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Copelli S.,University of Insubria | Fumagalli A.,Polytechnic of Milan | Gigante L.,INNOVHUB | Pasturenzi C.,INNOVHUB
Powder Technology | Year: 2017

In the last ten years, the search for new application materials has become one of the “must” in the field of powder technology. Particularly, as regards solid lubricants, concerns in the use of compounds containing Lead and Antimony have been raised, since the former is classified as a carcinogen and the second such as a suspect one. Therefore, as consequence of both more and more stringent law requirements for environmental emissions and low impact on human health, safe and cheap materials are strongly demanded. As the sake of example, Tin (II) Sulfide, SnS, has been widely tested and found to be not only technically superior with respect to other alternatives but also safer from the environmental point of view. Despite these properties, its development has been limited by the relatively high synthesis costs compared to its competitors. The aim of this work is to determine the kinetics of a safe “dry” batch process for the production of SnS using only cheap calorimetric techniques. The results obtained from this study (synthesized in a series of equations describing the dynamics of the process) have shown that a simple but complete calorimetric analysis is able to overcome the main criticality that characterizes a dry synthesis involving Sulfur and Tin: that is, the difficulty in the reactor temperature control (danger of thermal runaway) due to the extremely fast and high exothermicity of the reaction and the low thermal capacity of the reacting mixture. © 2017 Elsevier B.V.

Copelli S.,University of Insubria | Torretta V.,University of Insubria | Pasturenzi C.,INNOVHUB | Derudi M.,Polytechnic of Milan | And 2 more authors.
Journal of Loss Prevention in the Process Industries | Year: 2013

It is well-known that, for certain values of the operative parameters influencing the dynamic behavior of a chemical reactor, a phenomenon known as thermal runaway (that is, a loss of the reactor temperature control) may arise. Such a situation can be really dangerous because above a certain threshold temperature value unwanted side reactions or, worse, decompositions of the reacting mixture may be triggered evolving high amounts of flammable or toxic gases that can cause reactor pressurization and, eventually, its explosion. For this reason, since the beginning of the previous century a number of studies concerning the prediction of the so called runaway boundaries has been carried out. In this work, a modified version of the divergence criterion for runaway detection, originally developed by Zaldívar and co-workers, is presented. Such a modified divergence criterion is capable of treating whatever type of complex controlled reacting system (taking into account not only temperature control but also dosing strategies) and its reliability has been demonstrated for isoperibolic semibatch reactors using literature experimental data concerning the nitration of 4-Chlorobenzotrifluoride in mixed acids and the nitric acid oxidation of 2-octanol to 2-octanone and further carboxylic acids. © 2013 Elsevier Ltd. All rights reserved.

Frison R.,CNR Institute of Crystallography | Cernuto G.,University of Insubria | Cervellino A.,Paul Scherrer Institute | Zaharko O.,Paul Scherrer Institute | And 3 more authors.
Chemistry of Materials | Year: 2013

Very small superparamagnetic iron oxide nanoparticles were characterized by innovative synchrotron X-ray total scattering methods and Debye function analysis. Using the information from both Bragg and diffuse scattering, size-dependent core-shell magnetite-maghemite compositions and full size (number- and mass-based) distributions were derived within a coherent approach. The magnetite core radii in 10 nm sized NPs well match the magnetic domain sizes and show a clear correlation to the saturation magnetization values, while the oxidized shells seem to be magnetically silent. Very broad superstructure peaks likely produced by the polycrystalline nature of the surface layers were experimentally detected in room temperature oxidized samples. Effective magnetic anisotropy constants, derived by taking the knowledge of the full size-distributions into account, show an inverse dependence on the NPs size, witnessing a major surface contribution. Finally, an additional amorphous component was uncovered within the diffuse scattering of the "ordered" magnetite-maghemite NPs. Under the hypothesis that this material may form an external dead layer, an additional thickness varying between 0.3 and 1.0 nm should be added to the overall core-shell NPs size. © 2013 American Chemical Society.

