Synthesis of Polystyrene-Bound Organotin Derivatives as Intermediates for the Production of Hybrid Materials

Polystyrenes bearing tricyclohexylstannyl moieties with different stereoregularities, molecular weights, and chemical composition have been prepared and characterized through two synthetic routes. The suitability of the products obtained to be used as intermediate derivatives in the synthesis of the corresponding organotin trichlorides, precursors to organic–inorganic hybrid materials, has been investigated.     

Synthesis and Characterization of New Functional Polystyrenes Containing Tributyltin Carboxylate Moieties Linked to the Aromatic Ring by a Trimethylene Spacer

A novel trialkyltin carboxylate monomer, tributyltin 4-(p-styryl)-butanoate, characterized by the presence of a trimethylenic spacer linking the tin carboxylate moiety to the aromatic group, has been prepared and submitted to radical homo- and copolymerization with styrene in order to obtain the corresponding copolymers with variable contents of organometallic moiety. For the sake of comparison, tributyltin 4-(4-isopropylphenyl)-butanoate has also been synthesized as the structural model of the repeating unit of the polymers. All the products prepared have been characterized both in solution and in the solid state by spectroscopic and thermal techniques with the aim to establish the coordination state of the tin atom, a feature which is of importance for future application of these derivatives.     

Olive mill wastewater biological treatment by fungi biomass.

Olive oil extraction is one of the most important traditional food industries in the Mediterranean region, especially in Italy. In addition to olive oil, this industry produces by-products, in particular olive mill wastewaters (OMWs) and olive husks, which represent a serious environmental problem. OMWs can be rarely treated in a municipal WWTP, using conventional wastewater treatments. A novel biological process has to be considered in order to treat OMWs. Literature data show that yeasts and different kinds of fungi are able to reduce both the organic and the phenolic content of the OMW. The present work is aimed at investigating the growth of a biomass rich in fungi in a batch reactor filled with OMW and its capacity to degrade the organic and phenolic load. The aerobic OMW degradation obtained using this biomass reached a COD and TP removal efficiency of 86 and 70%, respectively. Respirometric tests have been carried out in order to measure the biomass activity on different substrates: OMW and phenolic compounds (gallic and p-coumaric acids). The polyphenolic biodegradation efficiency of fungi biomass was higher than the one of a non-acclimated activated sludge biomass. Fungi biomass was able to completely degrade pure phenolic compounds.     

Molding and replication of ceramic surfaces with nanoscale resolution

The design of reproducible and more efficient nanofabrication routes has become a very active research field in recent years. In particular, the development of new methods for micro- and nanopatterning materials surfaces has attracted the attention of many researchers in industry and academia as a consequence of the growing relevance of patterned surfaces in many technological fields, ranging from optoelectronics to biotechnology. In this work we explore, discuss, and demonstrate the possibility of extending the well-known molding and replication strategy for patterning ceramic materials with nanoscale resolution. To achieve this goal we have combined physical deposition methods, molecule-thick anti-sticking coatings, and nanostructured substrates as master surfaces. This new perspective on an "old technology", as molding is, provides an interesting alternative for high-resolution, direct surface-relief patterning of materials that currently requires expensive and time-consuming lithographic approaches.     

Hybrid Organic–Inorganic Copolymers from Oxohydroxoorganotin Dimethacrylate and Methyl Methacrylate

Organic–inorganic polymeric derivatives constituted by methyl methacrylate co-units and an oxohydroxobutyltin macrocation difunctionalized with methacrylate counterions have been prepared by radical polymerization in solution. The reaction affords soluble products, indicative of a substantial absence of cross-linking originated by the difunctional macrocationic comonomer, when the molar excess of methyl methacrylate is high. The organic–inorganic hybrid products obtained have been characterized by various techniques, thus allowing us to propose a mechanism for their formation which implies a role as chain termination agent for the macrocationic monomer.     

Synthesis, Characterization and Transesterification Activity of Cross-Linked Styrenic Resins Containing the Triphenyltincarboxylate Moiety Spaced by a Dimethylene from the Aromatic Ring

An organotin monomer, triphenyltin 3-(4-styryl)-propionate (TPTSPr) has been synthesized and copolymerized in different ratios with styrene and 1,4-divinylbenzene in order to obtain resins with catalytic activity in transesterification reactions. The resins and a low molecular weight model compound, triphenyltin 3-(4-ethylphenyl)-propionate (TPT-C2-Pr), mimicking the catalytic co-unit, have been characterized by FT-IR and NMR spectroscopy, with particular attention paid to the coordination at tin and how it correlates to the catalytic activity. The activity of both the resins and of the model compound have been tested in a transesterification model reaction between ethyl acetate and primary alcohol. All the resins show catalytic activity that decreases with increasing content of the active co-unit in the resins, owing to the interaction of the active sites among themselves.     

