Olive mill wastewaters decontamination based on organo-nano-clay composites

Green composites for environmental applications were successfully prepared by intercalation of the biosurfactant Quillaja saponin onto montmorillonite mineral clay on varying pH and surfactant/clay ratio. Equilibrium adsorption isotherms were constructed and the system was characterized by performing TGA and XRD analyses.The efficiency of the surfactant-modified clay in the removal of the organic content present in olive mill wastewaters (OMW) was evaluated by means of spectrophotometric measurements. The interest for this cogent issue comes from the consideration that, despite their high pollutant content, OMW can be considered as a potential resource of several organic compounds which can be recovered for a wide array of pharmaceutical and industrial applications. Two different strategies were proposed. In the first one, dried surfactant/clay hybrids were added to the batch samples under continuous stirring, while in the second alternative approach the organoclays were packed in chromatography column filled with multiple alternate layers of sand and organoclay.These studies revealed the efficacy of the methods used and suggested that the modification of the montmorillonite clay substrate significantly improves the performance of the clay.     

Stimulated Transitions of Directed Nonequilibrium Self‐Assemblies

Near‐equilibrium stimulus‐responsive polymers have been used extensively to introduce morphological variations in dependence of adaptable conditions. Far‐less‐well studied are triggered transformations at constant conditions. These require the involvement of metastable states, which are either able to approach the equilibrium state after deviation from metastability or can be frozen on returning from nonequilibrium to equilibrium. Such functional nonequilibrium macromolecular systems hold great promise for on‐demand transformations, which result in substantial changes in their material properties, as seen for triggered gelations. Herein, a diblock copolymer system consisting of a hydrophilic block and a block that is responsive to both pressure and temperature, is introduced. This species demonstrates various micellar transformations upon leaving equilibrium/nonequilibrium states, which are triggered by a temperature deflection or a temporary application of hydrostatic pressure.     

Magnetic polystyrene–palygorskite nanocomposite obtained by heterogeneous phase polymerization to apply in the treatment of oily waters

Water contaminated by oil poses challenges to the management of water resources. Magnetic nanoparticles has been issue of different potential applications including remotion oil from water. Magnetic polystyrene–palygorskite nanocomposites were prepared by a heterogeneous phase polymerization for the removal of organic contaminants from water. The organo‐Fe₃O₄‐palygorskite nanoparticles were coated with polystyrene, forming water repellent and oil absorbing surfaces to promote the removal of oil from the surfaces of nanocomposites by applying an external magnetic field. X‐ray fluorescence, X‐ray diffraction, scanning electron microscopy, zeta potential and size distribution measurement, surface area determination by BET, density measurement by He pycnometry, carbon grade determination, thermogravimetric analysis, Fourier‐transform infrared spectroscopy, Raman spectroscopy, and evaluation of hydrophobicity by contact angle were used to characterize the nanoparticles. The magnetic nanocomposite obtained showed excellent hydrophobicity, around 78° contact angle. In addition, oil removal capability tests were also performed, according to which the preliminary results indicated removal of approximately 98% of oil in synthetic oily water samples. The oil–water separation using this magnetic nanocomposite provides a promising alternative strategy for water treatment. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46162.     

Ceria‐coated diesel particulate filters for continuous regeneration

The potential of diesel particulate filters wash‐coated with highly dispersed nano‐metric ceria particles for continuous regeneration has been investigated. To this end, catalytic filters were prepared, soot‐loaded (avoiding the formation of the cake layer), and regenerated—under isothermal conditions—at temperature ranging from 200–600°C. Results have shown that catalytic oxidation of soot starts from 300°C and, at all temperatures, the selectivity to CO₂ is higher than 99%. 475°C is the minimum temperature at which the filter is regenerated via catalytic path. At this temperature, the catalytic filter maintains substantially the same performance over repeated cycles of soot loading and regeneration, indicating that the thermal stability of ceria is preserved. This has been further confirmed by comparison between the outcomes obtained from characterization (X‐ray powder diffraction, N₂ adsorption at 77 K, Hg intrusion porosimetry, and scanning electron microscope/energy dispersive X‐ray analysis) of fresh filter and filter subjected to repeated regeneration tests. © 2017 American Institute of Chemical Engineers AIChE J, 63: 3442–3449, 2017     

