Dissertations / Theses on the topic 'Materiali funzionali'
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Cocchi, Valentina <1986>. "Polimeri tiofenici funzionali e loro applicazioni nel fotovoltaico." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2014. http://amsdottorato.unibo.it/6413/1/cocchi_valentina_tesi.pdf.
Full textRecently, more and more attention has been directed to the application of organic dyes as light absorbers for the preparation of active polymeric layers in organic photovoltaic (OPV) solar cells. Organic dyes usually present a strong light-harvesting ability, thanks to their high extinction coefficient, and useful photophysical properties and are good candidates for the improvement of OPV solar cells photocurrent. In this work is described a new strategy for the incorporation of a porphyrin derivatives in the side chain of a polythiophene copolymers. The studies carried out have shown that poly[3-(6-bromohexyl)thiophene] can be variously functionalized with hydroxytetraphenylporphyrin [TPPOH] to obtain copolymers used as p-donors materials for the realization of the photoactive blend in OPV. The copolymers poly[3-(6-bromohexyl)thiophene-co-(3-[5-(4-phenoxy)-10,15,20-triphenylporphyrinyl]hexyl thiophene] P[T6Br-co-T6TPP] prepared at different chromophore contents were obtained through both not-regiospecific and regiospecific methods, with the aim to compare the properties and verify whether the macromolecular structure that presents the same regiochemistry of substitution along the system, promote the transport of electric charge, improving the efficiency. Was also carried out a further comparison between these derivatives and similar compounds P[T6H-co-T6TPP] which doesn’t link the bromine atom in the side chain, with the purpose to verify if the absence of the reactive group may improve the thermal and chemical stability of the polymer films, acting on the performance of photovoltaic devices. All the soluble and easily filmable copolymers, have been deeply characterized using different techniques, such as NMR, FT-IR and UV-Vis spectroscopy, DSC and TGA analyses, and GPC. The bulk heterojunction solar cells prepared using PCBM as electron-acceptor molecule and the copolymers as electron-donor molecules were tested using Keithley multimeter and Solar Simulator.
Cocchi, Valentina <1986>. "Polimeri tiofenici funzionali e loro applicazioni nel fotovoltaico." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2014. http://amsdottorato.unibo.it/6413/.
Full textRecently, more and more attention has been directed to the application of organic dyes as light absorbers for the preparation of active polymeric layers in organic photovoltaic (OPV) solar cells. Organic dyes usually present a strong light-harvesting ability, thanks to their high extinction coefficient, and useful photophysical properties and are good candidates for the improvement of OPV solar cells photocurrent. In this work is described a new strategy for the incorporation of a porphyrin derivatives in the side chain of a polythiophene copolymers. The studies carried out have shown that poly[3-(6-bromohexyl)thiophene] can be variously functionalized with hydroxytetraphenylporphyrin [TPPOH] to obtain copolymers used as p-donors materials for the realization of the photoactive blend in OPV. The copolymers poly[3-(6-bromohexyl)thiophene-co-(3-[5-(4-phenoxy)-10,15,20-triphenylporphyrinyl]hexyl thiophene] P[T6Br-co-T6TPP] prepared at different chromophore contents were obtained through both not-regiospecific and regiospecific methods, with the aim to compare the properties and verify whether the macromolecular structure that presents the same regiochemistry of substitution along the system, promote the transport of electric charge, improving the efficiency. Was also carried out a further comparison between these derivatives and similar compounds P[T6H-co-T6TPP] which doesn’t link the bromine atom in the side chain, with the purpose to verify if the absence of the reactive group may improve the thermal and chemical stability of the polymer films, acting on the performance of photovoltaic devices. All the soluble and easily filmable copolymers, have been deeply characterized using different techniques, such as NMR, FT-IR and UV-Vis spectroscopy, DSC and TGA analyses, and GPC. The bulk heterojunction solar cells prepared using PCBM as electron-acceptor molecule and the copolymers as electron-donor molecules were tested using Keithley multimeter and Solar Simulator.
