Disinfestazione di manufatti lignei da parassiti larvali mediante tecniche da vuoto

Wooden artifacts are subject to being heavily damaged by the attack of worms which develop in the wood through the eggs deposited by adult pests before their final transformation into flying insects. Among the most dangerous species are xylophagous (wood-boring) insects, whose larvae are responsible for one of the most efficient wood-destroying mechanisms in wooden cultural heritage. Their elimination has always been a huge problem for the conservation of wood. In this work, we present the experimentation of a simple vacuum technique to disinfest wood from the larval Hylotrupes bajolus. We will also introduce the possibility of treating large-sized wooden artifacts by means of a special vacuum chamber.I manufatti lignei sono soggetti ad essere fortemente danneggiati dall’attacco di parassiti che, nella loro forma adulta, prolificano nel legno depositando le loro uova. Tra le specie più pericolose ci sono gli insetti xilofagi, le cui larve sono responsabili di uno dei più efficaci meccanismi di degradazione dei manufatti artistici lignei. La loro eliminazione, da sempre, costituisce un problema enorme per lo stato di conservazione del legno. In questo lavoro, viene presentata la sperimentazione di una nuova semplice tecnica da vuoto per la disinfestazione del legno da parte del Hylotrupes bajulus nella sua forma larvale. Viene inoltre presentata la possibilità di trattare manufatti lignei di grandi dimensioni per mezzo di una speciale camera da vuoto

Thermotropic properties of new electrochromic viologen-based ionic liquid crystals.

Thermotropic ionic liquid crystals are considered very promising functional electrolytes in DSSCs, batteries, fuel cells and capacitors1,2 for their unique combination of anisotropic ion conductivity and high polarizability.3 Moreover, they are interesting in the optoelectronic field as electrooptical functional unit.3-5 Many efforts have been devoted to the design of liquid crystals salts based on the viologen unit as organic cation, due to their interesting electrochromic and electrochemical properties.6 Most of the reported structures contain flexible chains directly linked to the nitrogens of the bipyridine rings.6 Their thermotropic behavior depends on the nature of the anion and of the N-substituents. A suitable choice of the latter makes access to different molecular orbital energy levels allowing different colors of the corresponding radical cation. N-Aryl substituted viologens, are of great interest because they show green colored radical cations due to the delocalization of the radical-cation over an extended p-system.7. Herein, we present a series of new N-aryl substituted liquid-crystalline viologens based on mono(4-alkylphenyl) and bis(4-alkylphenyl) bipyridinium cations with the same counterion but different alkyl chains (n=8, 10,12, 14), reporting their thermal behavior, their mesomorphic properties as a function of the chain length and their electrochromic properties in solution and in the LC phase.7 References: [1] Pan, X.; Wang, M.; Fang, X.Q.; Zhang, C.N.; Huo, Z.P.; Dai, S.Y.; Sci. China: Chem., 2013, 56, 1463–1469. [2] Sasi, R.; Chandrasekhar, B.; Kalaiselvi, N.; Devaki, S.J.; Adv. Sustainable Syst., 2017, 1, 1600031. [3] Axenov, K.V., Laschat, S.; Materials, 2011, 4, 206. [4] Bhowmik, P.K.; Kareem, M.; Al-Karawi, M.K.M.; Killarney S.T.; Dizon, E.J.; Chang, A.; Kim, J.; Chen, S.L.; Principe, R.C.G.; Ho, A.; Han, H.; Mandal, H.D.; Cortez, R.G.; Gutierrez, B.; Mendez, K.; Sharpnack, L.; Agra-Kooijman, D. M.; Fisch, M.R.; Kumar, S.; Molecules 2020, 25(10), 2435. [5] K. Goossen, K. Lava, C. W. Bielewski, K. Binnemans, Chem. Rev., 2016, 116, 4643. [6] Monk, P.M.S., The viologens: physico-chemical properties, synthesis and application of the salt of 4,40-bipyridine, John Wiley and Sons, Inc., Wiley – VCH, New York, Weinheim, 1998. [7] Veltri, L.; Cavallo, G.; Beneduci, A.; Metrangolo, P.; Corrente, G.A.; Ursini, M.; Romeo, R.; Terraneo, G.; Gabriele, B.; New J. Chem., 2019, 43, 18285-18293

