal thickness varied between 0.023 m of the line fiber, and 0.082 m of the rock wool. From the economic point of view, saving was between 1.58 €/m2 with the linen fiber, and 9.63 €/m2 with the rock wool. Finally, considering the environmental aspect, savings in terms of CO2 was possible only for three of the ten materials, namely cork, sheep wool and fiber glass, respectively equal to 0.14 Kg/m2, 0.65 Kg/m2 and 0.34 Kg/m2. The study has important implications mainly regarding the issue of energy efficiency. Specifically, the opportunity to analyse and compare economic and environmental aspects of a series of alternative materials to improve energy efficiency may provide stakeholders with calculated and objective input for the support of sustainable actions. Sum up, this research has identified a "result oriented" methodology comparing traditional and sustainable materials and measuring the benefits from the correct insulation of a building. These benefits are mainly of an economic and environmental nature and, in this regard, the study helps to strengthen the leadership of the EU for a sustainable use of natural resources within an efficient bioeconomy, essential to achieve Sustainable Development Goals

Solar Photovoltaic Optimal Tilt Angles in Public Building

Abstract The reduction of the consumption of fossil fuels that cause climate change and the encouragement of the use of cleaner renewable sources, appears to be a fundamental objective for achieving the climate aims agreed in Paris. Moreover, the sustainability of the implementation of solutions for energy efficiency in public administration buildings has played a fundamental role in recent years, strengthened also by the regulatory context of energy and environmental policies of European countries. The research fits into this context and it intends to promote a methodology that is able to evaluate the economic and environmental performance of a photovoltaic system applied in a school located in Italy when only the roof inclination angle changes. The economic and environmental performances are evaluated respectively through Life Cycle Cost Analysis and the avoided CO2 emissions. The results show that although the case study does not present the optimal roof inclination angle, there are economic and environmental advantages. Furthermore, the research notes that, considering the characteristics of the photovoltaic system concerned, the optimal roof inclination angle is equal to 40 degrees from an economic and environmental point of view. This methodology could easily support the decision-making process of designers and administrators to make the energy upgrading choices for the promotion of renewable sources. It was applied to a case study, that is a school located in Italy, in the Abruzzo region, in the province of L'Aquila, but it could be easily replicated in other existing public buildings in different locations

Sustainability of Biogas Based Projects: Technical and Economic Analysis

Biomethane is a renewable gas produced by the transformation of organic matter. It can lead to emissions reduction and it contributes to increasing methane production. Incentive policies favour its development and for this reason, the objective of this paper is to investigate the economic performance of biomethane plants and their process monitoring by electronic systems. Mathematical modeling is here presented to study the financial feasibility of biomethane plants in function of the size (100 m3/h, 250 m3/h, 500 m3/h, 1000 m3/h), the feedstock used (organic fraction of municipal solid waste and a mixture of 30% maize and 70% manure residues on a weight basic) and the destination for final use (fed into the grid, destined for cogeneration or sold as vehicle fuel). From an economic point of view the plant performance is studied by economic tools as Net Present Value and Discounted Payback Time and the uncertainty analysis is implemented using Monte Carlo method. Moreover, from a technical point of view, process monitoring is analyzed to understand what happens in a biomethane plant and help to maintain a stable process. The results show that the profitability of biomethane plants is verified in several scenarios presenting losses only if subsidies were removed

Electrostatic interactions between viologens and a sulfated β-cyclodextrin; formation of insoluble aggregates with benzyl viologens

Viologens are important compounds and are used in several applications. The interactions between viologens and a negatively charged cyclodextrin, sulfated β-cyclodextrin (sβ-CD), were studied using electrochemistry, 1H NMR and UV–Vis spectroscopy. Weak electrostatic interactions were found between the dicationic viologens (V2+) and the anionic cyclodextrin. The diffusion coefficient of ethyl viologen (EV2+) was reduced from 5.33 × 10−6 to 1.98 × 10−6 cm2 s−1 with an excess of sβ-CD. More significant electrostatic interactions were found between benzyl viologen (BV2+) and sβ-CD. The H atoms in the benzyl substituent, which appear as a singlet in the NMR experiment, were split into a multiplet in the presence of the sβ-CD, while the chemical shift of the H in the β position to the quaternary nitrogen, was shifted by 0.17 ppm in the presence of sβ-CD. Greater electrostatic interactions were evident between the benzyl radical cation (BV·+) and sβ-CD. Using cyclic voltammetry, reduction of the radical cation to the neutral benzyl viologen (BV0) was shifted by 230 mV to a lower potential, indicating that the reduction of the radical cation becomes considerably more difficult in the presence of sβ-CD. This was attributed to the formation of an insoluble BV·+:sβ-CD aggregate, which was also evident in rotating disc voltammetry, where the typical diffusion-limited currents were not observed and in spectroelectrochemistry experiments, where the deposition of the aggregate at the ITO electrode increased the absorbance of the radical species

