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A simple and novel metal-free reduction of azides to amines in the presence of DBU is reported. Aromatic and sulfonyl azides are typically used to give the desired amines in moderate to excellent yields. This transformation features good functional group tolerance and high chemo-selectivity. In this reduction, functional groups such as alkynes, halides, ethers, esters and cyano groups are not affected. DBU is used as not only the solvent but also the reducing reagent. [ABSTRACT FROM AUTHOR]

Hydrophilic coating is frequently used to enhance the anti-fouling performance of membrane. However, traditional strategies often suffer from defects of cumbersome steps, high energy consumption, and unstable coating. Herein, radical and cationic photopolymerization are used for hydrophilic coating of membranes. Two photosensitive resins were first synthesized either by direct radical copolymerization of 3-ethyl-3-(methacryloyloxy) methyloxetane and 2-hydroxyethyl acrylate (Poly(HEA-EMO)) or through post-polymerization modification of poly(2-hydroxyethyl acrylate) with vinyl groups (Poly(HEA-MA)). Subsequently, hydrophilic coating was conducted on the membrane surface by UV-induced curing of different photosensitive resins, either through radical photopolymerization of vinyl-functional Poly(HEA-MA) or cationic photopolymerization of Poly(EMO-HEA) with pendent oxetane groups. The modified membranes showed enhanced hydrophilicity and underwater oleophobicity than the original membrane. Moreover, the coating (PAN / HEA(C5)) by cationic photopolymerization exhibited lower shrinkage, smoother surface, and more excellent antifouling performance than that by radical photopolymerization. After bovine albumin fouling-cleaning cycles, the flux recovery rate (FRR) of the original membrane was only 68.6 %, while the FRR of PAN / HEA(C5) was as high as 98.0 %. Furthermore, it showed superior long-term operational stability, proving the stability of the coating formed by cationic photopolymerization. [Display omitted] • Photosensitive resins were synthesized by radical photopolymerization and post-photopolymerization modification. • Photosensitive resins have multiple pendent oxetane or vinyl functional groups. • Hydrophilic coatings on PAN membrane were formed by radical photopolymerization and cationic photopolymerization. • The coating formed by cationic photopolymerization had lower shrinkage, smoother surface, and better antifouling performance. [ABSTRACT FROM AUTHOR]

Animal-keratin-wastes (AKWs), horns (HN), hair (HR), puffed waterfowl feathers (PF), hydrolyzed waterfowl feathers (HF), hydrolyzed fish meal (HM), crab meat (CM), feathers (FR), shrimp chaff (SC), fish scales (FS), and waste leather (WL) were used as modifiers to prepare animal-keratin-wastes biochars (AKWs-BC) derived from Trapa natans husks (TH). AKWs-BC have a well-developed microporous structure with a pore size mainly below 3 nm. Due to the doping of AKWs, the surface chemical properties of AKWs-BC (especially N functional groups) were improved. The utilization of APWs not only realizes the resource utilization of waste, but also can be used to prepare high-performance biochars. [ABSTRACT FROM AUTHOR]

Abstract: The extinction coefficient differs for different functional groups making the quantitative analysis of their infrared spectra problematic. Although the coefficients of some functional groups have been researched previously, they are inaccurate because of deviations in techniques used and linear fitting. The distribution and structural characteristics of functional groups from coal infrared spectra is therefore inaccurate. In this study, quantum chemistry methods are used for the quantification of coal infrared spectra based on the Beer–Lambert law. The effect of the extinction coefficients of different functional groups is eliminated. The experimental infrared intensities, unit absorption intensities and their ratios are obtained to calculate the percentage composition of coal functional groups and molecular structure parameters. Accurate distribution and structural characteristics of coal functional groups are obtained. A linear relationship between the distribution of some functional groups and structural parameters is obtained. Multiple structural parameters are used to determine the grade and maturity of coal samples. The ethylene in coal oxidation experiments below 200°C is consistent with the hydrocarbon-generating potential parameters. These results will improve the accuracy of the quantitative analysis of infrared spectra for determining coal structural features and provide an index for the utilization and prevention of the spontaneous combustion of coal. [Copyright &y& Elsevier]

