Crashworthiness and composite materials: development of an experimental test method for the energy absorption determination and implementation of the relative numerical model

In this PhD thesis the crashworthiness topic is studied with the perspective of the development of a small-scale experimental test able to characterize a material in terms of energy absorption. The material properties obtained are then used to validate a nu- merical model of the experimental test itself. Consequently, the numerical model, calibrated on the specific ma- terial, can be extended to more complex structures and used to simulate their energy absorption behavior. The experimental activity started at University of Washington in Seattle, WA (USA) and continued at Second Faculty of Engi- neering, University of Bologna, Forl`ı (Italy), where the numerical model for the simulation of the experimental test was implemented and optimized.

Composite materials design, manufacture and evaluation

Fibre-Reinforced-Plastics are composite materials composed by thin fibres with high mechanical properties, made to work together with a cohesive plastic matrix. The huge advantages of fibre reinforced plastics over traditional materials are their high specific mechanical properties i.e. high stiffness and strength to weight ratios. This kind of composite materials is the most disruptive innovation in the structural materials field seen in recent years and the areas of potential application are still many. However, there are few aspects which limit their growth: on the one hand the information available about their properties and long term behaviour is still scarce, especially if compared with traditional materials for which there has been developed an extended database through years of use and research. On the other hand, the technologies of production are still not as developed as the ones available to form plastics, metals and other traditional materials. A third aspect is that the new properties presented by these materials e.g. their anisotropy, difficult the design of components. This thesis will provide several case-studies with advancements regarding the three limitations mentioned. In particular, the long term mechanical properties have been studied through an experimental analysis of the impact of seawater on GFRP. Regarding production methods, the pre-impregnated cured in autoclave process was considered: a rapid tooling method to produce moulds will be presented, and a study about the production of thick components. Also, two liquid composite moulding methods will be presented, with a case-study regarding a large component with sandwich structure that was produced with the Vacuum-Assisted-Resin-Infusion method, and a case-study regarding a thick con-rod beam that was produced with the Resin-Transfer-Moulding process. The final case-study will analyse the loads acting during the use of a particular sportive component, made with FRP layers and a sandwich structure, practical design rules will be provided.

Experimental and Numerical Evaluation of Impact Damage Tolerance in composite materials

Composite materials characteristics are highly influenced by foreign objects impacts. My research focused on how a Low Velocity Impact and, therefore, Barely Visible Impact Damages, can reduce carbon/epoxy laminates compressive residual characteristics and which could be an improvement of their impact resistance. Solution was found out in Fibre Metal Laminates. Experimental and numerical analysis were performed on Carbon/Epoxy and Fibre Metal Laminate.

Novel bio-based amine curing agents for epoxy resins: the way towards fully bio-based composite materials

Epoxy resins are widely used in many applications, such as paints, adhesives and matrices for composites materials, since they present the possibility to be easily and conveniently tailored in order to display a unique combination of characteristics. In literature, various examples of bio-based epoxy resins produced from a wide range of renewable sources can be found. Nevertheless, the toxicity and safety of curing agents have not been deeply investigated and it was observed that all of them still present some environmental drawback. Therefore, the development of new environmentally friendly fully bio-based epoxy systems is of great importance for designing green and sustainable materials. In this context, the present project aims at further exploring the possibility of using bio-based compounds as curing agents for epoxy resin precursors. A preliminary evaluation of several amine-based compounds demonstrated the feasibility of using Adenine as epoxy resin hardener. In order to better understand the crosslinking mechanism, the reaction of Adenine with the mono-epoxy compound Glycidyl 2-methylphenyl ether (G2MPE), was study by 1H-NMR analysis. Then Adenine was investigated as hardener of Diglycidil ether of bisphenol A (DGEBA), which is the simplest epoxy resin based on bisphenol A, in order to determine the best hardener/resin stoichiometric ratio, and evaluate the crosslinking kinetics and conversion and the final mechanical properties of the cured resin. Then, Adenine was tested as hardener of commercial epoxy resins, in particular the infusion resin Elan-tron® EC 157 (Elantas), the impregnation resin EPON™ Resin 828 (Hexion) and the bio-based resin SUPER SAP® CLR (Entropyresins). Such systems were used for the production of composites materials reinforced with chopped recycled carbon fibers and natural fibers (flax and jute). The thermo-mechanical properties of these materials have been studied in comparison with those ones of composites obtained with the same thermosetting resin reinforced with chopped virgin carbon fibers.