Sustainability of Biogas Based Projects: Technical and Economic Analysis

Biomethane is a renewable gas produced by the transformation of organic matter. It can lead to emissions reduction and it contributes to increasing methane production. Incentive policies favour its development and for this reason, the objective of this paper is to investigate the economic performance of biomethane plants and their process monitoring by electronic systems. Mathematical modeling is here presented to study the financial feasibility of biomethane plants in function of the size (100 m3/h, 250 m3/h, 500 m3/h, 1000 m3/h), the feedstock used (organic fraction of municipal solid waste and a mixture of 30% maize and 70% manure residues on a weight basic) and the destination for final use (fed into the grid, destined for cogeneration or sold as vehicle fuel). From an economic point of view the plant performance is studied by economic tools as Net Present Value and Discounted Payback Time and the uncertainty analysis is implemented using Monte Carlo method. Moreover, from a technical point of view, process monitoring is analyzed to understand what happens in a biomethane plant and help to maintain a stable process. The results show that the profitability of biomethane plants is verified in several scenarios presenting losses only if subsidies were removed

Polypyrrole modified with sulfated β-cyclodextrin: characterization and application in the sensing of viologens

In this thesis a conducting polypyrrole (ppy) matrix doped with the anionic sulfated β-cyclodextrin (sβ-CD) was electrosynthesized and characterized. This modified polymer, ppysβ-CD, was used as a sensor for the detection of three compounds, methyl, ethyl and benzyl viologen. Methyl viologen is commonly known as paraquat and it is one of the most commonly used herbicides worldwide. The sβ-CD was permanently immobilized within the ppy backbone during the potentiostatic growth of the polymer. The incorporation of the macrocycle was confirmed by means of cyclic voltammetry (CV), quartz crystal microbalance (QCM) and differential scanning calorimetry (DSC). The large dopant was found not to significantly alter certain properties of the polymer such as diffusion of a probe analyte to the surface and charge transfer rate constant. The cyclodextrin modified polymer was shown to have cation exchange properties and this characteristic was used towards the sensing of the three electroactive viologen compounds. The three viologens were detected by means of differential pulse voltammetry (DPV), while for methyl viologen constant potential amperometry (CPA) experiments were also performed. These techniques gave a good linear response for the current measured at the polymer surface, as a function of the viologen concentration. Detection limits of 1.00 x 10-4 M for ethyl viologen (DPV), 2.50 x 10-5 M for benzyl viologen (DPV) and 1.56 x 10-5 M for methyl viologen (CPA) were measured experimentally. A detailed analysis was performed on the interaction of the sβ-CD with methyl, ethyl and benzyl viologen, using both electrochemistry (CV and RDV) and spectroscopy (UV-Vis, 1H NMR). It was established that a 1:1 interaction occurs between the sβ-CD and each of the viologens. The formation of inclusion complexes was verified not to occur. The generation of association complexes was instead suggested. These complexes result from an ion pairing interaction between the sβ-CD and the viologens, either in their dication state or in their radical state

Polypyrrole modified with sulfated β-cyclodextrin: characterization and application in the sensing of viologens

In this thesis a conducting polypyrrole (ppy) matrix doped with the anionic sulfated β-cyclodextrin (sβ-CD) was electrosynthesized and characterized. This modified polymer, ppysβ-CD, was used as a sensor for the detection of three compounds, methyl, ethyl and benzyl viologen. Methyl viologen is commonly known as paraquat and it is one of the most commonly used herbicides worldwide. The sβ-CD was permanently immobilized within the ppy backbone during the potentiostatic growth of the polymer. The incorporation of the macrocycle was confirmed by means of cyclic voltammetry (CV), quartz crystal microbalance (QCM) and differential scanning calorimetry (DSC). The large dopant was found not to significantly alter certain properties of the polymer such as diffusion of a probe analyte to the surface and charge transfer rate constant. The cyclodextrin modified polymer was shown to have cation exchange properties and this characteristic was used towards the sensing of the three electroactive viologen compounds. The three viologens were detected by means of differential pulse voltammetry (DPV), while for methyl viologen constant potential amperometry (CPA) experiments were also performed. These techniques gave a good linear response for the current measured at the polymer surface, as a function of the viologen concentration. Detection limits of 1.00 x 10-4 M for ethyl viologen (DPV), 2.50 x 10-5 M for benzyl viologen (DPV) and 1.56 x 10-5 M for methyl viologen (CPA) were measured experimentally. A detailed analysis was performed on the interaction of the sβ-CD with methyl, ethyl and benzyl viologen, using both electrochemistry (CV and RDV) and spectroscopy (UV-Vis, 1H NMR). It was established that a 1:1 interaction occurs between the sβ-CD and each of the viologens. The formation of inclusion complexes was verified not to occur. The generation of association complexes was instead suggested. These complexes result from an ion pairing interaction between the sβ-CD and the viologens, either in their dication state or in their radical state