Electrofluorochromism in π-conjugated ionic liquid crystals

Materials in which photoluminescence is modulated by redox processes are known as electrofluorochromic. Intrinsically switchable fluorophores, incorporating both redox and fluorescent moieties, could be ideal electrofluorochromic materials if they possess high fluorescence quantum yields in at least one of their redox states. Fluorescent liquid crystals with redox active centres could combine the above requirements with the advantage to work in bulk anisotropic phases. However, electrofluorochromic liquid crystals have not been reported yet because their synthesis is challenging due to aggregation-caused fluorescent quenching. Here we show the first examples of electrofluorochromic π-conjugated ionic liquid crystals based on thienoviologens. These ordered materials, combining ionic and electronic functions, are highly fluorescence in the bulk state (quantum yield>60%). Their direct electrochemical reduction leads to fast and reversible bulk electrofluorochromic response in both columnar and smectic phases allowing for fluorescence intensity modulation and colour tuning

Removal of endocrine disrupting chemicals from water: adsorption of bisphenol-A by biobased hydrophobic functionalized cellulose

The aim of this study is to examine the efficiency of biobased Spanish broom (SB) surface modified cellulose fibers to remove bisphenol A (BPA), a well-known endocrine disruptor, from water. Spanish brooms are flowering plants, which are native and abundant to Mediterranean regions. The functionalized fibers (FF) were found to have the best adsorption efficiency at pH 5, due to the optimal hydrophobic interaction between the FF fiber and BPA. Adsorption kinetics of BPA was found to fit well a pseudo-second order reaction. Equilibrium isotherm data were fitted by Langmuir and Freundlich models. A very fast and simple regeneration method was developed and it was observed that adsorption capacity of the fibers was kept almost unchanged after 3 consecutive uses. Bottled water and synthetic wastewater were also tested to assess the efficiency of the process under more realistic water and wastewater treatment conditions. It was found that BPA removal was slightly decreased from 77% in ultrapure water to 64% in synthetic wastewater matrix, indicating that FF has a high selectivity toward BPA, even in the presence of other organic compounds. Overall, it was observed that SB-modified fibers can be a new promising green biotechnology for water purification

Photocatalytic inactivation of Escherichia coli bacteria in water using low pressure plasma deposited TiO2 cellulose fabric

Fabrics obtained from cellulose spinning, extracted from Spanish broom, were coated with TiO2 film, through the low pressure plasma sputtering technique, in order to get antibacterial activity. The obtained fabrics were used for the photocatalytic degradation of Escherichia coli, by irradiation with UV-light emitting diodes (UV-LED), in a batch photocatalytic reactor. Before and after functionalization treatments, cellulosic substrates were chemically characterized by X-ray photoelectron spectroscopy (XPS) analyses. Water Contact Angle (WCA) measurements allowed obtaining information about the hydrophilicity of the materials, while their antibacterial efficiency was determined at several initial concentrations (from 103 up to 108 CFU mL−1) of bacteria in distilled water, bottled water and synthetic wastewater. It was found that photocatalytic reactions were capable of achieving up to 100% bacterial inactivation in 1 h of treatment, following a pseudo-first order kinetic model. No bacterial regrowth was observed after photocatalytic treatments in almost all experimental conditions. In contrast, during photolytic treatment (i.e. in the absence of the TiO2 coated fabrics) bacteria recovered their initial concentration after 3 h in the dark. Finally, the reusability of the plasma modified fibers to inactivate bacteria was studied

Use of Iron (II) Salts and Complexes for the Production of Soil Amendments from Organic Solid Wastes

