Adsorção de corantes têxteis aniônicos e catiônicos em resíduos do processamento de fios de algodão modificados quimicamente

The textile industry generates a large volume of high organic effluent loading whoseintense color arises from residual dyes. Due to the environmental implications caused by this category of contaminant there is a permanent search for methods to remove these compounds from industrial waste waters. The adsorption alternative is one of the most efficient ways for such a purpose of sequestering/remediation and the use of inexpensive materials such as agricultural residues (e.g., sugarcane bagasse) and cotton dust waste (CDW) from weaving in their natural or chemically modified forms. The inclusion of quaternary amino groups (DEAE+) and methylcarboxylic (CM-) in the CDW cellulosic structure generates an ion exchange capacity in these formerly inert matrix and, consequently, consolidates its ability for electrovalent adsorption of residual textile dyes. The obtained ionic matrices were evaluated for pHpcz, the retention efficiency for various textile dyes in different experimental conditions, such as initial concentration , temperature, contact time in order to determine the kinetic and thermodynamic parameters of adsorption in batch, turning comprehensive how does occur the process, then understood from the respective isotherms. It was observed a change in the pHpcz for CM--CDW (6.07) and DEAE+-CDW (9.66) as compared to the native CDW (6.46), confirming changes in the total surface charge. The ionized matrices were effective for removing all evaluated pure or residual textile dyes under various tested experimental conditions. The kinetics of the adsorption process data had best fitted to the model a pseudosecond order and an intraparticle diffusion model suggested that the process takes place in more than one step. The time required for the system to reach equilibrium varied according to the initial concentration of dye, being faster in diluted solutions. The isotherm model of Langmuir was the best fit to the experimental data. The maximum adsorption capacity varied differently for each tested dye and it is closely related to the interaction adsorbent/adsorbate and dye chemical structure. Few dyes obtained a linear variation of the balance ka constant due to the inversion of temperature and might have influence form their thermodynamic behavior. Dyes that could be evaluated such as BR 18: 1 and AzL, showed features of an endothermic adsorption process (ΔH° positive) and the dye VmL presented exothermic process characteristics (ΔH° negative). ΔG° values suggested that adsorption occurred spontaneously, except for the BY 28 dye, and the values of ΔH° indicated that adsorption occurred by a chemisorption process. The reduction of 31 to 51% in the biodegradability of the matrix after the dye adsorption means that they must go through a cleaning process before being discarded or recycled, and the regeneration test indicates that matrices can be reused up to five times without loss of performance. The DEAE+-CDW matrix was efficient for the removal of color from a real textile effluent reaching an UV-Visible spectral area decrease of 93% when applied in a proportion of 15 g ion exchanger matrix L-1 of colored wastewater, even in the case of the parallel presence of 50 g L-1 of mordant salts in the waste water. The wide range of colored matter removal by the synthesized matrices varied from 40.27 to 98.65 mg g-1 of ionized matrix, obviously depending in each particular chemical structure of the dye upon adsorption.

Evaluation of thermo-physical properties and drying kinetics of carrots in a convective hot air drying system

This paper presents an experimental study on the evolution of carrot properties along convective drying by hot air at different temperatures (50ºC, 60ºC and 70ºC). The thermo-physical properties calculated were: specific heat, thermal conductivity, diffusivity, enthalpy, heat and mass transfer coefficients. Furthermore, the data of drying kinetics were treated and adjusted according to the three empirical models: Page, Henderson & Pabis and Logarithmic. The sorption isotherms were also determined and fitted using the GAB model. The results showed that, generally, the thermo-physical properties presented a decline during the drying process, and the decrease was faster for the temperature of 70ºC. It was possible to verify that the Page model presented the best prediction ability for the representation of kinetics of the drying process. The GAB model used to fit the sorption isotherms showed a good prediction capacity and, at a given water activity, despite some variations, the amount of water sorbed increased with the decrease of drying temperature.