Nanostructured piezoelectric materials for the design and development of self-sensing composite materials and energy harvesting devices

The work activities reported in this PhD thesis regard the functionalization of composite materials and the realization of energy harvesting devices by using nanostructured piezoelectric materials, which can be integrated in the composite without affecting its mechanical properties. The self-sensing composite materials were fabricated by interleaving between the plies of the laminate the piezoelectric elements. The problem of negatively impacting on the mechanical properties of the hosting structure was addressed by shaping the piezoelectric materials in appropriate ways. In the case of polymeric piezoelectric materials, the electrospinning technique allowed to produce highly-porous nanofibrous membranes which can be immerged in the hosting matrix without inducing delamination risk. The flexibility of the polymers was exploited also for the production of flexible tactile sensors. The sensing performances of the specimens were evaluated also in terms of lifetime with fatigue tests. In the case of ceramic piezo-materials, the production and the interleaving of nanometric piezoelectric powder limitedly affected the impact resistance of the laminate, which showed enhanced sensing properties. In addition to this, a model was proposed to predict the piezoelectric response of the self-sensing composite materials as function of the amount of the piezo-phase within the laminate and to adapt its sensing functionalities also for quasi-static loads. Indeed, one final application of the work was to integrate the piezoelectric nanofibers in the sole of a prosthetic foot in order to detect the walking cycle, which has a period in the order of 1 second. In the end, the energy harvesting capabilities of the piezoelectric materials were investigated, with the aim to design wearable devices able to collect energy from the environment and from the body movements. The research activities focused both on the power transfer capability to an external load and the charging of an energy storage unit, like, e.g., a supercapacitor.

Production and characterization of novel thermoplastic (nano)composite materials for additive manufacturing applications

The increasing environmental global regulations have directed scientific research towards more sustainable materials, even in the field of composite materials for additive manufacturing. In this context, the presented research is devoted to the development of thermoplastic composites for FDM application with a low environmental impact, focusing on the possibility to use wastes from different industrial processes as filler for the production of composite filaments for FDM 3D printing. In particular carbon fibers recycled by pyro-gasification process of CFRP scraps were used as reinforcing agent for PLA, a biobased polymeric matrix. Since the high value of CFs, the ability to re-use recycled CFs, replacing virgin ones, seems to be a promising option in terms of sustainability and circular economy. Moreover, wastes from different agricultural industries, i.e. wheat and rice production processes, were valorised and used as biofillers for the production of PLA-biocomposites. The integration of these agricultural wastes into PLA bioplastic allowed to obtain biocomposites with improved eco-sustainability, biodegradability, lightweight, and lower cost. Finally, the study of novel composites for FDM was extended towards elastomeric nanocomposite materials, in particular TPU reinforced with graphene. The research procedure of all projects involves the optimization of production methods of composite filaments with a particular attention on the possible degradation of polymeric matrices. Then, main thermal properties of 3D printed object are evaluated by TGA, DSC characterization. Additionally, specific heat capacity (CP) and Coefficient of Linear Thermal Expansion (CLTE) measurements are useful to estimate the attitude of composites for the prevention of typical FDM issues, i.e. shrinkage and warping. Finally, the mechanical properties of 3D printed composites and their anisotropy are investigated by tensile test using distinct kinds of specimens with different printing angles with respect to the testing direction.

Studio di biomateriali usati come scaffold per Tissue Engineering e loro caratterizzazione con tecniche spettroscopiche vibrazionali e di analisi termica

