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Covalent organic frameworks (COFs) are nanoporous crystalline polymers with densely conjugated structures. This work discovers that imine-linked COFs exhibit remarkable photodegradation efficiency to azo dyes dissolved in water. Visible light generates different types of radicals from COFs, and superoxide radicals break N N bonds in dye molecules, resulting in 100% degradation of azo dyes within 1 h. In contrast, these dyes cannot be degraded by conventionally used photocatalysts, for example, TiO2. Importantly, the COF photocatalysts can be recovered from the dye solutions and re-used to degrade azo dyes for multiple times without loss of degradation efficiency. This work provides an efficient strategy to degrade synthetic dyes, and we expect that COFs with designable structures may use as new photocatalysts for other important applications.

Two rearranged triterpenoids, representing new subtypes of pentacyclic triterpenoids, with unique 6/6/6/7/5 and 6/6/5/6/6/6 ring systems were isolated from Alstonia scholaris. Their structures were established by spectroscopic analysis, single-crystal X-ray diffraction, and electronic circular dichroism calculations. Both compounds exhibited potent antihyperuricemic bioactivity in vitro and in vivo.

As an advanced gas phase deposition technique, molecular layer deposition (MLD) has recently emerged as a precisely controllable method to fabricate organic-inorganic hybrid materials such as metalcones and hybrid films. Porous structures can be prepared by thermally removing the organic constituents of the metalcones deposited by MLD. Herein, we revealed that there is a crystallization-induced volume shrinkage during thermal treatment of metalcone films. By taking advantage of both the chemical degradation of organic moieties of metalcone films and the crystallization-induced volume shrinkage, we built microporous TiO2 layers on porous ceramic substrates and obtained nanofiltration and tight ultrafiltration membranes with tunable molecular-weight-cut-off (MWCO) in the range between 630 Da and 3050 Da. Firstly, 50 MLD cycles of titanicone (TiEG) were deposited on the near-surface of plate ceramic ultrafiltration membranes to achieve a compact layer, which was then subjected to calcination at different temperatures to remove the organic constituents. The bare membrane with a water permeance of ∼130 L m−2 h−1 bar−1 and MWCO of ∼63 kDa was upgraded from ultrafiltration to nanofiltration with ∼7 L m−2 h−1 bar−1 permeance and ∼630 Da MWCO after MLD and calcination at 250 °C. Moreover, as the microporous TiO2 was transformed from amorphous to crystalline with rising calcination temperatures, there was higher volume shrinkage and larger effective pore sizes. Consequently, both water permeance and MWCOs of the membranes were increased. For instance, the membranes after calcination at 400 °C showed a tight ultrafiltration performance of ∼30 L m−2 h−1 bar−1 permeance and ∼3050 Da MWCO. This work provides a simple and effective way to fabricate ceramic membranes with tunable performances between ultrafiltration, tight ultrafiltration, and nanofiltration.

Synthetic dye pollution is a worldwide problem and quick remedies are urgently needed. Photocatalysis is a promising method to solve this problem and carbon nanotubes (CNTs) are promising components in producing high-performance composite photocatalysts. Nevertheless, the strong hydrophobicity dramatically impedes its application in aqueous environments. In this study, hydrophilic CNT-hybrid metal oxides (ZnO and TiO2) membranes were prepared by atomic layer deposition (ALD). We demonstrate that ALD is an efficient and flexible method to enhance the photocatalytic activity of CNT-based membranes, especially the membranes used in wastewater treatments. The hybrid hexagonal wurtzite ZnO and anatase TiO2 on CNTs after calcination could effectively enhance electron transfer and reduce photo-generated electron-holes recombination. The membranes exhibit preferable photocatalytic activity and stable reusability in dye degradation. This strategy of “ALD on CNTs” is expected to create other CNT-based membranes with additional functionalities and has bright prospect for wastewater treatments.

Endophytic fungi play important roles for host's stress tolerance including invasion by pathogenic microbes. Small molecules are common weapons in the microbe-microbe interactions. Panax notoginseng is a widely used traditional Chinese medicinal plant and harbors many endophytes, some exert functions against pathogens. Here, we report six new compounds named myrothins A-F (1-6) produced by Myrothecium sp. BS-31, an endophyte isolated from P. notoginseng, and their antifungal activities against pathogenic fungi causing host root-rot disease. Their structures were elucidated with analysis of spectroscopic data including 1D and 2D NMR, HR-ESI-MS. Myrothins B (2) and E (5) showed the weak activity against Fusarium oxysporum and Phoma herbarum, and myrothins F (6) showed weak activity against F. oxysporum.

