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Chemical nature and surface properties of plant disperse fillers are investigated: buckwheat (BH) and oat (OH) husk, wood (WF) and conifer flour (CF). Using IR spectroscopy, it was found that oxygen-containing atomic groups –OH, –C–O–, –C=O prevail in the filler components. It was found that a hydroxyl-hydrate layer of functional groups is present on the surface of air-dry fillers. By potentiometric titration of aqueous suspensions using the Parks–Bobyrenko method, it was determined that all fillers are of the «polyfunctional solid» type. It is shown that the hydroxyl-hydrate surface layer consists of functional groups with similar values of acid-base characteristics. Functional groups of acidic nature were additionally found on the surface of the fillers: groups withpKa≈4.37−5.66 on the BH surface, groups withpKa≈4.49−4.90 on the CF surface and groups withpKa≈3.91−4.30 on the WF surface. As a result of potentiometric titration, it was shown that the surface acidity of the fillers decreases in the WF>CF>BH>ОH series, which coincides with the one in which the total cellulose and lignin content decreases, and the resistance of fillers to thermal-oxidative breakdown increases. It was found that the rate of hydrolytic processes in aqueous suspensions at the interface decreases in the ОH>CF>BH>WF series and inversely depends on the concentration of functional groups on the surface of the fillers, and also that the change in the rate of hydrolytic processes at the interface depending on the content of fillers is described by step functions. It is revealed that for the effective use of the studied disperse waste in composite materials and as adsorbents for the extraction of pollutants, dispersion media with the following ranges of the hydrogen index are required: for BH − pH>4.4; OH − pH>6.4; WF − pH>3.9; CF − pH>4.5. The results obtained make it possible to predict and control acid-base interfacial interactions, as well as reasonably approach the development of new effective technologies

FeCoNiCrMn(Al)-based powdered high entropy alloys were synthesized by a short time mechanical alloying process in a high energy planetary ball milling from mixtures of elemental powders, and subsequently sintered by a pressureless procedure. The composition and microstructure of the HEA phases before and after the sintering process were studied by X-ray diffraction, energy dispersive X-ray analysis (EDX) and scanning electron microscopy. The microhardness and tensile strength values for FeCoNiCrMnAl HEA sintered at 1400 °C sample were 3,7 GPa and 1011 MPa, respectively. Statistical Fisher-Pearson coefficient of skewness and kurtosis were played to determine the optimum synthesis milling time. The use of NaCl as additive led on to a reduction of the as-milled grain size. After sintering, SEM study confirmed a segregation of the initial HEA phase directly related to the melting temperature of the elements. Three melting temperature groups were described (Cr, FeCoNi and Mn) and they agree with the observation in the elemental mapping study. The presence of Al favored the segregation of Cr., This work was supported by the Spanish government under grant MAT2014-52407-R, financed in part by the European Regional Development Fund and through the Ramón y Cajal Program RYC-2013-12437.

A high entropy alloy (HEA, CoCrFeNiMn) synthesized by mechanical alloying was used as the binder for the densification of WC by a pressureless high temperature procedure. Three different WC were used by modifying its microstructure with a high energy ball milling treatment. The alloy content in the HEA-WC mixture was varied from 10 to 30% vol. The microstructure and properties of the sintered composites were studied by X-ray diffraction, scanning electron microscopy and microindentation., This work was supported by the Spanish government under grant MAT2014-52407-R, financed in part by the European Regional Development Fund and through the Ramón y Cajal Program RYC-2013-12437. MINECO/ICTI2013-2016/RYC-2013-12437

We report the use of bis-catecholic polymers as candidates for obtaining effective, tunable gatekeeping coatings for mesoporous silica nanoparticles (MSNs) intended for drug release applications. In monomers, catechol rings act as adhesive moieties and reactive sites for polymerization, together with middle linkers which may be chosen to tune the physicochemical properties of the resulting coating. Stable and low-toxicity coatings (pNDGA and pBHZ) were prepared from two bis-catechols of different polarity (NDGA and BHZ) on MSN carriers previously loaded with rhodamine B (RhB) as a model payload, by means of a previously reported synthetic methodology and without any previous surface modification. Coating robustness and payload content were shown to depend significantly on the workup protocol. The release profiles in a model physiological PBS buffer of coated systems (RhB@MSN@pNDGA and RhB@MSN@pBHZ) showed marked differences in the “gatekeeping” behavior of each coating, which correlated qualitatively with the chemical nature of their respective linker moieties. While the uncoated system (RhB@MSN) lost its payload almost completely after 2 days, release from RhB@MSN@pNDGA was virtually negligible, likely due to the low polarity of the parent bis-catechol (NDGA). As opposed to these extremes, RhB@MSN@pBHZ presented the most promising behavior, showing an intermediate release of 50% of the payload in the same period of time., This work was supported by Projects MAT2015-70615-R from the Spanish Government and by FEDER funds. ICN2 acknowledges support from the Severo Ochoa Program (MINECO, Grant SEV-2013-0295) and the CERCA Programme/Generalitat de Catalunya. UCM acknowledges support by the European Research Council (Advanced Grant VERDI; ERC-2015-AdG Proposal No. 694160) and Project MAT2015-64831-R.

International audience; The temperature and pressure dependence of isobaric thermal expansivity,α p, in liquids is discussed in this paper. Reported literature data allow general trends in this property that are consistent with experimental evidence to be established. Thus, a negative pressure dependence is to be expected except around the critical point. On the other hand, α p exhibits broad regions of negative and positive temperature dependence in the (T, p) plane depending on the nature of the particular liquid. These trends are rationalized here in terms of various molecular-based equations of state. The analysis of the Lennard-Jones, hard sphere square well and restricted primitive model equations allows understanding the differences in the α p behavior between liquids of diverse chemical nature (polar, nonpolar, and ionic): broader regions of negative temperature and positive pressure dependencies are obtained for liquids characterized by larger ranges of the interparticle potential. Also, using the statistical associating fluid theory (SAFT) allowed the behavior of more complex systems (basically, those potentially involving chain and association effects) to be described. The effect of chain length is rather simple: increasing it is apparently equivalent to raise the interaction range. By contrast, association presents a quite complex effect on α p, which comes from a balance between the dispersive and associative parts of the interaction potential. Thus, if SAFT parameters are adjusted to obtain low association ability, α p is affected by each mechanism at clearly separate regions, one at low temperature, due to association, and the other to dispersive forces, which has its origin in fluctuations related with vapor-liquid transition.

Blends of chemically readily accessible, small-molecular arylacetylene derivatives with poly(vinylidene fluoride) (PVDF) are presented that allow reliable solution processing of field-effect transistor (FET) architectures with electronic characteristics comparable to those of the neat semiconductors. We demonstrate that having the chemical means and corresponding processing protocols to control solid-state microstructures by either adjusting the chemical nature of the organic semiconductor, blend composition or deposition temperature, permit straight-forward comparison between materials and allow probing if electronic characteristics are affected by the chemical structure of the organic semiconductor and/or selected processing protocols.