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A novel photosensitizer (PS) was developed by anchoring an Ir(III) complex on a macroscopic polymer substrate to prevent ligand dissociation of the PS, resulting in a long duration of over 730 h in photocatalytic hydrogen evolution. This study paves the way for designing new Ir(III) PSs and exploring the inactivation mechanism of PSs. [ABSTRACT FROM AUTHOR]

Imidazolium salts containing , , , , or ionic liquids were blended with an epoxy prepolymer, dyglycidylether of bisphenol A (DGEBA) to obtain a series of compositions. To characterize the resulting mixtures and determine the influence of the imidazolium anion on the reactivity and properties of epoxy systems, we performed the following analyses and tests: (i) differential scanning calorimetry (DSC), to determine the curing reaction characteristics, (ii) in situ fourier-transform infrared spectroscopy (FTIR), to assess chemical structure changes, (iii) mechanical property testing of the hardened epoxy material, and (iv) thermogravimetric analysis (TGA). The DSC and FTIR analyses indicate that [Hmim]BF4, and [Hmim]PF6 cannot induce the epoxy ring opening reaction and thus these materials are unable to function as epoxy curing agents. In contrast, the imidazolium ionic liquids [Hmim]FeCl4, [Hmim]N(CN)2, and [Hmim]Zn2Cl5 independently promote the epoxy ring opening reaction. TGA analyses show that the cured DGEBA/[Hmim]Zn2Cl5 system exhibits thermal stability similar to the cured DGEBA/[Hmim]FeCl4. These results can provide an essential reference not only for studying the synergistic effect of [C6mim]FeCl4/mixed-amines on the curing process of epoxy systems and the mechanism of the ring opening of epoxides with [C6mim]FeCl4/mixed-amines, but also for designing new epoxy curing systems. [ABSTRACT FROM AUTHOR]

We report the preparation of glycidyl azide polymers (GAPs) by the reaction of a prepolymer polyepichlorohydrin (PECH) with sodium azide (NaN3) in mixture solvents of different mass ratios with ionic liquid 1-butyl-3-methylimidazolium chloride ([Bmim]Cl) and water without catalysts. The formation of GAP was confirmed by IR and NMR spectroscopy, and the molecular weight of the product was determined by gel permeation chromatography (GPC). The conversion of PECH was identified via quantitative 13C-NMR spectroscopy. This method avoids solvent pollution and simplifies the reaction post-processing. The reaction was monitored by IR and 13C-NMR. We concluded that the relative solubility of the reaction substrate in the mixed solvents has an important effect on the degree of the reaction. [ABSTRACT FROM AUTHOR]

Abstract: Polylactic acid (PLA) is as a well-known biodegradable polymer with strong potential for extending its applications into the commodity industry, which is still limited by its relative low heat distortion temperature (HDT). In this paper, poly(ethylene-co-vinyl alcohol) (EVOH) was blended with PLA by melt blending and followed by a gamma-irradiation at various absorbed doses in the presence of a multi-functional monomer, triallyl isocyanurate (TAIC). The results show that the enhanced irradiation is an effective method for improving the mechanical properties and HDT of PLA/EVOH blends. Remarkably, the HDTs of the irradiated blends have dramatically increased to 140°C, double the value of neat PLA (70°C). The content of TAIC and the absorbed dose of irradiation were found to play important roles in the enhancement. Gel extraction, scanning electronic microscopy (SEM) and Fourier Transform Infrared (FTIR) spectroscopy analyses also demonstrate that new co-crosslinked networks have been formed in the irradiated PLA/EVOH blends. [Copyright &y& Elsevier]

Mercury is one of the most toxic heavy metals that can cause terrible disease for human beings. Among different absorption materials, MOF (metal–organic framework) materials show potential as very attractive materials for the rapid removal of mercury. However, the instability and difficulty for regeneration of MOF crystals limit their applications. Here, a continuous sulfur-modified MOF (UiO-66-NHC(S)NHMe) layer was synthesized in situ on polymeric membranes (PP non-woven fabrics) by post-synthetic modification and used for rapid mercury removal. The MOF-based membrane (US-N) showed high selectivity for mercury in different aqueous systems, which is better than sulfur-modified MOF powders. A thinner MOF layer on US-N showed a much better mercury ion removal performance. US-N with a 59.3 nm MOF layer could remove more than 85% of mercury in 20 min from an aqueous solution. In addition, the US-N can simply regenerate several times for mercury removal and maintain the initial performance (removal ratio > 98%), exhibiting excellent durability and stability. This work promotes the application of MOF materials in the rapid removal of hazardous heavy metal ions from practical environments. [ABSTRACT FROM AUTHOR]

• Novel self-lubricated nanothickness MOF coating (SLNTMC) is developed. • SLNTMC is designed based on the synergistic effect of hydrophobic micro/nanostructures and lubricating layer. • Organosilane is covalently bound to ultrathin UiO-66-NH 2 coating. • SLNTMC shows good anti-icing performance which can be tuned by surface morphology and molecular weight of lubricating liquid. • SLNTMC exhibits long-term durability, high flexibility and transparency. In this paper, a novel self-lubricated nanothickness MOF coating (SLNTMC) with excellent and long-term anti-icing performance is designed based on the synergistic anti-icing mechanism of hydrophobic porous micro/nanostructures and lubricating layer. The organosilicone grafted thin UiO-66-NH 2 coating is prepared through a three-step reaction. SLNTMCs could reduce the ice adhesion to 9.4 kPa, and lower the freezing temperature of condensed water to -36.0 °C, due to the organosilicone layer of SLNTMC covering the ice nucleation sites on surface and reducing the water/ice adhesion, whilst combined with the porous micro/nano structures which introduce air pockets between water and surface and hinder their thermal conduction. SLNTMCs with larger MOF particle size show lower ice nucleation temperature and the organosilicone molecular weight of 4000–7700 is benefical to improve surface anti-icing performance. The SLNTMC exhibits a long-term durability, it maintains a low ice adhesion after 20 icing/de-icing cycles. Moreover, SLNTMC is a ultrathin, transparent, flexible solid thin film that could be prepared on different polymeric substrates, making them suitable for practical application having different requirements. [ABSTRACT FROM AUTHOR]

In this work, a series of heptaphenyl siloxane trisilanol/polyhedral oligomeric silsesquioxane (T7-POSS) modified by polyols with different molecular weights were synthesized into liquid-like nanoparticle–organic hybrid materials using the grafted-from method. All grafted POSS nanoparticles changed from solid powders to liquid at room temperature. Polyurethane (PU) nanocomposites with POSS contents ranging from 1.75 to 9.72 wt % were prepared from these liquefied polyols-terminated POSS with polyepichlorohydrin (POSS–PECH). Transmission electron microscopy (TEM), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) were used to characterize the morphology of the POSS–PECH/PU nanocomposites. The results showed that the polyol-terminated POSS particles overcame the nanoagglomeration effect and evenly disperse in the polymeric matrix. The damping factor (tan δ) of resultant nanocomposites increased from 0.90 to 1.16, while the glass transition temperature decreased from 15.8 to 9.4 °C when POSS contents increased from 0 to 9.75 wt %. The gel content, tensile strength and Fourier transform infrared (FTIR) analyses demonstrated that the molecular thermal movement ability of the polyurethane (PU) matrix increased with increasing POSS hybrid content. Therefore, the improvement of the damping properties of the composites was mainly due to the friction-related losses occurring in the interface region between the nanoparticles and the matrix. [ABSTRACT FROM AUTHOR]