Porous polypropylene hollow fiber (PPHF) membranes are widely used in liquid purification. However, the hydrophobicity of polypropylene (PP) has limited its applications in water treatment. Herein, we demonstrate that, for the first time, atomic layer deposition (ALD) is an effective strategy to conveniently upgrade the filtration performances of PPHF membranes. The chemical and morphological changes of the deposited PPHF membranes are characterized by spectral, compositional, microscopic characterizations and protein adsorption measurements. Al2O3 is distributed along the cross section of the PP hollow fibers, with decreasing concentration from the outer surface to the inner surface. The pore size of the outer surface can be easily turned by altering the ALD cycles. Interestingly, the hollow fibers become much more ductile after deposition as their elongation at break is increased more than six times after deposition with 100 cycles. The deposited membranes show simultaneously enhanced water permeance and retention after deposition with moderate ALD cycle numbers. For instance, after 50 ALD cycles a 17% increase in water permeance and one-fold increase in BSA rejection are observed. Moreover, the PP membranes exhibit improved fouling-resistance after ALD deposition.

Carbon nanotubes (CNTs) are important building blocks to produce high-performance membranes. However, the strong hydrophobicity significantly hinders their applications in aqueous systems. Herein, we demonstrate, for the first time, that atomic layer deposition (ALD) is an efficient and flexible method to upgrade the permselectivity of CNT-based membranes. We ALD-deposit ZnO on fabrics of multi-walled carbon nanotubes. ZnO grows on the CNT surface as nanoparticulates initially and then forms conformal layers wrapping the CNTs. The originally hydrophobic surface of CNTs is progressively turned to be highly hydrophilic with rising ALD cycles. The deposition of ZnO on CNTs significantly promotes the surface wettability of the CNT membranes on one hand, and endows the membrane an enhanced mechanical stability on the other. The CNT membranes exhibit simultaneously upgraded water permeability and retention in the ultrafiltration category after ALD for moderate cycle numbers. With ever increased ALD cycles, the retention is further improved while the water permeability is decreased due to the competing effect of the increased hydrophilicity and narrowed pores. The strategy of “ALD on CNT substrates” is expected to produce other robust membranes with additional functionalities dependent on the materials to be deposited by ALD.

Processing two-dimensional (2D) covalent organic frameworks (COFs) into nanofilms has gained widespread attention in water treatment. However, the designed synthesis of COF-based membranes for ion separations still remains a huge challenge though the strategies to produce COF molecular separation membranes have been greatly developed. Herein, we report the construction of bi-layered COF nanofilms for efficient desalination through a simple yet effective secondary growth. The suggested strategy is capable of easily regulating the growth of another COF layer on the pre-synthesized first layer, thus producing crystalline and defect-free bi-layered COF nanofilms with distinct laminated structures. Most importantly, the offset channels are involved at the interface of two nanofilms obtained from the first and secondary growth, which leads to a constricted effective aperture that significantly enhances the ion separation performance. Specifically, the bi-layered COF nanofilms composited with macroporous supports exhibit high rejection rates (~95.8%) to Na2SO4, observably surpassing the desalination performance of single-layered COF nanofilms (rejection

Absorption is an effective method to collect oil spills and solvent leakages from water. However, the currently used oil absorbents are still suffering from high cost, tedious preparation, and low recyclability. In this work, we report an extremely simple and low-cost strategy to produce oil absorbents by directly coupling alkoxysilane onto the surface of polyurethane foams. Such direct silanization renders the initially amphiphilic foams a strong hydrophobicity and consequently a water-repelling and oil-absorptive functionality. The silanized foams exhibit highest absorption capacities as well as best recyclability among all polyurethane-based oil absorbents. More practically, the silanized PU foams can be used to recover crude oil spills with an absorption capacity of higher than 75 times of their own weight, and maintain 90% of the initial absorption capacity after 8 times reusage. Interestingly, we invent portable oil suckers for continuous oil absorption from water by filling vacuum cleaners with the silanized foams. This article is protected by copyright. All rights reserved.

To fabricate a novel photocatalyst material with high efficiency, ZnO seeds were uniformly deposited on carbon fibers (CFs) via atomic layer deposition (ALD) followed by hydrothermal growth of ZnO nanorods (NRs). Then Pt particles were dispersed on ZnO NRs using the magnetron sputtering method, and the grain size of Pt particles was in the range of 2–5 nm. Significantly, the resultant Pt@ZnO NRs/CFs composites exhibited better photocatalytic performance than normal ZnO NR coated CFs as demonstrated in the degradation of methyl orange (MO) solution, which may be due to the synergistic effect between the Pt nanoparticles and ZnO NRs. After a period of light irradiation, the degradation rates of methyl orange (MO) dye solution are as follows: 72% for ZnO NRs/CFs and 99.8% for Pt@ZnO NRs/CFs. In addition, this novel hierarchical photocatalyst can be easily recycled with good performance and stability.