Preparation and evaluation of inclusion complexes of commercial sunscreens in cyclodextrins and montmorillonites: performance and substantivity studies

Herein we describe inclusion complexes of commercial sunscreens in cyclodextrins and montmorillonites to generate new sunscreen derivatives with optimized functional properties such as water resistance and skin adherence. Four cyclodextrins (alpha-, beta-, and gamma-cyclodextrin, and beta-dimethyl cyclodextrin) and two montmorillonites (sodium and alkylammonium) were investigated for encapsulating some commercial sunscreens. Our results reveal a good yield and inclusion products with functional properties obtained by using kneading technique on Eusolex 2292 and Eusolex 6007 in beta-cyclodextrin and solubilization method on Eusolex 6007 and NeoHeliopan MA in montmorillonite. In addition, molecular modeling studies indicated flexibility as important for the intercalation of the host molecule.     

The microscopical characterization of membranes poly (<Emphasis Type="SmallCaps">l</Emphasis>-glycolic-co-lactic acid) with and without added plasticizer: an in vivo study

The development of biodegradable materials has lead to renewed interest in the study of their interactions with the host organism in order to make the resulting products appropriate for use as temporary materials in clinical research, as well as important therapeutic applications. The copolymer poly (l-lactic-co-glycolic acid) or PLGA membranes have been used for several purposes. The physical properties of these materials can be modified by the addition of a plasticizer, such as the triethylcitrate, to provide flexibility and porosity to the implants, and enhance control of the polymer degradation time. Membranes with 7% plasticizer and without plasticizer (triethylcitrate) were compared. Membranes without plasticizer were denser and more compact than those with plasticizer. Two days and 30 days after implantation, the membranes with and without plasticizer showed little degradation. Sixty days and 120 days after implantation, the membranes with 7% plasticizer showed more cell invasion, and tissue adherence, as well as rapid degradation when compared to membranes without plasticizer.     

TiO2 doped with nitrogen: synthesis and characterization

In this study, nitrogen-doped titanium dioxide (TiO2) powders were synthesized in two ways: by heating of titanium hydroxide with urea and by direct hydrolysis of titanium tetraisopropoxide (TTIP) with ammonium hydroxide. The samples were characterized by structural (XRD), analytical (XPS), optical (UV/Vis absorption/reflection and Raman spectroscopy) and morphological (SEM, TEM) techniques. The characterization suggested that the doped materials have anatase crystalline form without any detectable peaks that correspond to dopants. The absorption threshold of titanium dioxide was moved in the visible range of optical spectrum from 3.2 eV to 2.20 eV. Particle sizes of synthesized powders were obtained from XRD measurements and from TEM data ranging from 6-20 nm. XPS and Raman spectroscopy were used for detection of nitrogen in doped samples.     

CMOS Non‐tailed differential pair

A continuous‐time complementary metal–oxide–semiconductor differential pair that does not require the traditional tail current source as a way to control the direct current and common‐mode current is presented. Compared with a p‐channel long‐tailed pair, the proposed non‐tailed solution operates under a higher maximum input common‐mode voltage that includes (V_DD + V_SS)/2 even under low supply voltages. Experimental measurements on a prototype fabricated in a 0.35‐µm technology (with metal – oxide – semiconductor thresholds greater than 0.6 V) confirm this behavior for supply voltages as low as 1.2 V, whereas the long‐tailed pair with the same technology offers the same capability only for supplies higher than 1.6 V. Copyright © 2015 John Wiley & Sons, Ltd.