TAWFILAS, MASSIMO. "Surface decoration of inorganic nanoparticles for novel polymer-based nanocomposite materials." Doctoral thesis, Università degli Studi di Milano-Bicocca, 2019. http://hdl.handle.net/10281/241271.
Full textSurface ligand engineering is an effective tool used to enhance polymer nanocomposites materials performance, since it plays a key role on one of the trickiest issues: the incompatibility between the organic and inorganic phase. The introduction of a thin polymeric layer enables a good dispersion of the inorganic nanocrystals (NCs) in polymer matrices, where otherwise bare particles aggregate and precipitate. The surface modification is an effective method to introduce additional functionalities to the NPs, giving new properties for a large number of applications. During my research I synthesized different titanium dioxide NCs of different phase and size. I investigated the behavior of bare TiO2 NCs in water. Taking advantage of the interaction between water molecules and titanium dioxide NCs, we found that water interacts in a way that make it a probe able to identify the titanium dioxide crystalline phase. Then an intensive study was done to understand the role of solvents during the grafting process in terms of interaction with polymer chains and inorganic surface. At first a study was done on the grafting-to process of polyethylene oxide monomethylether (mPEO) and polystyrene (PS) on spherical anatase NCs. Commercial mPEO of different molecular weight and polystyrene, synthesized via RAFT polymerization, were used and modified with different anchoring group. The polymers were grafted on anatase NCs through grafting-to approach using different solvents and experimental conditions. Water and methylene chloride were selected according to their ability to interact with the polymer chains and the NC’s surface. Thanks to this massive work we improved our knowledge on the grafting-to approach; we produced a method to create NCs with controlled graft densities and well-defined conformations. Thanks to our experience built during these years of research activity, we were able to prepare a nanocomposite material based on thermoplastic polyurethane (TPU). We started from a mixed double layer system tethered on rod-like anatase nanocrystal. The NCs covered with oleic acid (OA) were synthesized with a colloidal process and modified with a grafting-to approach using a high molecular weight mPEO. The as synthesized object is composed by a high density layer of OA and a low density layer of mPEO (mPEO-OA@Anatase). In order to investigate the properties of this type of objects, a set of nanocomposite materials based on mPEO-OA@Anatase and OA@Anatase were produced in a highly aliphatic TPU matrix with a solvent casting process. It was observed that for both mPEO-OA@Anatase and OA@Anatase optically clear films with improved refractive index (1.63) were obtained. The mechanical tests showed better elastic modulus for filler loaded nanocomposite materials. In particular the mPEO-OA@Anatase presented a higher elastic modulus than OA@Anatase when loaded with the same amount of nanofiller without affecting the optical properties. During my research period abroad, I spent 7 months at Dr. Benicewicz’s group in the University of South Carolina (USA). The aim of my project was focused on the synthesis of new nanocomposite material in the gas separation field. In the first part of the project we prepared a set of samples based on fumed silica (FS) particles using a grafting-from approach to modify the surface with RAFT polymerization. This kind of particles were not able to self-assemble in an organized and no improvement of the the gas permeation properties, even if FS were well dispersed into the polymer matrix. Experimental data confirmed that FS acts as a physical gas barrier. In the second part of the project were synthesized a nanocomposite material using the same approach on silica NP with polymethacrylamide with oligoaniline side chain. These NPs were able to self-assemble in a controlled fashion and thanks to a more selective polymer we obtained a material with enhanced permeability and selectivity to CO2.
Acquasanta, Francesco <1982>. "Materiali compositi e ibridi con predefinite proprietà funzionali. Sviluppo ed applicazioni, con particolare riguardo alla funzionalizzazione superficiale di materiali ceramici." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2011. http://amsdottorato.unibo.it/3813/1/Acquasanta_Francesco_Tesi.pdf.
