Room Temperature Hydroxyl Group-Assisted Preparation of Hydrophobicity-Adjustable Metal-Organic Framework UiO-66 Composites: Towards Continuous Oil Collection and Emulsion Separation.

Developing a straightforward and effective hydrophobic modification for metal-organic frameworks (MOFs) under mild conditions is meaningful for MOF applications. Here, a post-synthetic modification approach assisted with metal hydroxyl groups at room temperature is reported to induce hydrophobicity in the hydrophilic UiO-66. The bonding between Zr-OH in UiO-66 and n-tetradecylphosphonic acid (TDPA) is the vital force for the modifier TDPA. Superhydrophobic and superoleophilic composites were constructed for efficient oil-water separation by coating TDPA-modified UiO-66 (P-UiO-66) on commercial melamine sponges (MS) and filter papers (FP) with water contact angles of 153.2° and 155.6°, respectively. The P-UiO-66/MS composite could quickly and selectively absorb oily liquids up to 43 times its weight from water. The P-UiO-66/MS achieved continuous oil collection with high separation efficiencies (≥99.4 %). In addition, P-UiO-66/FP and P-UiO-66/MS showed high separation efficiencies for water-in-oil emulsions (≥98.5 %) and oil-in-water emulsions, respectively, with high resistance to low/high temperatures and acid/base conditions. The metal hydroxyl group-assisted post-synthetic modification strategy offers a facile and broad way to prepare hydrophobic MOFs for promising applications in environmental fields.

Eco-Friendly Fluorine Functionalized Superhydrophobic/Superoleophilic Zeolitic Imidazolate Frameworks-Based Composite for Continuous Oil-Water Separation.

Superhydrophobic metal-organic framework (MOF)-based sponges have received increasing attention in terms of treating oil-water mixtures. However, highly fluorinated substances, commonly used as modifiers to improve the hydrophobicity of MOFs, have aroused much environmental concern. Developing a green hydrophobic modification is crucial in order to prepare superhydrophobic MOF-sponge composites. Herein, we report the preparation of a porous composite sponge via a polydopamine (PDA)-assisted growth of zeolitic imidazolate frameworks (ZIF-90) and eco-friendly hydrophobic short-chain fluorinated substances (trifluoroethylamine) on a melamine formaldehyde (MF) sponge. The composite sponge (F-ZIF-90@PDA-MF) exhibited superhydrophobicity (water contact angle, 153°) and superoleophilicity (oil contact angle, 0°), which is likely due to the combination of the low surface energy brought on by the grafted CF3 groups, as well as the rough surface structures that were derived from the in situ growth of ZIF-90 nanoparticles. F-ZIF-90@PDA-MF showed an excellent adsorption capacity of 39.4-130.4 g g-1 for the different organic compounds. The adsorbed organic compounds were easily recovered by physical squeezing. Continuous and selective separation for the different oil-water mixtures was realized by employing the composite sponge as an absorbent or a filter. The separation efficiency and flux reached above 99.5% and went up to 7.1 ×105 L m-2 h-1, respectively. The results illustrate that the superhydrophobic and superoleophilic F-ZIF-90@PDA-MF sponge has potential in the field of water-oil separation, especially for the purposes of large-scale oil recovery in a water environment.

Nanoparticle/Metal-Organic Framework Composites for Catalytic Applications: Current Status and Perspective.

Nanoparticle/metal-organic frameworks (MOF) based composites have recently attracted significant attention as a new class of catalysts. Such composites possess the unique features of MOFs (including clearly defined crystal structure, high surface area, single site catalyst, special confined nanopore, tunable, and uniform pore structure), but avoid some intrinsic weaknesses (like limited electrical conductivity and lack in the "conventional" catalytically active sites). This review summarizes the developed strategies for the fabrication of nanoparticle/MOF composites for catalyst uses, including the strategy using MOFs as host materials to hold and stabilize the guest nanoparticles, the strategy with subsequent MOF growth/assembly around pre-synthesized nanoparticles and the strategy mixing the precursors of NPs and MOFs together, followed by self-assembly process or post-treatment or post-modification. The applications of nanoparticle/MOF composites for CO oxidation, CO2 conversion, hydrogen production, organic transformations, and degradation of pollutants have been discussed. Superior catalytic performances in these reactions have been demonstrated. Challenges and future developments are finally addressed.

Injectable, self-healing and degradable dynamic hydrogels with tunable mechanical properties and stability by thermal-induced micellization.

Dynamic hydrogels possessing injectable, degradable and self-healing abilities have attracted considerable attention in the biomedical field in recent years, but it is difficult to tune the mechanical properties and stability of conventional dynamic hydrogels. In this work, we synthesized ABA-triblock copolymers via RAFT polymerization, where the A block consisted of thermo-sensitive poly(N-isopropylacrylamide-co-diacetone acrylamide) and the B block was hydrophilic poly(acrylamide). Subsequently, dynamic hydrogels were obtained based on the acylhydrazone bonds between the triblock copolymers and adipic acid dihydrazide (ADH). The obtained hydrogels exhibited injectable and self-healable abilities. In response to the thermal-induced micellization of their temperature-responsive blocks, the mechanical strength of the hydrogels not only increased, but also they exhibited high stability even at pH 2.0. Moreover, the hydrogel in the stable state could be degraded by the fracture of its trithiocarbonate groups. In addition, the hydrogels exhibited good cytocompatibility and controlled release behavior for doxorubicin (DOX). Considering these attractive tunable properties, these dynamic hydrogels show various potential applications in the biomedical field, such as drug carriers and cell or tissue engineering scaffolds.

Molecular epidemiology of norovirus gastroenteritis in children in Jiangmen, China, 2005-2007.

Human noroviruses (NoVs) are an important cause of epidemic acute gastroenteritis. Their role in sporadic cases, however, is less clear. In this study, we performed a two-year surveillance (September 2005 to August 2007) of NoV gastroenteritis in outpatient clinics in a southern city of China, Jiangmen City. NoVs were detected in 115 patients (115/881, 13.1%) with 30 (26.1%) co-infections with rotaviruses. Sequence analysis showed that all 115 NoVs belonged to genogroup II, with GII.4 being the most predominant (87.8%). NoV-associated infection can be seen year-around, with autumn and winter peaks. This study provides basic information on sporadic cases of major NoV gastroenteritis in children in different seasons, which is valuable for future disease control and prevention.

[Detection and genotype analysis of sapovirus associated with sporadic diarrhea in Shenzhen in 2009].

OBJECTIVE: To conduct an epidemiological and genotype analysis of sapovirus (SaV) associated with sporadic diarrhea in Shenzhen in the year 2009. METHODS: A total of 852 fecal samples were collected from sporadic cases of diarrhea in Shenzhen in 2009 and detected by reverse-transcription polymerase chain reaction (RT-PCR) using the primers of SLV5317/5749. The PCR products were analyzed with 1.5% agarose gel electrophoresis and sequenced to construct the phylogenetic tree. RESULTS: Sixteen samples were found positive for SaV, with a positivity rate of 1.88%. Sequence analysis identified 8 isolates as SaV GI genotype (including 3 SaV GI.1 and 5 SaV GI.2), 7 as SaV GIV genotype, and 1 as GII genotype. CONCLUSIONS: SaV infection is present in Shenzhen with GI as the predominant genotype. This is the first report of SaV GIV strains in China, which differs from the strains of Anhui-A141 and Beijing-CHN99/BJ360, suggesting the genotypic variety of SaV infection in China.