Variação da composição nutricional e propriedades de cenouras durante a secagem

Este trabalho teve como objetivo a determinação das propriedades da cenoura (Daucus carota L.), da variedade Nantes, antes, durante e após a secagem por convecção a três temperaturas diferentes (50, 60 e 70 ºC).De forma a verificar as alterações ao nível de diferentes propriedades, tais como: propriedades químicas (humidade, proteínas, fibras, cinzas, açúcares e 'aw') propriedades físicas (textura, cor, porosidade e densidade) e propriedades termofísicas (calor específico, condutividade térmica, difusividade e entalpia). Dos resultados obtidos foi possível concluir que a temperatura de secagem de 70 º C foi a que mais afetou as propriedades químicas analisadas, tais como a humidade, proteínas e açúcares redutores, onde estes sofreram uma diminuição ao longo das secagens. A 'aw' também apresentou uma diminuição ao longo das secagens, onde apresentou um menor valor na secagem a 70 ºC, tendo passado de 0,97 para 0,69, enquanto as temperaturas de 50 ºC e 60 ºC apresentaram um valor final igual, de 0,74. No que diz respeito às propriedades físicas, verificou-se que em relação à textura registaram-se evoluções semelhantes em termos de dureza, mastigabilidade e gomosidade, na medida em que sofreram uma acentuada diminuição nas primeiras horas de secagem, e a temperatura de 70 ºC foi a que mais afetou estas propriedades. No caso da cor a temperatura de 60 ºC foi a que provocou uma maior diferença de cor, a qual ao longo da secagem esta foi aumentando. A porosidade sofreu um aumento com as secagens devido à diminuição da humidade, no entanto a temperatura de 70 ºC foi a que obteve uma menor porosidade, e as temperaturas de 50 ºC e 60 ºC apresentaram valores de porosidade semelhantes. As propriedades termofísicas registaram uma diminuição ao longo da secagem, onde o calor específico sofreu uma maior diminuição com a temperatura de 70 ºC, passando de 3,90 kJ/kg.K para 1,99 kJ/kg.K. A condutividade térmica também sofreu uma maior diminuição com a temperatura de 70 ºC, diminuindo de 0,5243 W/m.K para 0,2782 W/m.K. A difusividade foi de igual forma afetada pela temperatura de 70 ºC, tendo diminuído de 1,50×10-7 m2/s para 1,06×10-7 m2/s. No caso da entalpia, esta sofreu uma maior diminuição com a temperatura de 50 ºC, passando de 233 J/kg para 96,7 J/kg. As isotérmicas de sorção foram ajustadas ao modelo de GAB, onde se verificou que apesar de algumas oscilações a quantidade de água sorvida a uma determinada aw, aumentou com a diminuição da temperatura.Os dados da cinética de secagem foram tratados e ajustados de acordo com três modelos: Page, Henderson & Pabis e Logarítmico, tendo-se verificado que o modelo de Page foi o que mostrou melhor descrever os processos em estudo, enquanto o pior modelo para descrever a cinética de secagem foi o Logarítmico.

Biossorção do corante têxtil preto reafix super 2R com bagaço de malte

Na indústria têxtil grandes volumes de efluentes são gerados, os quais são caracterizados por serem coloridos e poluentes , devido à presença de corantes em sua composição. Com a necessidade de descontaminação, diferentes métodos são utilizados no tratamento, sendo um deles, a biossorção. Este consiste na remoção das substâncias tóxicas recorrendo a biossorventes obtidos a partir de resíduos agrícolas e sub-produtos de processos industriais. O objetivo principal deste trabalho foi estudar a remoção do corante Preto Reafix Super 2R em soluções aquosas por meio de biossorção com bagaço de malte. Baseando-se sobretudo no estudo da cinética e equilíbrio entre o biossorvente e o corante. Numa primeira fase foi estudada a influência dos parâmetros operacionais, como a influência do diâmetro médio das partículas do biossorvente, o pH da solução e a velocidade de agitação da solução. Sendo as condições ótimas de biossorção definidas a pH 2, velocidade de agitação de 150 rpm e biomassa sem peneiramento. Posteriormente, ajustaram-se os modelos cinéticos de Pseudo-primeira ordem, Pseudo-segunda ordem e de Difusão intrapartícula aos resultados experimentais obtidos pela cinética de adsorção avaliando também a influência da temperatura no tempo de contato para se alcançar o equilibrio. O modelo de Pseudo-segunda ordem conduziu ao melhor ajuste, com um coeficiente de correlação (R2) de apróximadamente 1. A partir dos testes de equilíbrio realizados com diferentes concentrações de corante, foram ajustadas as isotermas de Langmuir, Freundlich, Tempkin aos resultados experimentais tendo-se obtido parâmetros bastante significativos para o modelo Langmuir, cuja capacidade máxima de remoção (qmax) obtida foi de 40,16 mg.g-1. A análise dos parâmetros termodinâmicos permitiram avaliar que o processo de adsorção ocorre espontaneamente, sendo endotérmico e que ao longo do processo aumenta a aleatoriedade na interface sólido/solução, devido à desorganização do processo em virtude das interações que ocorrem.

