Morphology, thermal, mechanical properties and ageing of nylon 6,6/graphene nanofibers as Nano2 materials

Nylon 6,6 nanofibers loaded with different Graphene (G) amounts were successfully produced with stable process and good fiber quality, using an optimized solvent system suitable both for electrospinning and for G-suspension. G addition is found to significantly affect diameter but not thermal behaviour. A new phenomenological model is proposed for the interpretation of mechanical behaviour of nanofibrous mat, trying to take into account the nanofibrous morphology. The model highlights a G contribution to mechanical properties that mainly affects the initial steps of deformation where fibers stretch, slide, twist and re-orient. Finally, the nanofibers were analysed after 20 months ageing, showing no significant alteration with respect to the pristine ones, thus the lack of detrimental ageing-effects due to G addition

Production of Thermoplastic Composite Filaments for Additive Manufacturing using Recycled Carbon Fibers

The present work reports the use of recycled carbon fibers (rCF), obtained from pyro-gasification treatment of carbon fibers reinforced polymers (CFRP), to produce a thermoplastic composite filament for additive manufacturing, in particular fused deposition modeling (FDM) process. Polylactic acid (PLA), a thermoplastic biobased and biodegradable polymer, is used as matrix for the composite filament, as it is the most common plastic used in FDM due to its good mechanical properties, stiffness, and strength. Upon production process optimization, filaments with rCF loadings of 5 and 10% wt are produced and analyzed. A particular attention is devoted to the evaluation of the production process on the carbon fibers (CFs) length and the study of the thermal and mechanical properties of the obtained composite materials

Designing for the next generation. Children urban design as a strategic method to improve the future in the cities

Nowadays, society recognizes the childhood as an important step able to generate a social value: children are the main actors of the future but it is necessary to consider the children as children and not as the next adult. Traditionally, the design for kids consider them little adults in a transition phase. The research intention is to spread a new design culture conceived expressly for children, which shall be able to communicate to them using their languages. The project is dedicated to the children - the next generation - from 3 to 11 years old. The aim of this research is to propose a methodological system to design public spaces in the cities able to orient, inform, communicate, entertain, interact, educate, and integrate all kind of children (and their parents) belonging to different cultures with one universal language.6n

Water-Resistant Photo-Crosslinked PEO/PEGDA Electrospun Nanofibers for Application in Catalysis

Catalysts are used for producing the vast majority of chemical products. Usually, catalytic membranes are inorganic. However, when dealing with reactions conducted at low temperatures, such as in the production of fine chemicals, polymeric catalytic membranes are preferred due to a more competitive cost and easier tunability compared to inorganic ones. In the present work, nanofibrous mats made of poly(ethylene oxide), PEO, and poly(ethylene glycol) diacrylate, PEGDA, blends with the Au/Pd catalyst are proposed as catalytic membranes for water phase and low-temperature reactions. While PEO is a water-soluble polymer, its blending with PEGDA can be exploited to make the overall PEO/PEGDA blend nanofibers water-resistant upon photo-crosslinking. Thus, after the optimization of the blend solution (PEO molecular weight, PEO/PEGDA ratio, photoinitiator amount), electrospinning process, and UV irradiation time, the resulting nanofibrous mat is able to maintain the nanostructure in water. The addition of the Au-6/Pd-1 catalyst (supported on TiO2) in the PEO/PEGDA blend allows the production of a catalytic nanofibrous membrane. The reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP), taken as a water phase model reaction, demonstrates the potential usage of PEO-based membranes in catalysis

Rubbery nanofibrous interleaves enhance fracture toughness and damping of CFRP laminates

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Omalizumab effectiveness in patients with a previously failed oral immunotherapy for severe milk allergy

