1,721,122 research outputs found
Synthesis of talc-like filler with covalently bonded organic modifiers as novel additive for polymer nanocomposites
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Method for the preparation of polyaniline/reduced graphene oxides composites
Full text linkThe present invention concerns a method for obtaining polyaniline/reduced graphene oxide composites comprising the steps of dispersing the graphene oxide in an acid aqueous solution containing an emulsifying agent to obtain a graphene oxide dispersion; dissolving one or more aniline oligomers in an organic solvent to obtain an oligomer solution; mixing the oligomer solution with the graphene oxide dispersion, said oligomer being added in a stoichiometric excess compared to the quantity required to complete the graphene oxide reduction; adding to the suspension of the polyaniline/reduced graphene oxide composite an oxidizing agent in a stoichiometric quantity compared to said excess of oligomer so as to oxidize the excess of said oligomer to obtain a suspension of the polyaniline/reduced graphene oxide composite
Nanocomposites combustion peculiarities. A case history: Polylactide-clays
No full textThis paper addresses the combustion behaviour of polylactide (PLA) nanocomposites based on organomodified montmorillonite clays. It is shown that PLA nanocomposites burn in a very different way compared to virgin PLA. Indeed, nanocomposites burning rate is usually lower respect to PLA, with a rate decrease depending on clay type and concentration. However, an easier ignition is shown by PLA nanocomposites as compared to PLA which is due to a catalytic effect of the clays. It is shown that these peculiar features of nanocomposites burning behaviour may prevent reliable comparison between polymers and nanocomposites based only on a single parameter such as UL 94 test ranking or the Limiting Oxygen Index value (LOI). It is also shown that by an extended use of data provided by the LOI apparatus, the peculiarities of nanocomposites combustion process are easily detecte
Thermal Evolution of Nanocomposites. When Nanoparticles are Effective in Polymer Fire Retardancy
Full text linkA decade of research and development concerning polymer nanocomposites has shown the essential features of their combustion process. Nanocomposites actually display a fire retardant behaviour because they avoid fire propagation by dripping of hot and flaming polymer particles and reduce the rate of combustion. The mechanism involved in nanocomposites fire retardance is based on formation on heating of a ceramic protective, insulating layer on the surface of the burning material resulting from coalescence of nanofillers enclosing char from surface polymer charring, catalysed by the nanofiller. The thermal evolution of nanocomposites to the fire protective structure is discussed in relation with dispersion and distribution of the nanofillers in the polymer matrix either as it results from nanocomposite preparation or from its thermal evolution.
Evaluation of the fire retardant performance of polymer nanocomposites in fire tests representing different fire scenarios (i.e. ignition, flammability and forced combustion) will be discussed in this talk
A Perspective on Hydrogen Storage in the Energetic Transition Scenario
Full text linkHydrogen is key player in the energetic transition towards a more sustainable society as a very versatile energy carrier. Nevertheless, hydrogen storage represents the main limitation to the spread of a hydrogen driven economy on a small and medium scale. Clearly, achieving this requires a balance among material engineering, system optimization, and techno-economic assessments to optimize performance, safety, and scalability. In this work we briefly and critically discuss the progress in hydrogen storage focusing on the necessity to create a bridge to overcome the actual limitations. We explore the most recent advancement in the field drawing a picture of the complex scenario of hydrogen storage in the framework to the transition to a net zero or carbon negative society providing an updated opinion on the challenges addressed and those still to be solved
A Comprehensive Review on Hydrogen Production from Biomass Gasification
Full text linkHydrogen production from biomass gasification has emerged as a strategic pathway for achieving carbon-neutral energy systems, circular resource utilization, and sustainable fuel generation. As global energy systems transition toward renewable sources, biomass-derived hydrogen represents a cornerstone of waste valorization, negative-emission bioenergy, and green hydrogen economies. Among all technologies, hydrogen production through gasification is one of the most consolidated routes with plenty of operative industrial-scale plants. The field of gasification is quite complex, and this comprehensive review describes the current scientific and technological achievements of biomass gasification for hydrogen production, describing the effect of feedstock, reactivity phenomena, reactor design, and catalyst systems. Furthermore, we report on a quantitative analysis regarding the operative cost of gasification of biomass compared with green hydrogen production and methane reforming. We provide a complete and synthetic picture for one of the most critical fields in the hydrogen economy that can actively promote a transition towards a more sustainable society
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