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The decomposition of long-chain perfluorocarboxylic acids (PFCAs), including perfluorononanoic acid (PFNA) and perfluorodecanoic acid (PFDA), were investigated by electrochemical activation of peroxymonosulfate (PMS) on porous Ti/SnO2-Sb membrane anode. The results indicated that PMS activation could efficiently promote PFNA/PFDA decomposition, with pseudo-first-order rate constants about 3.12/2.06 times as compared with that of direct electro-oxidations. The energy consumptions of PFNA and PFDA decomposition were 36.31 and 37.46 kWh·m−3·order−1, respectively. The quantitative detection results of •OH with electron paramagnetic resonance (EPR) demonstrated that PMS activation promoted •OH formation. The inhibited performance in radical scavengers indicated both •OH and SO4•− might be mainly involved in PFNA decomposition, while SO4•− might be mainly involved in PFDA decomposition during PMS activation process. The mineralization mechanism for long-chain PFCAs decomposition which was mainly by repeating CF2-unzipping cycle via radical reaction based on the intermediates verification and mass balance of C and F, was proposed. These results suggested that electrochemical activation of PMS on porous Ti/SnO2-Sb membrane anode exhibited high efficiency in mineralizing PFNA and PFDA under mild conditions. This work might provide an efficient way for persistent organic pollutants, including, but not limited to long-chain PFCAs elimination from wastewater.

Nanocarriers (NCs) for delivery anticancer therapeutics have been under development for decades. Although great progress has been achieved, the clinic translation is still in the infancy. The key challenge lies in the biological barriers which lie between the NCs and the target spots, including blood circulation, tumor penetration, cellular uptake, endo-/lysosomal escape, intracellular therapeutics release and organelle targeting. Each barrier has its own distinctive microenvironment and requires different surface charge. To address this challenge, charge-reversal polymeric NCs have been a hot topic, which are capable of overcoming each delivery barrier, by reversing their charges in response to certain biological stimuli in the tumor microenvironment. In this review, the triggering mechanisms of charge reversal, including pH, enzyme and redox approaches are summarized. Then the corresponding design principles of charge-reversal NCs for each delivery barrier are discussed. More importantly, the limitations and future prospects of charge-reversal NCs in clinical applications are proposed.

AIMS: To investigate control measures for COVID-19 pandemic in GIE centers in China. METHODS: This is a retrospective multi-center research, including seven centers. Data collection was from 1 February to 31 March 2020 and the same period in 2019. RESULTS: There were a total of 28 COVID-19 definite cases in these hospitals. Six out of seven GIE centers were arranged to shut down on 1 February, with a mean number of shutdown days of 23.6 ± 5.3. The actual workloads were only 10.3%-62.9% compared to those last year. All centers had a preoperative COVID-19 screening process. Epidemiological questionnaire, temperature taking and QR-code of journey were conducted. Chest CT scan was conducted during the shutdown period and continued in five centers after return to work. Antibody and nucleic acid test were applied in one to three centers. All endoscopists had advanced PPE. Five centers used surgical mask and the rest used N95 mask. Six centers used goggles or face shield. Five centers selected isolation gowns and the rest selected protective suits. The change frequency of these PPE was 4 h. Sterilizing measures were improved in six centers. Five centers utilized ultraviolet and six centers strengthened natural ventilation. Four and six centers used peracetic acid during the period of shutdown and return to work, alone or matched with OPA or acidified water. CONCLUSIONS: Many effective control measures were conducted in GIE centers during the outbreak, including patients' volume limitation, preoperative COVID-19 screening, advanced PPE and disinfection methods.

Trichomoniasis is caused by Trichomonas vaginalis (T. vaginalis), which is a widespread and serious sexually transmitted pathogen in humans. The procedure of T. vaginalis adherence to the host cell is the precondition for T. vaginalis parasitism and pathogenicity. The AP33 adhesin of T. vaginalis (TvAP33) plays a key role in the process of adhesion. In this study, the specific primers for polymerase chain reaction (PCR) were designed based on the sequence of TvAP33 (GenBank Accession No. U87098.1) to amplify the open reading frame (ORF), and the ORF was inserted into pET-32a (+) to produce recombinant TvAP33 (rTvAP33). The sequence analysis indicated that the TvAP33 gene encoded a protein of 309 amino acids with 32.53 kDa, and the protein was predicted to have a high antigen index. Western blotting assay showed rTvAP33 was successfully recognized by the sera of mice experimentally infected with T. vaginalis, while native TvAP33 in the somatic extract of T. vaginalis trophozoite was as well detected by sera from rats immunized with the rTvAP33. Immunofluorescence analysis using an antibody against rTvAP33 demonstrated that the protein was expressed and located on the surface of T. vaginalis trophozoites. The recombinant protein was emulsified in Freund’s adjuvant and used to immunize BALB/C mice three times at days 0, 14, and 28. The result of animal challenge experiments revealed the levels of IgG, IgG1, and IgG2a, and IL-4, IL-10, and IL17 among rTvAP33 vaccinated animals were integrally increased. Moreover, the rTvAP33 vaccinated animals were apparently prolonged survival time (26.45 ± 4.10) after challenge infection with this parasite. All these results indicated that TvAP33 could be used as vaccine candidate antigen to induce cell-mediated and humoral immunity.