This research investigated someone of the main problems connected to the application of Tissue Engineering in the prosthetic field, in particular about the characterization of the scaffolding materials and biomimetic strategies adopted in order to promote the implant integration. The spectroscopic and thermal analysis techniques were usefully applied to characterize the chemico-physical properties of the materials such as – crystallinity; – relative composition in case of composite materials; – Structure and conformation of polymeric and peptidic chains; – mechanism and degradation rate; – Intramolecular and intermolecular interactions (hydrogen bonds, aliphatic interactions). This kind of information are of great importance in the comprehension of the interactions that scaffold undergoes when it is in contact with biological tissues; this information are fundamental to predict biodegradation mechanisms and to understand how chemico-physical properties change during the degradation process. In order to fully characterize biomaterials, this findings must be integrated by information relative to mechanical aspects and in vitro and in vivo behavior thanks to collaborations with biomedical engineers and biologists. This study was focussed on three different systems that correspond to three different strategies adopted in Tissue Engineering: biomimetic replica of fibrous 3-D structure of extracellular matrix (PCL-PLLA), incorporation of an apatitic phase similar to bone inorganic phase to promote biomineralization (PCL-HA), surface modification with synthetic oligopeptides that elicit the interaction with osteoblasts. The characterization of the PCL-PLLA composite underlined that the degradation started along PLLA fibres, which are more hydrophylic, and they serve as a guide for tissue regeneration. Moreover it was found that some cellular lines are more active in the colonization of the scaffold. In the PCL-HA composite, the weight ratio between the polymeric and the inorganic phase plays an essential role both in the degradation process and in the biomineralization of the material. The study of self-assembling peptides allowed to clarify the influence of primary structure on intermolecular and intermolecular interactions, that lead to the formation of the secondary structure and it was possible to find a new class of oligopeptides useful to functionalize materials surface. Among the analytical techniques used in this study, Raman vibrational spectroscopy played a major role, being non-destructive and non-invasive, two properties that make it suitable to degradation studies and to morphological characterization. Also micro-IR spectroscopy was useful in the comprehension of peptide structure on oxidized titanium: up to date this study was one of the first to employ this relatively new technique in the biomedical field.

Biomimetic Materials for Biomedical Applications

Objects with complex shape and functions have always attracted attention and interest. The morphological diversity and complexity of naturally occurring forms and patterns have been a motivation for humans to copy and adopt ideas from Nature to achieve functional, aesthetic and social value. Biomimetics is addressed to the design and development of new synthetic materials using strategies adopted by living organisms to produce biological materials. In particular, biomineralized tissues are often sophisticate composite materials, in which the components and the interfaces between them have been defined and optimized, and that present unusual and optimal chemical-physical, morphological and mechanical properties. Moreover, biominerals are generally produced by easily traceable raw materials, in aqueous media and at room pressure and temperature, that is through cheap process and materials. Thus, it is not surprising that the idea to mimic those strategies proper of Nature has been employed in several areas of applied sciences, such as for the preparation of liquid crystals, ceramic thin films computer switches and many other advanced materials. On this basis, this PhD thesis is focused on the investigation of the interaction of biologically active ions and molecules with calcium phosphates with the aim to develop new materials for the substitution and repair of skeletal tissue, according to the following lines: I. Modified calcium phosphates. A relevant part of this PhD thesis has been addressed to study the interaction of Strontium with calcium phosphates. It was demonstrated that strontium ion can substitute for calcium into hydroxyapatite, causing appreciable structural and morphological modifications. The detailed structural analysis carried out on the nanocrystals at different strontium content provided new insight into its interaction with the structure of hydroxyapatite. At variance with the behaviour of Sr towards HA, it was found that this ion inhibits the synthesis of octacalcium phosphate. However, it can substitute for calcium in this structure up to 15 atom %, in agreement with the increase of the cell parameters observed on increasing ion concentration. A similar behaviour was found for Magnesium ion, whereas Manganese inhibits the synthesis of octacalcium phosphate and it promotes the precipitation of dicalcium phosphate dehydrate. It was also found that Strontium affects the kinetics of the reaction of hydrolysis of α-TCP. It inhibits the conversion from α-TCP to hydroxyapatite. However, the resulting apatitic phase contains significant amounts of Sr2+ suggesting that the addition of Sr2+ to the composition of α-TCP bone cements could be successfully exploited for its local delivery in bone defects. The hydrolysis of α-TCP has been investigated also in the presence of increasing amounts of gelatin: the results indicated that this biopolymer accelerates the hydrolysis reaction and promotes the conversion of α-TCP into OCP, suggesting that its addition in the composition of calcium phosphate cements can be employed to modulate the OCP/HA ratio, and as a consequence the solubility, of the set cement. II. Deposition of modified calcium phosphates on metallic substrates. Coating with a thin film of calcium phosphates is frequently applied on the surface of metallic implants in order to combine the high mechanical strength of the metal with the excellent bioactivity of the calcium phosphates surface layers. During this PhD thesis, thank to the collaboration with prof. I.N. Mihailescu, head of the Laser-Surface-Plasma Interactions Laboratory (National Institute for Lasers, Plasma and Radiation Physics – Laser Department, Bucharest) Pulsed Laser Deposition has been successfully applied to deposit thin films of Sr substituted HA on Titanium substrates. The synthesized coatings displayed a uniform Sr distribution, a granular surface and a good degree of crystallinity which slightly decreased on increasing Sr content. The results of in vitro tests carried out on osteoblast-like and osteoclast cells suggested that the presence of Sr in HA thin films can enhance the positive effect of HA coatings on osteointegration and bone regeneration, and prevent undesirable bone resorption. The possibility to introduce an active molecule in the implant site was explored using Matrix Assisted Pulsed Laser Evaporation to deposit hydroxyapatite nanocrystals at different content of alendronate, a bisphosphonate widely employed in the treatments of pathological diseases associated to bone loss. The coatings displayed a good degree of crystallinity, and the results of in vitro tests indicated that alendronate promotes proliferation and differentiation of osteoblasts even when incorporated into hydroxyapatite. III. Synthesis of drug carriers with a delayed release modulated by a calcium phosphate coating. A core-shell system for modulated drug delivery and release has been developed through optimization of the experimental conditions to cover gelatin microspheres with a uniform layer of calcium phosphate. The kinetics of the release from uncoated and coated microspheres was investigated using aspirin as a model drug. It was shown that the presence of the calcium phosphate shell delays the release of aspirin and allows to modulate its action.