Abstract: To remove bilirubin from human plasma, amine/methyl bifunctionalized SBA-15 materials were directly synthesized from the co-condensation of 3-aminopropylmethyldiethoxysilane and tetraethoxysilane with an amphiphilic block copolymer P123 as template. XRD, N2 sorption analysis, FTIR and 29Si MAS NMR were used to identify their well-ordered mesostructure and the grafting of amine and methyl groups on the surface of as-synthesized materials. Both SEM and TEM indicated that the bifunctionalized SBA-15 possessed platelet morphology. This might be attributed to the charge repulsion brought by protonated amine groups and the diminution of hydroxyl groups on the end of silicate-micelles, which passivated the end-to-end anchoring of silicate-micelles along the longitudinal axis. Such a material was investigated as the adsorbent for selective bilirubin removal from human plasma, which showed a high bilirubin clearance of 51.4% within 1.5h with a little amount of albumin adsorption. The results of hemolysis assay suggested that the bifunctionalized SBA-15 caused serious hemolysis of red blood cells. However, in practical application, plasma separation technique could avoid direct contact between the adsorbent and red blood cells. The further hemeolysis assay proved that the plasma after contacting with the bifunctionalized SBA-15 could not lead to the hemolysis of red blood cells. Thus, the bifunctionalized SBA-15 is expected to be a potential candidate as a clinical hemoperfusion material. [Copyright &y& Elsevier]

Abstract: A new design in efficient sorbents for the removal of trace pollutants from water was proposed: grafting the external surface of γ-alumina (γ-Al2O3) nanofibers with functional groups that have a strong affinity to the contaminants. This new grafting strategy greatly improves the accessibility of these sorption sites to adsorbates and thus efficiency of the fibrous sorbents. The product sorbents could capture the pollutants selectively even when the concentration of the contaminants is extremely low. Two types of γ-Al2O3 nanofibers with different size were prepared via facile hydrothermal methods. Thiol groups were then grafted on the γ-Al2O3 fibers by refluxing the toluene solution of 3-mercaptopropyltrimethoxysilane (MPTMS). The thiol group modified fibers not only can efficiently remove heavy metal ions (Pb2+ and Cd2+) from water at a high flux, but also display high sorption capacity under sorption equilibrium conditions. Similar result was obtained from the nanofibers grafted with octyl groups which are employed to selectively adsorb highly diluted hydrophobic 4-nonylphenol molecules from water. This study demonstrates that grafting nanofibers is a new and effective strategy for developing efficient sorbents. [Copyright &y& Elsevier]

Abstract: Dimethylsilyl (DMS) modified mesoporous silicas were successfully prepared via co-condensation and post-grafting modification methods. The post-grafting modification was carried out by the reaction of the as-synthesized MCM-41 material (before CTAB removal) with diethoxydimethylsinale (DEDMS). N2 adsorption–desorption and 29Si MAS NMR characterization demonstrated that different amount of DMS groups were successfully incorporated into the co-condensation modified samples, and the functional DMS groups were placed selectively on the pore openings and external pore surfaces in the post-grafting modified samples. Subsequently, the controlled drug delivery properties from the resulting DMS-modified mesoporous silicas were investigated in detail. The drug adsorption experiments showed that the adsorption capacities were mainly depended on the content of silanol group (CSG) in the corresponding carriers. The in vitro tests exhibited that the incorporation of DMS groups greatly retarded the ibuprofen release rate. Moreover, the ibuprofen release profiles could be well modulated by varying DMS modification levels and site-selective distribution of functional groups in mesoporous carriers. [Copyright &y& Elsevier]