Laboratory-reared Schizothorax davidi larvae and juveniles were examined to assess the formation and characteristics of David’s schizothoracin otoliths. Otolith development was observed and their formation period was verified by monitoring larvae and juveniles of known age. The results revealed that lapilli and sagittae developed before hatching, and the first otolith increment was identified at 2 days post hatching in both. The shape of lapilli was relatively stable during development compared with that of sagittae; however, growth of four sagittae and lapilli areas was consistent, but the posterior area grew faster than the anterior area and the ventral surface grew faster than the dorsal surface. Similarly, the sum length of the radius of the anterior and posterior areas on sagittae and lapilli were linearly and binomially related to total fish length, respectively. Moreover, daily deposition rates were validated by monitoring known-age larvae and juveniles. The increase in lapilli width was 1.88±0.080 0 μm at the ninth increment, which reached a maximum and the decreased gradually toward the otolith edge, whereas that of sagittae increased more slowly. These results illustrate the developmental biology of S. davidi, which will aid in population conservation and fish stock management.

Molecular layer deposition (MLD) for the deposition of polyimide (PI) at low temperature of 110 °C has been firstly introduced into the field of membrane separation. With the optimized MLD deposition parameters, such low deposition temperature has successfully expanded the application of MLD for the surface modification of polymeric materials. Globular PI particulates grow on both the free surfaces as well as the pore walls of the polypropylene (PP) membranes as isolated islands during progressive precursor exposures. The PI-deposited PP membranes exhibit synergistically improved performances in various aspects. Evidently improved surface hydrophilicity and permeation performance (30%) have been achieved via the MLD deposition of polyimide films. The overall separation efficiency maintained higher than 85% even after 250 cycles of MLD deposition. More importantly, the thermal stability has been improved and the integrity of the porous structure for PI-deposited PP membranes has been well preserved even after harsh treatment, which ensures its potential application in industries.

In this work, zinc oxide (ZnO) is deposited onto porous polytetrafluoroethylene (PTFE) membranes via atomic layer deposition (ALD) and thus produced ZnO-deposited PTFE membranes are used as adsorbents for the removal of dyes from aqueous solutions. We first examine the evolution of morphology, wettability, and crystallization of PTFE membranes with ZnO ALD. The presence of ZnO nanoparticulates significantly promotes the diffusion and contact of the aqueous solutions within the membrane on one hand, and endows the membrane a strong capability to adsorb dyes from the solutions on the other. Kinetic studies reveal that the adsorption of rhodamine B and acid orange 7 by the ZnO-deposited PTFE membranes can be described by the pseudo-second-order and pseudo-first-order model, respectively, and the adsorption of both dyes follows the Langmuir isotherm. The used membranes can be easily regenerated by rinsing with ethanol and reused for multiple times without loss of removal efficiency. © 2016 American Institute of Chemical Engineers AIChE J, 62: 3982–3991, 2016

Polytetrafluoroethylene hollow-fiber membranes (PTFE HFMs) with attractive advantages are highly promising for many applications, but strong hydrophobicity limits their uses in aqueous systems. To address this challenge, we propose to coat ultra-thin layers of alumina by atomic layer deposition (ALD) to upgrade performances of PTFE HFMs in water treatment. However, ALD usually requires time- and labor-consuming trial-and-error to optimize operating parameters. Herein, we use computational fluid dynamics (CFD) to identify most appropriate ALD parameters for PTFE HFMs functionalization. Following the CFD-optimized parameters, the ALD-treated membranes obtain significantly improved permselectivity and fouling resistance because of the remarkable increase in wettability at negligible cost in pore sizes. Impressively, water permeability of membranes is nearly doubled while rejection is increased by ~20%, which is seldom achieved by other methods. This CFD-optimized ALD process is expected to be a universal strategy to efficiently enhance the performances of polymeric membranes.

The complete mitochondrial genome of Gymnocypris potanini firmispinatus was sequenced and compared with others Gymnocypris species. The mitochondrial genome, consisting of 16,680 base pairs (bp), encoded 13 protein-coding genes, 2 ribosomal RNAs, 22 transfer RNAs and a non-coding control region, as those found in other Gymnocypris species. These results can provide useful data for further studies on taxonomic status, molecular systematics and stock evaluation.

In the study, the complete mitochondrial genome of Gymnocypris potanini Herzensten was sequenced and compared with other Gymnocypris species. The mitochondrial genome, consisting of 16,749 base pairs (bp), encoded 13 protein-coding genes, 2 ribosomal RNAs, 22 transfer RNAs, and a noncoding control region, similar as that found in other Gymnocypris species. These results can provide useful information for further studies on taxonomic status, molecular systematics, and stock evaluation.