Modifications neurométaboliques et microstructurales à la suite d'une commotion cérébrale chez les athlètes féminines

L’utilisation de méthodes d’investigation cérébrale avancées a permis de mettre en évidence la présence d’altérations à court et à long terme à la suite d’une commotion cérébrale. Plus spécifiquement, des altérations affectant l’intégrité de la matière blanche et le métabolisme cellulaire ont récemment été révélées par l’utilisation de l’imagerie du tenseur de diffusion (DTI) et la spectroscopie par résonance magnétique (SRM), respectivement. Ces atteintes cérébrales ont été observées chez des athlètes masculins quelques jours après la blessure à la tête et demeuraient détectables lorsque les athlètes étaient à nouveau évalués six mois post-commotion. En revanche, aucune étude n’a évalué les effets neurométaboliques et microstructuraux dans la phase aigüe et chronique d’une commotion cérébrale chez les athlètes féminines, malgré le fait qu’elles présentent une susceptibilité accrue de subir ce type de blessure, ainsi qu’un nombre plus élevé de symptômes post-commotionnels et un temps de réhabilitation plus long. Ainsi, les études composant le présent ouvrage visent globalement à établir le profil d’atteintes microstructurales et neurométaboliques chez des athlètes féminines par l’utilisation du DTI et de la SRM. La première étude visait à évaluer les changements neurométaboliques au sein du corps calleux chez des joueurs et joueuses de hockey au cours d’une saison universitaire. Les athlètes ayant subi une commotion cérébrale pendant la saison ont été évalués 72 heures, 2 semaines et 2 mois après la blessure à la tête en plus des évaluations pré et post-saison. Les résultats démontrent une absence de différences entre les athlètes ayant subi une commotion cérébrale et les athlètes qui n’en ont pas subie. De plus, aucune différence entre les données pré et post-saison a été observée chez les athlètes masculins alors qu’une diminution du taux de N-acetyl aspartate (NAA) n’a été mise en évidence chez les athlètes féminines, suggérant ainsi un impact des coups d’intensité sous-clinique à la tête. La deuxième étude, qui utilisait le DTI et la SRM, a révélé des atteintes chez des athlètes féminines commotionnées asymptomatiques en moyenne 18 mois post-commotion. Plus spécifiquement, la SRM a révélé une diminution du taux de myo-inositol (mI) au sein de l’hippocampe et du cortex moteur primaire (M1) alors que le DTI a mis en évidence une augmentation de la diffusivité moyenne (DM) dans plusieurs faisceaux de matière blanche. De iii plus, une approche par région d’intérêt a mis en évidence une diminution de la fraction d’anisotropie (FA) dans la partie du corps calleux projetant vers l’aire motrice primaire. Le troisième article évaluait des athlètes ayant subi une commotion cérébrale dans les jours suivant la blessure à la tête (7-10 jours) ainsi que six mois post-commotion avec la SRM. Dans la phase aigüe, des altérations neuropsychologiques combinées à un nombre significativement plus élevé de symptômes post-commotionnels et dépressifs ont été trouvés chez les athlètes féminines commotionnées, qui se résorbaient en phase chronique. En revanche, aucune différence sur le plan neurométabolique n’a été mise en évidence entre les deux groupes dans la phase aigüe. Dans la phase chronique, les athlètes commotionnées démontraient des altérations neurométaboliques au sein du cortex préfrontal dorsolatéral (CPDL) et M1, marquées par une augmentation du taux de glutamate/glutamine (Glx). De plus, une diminution du taux de NAA entre les deux temps de mesure était présente chez les athlètes contrôles. Finalement, le quatrième article documentait les atteintes microstructurales au sein de la voie corticospinale et du corps calleux six mois suivant une commotion cérébrale. Les analyses n’ont démontré aucune différence au sein de la voie corticospinale alors que des différences ont été relevées par segmentation du corps calleux selon les projections des fibres calleuses. En effet, les athlètes commotionnées présentaient une diminution de la DM et de la diffusivité radiale (DR) au sein de la région projetant vers le cortex préfrontal, un volume moindre des fibres de matière blanche dans la région projetant vers l’aire prémotrice et l’aire motrice supplémentaire, ainsi qu’une diminution de la diffusivité axiale (DA) dans la région projetant vers l’aire pariétale et temporale. En somme, les études incluses dans le présent ouvrage ont permis d’approfondir les connaissances sur les effets métaboliques et microstructuraux des commotions cérébrales et démontrent des effets délétères persistants chez des athlètes féminines. Ces données vont de pair avec la littérature scientifique qui suggère que les commotions cérébrales n’entraînent pas seulement des symptômes temporaires.