Full textAcquasanta, Francesco <1982>. "Materiali compositi e ibridi con predefinite proprietà funzionali. Sviluppo ed applicazioni, con particolare riguardo alla funzionalizzazione superficiale di materiali ceramici." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2011. http://amsdottorato.unibo.it/3813/.
Full textMAGRINI, ISABELLA. "Malte ecosostenibili con proprietà funzionali avanzate per l'efficienza energetica." Doctoral thesis, Università Politecnica delle Marche, 2017. http://hdl.handle.net/11566/245366.
Full textENVIRONMENTAL SUSTAINABLE MORTARS WITH INNOVATIVE FUNCTIONAL PROPRIETIES FOR ENERGY EFFICIENCY Introduction: The reduction of energy consumption in construction, the production of thermally insulating materials, as well as the solution of environmental problems by recycling municipal waste are key challenges for the next future. For this reason, several plasters have been studied, in which virgin raw materials such as natural sand and limestone filler were replaced by lightweight expanded silica filler, pumice, recycled expanded glass. Materials and Methods: Mixtures of white cement Portland type CEM II/B-LL 32,5 R and lime type CL 80 S-01 were used as binder to realize six different lightweight plasters. The ratios between cement Portland and lime were changed, more or less significantly, for each mixtures in order to improve plasters. To increase the plasters’ workability, lightweight silica filler was added to the six mixtures and the behavior of different ratios used was observed. The rheology of the plasters was modified from the lightweight silica, which was blended to achieve the right fresh mortar density. The particle size distribution was evaluated with laser method with value of 0 ÷ 150 μm. The lightweight silica was employed to bring good thermal property to the plasters, its thermal conductivity is 0.054 W/mK, and to give lightness to the binder because its bulk density is 150 kg/mc. Major ratio of lightweight silica filler to improve thermal insulation property was demonstrated and was widely employed into commercial insulating materials. Furthermore sustainable construction building was focused on the choice of natural raw materials and recyclable materials, as lightweight silica, to promote environmental responsibility. It was mainly composed by 74% - 78% SiO2 and 11% - 14% Al2O3. The workability and the correct particle size distribution were achieved to use the limestone powder with fine grain 1.8 ÷ 3.3 μm: particle size distribution was measured using the sedimentation method (Micromeritics Sedigraph III Plus). The tamped bulk density was evaluated according to ISO 787-2 with a value of 0.80 ÷1.0 g/cm3. Its chemical composition was 95% - 97% CaO3. Alternatively to highly pulverized powder as limestone, calcined kaolin was used. The ultra fine particle size grain of calcined kaolin was chosen to give more cohesiveness to the hardened mortar. The tamped bulk density is 0.290 g/cm3, which gave more lightness to improve the thermal property. The chemical structure, as expanded grain, should develop better values of thermal insulation. The natural mineral aggregate quartz sand, was replaced with natural lightweight aggregates, which were used to obtain a good thermal values in plasters. Two type of lightweight expanded silica were used to produce a thermal insulating plaster. The LES type 1 and the LES type 2 had a particle size of 0.1 – 0.3 mm and 2 – 5 mm respectively, however the highest value of thermal conductivity was obtained to LES type 1 which also has a bulk density of 0.060 g/cm3. The chemical composition showed a higher content of SiO2 and Na2O in LES type 1 while a higher content of AL2O3 was in LES type 2. The analysis with the electron microscope has disclosed a diffused internal porosity from which depended the technical properties in energy field of plaster coatings. Different mixtures with LES type 1 and type 2 were made to study the relationship between the two materials, the different ratios, the plaster weight and the thermal conductivity. In this research were investigated another natural lightweight aggregates, three type of pumice which were used to realize five out of six mixtures. The bulk density of pumice type 1 and type 2 is better than pumice type 3: 0.300 to 0.390 g/cm3 and 0.550 to 900 