A method to obtain rapidly stabilized composts for crops from solid organic wastes is evaluated. Here we used a laboratory scale reaction chamber where solid waste treatment was performed under strictly controlled temperature and pressure conditions. The row organic waste was mixed with acid solutions containing iron (II) ions either in the fully hydrated form or in the form of complexes with the diethylentriaminopentaacetic acid. Data from elemental analysis distribution and GC/MS analysis of the polar and non polar dissolved organic matter, clearly showed that Fe(II) ions significantly enhance organic substrate oxidation of the initial solid waste, compared to a material obtained without the addition of the Fe(II) ions to the raw organic matrix. These results suggest that Fe(II) ions might be involved in a catalytic oxidation pathway that would be activated under the experimental conditions used. The extent of the oxidation process was evaluated by the value of the C/N ratio and, qualitatively, by the molecular composition of the dissolved organic matter. After about 6 hours of incubation, dark-brown and dry organic matrices were obtained with C/N ratio as low as 12 and a high degree of oxidative decomposition into low-molecular-weight compounds at high oxidation state

Millimeter Wave Radiations Affect Membrane Hydration in Phosphatidylcholine Vesicles

A clear understanding of the response of biological systems to millimeter waves exposure is of increasing interest for the scientific community due to the recent convincing use of these radiations in the ultrafast wireless communications. Here we report a deuterium nuclear magnetic resonance spectroscopy (2H-NMR) investigation on the effects of millimeter waves in the 53–78 GHz range on phosphocholine bio-mimetic membranes. Millimeter waves significantly affect the polar interface of the membrane causing a decrease of the heavy water quadrupole splitting. This effect is as important as inducing the transition from the fluid to the gel phase when the membrane exposure occurs in the neighborhood of the transition point. On the molecular level, the above effect can be well explained by membrane dehydration induced by the radiation

Mixed-Valence Compounds as a New Route for Electrochromic Devices with High Coloration Efficiency in the Whole Vis-NIR Region

Electrochromic devices (ECDs) that allow the modulation of light transmission are very attractive in the research field of energy saving. Here all-in-one gel switchable ECDs based on mixed-valence electroactive compounds were developed. The use of the thienoviologen/ferrocene couple as cathode and anode, respectively, leads to a significant electrochromic band in the visible range (550–800 nm), with a color change from yellow to green, and to a lower band in the NIR region (1000–1700 nm), due to the presence of one electroactive-chromic species. Replacement of the electroactive ferrocene with a fluorene-diarylamine electroactive-chromic species, allows to extend and intensify the absorption in the NIR region, thus affording modulation of the solar radiation from 500 up to 2200 nm. High optical contrast, fast coloration and bleaching times and outstanding coloration efficiencies were measured for all observed absorption bands upon the application of small potential differences (1.4 V < DV < 2 V)

BTX Removal from Open Aqueous Systems by Modified Cellulose Fibers and Evaluation of Competitive Evaporation Kinetics

BTX stands for Benzene, Toluene, and Xylenes, which are volatile organic compounds contained in petroleum products such as gasoline. They have negative health effects and are sadly known for soil, air, and water contamination. This paper provides an investigation on BTX removal from open water systems like those represented by natural water bodies. In such systems, the evaporation process takes place, stealing the pollutants from the aqueous matrix by transferring them into the air, resulting in a secondary pollution. To prevent this situation, adsorption of these organic compounds on cellulose fibers, extracted from Spanish Broom vegetable, was studied. Raw and surface modified cellulose fibers were used for this purpose. The second ones were hydrophobized by two different green and low-cost functionalization systems (no solvent urethane functionalization and low pressure plasma treatments). Batch experiments were performed in an open system where BTX underwent two competing removing mechanisms: volatilization, and adsorption/desorption on/from the fibers dispersed in the water system. A mathematical model was implemented for the interpretation of the observed time-varying pollutant concentrations and the estimation of the kinetic constants for adsorption, desorption, and evaporation. The developed model, provided with the aforementioned parameters calibrated for each type of fibers, was then used for the prediction of their adsorption capacities both into open and closed systems