Estudo do comportamento plástico, mecânico, microestrutural e térmico do concreto produzido com resíduo de porcelanato

Population growth experienced in major cities, allied to society s need of infra-structure, especially ones related to habitational demands, increases the consumption of construction materials. As a consequence, consumption of natural resources itself. Thus, due to this process, concrete is one of the most produced materials in civil construction. This is also due to the great diversity of its application, easiness in its execution and adequate mechanical performance, as well as low production costs. Following the same tendencies in construction development, the ceramic industry has intensified the production of porcelain ceramic tiles and floors. These are achieved by a fine finishing and receive polishing at the end of the fabrication process. This work researched the use of porcelain residues in polishing for the production of concrete. All of which; due to economical and environmental issues. This process aims to prove adequate destiny for this type of residue, due to environmental issues, incorporating it to the concrete itself; all of which provides economy in consumption of the materials that constitute concrete. Thus, the main characteristics of concrete were investigated through the inclusion of different concentration of the porcelain residue as additional trait element. The residue rates incorporated to the trait varied from 10% to 50% in relation to the cement mass, in the traits with plastic additives and without plastic additives. It is observed that the inclusion of porcelain residue produced a meaningful alteration in the consistency of fresh concrete. This residue has a fine granulometry and it considerably absorbed the water used in the concrete spreading, influencing the way this material is dealt with. Thus, the value of cement striking decreases with the increase of residues present in trait. The maximal incorporation of the residue was of 50%, massively, for the same factor water/initial cement. The use of residues in concrete results in an 40% increase in the compression resistance. It is also proportional to residue concentration of porcelain in the trait. The microstructure was also favored once porosity and concrete absorption decreases with the use of this residue. The parameters demonstrate the quality and durability of the concrete produced with this residue. The use of porcelain residue in concrete composition has not produced meaningful thermal behavior changes. Thermal conductivity, heat capacity and thermal diffusivity have been maintained basically constant

Stable spike clusters for the one-dimensional Gierer-Meinhardt system

We consider the Gierer-Meinhardt system with precursor inhomogeneity in a one-dimensional interval. A spike cluster is the combination of several spikes which all approach the same point in the singular limit of small activator diffusivity. We rigorously prove the existence of a steady-state spike cluster consisting of N spikes near a non-degenerate local minimum point of the smooth inhomogeneity, where N is an arbitrary positive integer. Further, we show that this solution is linearly stable. We explicitly compute all eigenvalues, both large (of order O(1)) and small (of order o(1)). The main features of studying the Gierer-Meinhardt system in this setting are as follows: (i) it is biologically relevant since it models a hierarchical process (pattern formation of small-scale structures induced by a pre-existing large-scale inhomogeneity), (ii) it contains three different spatial scales two of which are small. (iii) all the expressions can be made explicit and often have a particularly simple form.

The bioconcentration factor of pesticides in potatoes.

We presented a model that estimates the bioconcentration factor (BCF) of pesticides in potatoes supposing that the pesticide in the soil solution is absorbed by the potato by passive diffusion, following Fick?s second law. The pesticides in the model are nonionic organic substances, traditionally used in potato crops that degrade in the soil according to a first order kinetic equation. This presents an expression that relates BCF with the pesticide elimination rate by the potato, with the pesticide accumulation rate within the potato, with the rate of growth of the potato and with the pesticide degradation rate in the soil. BCF was estimated supposing steady state equilibrium of the quotient between the pesticide concentration in the potato and the pesticide concentration in the soil solution. It is suggested that a negative correlation exists between the pesticide BCF and the soil sorption partition coefficient. The model was built based on the work of Trapp et al. (2007), [Diffusion of PAH in Potato and Carrot Slices and Applications for a Potato Model] in which an expression to calculate the diffusivity of persistent organic substances in potatoes is presented. The model consists in adding to the expression of Trapp et al. (2007) the hypothesis that the pesticide degrades in the soil. The value of BCF suggests which pesticides should be monitored in potatoes.