g/cm3 respectively. The density has an important effect on thermal properties and the connection between density and thermal conductivity was demonstrated. Furthermore, the chemical composition of pumice is different according to the type. Pumice type 1 and type 2 has a major content of SiO2 (71.7%) and a good percentage of Na2O (13.3%) and CaO (8.9%), instead pumice type 3 has a lower content of SiO2 (62,5%) and a good percentage of Al2O3 (17.5%) and K2O (9.5%). The use of pumice was evaluated in relationship with the compressive strength at 28 day of the various mixtures, which studied the effects of the different type of pumice and the particle size distribution also. Furthermore, a post consumer glass was used into the mixtures as recycled lightweight aggregates and the effects on compressive strength, thermal conductivity and porosity were studied. The recycled expanded glass has a particle size of 2 – 4 mm and it was mixed together pumice type 2 to obtain the particle size distribution and to achieve a good mechanical resistance. The recycled expanded glass has showed an optimum ratio between bulk density and crushing resistance, 190 g/cm3 and 1.4 N/mm2 respectively. These aggregates produced by post consumer glass have a chemical composition as follows: SiO2 (56%), Al2O3 (22%) and K2O+Na2O (5% - 7%). The recycled expanded glass is an alkali-resistant raw material and therefore suitable for working with lime and cement solvent-free. In order to improve workability and cohesiveness of the fresh mortars, rheological additives, as cellulose, and resin in powder dispersion and vinyl acetate were added. A shrinkage reduction agent, a combination of aliphatic alcohols, was added to the mixtures which had the highest water/cement. In each mixture were also added air entraining admixtures with different ratio, to evaluate the relationship between additive and thermal properties. Finally, polypropylene fiber was used to reduce the shrinkage action. After optimization of mortar mixture proportions, 16 selected mixtures were characterized at fresh state by means of fresh consistency evaluation, as well as bulk density of fresh mortar measurements, then at the hardened state by means of compression and bending tests as well as thermal conductivity measurements by means of heat flow meter apparatus according to EN 12667. The selected plasters were also characterized by means of Porosimetry, used to determine various quantifiable aspects of a material's porous nature, such as pore diameter, total pore volume, surface area, and bulk and absolute densities. Finally, a relationship with this main functional characteristics was found to forecast acoustic behavior of lightweight plasters. Results: Fresh consistency was always in the range 12.5-13.5% (target value for plasters), bulk density values of fresh mortars were in the range 350-1020 kg/m3, with the minimum value obtained by adding the maximum dosage of lightweight expanded silica, silica filler and cork (see mixtures PM 10, PM 14 and MIX 5). Concerning 28-day compressive strength the values achieved were in the range 0.3-5.0 MPa (in general the minimum accepted value for a plaster is at least 1.5-2.0 MPa). Concerning 28-day flexural strength the values achieved during the first step of this research were in the range 0.1 – 0.80 MPa. In the optimization stage, the mechanical resistances were increased up to reach values in the range 1.5 – 4.5 MPa. Finally, thermal conductivity measurements showed extremely low values for a plaster ranging from 0.05 to 0.09 Wm-1K-1. Discussion: On the basis of the obtained results, the use of volcanic raw materials, such as lightweight expanded silica and pumice, as well as of expanded glass obtained by recycling municipal waste, proved to be extremely promising in order to produce lightweight and thermal insulating plasters, suitable for energy efficiency improvement in building. Moreover, satisfactory plaster mechanical performances were obtained in most cases.
SCORZONI, CINZIA. "Percorsi di indagine sperimentale delle proprietà di materiali funzionali: un’occasione per introdurre i concetti chiave delle nanoscienze e della fisica moderna nelle scuole superiori." Doctoral thesis, Università degli studi di Modena e Reggio Emilia, 2020. http://hdl.handle.net/11380/1210539.