Background: Some studies addressed the issue of omalizumab (OML) effectiveness in children starting their first oral immunotherapy (OIT) attempt but no study investigated the possible role of OML in the setting of patients with persisting milk allergy after a failed OIT attempt.Methods: Single-center, prospective, observational study in a selected group of patients with a persisting and severe cow milk (CM) allergy associated with moderate allergic asthma, in which a previous OIT attempt had already failed. We performed an open oral food challenge (OFC) to identify patients who tolerated less than 173 mg of cow's milk protein. At the end of the recruitment, we have found four patients with a mean age of 16.25 years (8-24) who had suspended a previous OIT attempt and still reacted to an amount of CM equal or below 173 mg. Enrolled patients, after an 8-week course of OML along with a CM avoiding diet, underwent again an open OFC with CM to re-evaluate their threshold. Eventually, a new OIT course was started using the same OIT protocol of the previous attempt, maintaining cotreatment with OML for the first 12 months. For each patient, we documented: the threshold of CM at OFC, level of specific immunoglobulin E (IgE) and IgG4 for milk, and quality of life (QoL).Results: During OIT the four patients experienced no reactions or extremely mild ones (oral itching, transient mild abdominal pain). All increased their threshold of CM in OML if compared with the baseline and maintained it long after that biologic therapy had discontinued. Specific milk proteins IgG4 levels significantly increased in all.Conclusion: In this series, OML was effective in patients with severe CM allergy who had previously failed OIT, allowing milk intake without adverse reactions and improving the QoL

How Nanofibers Carry the Load: Toward a Universal and Reliable Approach for Tensile Testing of Polymeric Nanofibrous Membranes

Nanofibrous nonwovens show high versatility and outstanding properties, with reduced weight. Porous morphology, high material flexibility and deformability challenge their mechanical testing, severely affecting results reliability. Still today, a specific technical standard method to carry out tensile testing of nonwoven nanofibrous mats is lacking, as well as studies concerning tensile test data reliability. In this work, an accurate, systematic, and critical study is presented concerning tensile testing of nonwovens, using electrospun Nylon 66 random nanofibrous mats as a case study. Nanofibers diameter and specimen geometry are investigated to thoroughly describe the nanomat tensile behavior, also considering the polymer thermal properties, and the nanofibers crossings number as a function of the nanofibers diameter. Below a threshold value, which lies between 150 and 250 nm, the overall mat mechanical behavior changes from ductile to brittle, showing enhanced elastic modulus for a high number of nanofibers crossings. While specimen geometry does not affect tensile results. Stress\u2013strain data are analyzed using a phenomenological data fitting model to better interpret the tensile behavior. The experimental results demonstrate the high reliability of the proposed mass-based load normalization, providing a simple, effective, and universally suitable method for obtaining high reproducible tensile stress\u2013strain curves

How Nanofibers Carry the Load: Toward a Universal and Reliable Approach for Tensile Testing of Polymeric Nanofibrous Membranes

Nanofibrous nonwovens show high versatility and outstanding properties, with reduced weight. Porous morphology, high material flexibility and deformability challenge their mechanical testing, severely affecting results reliability. Still today, a specific technical standard method to carry out tensile testing of nonwoven nanofibrous mats is lacking, as well as studies concerning tensile test data reliability. In this work, an accurate, systematic, and critical study is presented concerning tensile testing of nonwovens, using electrospun Nylon 66 random nanofibrous mats as a case study. Nanofibers diameter and specimen geometry are investigated to thoroughly describe the nanomat tensile behavior, also considering the polymer thermal properties, and the nanofibers crossings number as a function of the nanofibers diameter. Below a threshold value, which lies between 150 and 250 nm, the overall mat mechanical behavior changes from ductile to brittle, showing enhanced elastic modulus for a high number of nanofibers crossings. While specimen geometry does not affect tensile results. Stress–strain data are analyzed using a phenomenological data fitting model to better interpret the tensile behavior. The experimental results demonstrate the high reliability of the proposed mass-based load normalization, providing a simple, effective, and universally suitable method for obtaining high reproducible tensile stress–strain curves