Fracture Toughening and Self-Healing of Composite Laminates by Nanofibrous Mats Interleaving

Composite laminates present important advantages compared to conventional monolithic materials, mainly because for equal stiffness and strength they have a weight up to four times lower. However, due to their ply-by-ply nature, they are susceptible to delamination, whose propagation can bring the structure to a rapid catastrophic failure. In this thesis, in order to increase the service life of composite materials, two different approaches were explored: increase the intrinsic resistance of the material or confer to them the capability of self-repair. The delamination has been hindered through interleaving the composite laminates with polymeric nanofibers, which completed the hierarchical reinforcement scale of the composite. The manufacturing process for the integration of the nanofibrous mat in the laminate was optimized, resulting in an enhancement of mode I fracture toughness up to 250%. The effect of the geometrical dimensions of the nano-reinforcement on the architecture of the micro one (UD and woven laminates) was studied on mode I and II. Moreover, different polymeric materials were employed as nanofibrous reinforcement (Nylon 66 and polyvinylidene fluoride). The nano toughening mechanism was studied by micrograph analysis of the crack path and SEM analysis of the fracture surface. The fatigue behavior to the onset of the delamination and the crack growth rate for woven laminates interleaved with Nylon 66 nanofibers was investigated. Furthermore, the impact behavior of GLARE aluminum-glass epoxy laminates, toughened with Nylon 66 nanofibers was investigated. Finally, the possibility of confer to the composite material the capability of self-repair was explored. An extrinsic self-healing-system, based on core-shell nanofibers filled with a two-component epoxy system, was developed by co-electrospinning technique. The healing potential of the nano vascular system has been proved by microscope electron observation of the healing agent release as result of the vessels rupture and the crosslinking reaction was verified by thermal analysis.

Experimental and numerical investigation on short and long term performance of macro-synthetic fibre reinforced concrete materials

Fibre Reinforced Concretes are innovative composite materials whose applications are growing considerably nowadays. Being composite materials, their performance depends on the mechanical properties of both components, fibre and matrix and, above all, on the interface. The variables to account for the mechanical characterization of the material, could be proper of the material itself, i.e. fibre and concrete type, or external factors, i.e. environmental conditions. The first part of the research presented is focused on the experimental and numerical characterization of the interface properties and short term response of fibre reinforced concretes with macro-synthetic fibers. The experimental database produced represents the starting point for numerical models calibration and validation with two principal purposes: the calibration of a local constitutive law and calibration and validation of a model predictive of the whole material response. In the perspective of the design of sustainable admixtures, the optimization of the matrix of cement-based fibre reinforced composites is realized with partial substitution of the cement amount. In the second part of the research, the effect of time dependent phenomena on MSFRCs response is studied. An extended experimental campaign of creep tests is performed analysing the effect of time and temperature variations in different loading conditions. On the results achieved, a numerical model able to account for the viscoelastic nature of both concrete and reinforcement, together with the environmental conditions, is calibrated with the LDPM theory. Different type of regression models are also elaborated correlating the mechanical properties investigated, bond strength and residual flexural behaviour, regarding the short term analysis and creep coefficient on time, for the time dependent behaviour, with the variable investigated. The experimental studies carried out emphasize the several aspects influencing the material mechanical performance allowing also the identification of those properties that the numerical approach should consider in order to be reliable.