Full textNanotechnologies are already part of everyday life and are indicated in HO2020 as fundamental key-enabling technologies for the scientific, economic and social development of EU. EU has indeed recommend the introduction of nanoscience and nanotechnology in high school curricula [1] since the beginning of the new millennium, due to their highly interdisciplinary character and also because they are particularly well-suited for effective hands-on activities [2]. One of the most relevant goal of nanoscience is to design and realize novel materials with peculiar properties, the so-called functional materials, by fine tuning their structure, chemical composition and morphology at the micro and nanoscale. Indeed, the microscopic characteristics of such materials strongly affect their macroscopic properties, often in highly surprising ways. Several functional materials are nowadays easily purchased and are used in the school labs to trigger pupils’ curiosity and interest, exploiting the so-called wow-effect. The Unimore Nanolab project [3] goes beyond this approach, designing fully quantitative experiments based on functional materials, which are aimed at introducing selected key-concepts (“big-ideas”) in nanoscience. In this PhD thesis work, as a part of the Nanolab project, I designed and test a few new teaching learning sequences (TLS), developing a novel educational approach to experimental activities, inspired by ISLE (Investigative Science Learning Environment)[4] and Instructional 5E models[5]. Tribology, i.e. the study of friction, wear and adhesion phenomena, is an extremely active field of research of paramount technological relevance. Achieving a comprehensive understanding of these phenomena at the nano- and meso-scale is currently an open issue. As far as education is concerned, friction has been considered a trivial topic which deserved little attention in traditional high-school curricula. In fact, it actually provides an appealing way to introduce fundamental interdisciplinary concepts, such as atomic and molecular interactions and their key role in determining the behaviour and properties of two surfaces in intimate contact [6-7]. In this work, I designed a TLS on friction and wetting, which inquires the properties of the Gecko Tape ®, a micro-structured adhesive, bio-inspired by the gecko feet. The TLS aims to convey one of nanoscience Big Ideas, i.e. Structure is function and underlying the strict connections between physics and chemistry. The teaching sequence is intended to mimic the different steps of a true scientific research, including results dissemination and discussion.This TLS has been validated with a few groups of students, with different backgrounds and levels of involvement, and also tested in a peer education set with very good results. A second TLS, addressing the big ideas "Tools and Instrumentation" was also designed, exploiting Gecko Tape® as a flexible and deformable diffraction grating. This activity is part of a sequence regarding optics and is also proposed in a flipped-classroom approach. All the designed educational materials, including films and video tutorials, are available on-line and have been also used in in-service teachers training activities. 1. I. Malsch; Nanotech. Rev 3, 211 (2014) 2. M. Prince; J. Engr.Ed Rev 93, 223 (2004) 3. http://www.nanolab.unimore.it 4. E. Etkinaa, Physics World 27, 48 (2014) 5. R.W. Bybee; Science& children 51,10 (2014) 6. U. Besson et al. Am. J. Phys. 75, 1106 (2007) 7. V. Montalbano Proceedings of the GIREP-MPTL conference, 863 (2014)
Salvatori, Pierluigi. "Studio ed analisi sperimentale di processi plasma assistiti di deposizione di film sottili a base silicio su materiali polimerici: effetto della potenza sulle caratteristiche funzionali del coating." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2020.
Find full textCerardi, Andrea. "CARATTERIZZAZIONE MECCANICA, GEOMETRICA E FUNZIONALE DI DISPOSITIVI BIOMEDICALI." Doctoral thesis, Università degli studi di Padova, 2010. http://hdl.handle.net/11577/3427007.