Copelli S.,University of Insubria | Torretta V.,University of Insubria | Lunghi A.,INNOVHUB | Derudi M.,Polytechnic of Milan | And 2 more authors.
Industrial and Engineering Chemistry Research | Year: 2013

Fast and strongly exothermic emulsion polymerization processes are particularly difficult to optimize from both safety and productivity points of view because of the occurrence of a number of undesired side reactions (e.g., propagation of tertiary radicals, chain transfer to monomer, backbiting, termination by disproportionation, etc.) and the triggering of boiling phenomena with consequent stable foam formation under atmospheric pressure. Therefore, it would be useful to develop a suitable combined theoretical and experimental procedure able to detect both the optimum process dosing time and initial reactor temperature. In this work, it is discussed how an extended version of the topological criterion theory, originally developed for isoperibolic semibatch reactors, can be used to safely optimize an indirectly cooled isothermal semibatch reactor. Moreover, such a methodology is applied to a case study represented by the synthesis of poly(butyl acrylate) through the radical emulsion polymerization of butyl acrylate. © 2013 American Chemical Society.

Bondioli P.,INNOVHUB | Della Bella L.,INNOVHUB | Rivolta G.,INNOVHUB
European Journal of Lipid Science and Technology | Year: 2013

Monoglycerides represent a reaction residue in renewable biodiesel fuel. Among the possible glyceridic forms they are poorly soluble and have high melting point. For this reason during the in field use of biodiesel neat or in blend with diesel, monoglycerides can cause problems as regards to the cold stability of the fuel and the plugging of filters. The problem of quantitatively evaluating the monoglycerides content in biodiesel has been addressed and solved during the last 20 years, generally by means of GC. Recently the need for a strong reduction of total and saturated monoglycerides content appeared. In parallel with the technology changes new analytical methods have to be developed, in order to fulfill the requirement of accuracy and precision at low concentration levels. The technique presented here allows the determination of total monoglycerides content and the separate quantification of glycerol monopalmitate and stearate. The proposed method is based on acetylation of hydroxy groups of the sample, followed by micro column solid phase separation, isolation of polar fraction containing all acetylated glycerides, and GC quantification with internal standard. By using this technique a low noise GC path is obtained thus allowing the identification and the quantification of peaks. Our results are discussed in comparison to those obtained with the existing standards and demonstrated a good repeatability even at low concentration levels. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Bondioli P.,INNOVHUB | Rivolta G.,INNOVHUB
Rivista Italiana delle Sostanze Grasse | Year: 2013

This short paper reports about the quantity and the composition of the liquid oil that can be obtained from Sarcophaga carnaria L larvae by means of hexane extraction. The obtained oil contains palmitic, palmitoleic, oleic and linoleic as the main fatty acids. In particular 2 different positional isomers of palmitoleic, for a total content of approx. 18% were detected. Data are reported about the sterol composition of oil. The residual meal is constituted of 70% of protein and could be of potential interest as a feed. The amino acid composition of the protein fraction is reported.

This paper describes the application of multiscreening methods aimed to the determination of mycotoxins, phthalates, polycyclic aromatic hydrocarbons, metals and phytoresidues in oil and flour obtained from Cannabis sativa L This plant is cultivated for textile fiber production and extraction of oil from seeds and is used in food and folk medicinal preparations for its positive health benefits, including lowering of cholesterol and blood pressure. Moreover, due to the high content of polyunsaturated compounds, hemp seed oil has been used for printer's ink, wood preservative and also for detergents and soaps. The multiscreening analysis regarding mycotoxins (aflatoxin B 1, B2, G1, G2, deoxynivalenol, ochratoxin A, zearalenone) and polycyclic aromatic hydrocarbons on oil and flour were negative for all components. The analysis of the main phthalates, used in plastic production, showed a fairly high content of diethylhexylphthalate in hemp oil, probably due to the type of packaging in which the sample was stored. The analysis of heavy metals (lead, cadmium, nickel, arsenic and chromium) and some metals from industrial processes (iron, copper and phosphorus) in the oil found no presence for the former and only few amounts of iron, copper and phosphorus. The hemp flour is instead found to be a potential source of micronutrients, such as iron, manganese and zinc, useful in human and animal nutrition, in addition to a high amount of phosphorus highly available, while the concentrations of the toxic metal compounds were below the limit of detection of the analytical methods. Execution of multiscreening analysis for pesticides revealed positive results for certain residues on oil, flour, and oil extracted from the flour, even if at low concentrations.