Elemental Anisotropic Growth and Atomic-Scale Structure of Shape-Controlled Octahedral Pt–Ni–Co Alloy Nanocatalysts

Multimetallic shape-controlled nanoparticles offer great opportunities to tune the activity, selectivity, and stability of electrocatalytic surface reactions. However, in many cases, our synthetic control over particle size, composition, and shape is limited requiring trial and error. Deeper atomic-scale insight in the particle formation process would enable more rational syntheses. Here we exemplify this using a family of trimetallic PtNiCo nanooctahedra obtained via a low-temperature, surfactant-free solvothermal synthesis. We analyze the competition between Ni and Co precursors under coreduction “one-step” conditions when the Ni reduction rates prevailed. To tune the Co reduction rate and final content, we develop a “two-step” route and track the evolution of the composition and morphology of the particles at the atomic scale. To achieve this, scanning transmission electron microscopy and energy dispersive X-ray elemental mapping techniques are used. We provide evidence of a heterogeneous element distribution caused by element-specific anisotropic growth and create octahedral nanoparticles with tailored atomic composition like Pt1.5M, PtM, and PtM1.5 (M = Ni + Co). These trimetallic electrocatalysts have been tested toward the oxygen reduction reaction (ORR), showing a greatly enhanced mass activity related to commercial Pt/C and less activity loss than binary PtNi and PtCo after 4000 potential cycles.

Post-combustion CO2 adsorption on activated carbons with different textural properties

Fixed bed CO2 adsorption tests were carried out in model flue-gas streams onto two commercial activated carbons, namely Filtrasorb 400 and Nuchar RGC30, at 303 K, 323 K and 353 K. Thermodynamic adsorption results highlighted that the presence of a narrower micropore size distribution with a prevailing contribution of very small pore diameters, observed for Filtrasorb 400, is a key factor in determining a higher CO2 capture capacity, mostly at low temperature. These experimental evidences were also corroborated by the higher value of the isosteric heat derived for Filtrasorb 400, testifying stronger interactions with CO2 molecules with respect to Nuchar RGC30. Dynamic adsorption results on the investigated sorbents highlighted the important role played by both a greater contribution of mesopores and the presence of wider micropores for Nuchar RGC30 in establishing faster capture kinetics with respect to Filtrasorb 400, in particular at 303 K. Furthermore, the modeling analysis of 15% CO2 breakthrough curves allowed identifying intraparticle diffusion as the rate-determining step of the process.

Evaluation of dry protonated calcium alginate beads for biosorption applications and studies of lead uptake

Alginate polysaccharide is a promising biosorbent for metal uptake. Dry protonated calcium alginate beads for biosorption applications were prepared, briefly characterized and tested for lead uptake. Several advantages of this biosorbent are reported and discussed in comparison with other alginate-based sorbents. The alginate beads contained 4.7 mmol/g of COOH groups, which suffered hydrolysis near pH 4. The Weber and Morris model, applied to kinetic results of lead uptake, showed that intraparticle diffusion was the rate-controlling step in lead sorption by dry alginate beads. Equilibrium experiments were performed and the data were fitted with different isotherm models. The Langmuir equation was the most adequate to model lead sorption. The maximum uptake capacity (qmax) was estimated as 339 mg/g and the Langmuir constant (b) as 0.84 l/mg. These values were compared with that of other sorbents found in the literature, indicating that dry protonated calcium alginate beads are among the best biosorbents for the treatment and recovery of heavy metals from aqueous streams.

Evaluation of dry protonated calcium alginate beads for biosorption applications and studies of lead uptake

Alginate polysaccharide is a promising biosorbent for metal uptake. Dry protonated calcium alginate beads for biosorption applications were prepared, briefly characterized and tested for lead uptake. Several advantages of this biosorbent are reported and discussed in comparison with other alginate-based sorbents. The alginate beads contained 4.7 mmol/g of COOH groups, which suffered hydrolysis near pH 4. The Weber and Morris model, applied to kinetic results of lead uptake, showed that intraparticle diffusion was the rate-controlling step in lead sorption by dry alginate beads. Equilibrium experiments were performed and the data were fitted with different isotherm models. The Langmuir equation was the most adequate to model lead sorption. The maximum uptake capacity (qmax) was estimated as 339 mg/g and the Langmuir constant (b) as 0.84 l/mg. These values were compared with that of other sorbents found in the literature, indicating that dry protonated calcium alginate beads are among the best biosorbents for the treatment and recovery of heavy metals from aqueous streams.

