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Critical parameters for product quality and yields in the polymerisation of 3,3'-didodecyl-2,2':5,2"-terthiophene
No full texthe yield and molecular weight of CHCl3 soluble poly(3,300-didodecyl-2,20:50,200-terthiophene) in the presence of FeCl3 were shown to depend strongly on quality and addition rate of the reagents, and on temperature. Best results were obtained by further drying commercial anhydrous FeCl3 and by slow addition of the reagents. Under these conditions the product molecular weight (Mw) and the yield of the CHCl3 soluble polymer were, respectively, 23 000–25 000 Da and 38–66%, and no insoluble polymer residue was obtained. Using raw commercial FeCl3 and/or adding the reagents all at once gave significant amounts of insoluble polymer fraction. Comparison with literature runs confirms that the polymerisation at 40 8C yields higher molecular weight product than at room temperature, and no insoluble polymer was still formed, provided that the above optimum reagents parameters were used
Compost effect on soil humic acid : a NMR study
No full textThe humic acid (HA) fraction of a food and vegetable residues compost (CM) was taken as indicator to trace the fate of CM organic matter in four years CM amended soil. H-1 and C-13 NMR spectroscopy were used to investigate the nature of the HA isolates from CM, control Soil (S-4) and amended soil. The result indicated a significant structural difference between CM HA and S-4 HA, and supported the presence of both HA fractions in soil at the end of the amendment trials. However, the nature and content of CM HA in soil did not fully explain the increase of soil cation exchange capacity (CEC) after amendment. All CM humic fractions (i.e., fulvic acid, humic acid and humin) were found to contribute to the change of the soil organic matter composition. It is concluded that although CM HA is a suitable indicator of the survival of compost organic matter in soil during amendment, all three humic fractions should be monitored and analyzed to fully understand changes in the composition and properties of amended soil. (c) 2006 Elsevier Ltd. All rights reserved
Protonic conductivity of layered zirconium phosphonates containing −SO3H groups. I. Preparation and characterization of a mixed zirconium phosphonate of composition Zr(O3PR)0.73(O3PR′)1.27·nH2O, with R=−C6H4−SO3H and R′ = −CH2−OH
No full textOrgano-inorganic composite membranes – a mathematical-modeling approach to the solid liquid interaction properties of asbestos in its composites
No full textProton conductivity of poly(dipropyl)phosphazene-sulfonated poly (hydroxy)propyl, phenyl ether-H3PO4 composite in dry environment
No full textA new composite material was fabricated by heat pressing a powder mix containing a sulfonated poly[(hydroxy)propyl, phenyl]ether (SPHPE), with empirical formula [-O-Ar-C(Me)(2)-Ar(SO3H)(0.4)-O-CH2CH(OH)-CH2-(center dot)1.5 H2O](n), and poly(dipropyl)phosphazene (PDPrP) to yield a film which was soaked in 85% H3PO4 (PA) and dried. The final SPHPE-PDPrP-PA film (0.15 cm thick) contained -SO3H functional groups and H3PO4 at 0.16 SO3H/N and 1.72 H3P04/N mole ratios. For the phosphazene polymer, at least two types of repeating units were present, i.e., -P(CH2CH2CH3)(2)=N- and -P(CH2CH2CH3)(2)=NH+(H2PO4-center dotH3PO4)- at 0.18 N/NH+ mole ratio. This material exhibited proton conductivity (sigma, Omega(-1) cm(-1)) of 2.27 10(-4) -7.10 10(-3) at 24 - 127 degrees C in dry environment, and of 4.79 10(-4)-1.54 10(-3) at 45-65 degrees C and 11% relative humidity. The results for SPHPE-PDPrP-PA composite are discussed by comparison to available literature data for other composites and polymers containing N protonated by H3PO4
Modification of soil humic matter after 4 years of compost application
No full textTwo soil plots, 1ha each, were amended yearly for 4 years, respectively, with 35.8 and 71.6Mgha(-1)yr(-1) of mature compost (CM) obtained from food and vegetable residues. The compost, amended soils, and a control soil plot after 4 years (S(4)), were analyzed for humin (HUC), humic acid (HAC), fulvic acid (FAC), and non-humic carbon (NHC) content. Compared to S(4), the amended soil contained more humified C (HAC, FAC and HUC) and less NHC. Further evidence of the effect of compost on soil organic matter was obtained by the analysis of the humic acid (HA) fractions isolated from both the compost and the soils. These were characterized by elemental analyses and Diffuse Reflectance Infrared Fourier Transformed spectroscopy. The HAs isolated from CM and from S(4) were significantly different. The HAs isolated from the amended plots were more similar to HA isolated from CM than to HA isolated from S(4). The experimental data of this work indicate that the compost application may affect significantly the soil organic matter composition, and that the approach used in this work allows one to trace the fate of compost organic matter in soil
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