Recent advances and trends of heterogeneous electro-Fenton process for wastewater treatment-review

Electrochemical advanced oxidation processes （EAOPs） are effective and environmentally friendly for the treatment of refractory organic pollutants.Among EAOPs,heterogeneous electro-Fenton （EF） process with in-situ formation of hydrogen peroxide （H₂O₂） is an eco-friendly,cost-effective and easy-operable technology to generate hydroxyl radicals （^·OH） with high redox potential.The generation of^·OH is determined by the synergistic H₂O₂     

Synthesis of comb‐like dispersants and a study on the effect of dispersant architecture and carbon black dispersion

Comb dispersants suitable for stabilization of carbonaceous deposits found in automotive lubricating oils were derived from the copolymerization of vinyl‐ether terminated polyisobutylene (VE‐PIB) macromonomers with maleic anhydride (MAH). The rate and degree of copolymerization of VE‐PIB with MAH was greatly influenced by the molecular weight of the VE‐PIB. Longer PIB tails imposed greater hindrance of the chain end resulting in slower propagation and lower degrees of copolymerization for PIB‐alt‐MAH copolymers. Functionalization of PIB‐alt‐MAH with a polyamine proceeded smoothly at elevated temperatures as evidenced by disappearance of anhydride stretches via Fourier transform infrared spectroscopy. Analogous linear and grafted dispersants were prepared to investigate the influence of architecture on the physical properties of the dispersants. Characterization of the intermediates and final dispersants was conducted by nuclear magnetic resonance, gel permeation chromatography, thermogravimetric analysis, and ultraviolet–visible. Using Langmuir adsorption studies and carbon black as a substitute for carbonaceous deposits, it was found that comb and grafted dispersants exhibit greater affinities for adsorption but decreased packing efficiencies in comparison to linear dispersants. Rheological studies investigating viscosity as a function of loading for dispersant/oil mixtures with carbon black present a similar finding. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019, 57, 1682–1696     

“Geländer” macrocycles: Synthesis,chirality and racemisation barriers

A new class of axially-chiral o,o′-bridged biphenyls containing etheroxime chains was obtained in good yields by the macrocyclisation reaction of o,o′-diformylbiphenyl dioxime with several ditosylated or dibrominated reagents. In all cases the enantiomers of the compounds were separated by HPLC using a chiral column (Chiralpack IC) and the stability of the enantiomers (barriers of racemisation) was investigated employing chiral HPLC or chiral Dynamic HPLC techniques. A slight influence on the barrier to rotation was noticed when the enantiomerisation was performed in the presence of suitable alkali cations.     

The oxidation of calcium implanted titanium in water: A depth profiling study

Ion implantation of calcium has been proposed previously as a route to bioactive titanium surfaces and has been shown to stimulate promising cell and tissue responses. While the precise reasons for this behaviour remain poorly understood, it is clear that the nature of the Ca implanted surface changes rapidly on exposure to body fluids. In order to understand the processes taking place more clearly, the current work examined the simple interaction of Ca implanted Ti with water. The surface chemistry and compositional changes within the sub-surface region of the modified Ti were examined. On immersion in water, the concentration of implanted Ca ions was found to decrease both at the surface and throughout the implanted region. At the same time, the sub-surface oxygen concentration was found to increase dramatically. Although Ca implantation into Ti results in a thicker oxide layer at the surface, it appears that this layer no longer affords the underlying Ti the same protection from further oxidation provided by the native oxide. By examining samples implanted with O, Ti or Ar it was possible to conclude that this was specific to Ca implantation and not a result of the ion implantation process itself.     

The Effect of Sodium Total Substitution on the Quality Characteristics of Green Pickled Tomatoes (Solanum lycopersicum L.)

Green pickled tomatoes are a traditional fermented product in Romania. This study was focused on the effect of total substitution of NaCl with KCl and MgCl₂ on physicochemical and microbiological quality; bioactive compounds; and microstructural, textural, and sensorial properties of fresh and pickled green tomatoes during 28 days of fermentation. By the means of physicochemical composition, the NaCl addition induced the most stable characteristics for the pickles compared to the other two types of salts. The content of total flavonoids in green pickled tomatoes with NaCl (34.72 ± 0.43 mg CE/g DW) was significantly lower compared with the control sample (63.80 ± 0.55 mg CE/g DW). The total number of lactic acid bacteria (LAB) at the final stage of fermentation varied between 4.11 and 4.63 log CFU for all variants. The textural analysis revealed that the NaCl has the lowest influence on the textural parameters. Finally, the overall acceptance of green pickled tomatoes containing KCl and MgCl₂ was found to be proper to be consumed as a substitute for pickles with NaCl.     

Mimicking the morphology of long bone

The aim of this work was to mimic the stratified structure of the median region of long bones. Starting from this desideratum, more COLL/HA composite materials with different morphology were synthesized and characterized, each of these materials mimicking one layer of long bone (endo- and periosteum, compact and cancellous bony tissue). Stratified bone grafts were obtained by assembling these layers; the obtained grafts were similar to the median region of long bones. Even though, natural bones have a more complex microstructure, this is a pioneering work since for the first time a stratified COLL/HA composite material similar to bone was produced.      

A novel amphiphilic pH-sensitive hydrogel based on pullulan

Novel polyelectrolyte and amphiphilic hydrogels based on pullulan have been prepared using 1-ethyl-3-[3-(dimethylamino)-propyl]carbodiimide hydrochloride and N-hydroxysuccinimide. The cross-linking reaction is fast and lead to zero length ester cross-links by the reaction of a carboxylate group with an alcohol function of the polysaccharide. The charge density and the hydrophobic rate of the precursor carboxymethylpullulan (CMP) are controlled during the carboxymethylation of pullulan and the grafting reaction of octyl chains on CMP, respectively. The grafting degree influences the conformation of the hydrophobically modified CMP (HMCMP) in solution and leads to the formation of hydrophobic clusters firstly in the HMCMP solutions and further in the HMCMP hydrogels. The swelling measurements of HMCMP hydrogels at different salt concentrations (0–0.2 M NaCl) and different pH (3–11) shows the ionic strength and pH sensitivity of the gels. The loading of a hydrophobic probe molecule can be controlled by the grafting degree of HMCMP hydrogels.     

Synthesis and Reactivity of a Strained Silicon‐Bridged [1]Ferrocenophanium Ion

Not blue but red‐brown : A [1]ferrocenophanium ion has been synthesized and isolated as a red‐brown crystalline salt, surprisingly different in color from characteristically blue‐green unstrained ferrocenium ions. Compared to the neutral iron(II) counterpart, the [1]ferrocenophanium ion displays a considerably higher ring tilt and an increased propensity for ring‐opening reactions.