Full textObiettivo del lavoro è sviluppare e validare metodologie che permettano di investigare in modo sistematico gli aspetti meccanici, geometrici e funzionali che hanno un impatto diretto sulle caratteristiche di qualità e sicurezza dei dispositivi biomedicali. I fabbricanti del dispositivo medico sono i primi responsabili nel caso in cui si manifestassero dei danni arrecati all’utente durante il corretto utilizzo. Da un’analisi della normativa vigente e dalla letteratura tecnica-scientifica del settore è emerso che i requisiti di sicurezza non risultano accettati universalmente e quindi non sono adottati nella fase di progettazione delle protesi. Ciò fa si che gli operatori del settore si affidino alle buone pratiche di fabbricazione in sostituzione dei controlli e prove finalizzate a limitare i rischi di insuccesso. Inoltre l’introduzione di nuovi metodi e tecnologie nel processo produttivo dei dispositivi dentali aumenta le difficoltà nel valutare la ricaduta delle scelte metodologiche sul rispetto dei requisiti funzionali, di qualità e di sicurezza. Per tale ragione, in riferimento alle norme vigenti e al background scientifico, otto tipologie di prove sono state sviluppate e sottoposte a laboratori odontotecnici. Le prove hanno riguardato la verifica strutturale dei dispositivi, il controllo della precisione geometrica e gli aspetti funzionali delle protesi in esercizio. Nel seguito sono descritte le modalità di prova e presentati i risultati della campagna sperimentale effettuata. I risultati consentono di osservare come il metodo proposto sia adatto alla caratterizzazione dei dispositivi medici oggetto dello studio e che su tale base si può pervenire alla definizione di requisiti di qualità e sicurezza condivisi e pertanto utilizzabili in sede progettuale e di controllo di processo.
Tobaldi, David Maria <1975>. "Materiali Ceramici per Edilizia con Funzionalità Fotocatalitica." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2009. http://amsdottorato.unibo.it/1535/1/DavidMaria_Tobaldi_Tesi.pdf.
Full textTobaldi, David Maria <1975>. "Materiali Ceramici per Edilizia con Funzionalità Fotocatalitica." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2009. http://amsdottorato.unibo.it/1535/.
Full textBERNARDINI, LORENA. "La coroplastica di tipo tanagrino come dono votivo nel santuario della Sorgente di Saturo: dall’analisi del materiale alla ricostruzione delle funzioni e della tradizione culturale." Doctoral thesis, Università degli Studi di Roma "Tor Vergata", 2013. http://hdl.handle.net/2108/201809.
Full textVENUTA, MARIA LUISA. "La città da energivora a nodo attivo delle reti di produzione e di scambio energetico." Doctoral thesis, Università Cattolica del Sacro Cuore, 2007. http://hdl.handle.net/10280/85.
Full textCan internet logic scheme be used as a basis to describe public policies evolution on renewable energies production and sharing in urban areas all over the world? The research project analyses the two networks (internet and energetic grids) architectures in actual and future urban areas. This analysis is connected with present and future forecasts energy productions from traditional fuels and from renewable sources. Theoretical analysis is conducted following a double conceptual pathway: - societal networks (Manuel Castells theory) and urban areas evolution (Saskia Sassen and Mike Davis) in order to picture the evolution of cities and towns in modern economies and in developing countries (Chapters 2 and 5); - Material and Energy Flow Analysis (approach by Wuppertal Institute for Climate, Environment and Energy) applied to renewable energy (Chapters 3 and 4) In Chapter 6 case studies are exposed on the deep cleavage between two different worlds: innovative, rich towns on a side and the landfills cities, slums on the other side. In the last part hypothesis and thesis are put together and open questions are explained (Chapter 7).
PANTINI, SARA. "Analysis and modelling of leachate and gas generation at landfill sites focused on mechanically-biologically treated waste." Doctoral thesis, Università degli Studi di Roma "Tor Vergata", 2013. http://hdl.handle.net/2108/203393.
Full textFerrarelli, Teresa, Roberto Bartolino, Sonia Trombino, and Bartolo Gabriele. "Materiali polimerici funzionali per applicazioni farmaceutiche e biomedicali." Thesis, 2011. http://hdl.handle.net/10955/1052.
Full textPETRINI, Maria Celeste. "IL MARKETING INTERNAZIONALE DI UN ACCESSORIO-MODA IN MATERIALE PLASTICO ECO-COMPATIBILE: ASPETTI ECONOMICI E PROFILI GIURIDICI. UN PROGETTO PER LUCIANI LAB." Doctoral thesis, 2018. http://hdl.handle.net/11393/251084.
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