Polypyrrole modified with sulfated β-cyclodextrin: characterization and application in the sensing of viologens

In this thesis a conducting polypyrrole (ppy) matrix doped with the anionic sulfated β-cyclodextrin (sβ-CD) was electrosynthesized and characterized. This modified polymer, ppysβ-CD, was used as a sensor for the detection of three compounds, methyl, ethyl and benzyl viologen. Methyl viologen is commonly known as paraquat and it is one of the most commonly used herbicides worldwide. The sβ-CD was permanently immobilized within the ppy backbone during the potentiostatic growth of the polymer. The incorporation of the macrocycle was confirmed by means of cyclic voltammetry (CV), quartz crystal microbalance (QCM) and differential scanning calorimetry (DSC). The large dopant was found not to significantly alter certain properties of the polymer such as diffusion of a probe analyte to the surface and charge transfer rate constant. The cyclodextrin modified polymer was shown to have cation exchange properties and this characteristic was used towards the sensing of the three electroactive viologen compounds. The three viologens were detected by means of differential pulse voltammetry (DPV), while for methyl viologen constant potential amperometry (CPA) experiments were also performed. These techniques gave a good linear response for the current measured at the polymer surface, as a function of the viologen concentration. Detection limits of 1.00 x 10-4 M for ethyl viologen (DPV), 2.50 x 10-5 M for benzyl viologen (DPV) and 1.56 x 10-5 M for methyl viologen (CPA) were measured experimentally. A detailed analysis was performed on the interaction of the sβ-CD with methyl, ethyl and benzyl viologen, using both electrochemistry (CV and RDV) and spectroscopy (UV-Vis, 1H NMR). It was established that a 1:1 interaction occurs between the sβ-CD and each of the viologens. The formation of inclusion complexes was verified not to occur. The generation of association complexes was instead suggested. These complexes result from an ion pairing interaction between the sβ-CD and the viologens, either in their dication state or in their radical state

Polypyrrole modified with sulfated β-cyclodextrin: characterization and application in the sensing of viologens

In this thesis a conducting polypyrrole (ppy) matrix doped with the anionic sulfated β-cyclodextrin (sβ-CD) was electrosynthesized and characterized. This modified polymer, ppysβ-CD, was used as a sensor for the detection of three compounds, methyl, ethyl and benzyl viologen. Methyl viologen is commonly known as paraquat and it is one of the most commonly used herbicides worldwide. The sβ-CD was permanently immobilized within the ppy backbone during the potentiostatic growth of the polymer. The incorporation of the macrocycle was confirmed by means of cyclic voltammetry (CV), quartz crystal microbalance (QCM) and differential scanning calorimetry (DSC). The large dopant was found not to significantly alter certain properties of the polymer such as diffusion of a probe analyte to the surface and charge transfer rate constant. The cyclodextrin modified polymer was shown to have cation exchange properties and this characteristic was used towards the sensing of the three electroactive viologen compounds. The three viologens were detected by means of differential pulse voltammetry (DPV), while for methyl viologen constant potential amperometry (CPA) experiments were also performed. These techniques gave a good linear response for the current measured at the polymer surface, as a function of the viologen concentration. Detection limits of 1.00 x 10-4 M for ethyl viologen (DPV), 2.50 x 10-5 M for benzyl viologen (DPV) and 1.56 x 10-5 M for methyl viologen (CPA) were measured experimentally. A detailed analysis was performed on the interaction of the sβ-CD with methyl, ethyl and benzyl viologen, using both electrochemistry (CV and RDV) and spectroscopy (UV-Vis, 1H NMR). It was established that a 1:1 interaction occurs between the sβ-CD and each of the viologens. The formation of inclusion complexes was verified not to occur. The generation of association complexes was instead suggested. These complexes result from an ion pairing interaction between the sβ-CD and the viologens, either in their dication state or in their radical state