Search results for " chimica"
showing 10 items of 3438 documents
Gelled electrolyte for nanostructured lead-acid battery
2019
In recent years, the storage of energy produced by renewable sources has become a topic of great interest. Lead-acid batteries are widely used in this field, in particular those based on VRLA (Valve-Regulated-Lead Acid) technology, in which the electrolyte is immobilized inside the battery. In this paper, the use of a hydrogel as an electrolyte was considered. Hydrogel can be described as a three-dimensional network of a hydrophilic polymer that can absorb large amounts of water (or aqueous solutions) without dissolving. Pb and PbO2 nanostructured electrodes were used in the battery that used hydrogel as an electrolyte. Two different types of hydrogels were synthesised, both based on PVA th…
Polyoxometalates complex architectures in thin films by exploiting physical and chemical processes at surfaces
2010
Interazioni tra nanotubi e molecole organiche
Nell'ampio scenario dei nanomateriali, i sistemi nanotubolari godono di un consolidato e crescente interesse sia nell'ambito scientifico che industriale. Fra la miriade di sistemi tubolari, i più utilizzati sono i nanotubi a base di carbonio e carbon nanohorns e più recentemente, vista l'elevata biocompatibilità e il loro basso costo, nanotubi inorganici quali i nanotubi di allosite. la funzionalizzazione di questi materiali con diverse tipologie di molecole organiche, ha permesso la sintesi di materiali che potrebbero o hanno trovato applicazione come filler polimerici, come supporti eterogenei in catalisi e nel campo del drug carrier e delivery. Inoltre, nel caso di nanotubi di allosite, …
Pb-PbOHCl Composite Nanowires Synthesized by Galvanic Deposition in Template
2019
In this paper, we report a detailed study on the synthesis of composite nanowires of Pb-PbOHCl via galvanic deposition into the pores of a membrane acting as a template. PbOHCl deposition quantitatively occurs as the solution pH exceeds the value of about 4.12. Simultaneously, owing to the galvanic coupling, electro-deposition of lead occurs, so composite nanowires were formed. The role of different parameters controlling the kinetic evolution of the process, such as oxygen bubbling, solution pH, surface area and type of sacrificial anode were investigated one at a time. The results suggest that every modification accelerating the alkalization of the solution inside the template pores favor…
Nanowire ordered Arrays for electrochemical sensing of H2O2
2016
In this work, we present the performance of nanostructured array of Cu for electrochemical sensors of hydrogen peroxide. Nanostructured sensors are obtained by template synthesis in commercial polycarbonate membranes. Arrays of Cu nanowires were fabricated through a displacement deposition reaction that permits to obtain nanostructures directly and without the use of an external power supply. To test the performance of nanostructured sensors, electrochemical experiments were carried out in an aqueous solution with different amounts of hydrogen peroxide. In order to obtain sensors with stable performance, we found that it is essential to increase wettability of the nanostructures through add…
3D Order for Improved Organic Solar Cells Effiency
2010
Four-Component Relativistic DFT Calculations of C-13 Chemical Shifts of Halogenated Natural Substances
2015
We have calculated the (13) C NMR chemical shifts of a large ensemble of halogenated organic molecules (81 molecules for a total of 250 experimental (13) C NMR data at four different levels of theory), ranging from small rigid organic compounds, used to benchmark the performance of various levels of theory, to natural substances of marine origin with conformational degrees of freedom. Carbon atoms bonded to heavy halogen atoms, particularly bromine and iodine, are known to be rather challenging when it comes to the prediction of their chemical shifts by quantum methods, due to relativistic effects. In this paper, we have applied the state-of-the-art four-component relativistic density funct…
Medicinal and aromatic plants in agricultural research, when considering criteria of multifunctionality and sustainability
2022
Over the last twenty years, agriculture has witnessed significant changes in terms of energy requirements, advanced technologies and practices. This is in response to the impacts of crop production on the climate and environment and increasing awareness of the importance of agricultural sustainability through organic farming. Agriculture encompasses complex production systems and certain aspects of multifunctionality and sustainability have become fundamental for these systems. Agricultural activity can provide various functions in agro-ecosystems, such as producing food, managing natural resources, and conserving landscape and plant biodiversity; contributing to the cultural, historical an…
General approaches of processes involved in neurodegeneration using protein and printed phospholipids models
2023
Template Fabrication of Nano-Structures using Anodic Alumina Membranes
2007
The influence of experimental parameters on the morphology of the porous structure and on the formation kinetics has been investigated for anodic alumina membranes (AAM) grown in aqueous H3PO4 at 160 V. It was found that pore aspect ratio and membrane porosity on the solution-side surface are influenced by tensiostatic charge, bath temperature and the presence of Al3+ ions in solution. Morphological and kinetic data, recorded in different conditions, give useful information on the growth mechanism of pore channels in phosphoric acid solution. Nickel nano-structures have been fabricated using AAM as ternplate.