Relación entre atrofia cortical difusa y desempeño cognitivo : estudio en población mayor de 60 años en un hospital universitario en la ciudad de Bogotá

El presente trabajo tuvo como objetivo evaluar la existencia de la relación entre la atrofia cortical difusa objetivada por neuroimagenes cerebrales y desempeños cognitivos determinados mediante la aplicación de pruebas neuropsicológicas que evalúan memoria de trabajo, razonamiento simbólico verbal y memoria anterógrada declarativa. Participaron 114 sujetos reclutados en el Hospital Universitario Mayor Méderi de la ciudad de Bogotá mediante muestreo de conveniencia. Los resultados arrojaron diferencias significativas entre los dos grupos (pacientes con diagnóstico de atrofia cortical difusa y pacientes con neuroimagenes interpretadas como dentro de los límites normales) en todas las pruebas neuropsicológicas aplicadas. Respecto a las variables demográficas se pudo observar que el grado de escolaridad contribuye como factor neuroprotector de un posible deterioro cognitivo. Tales hallazgos son importantes para determinar protocoles tempranos de detección de posible instalación de enfermedades neurodegenerativas primarias.

New methodologies in CT perfusion and MRI analysis to develop cancer imaging biomarkers

Quantitative imaging in oncology aims at developing imaging biomarkers for diagnosis and prediction of cancer aggressiveness and therapy response before any morphological change become visible. This Thesis exploits Computed Tomography perfusion (CTp) and multiparametric Magnetic Resonance Imaging (mpMRI) for investigating diverse cancer features on different organs. I developed a voxel-based image analysis methodology in CTp and extended its use to mpMRI, for performing precise and accurate analyses at single-voxel level. This is expected to improve reproducibility of measurements and cancer mechanisms’ comprehension and clinical interpretability. CTp has not entered the clinical routine yet, although its usefulness in the monitoring of cancer angiogenesis, due to different perfusion computing methods yielding unreproducible results. Instead, machine learning applications in mpMRI, useful to detect imaging features representative of cancer heterogeneity, are mostly limited to clinical research, because of results’ variability and difficult interpretability, which make clinicians not confident in clinical applications. In hepatic CTp, I investigated whether, and under what conditions, two widely adopted perfusion methods, Maximum Slope (MS) and Deconvolution (DV), could yield reproducible parameters. To this end, I developed signal processing methods to model the first pass kinetics and remove any numerical cause hampering the reproducibility. In mpMRI, I proposed a new approach to extract local first-order features, aiming at preserving spatial reference and making their interpretation easier. In CTp, I found out the cause of MS and DV non-reproducibility: MS and DV represent two different states of the system. Transport delays invalidate MS assumptions and, by correcting MS formulation, I have obtained the voxel-based equivalence of the two methods. In mpMRI, the developed predictive models allowed (i) detecting rectal cancers responding to neoadjuvant chemoradiation showing, at pre-therapy, sparse coarse subregions with altered density, and (ii) predicting clinically significant prostate cancers stemming from the disproportion between high- and low- diffusivity gland components.

Determinazione della performance di membrane composite per la purificazione di gas

In questo elaborato vengono presentati i risultati di una attività sperimentale incentrata sulla ricerca di membrane a matrice mista per la separazione di gas da miscele. In questo lavoro viene descritta la preparazione di membrane in polisulfone e membrane a matrice mista polisulfone con ZIF-8 a quattro diversi caricamenti percentuali, PSf+ZIF-8 2%, 4%, 8% e 16%. Vengono anche esposti i risultati delle prove di caratterizzazione di tali membrane. E' stato condotto un esame attraverso microscopia elettronica a scansione (SEM) sulla sezione e sulla superficie delle cinque membrane. Sono esposti i risultati dei test di permeazione condotti attraverso un permeometro a volume costante. Le prove sono state fatte per tutte le membrane con sei diversi gas penetranti (H2, He, O2, CO2, CH4 e N2) a tre diverse temperature (35°C, 50°C e 65°C) ottenendo i valori dei coefficienti di permeabilità, solubilità e diffusività. Sono state calcolate le selettività ideali per ogni coppia di gas per tutte le membrane e le energie di attivazione. Sono stati fatti paragoni con i risultati di letteratura e ricercate correlazioni predittive per le proprietà di trasporto delle membrane in funzione di diversi parametri.