Colleoni C.,University of Bergamo | Donelli I.,INNOVHUB | Freddi G.,INNOVHUB | Guido E.,University of Bergamo | And 2 more authors.
Surface and Coatings Technology | Year: 2013

The way of producing functional textile finishings by the sol-gel process using a multistep approach, consisting of consecutive depositions of sol layers on cotton fabric, for obtaining architectures with a different number of layers (namely, 1, 3 or 6 layers) is discussed. To this aim, tetraethoxysilane (TEOS) has been used as a precursor and the role of such architectures has been deeply investigated and correlated with the sol concentration and with the presence of the condensation catalyst DBTA (Dibutyltindiacetate). The multi-layer coatings were applied by padding using sols containing appropriate molar ratios of the precursor, anhydrous ethanol, catalyst and hydrochloric acid. The effects of the catalyst during the alkoxide reaction and the silica amount applied by sol-gel treatment on the thermo-oxidative behavior of the treated fabrics were deeply studied. FT-IR ATR spectroscopy, SEM analysis, thermal and thermo-oxidative stability, washing fastness, flammability and mechanical properties of the sol-gel treated cotton fabrics have been also investigated. The results obtained should be interpreted according to the properties investigated. The higher the concentration and the number of layers of the inorganic matrix, the higher the heat protection of textile samples. However, the resulting coating was so rigid that it modified the mechanical properties and particularly it decreased the wear resistance according to Martindale test. To improve the mechanical properties the best results were obtained by modulating a lower concentration of the matrix using a layered approach. In all cases, high adhesion of the coating to the textile fabrics was observed. © 2013 Elsevier B.V.

Laincer F.,University of Abderrahmane Mira de Béjaïa | Laribi R.,University of Abderrahmane Mira de Béjaïa | Tamendjari A.,University of Abderrahmane Mira de Béjaïa | Arrar L.,Ferhat Abbas University Setif | And 2 more authors.
Grasas y Aceites | Year: 2014

The phenolic compositions, antioxidant and antimicrobial activities against six bacteria of phenolic extracts of olive oil varieties from eleven Algerian varieties were investigated. The antioxidant activity was assessed by determining the scavenging effect on the DPPH and ABTS.+ radicals. The antimicrobial activity was measured as a zone of inhibition and minimum inhibitory concentration (MIC) on human harmful and foodborne pathogens. The results show that total phenols was significantly (p< 0.05) correlated with DPPH (r = 0.72) and ABTS.+ radicals (r = 0.76). Among the bacteria tested, S. aureus and to a lesser extent B. subtilis showed the highest sensitivity; the MIC varied from 0.6 to 1.6 mg·mL-1 and 1.2 to 1.8 mg·mL-1, respectively. The results reveal that Algerian olive oils may constitute a good source of antioxidant and antimicrobial agents. © 2014 CSIC.

PubMed | Niguarda Hospital, University of Pavia, University of Milan and Innovhub
Type: Journal Article | Journal: Pharmaceutical development and technology | Year: 2016

With the aim of establishing the formulation of a new hydrophilic auto-gelling medical device for biomedical applications, fibroin-based microspheres were prepared. The proposed microspheres were produced by a cost-effective and industrially scalable technique, such as the spray-drying. Spray-dried silk fibroin microspheres were obtained and the effects of different hydrophilic polymer on the process yield, microsphere morphology and conformation transition of fibroin were evaluated. The final auto-gelling formulations were obtained by adding calcium gluconate (as a calcium source for alginate crosslinking) to the prepared microspheres and tested by an in vitro gelling test. This study showed that the combination of fibroin with sodium alginate and poloxamer produced the most promising auto-gelling formulation for specific biomedical applications, such as the treatment of pressure ulcers.

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