Nanostructured smart materials as functional components of medical devices

The field of medical devices has experienced, more than others, technological advances, developments and innovations, thanks to the rapidly expanding scientific knowledge and collaboration between different disciplines such as biology, engineering and materials science. The design of functional components can be achieved by exploiting composite materials based on nanostructured smart materials, that due to the inherent characteristics of single constituents develop unique properties that make them suitable for different applications preserving excellent mechanical proprieties. For instance, recent developments have focused on the fabrication of piezoelectric devices with multiple biomedical functions, as actuation and sensing functions in one component for monitoring pressure signals. The present Ph.D. Thesis aims at investigating nanostructured smart materials embedded into a polymeric matrix to obtain a composite material that can be used as a functional component for medical devices. (i) Nanostructured piezoelectric material with self-sensing capability was successfully manufactured by using ceramic (i.e. lead zirconate titanate (PZT)) and (ii) polymeric (i.e. poly(vinylidene fluoride-trifluoro ethylene (PVDF-TRFE)) piezoelectric materials. PZT nanofibers were obtained by sol-gel electrospinning starting from synthetized PZT precursor solution. Synthesis, sol-gel electrospinning process, and thermal treatment were accurately controlled to obtain PZT nanofibers dimensionally stable with densely packed grains in the perovskite phase. To guarantee the impact resistance of the laminate, the morphology and size of the hosting filler were accurately designed by increasing the surface area to volume ratio. Moreover, to solve the issue relative to the mechanical discrepancy between rigid electronic materials/soft human tissues/different material of the device (iii) a nanostructured flexible composite material based on a network of Poly-L-lactic acid (PLLA) made of curled nanofibers that present a tuneable mechanical response as a function of the applied stress was successful fabricated.

Smart tracking of composite parts: feasibility study and effect on mechanical behaviour

This research proposes a solution for integrating RFID - Radio Frequency Identification technology within a structure based on CFRPs - Carbon Fiber Reinforced Polymers. Therefore, the main objective is to use technology to monitor and track composite components during manufacturing and service life. The study can be divided into two macro-areas. The first portion of the research evaluates the impact of the composite materials used on transmitting the electromagnetic signal to and from the tag. RFID technology communicates through radio frequencies to to track and trace items associated with the tags. In the first instance, a feasibility study was carried out to assess using commercially available tags. Then, after evaluating different solutions, it was decided to incorporate the tags into coupons during production. The second portion of the research is focused on evaluating the impact on the composite material's resistance to tag embedding. It starts with designing tensile test specimens through the FEM model with different housing configurations. Subsequently, the best configuration was tested in the facilities of the In the Faculty of Aerospace Engineering at TU Delft, particularly in the Structure & Materials Laboratory, two tests were conducted: the first one based on ASTM D3039/D3039 - 14 - Standard Test Method for Tensile Properties of Polymer Matrix Composite Materials, the second one dividing the path to failure into failure intervals in a load-unload-reload. Both tests were accompanied by instruments such as DIC, AE, C-Scan and Optical Microscopes. The expected result of the inclusion of RFID tags in composite components is that it brings added value to the parts with which it is associated without affecting too much its mechanical properties. This comes first from the automatic identification of RFID during the production cycle and its useful life. As a result, improvements were made in the design of production facilities.

A glassful of graphene: graphene-based materials for drinking water remediation

Modern world suffers from an intense water crisis. Emerging contaminants represent one of the most concerning elements of this issue. Substances, molecules, ions, and microorganisms take part in this vast and variegated class of pollutants, which main characteristic is to be highly resistant to traditional water purification technologies. An intense international research effort is being carried out in order to find new and innovative solutions to this problem, and graphene-based materials are one of the most promising options. Graphene oxide (GO) is a nanostructured material where domains populated by oxygenated groups alternate with interconnected areas of sp2 hybridized carbon atoms, on the surface of a one-atom thick nanosheets. GO can adsorb a great number of molecules and ions on its surface, thanks to the variety of different interactions that it can express, such as hydrogen bonding, p-p stacking, and electrostatic and hydrophobic interaction. These characteristics, added to the high superficial area, make it an optimal material for the development of innovative materials for drinking water remediation. The main concern in the use of GO in this field is to avoid secondary contaminations (i.e. GO itself must not become a pollutant). This issue can be faced through the immobilization of GO onto polymeric substrates, thus developing composite materials. The use of micro/ultrafiltration polymeric hollow fibers as substrates allows the design of adsorptive membranes, meaning devices that can perform filtration and adsorption simultaneously. In this thesis, two strategies for the development of adsorptive membranes were investigated: a core-shell strategy, where hollow fibers are coated with GO, and a coextrusion strategy, where GO is embedded in the polymeric matrix of the fibers. The so-obtained devices were exploited for both fundamental studies (i.e. molecular and ionic behaviour in between GO nanosheets) and real applications (the coextruded material is now at TRL 9).