In vitro fermentation kinetics of carbohydrate fractions of fresh forage,silage and hay of Avena sativa

The objective of this experiment was to evaluate the influence of preservation methods on the fermentation kinetics of carbohydrate fractions of fresh forage, hay and silage of oats, which have been harvested at the milky stage of grain ripening. Samples of unfractionated forage (WF), residue insoluble in 90% ethanol (EIR) and isolated neutral detergent fibre (NDF) were fermented in vitro and the gas production was monitored. To obtain the gas production and fermentation kinetics of the ethanol‐soluble fraction (A fraction) the gas produced from the EIR fermentation was subtracted from the WF gas at each time point. The same approach was used to obtain the gas production and fermentation kinetics of the fraction insoluble in 90% ethanol but soluble in neutral detergent solution (B₁ fraction), by subtracting the isolated NDF gas curve from the corresponding EIR curve. The fractional maximum rate of gas production (R_M) was lower for both preserved forages (p < 0.01 for silage; p < 0.05 for hay) than for fresh forage. Ensiling did not change the size of the A fraction but reduced by 40% its R_M (p < 0.01) compared with fresh forage. The potential gas production from the B₁ fraction and its R_M were reduced by 19% (p < 0.01) and 44% (p < 0.05), respectively. R_M of both A and B₁ fractions was the same for hay and fresh forage. The curve subtraction technique may be used to obtain an estimation of the rate for neutral detergent‐soluble fractions and to determine changes due to ensiling and haymaking on the rate of gas produced. Copyright © 2005 Society of Chemical Industry     

In vitro degradability of three forages: fermentation kinetics and gas production of NDF and neutral detergent‐soluble fraction of forages

The fermentation of the neutral detergent‐soluble (NDS) fraction of three forages (alfalfa hay, Italian ryegrass + oats hay and corn silage) was measured using a curve subtraction technique with in vitro gas production data from the whole forage (WF) and the isolated neutral detergent fibre (NDF). NDF disappearance and volatile fatty acid (VFA) production were determined. There was no significant difference between the VFA patterns from the whole forage and the isolated NDF. There were significant (P < 0.001) linear correlations between the volume of gas and moles of VFA produced and the mass of fibre digested in the NDF samples. Using the monophasic curve model, maximum gas production rates (R_M) for the whole forages and the isolated NDF and NDS fractions can be calculated. For all three forages we obtained R_M‐NDS > R_M‐WF > R_M‐NDF. Trends in the rates of gas and VFA production were similar in the whole forages. The NDF showed a high superimposition between substrate degradability and VFA production. Our experiment confirmed the curve subtraction technique as a simple method to obtain information on the size and digestion kinetics of the NDS fraction, which helps in understanding the nutritional significance of this important fraction of the forages studied. © 2001 Society of Chemical Industry     

Effects of tillage and nitrogen fertilisation on triticale grain yield,chemical composition and nutritive value

BACKGROUND: Given the interest in the development of cultivation systems with low agronomic input and environmental impact, the aim of this study was to determine the influence of tillage system (conventional tillage (CT), two‐layer tillage (TT), surface tillage (ST) and minimum tillage (MT)) and nitrogen (N) fertilisation rate (0, 50 and 100 kg ha^?1) on triticale grain and protein yields, chemical composition and nutritive value. RESULTS: There were no significant differences among tillage treatments in grain and protein yields. ST resulted in significantly higher crude protein (CP) and true soluble protein (TSP) contents as well as in vitro crude protein digestibility (CPD). Neutral detergent fibre concentration was significantly higher with ST than with MT, and this led to a small reduction (2 g kg^?1 dry matter (DM)) in in vitro true DM digestibility (IVTDMD). N fertilisation significantly increased grain and protein yields as well as CP, non‐protein nitrogen and TSP contents and CPD. IVTDMD was significantly lower with 0 kg N ha^?1 than with 50 and 100 kg N ha^?1. CONCLUSION: Reducing tillage intensity improved the CP content and CPD of triticale grain. The application of 50 kg N ha^?1 resulted in good grain quality parameters and grain and protein yields. Copyright © 2010 Society of Chemical Industry