Synthesis and characterization of implants for bone substitutions made of biomedical apatites containing silicon

In the last decades the development of bone substitutes characterized by a superior biomimetism has become of particular interest, owing to the increasing economic and societal impact of the bone diseases. In the present work of research the development of bone substitutes characterized by improved biomimetism, has been faced in a chemical, structural and morphological perspective. From a chemical point of view, it has been developed the synthesis of hydroxyapatite powders, exhibiting multiple ionic substitutions in both cationic and anionic sites, so to simulate the chemical composition of the natural bone. Particular emphasis has been given to the effect of silicon on the chemical-physical and solubility properties of the obtained hydroxyapatites. From a structural point of view, it has been developed the synthesis of ceramic composite materials, based on hydroxyapatite and calcium silicates, employed both as a reinforcing phase, to raise the mechanical strength of the composite compared to hydroxyapatite, and as a bioactive phase, able to increase the bioactivity properties of the whole ceramic. Finally the unique morphological features of the bone were mimicked by taking inspiration by Nature, so that native wood structures were treated in chemical and thermal way to obtain hydroxyapatite porous materials characterized by the same morphology as the native wood. The results obtained in the present work were positive in all the three different areas of investigation, so to cover the three different aspects of biomimetism, chemical, structural and morphological. Anyway, only at the convergence of the three different fields it is possible to find out the best solutions to develop the ideal bone-like scaffold. Thus, the future activity should be devoted to solve the problems at the borderline between the different research lines, which hamper this convergence and in consequence, the achievement of a bone scaffold able to mimic the various aspects exhibited by the bone tissue

Mass transport in polymers

The study of mass transport in polymeric membranes has grown in importance due to its potential application in many processes such as separation of gases and vapors, packaging, controlled drug release. The diffusion of a low molecular weight species in a polymer is often accompanied by other phenomena like swelling, reactions, stresses, that have not been investigated in all their aspects yet. Furthermore, novel materials have been developed that include inorganic fillers, reactive functional groups or ions, that make the scenery even more complicated. The present work focused on the experimental study of systems where the diffusion is accompanied by other processes; suitable models were also developed to describe the particular circumstances in order to understand the underlying concepts and be able to design the performances of the material. The effect of solvent-induced deformation in polymeric films during sorption processes was studied since the dilation, especially in constrained membranes, can cause the development of stresses and therefore early failures of the material. The bending beam technique was used to test the effects of the dilation and the stress induced in the polymer by penetrant diffusion. A model based on the laminate theory was developed that accounts for the swelling and is able to predict the stress that raise in the material. The addition of inorganic fillers affects the transport properties of polymeric films. Mixed matrix membranes based on fluorinated, high free volume matrices show attractive performances for separation purposes but there is a need for deeper investigation of the selectivity properties towards gases and vapors. A new procedure based on the NELF model was tested on the experimental data; it allows to predict solubility of every penetrant on the basis of data for one vapor. The method has proved to be useful also for the determination of the diffusion coefficient and for an estimation of the permeability in the composite materials. Oxygen scavenging systems can overcome lack of barrier properties in common polymers that forbids their application in sensitive applications as food packaging. The final goal of obtaining a membrane almost impermeable to oxygen leads to experimental times out of reach. Hence, a simple model was developed in order to describe the transport of oxygen in a membrane with also reactive groups and analyze the experimental data collected on SBS copolymers that show attractive scavenging capacity. Furthermore, a model for predicting the oxygen barrier behavior of a film formed as a blend of OSP in a common packaging material was built, considering particles capable of reactions with oxygen embedded in a non-reactive matrix. Perfluorosulphonic acid ionomers (PFSI) are capturing attention due to a high thermal and chemical resistance coupled with very peculiar transport properties, that make them appropriate to be used in fuel cells. The possible effect of different formation procedure was studied together with the swelling due to water sorption since both water uptake and dilation can dramatically affect the fuel cells performances. The water diffusion and sorption was studied with a FTIR-ATR spectrometer that can give deeper information on the bonds between water molecules and the sulphonic hydrophilic groups and, therefore, on the microstructure of the hydrated ionomer.