Inspired by cell membrane structures, synthetic polymer vesicles caused great expectations for the preparation of biomedicine for decades. However, in contrast to bio-membranes, which consist of inhomogeneous features, conventional synthetic polymer vesicles usually consist of a homogeneous membrane which is purely made out of hydrophobic components. This significantly limited the versatility of synthetic polymer vesicle membranes. Fortunately, polymer vesicles with inhomogeneous membranes were recently developed to address this limitation. These new inhomogeneous membrane features introduced secondary functions to the vesicle membrane. Indeed, the membrane of polymer vesicles no longer only serves as a simple barrier that separates the interior from the exterior environment. Introduced membrane features can act as a versatile platform for tailorable nanoparticle functionalities, which allow functions such as biomacromolecule transportation, diabetes treatment, and cancer theranostics. This review highlights recent advances made with polymer vesicles with inhomogeneous membrane structures. More specifically, design principles, biomedical applications, and the future perspectives of such vesicles are summarized.

The softening behavior of a cold-drawn Cu&ndash, Cr&ndash, In alloy was investigated during annealing between 450 &deg, C and 700 &deg, C. The properties and microstructure evolution of the alloy were characterized using a microhardness tester, electron back-scatter diffraction, and transmission electron microscopy. Elemental In addition was found to hinder the dislocation movement and delay the recovery and recrystallization of the Cu&ndash, In alloy. The experimental data were analyzed using the Johnson&ndash, Mehlv&ndash, Avramiv&ndash, Kolmogorov model. The activation energy of recrystallization of the 60% cold-drawn Cu0.54Cr0.17In alloy was 188.29 &plusmn, 18.44 kJ/mol, and the recrystallization mechanism of the alloy was attributed mainly to Cu self-diffusion.

The effective electrochemical oxidation of aqueous carbamazepine (CBZ) using a novel blue-colored TiO

The surgical implant is an interdisciplinary therapeutic modality that offers unique advantages in the daily practice of otorhinolaryngology. Some well-known examples include cochlear implants, bone-anchored hearing aids, sinus stents, and tracheostomy tubes. Neuroprotective, osteogenic, anti-inflammatory, and antimicrobial effects are among their established or pursued functions. Implant-based drug delivery affords an efficient and potent approach to enhancing these therapeutic functions. Recent innovations have infiltrated all four elements of a drug-eluting implant. The purpose of this pre-clinical, biotechnology-oriented review is to discuss these developments in terms of the implant biomaterial, loaded medication, delivery pattern, and system fabrication. Cell-mediated neurotrophin release, fabrication of a hydroxyapatite-supported system, biodegradable polymer-based implants, and multiclass and multidrug delivery are some representative advancements. The ultimate goal here is to bridge the gap between biotechnology advances and clinical needs. The review is concluded with a perspective regarding the future opportunities and challenges in this popular and rapidly developing subject of research. STATEMENT OF SIGNIFICANCE: Surgical implants and local drug delivery are representative modern modalities of surgical treatment and medical treatment, respectively. Their synergy offers unique therapeutic advantages, such as minimal systemic side effects, proximity-related high efficiency, and potential absorbability. The applications of implant-based drug delivery have infiltrated otorhinolaryngology and head & neck surgery, which is well known for its related tissue diversity and surgical complexity. Examples discussed here include cochlear implants, bone-anchored hearing aids, sinus stents, and airway tubes. This timely review focuses primarily on the four fundamental components of an implant-based drug delivery system, namely implant biomaterial, loaded medication, delivery pattern, and system fabrication. A particular emphasis is placed upon the in vitro cellular and in vivo animal studies that demonstrate pre-clinical potentials.

Surface-induced crystallization of an isotropic Bi nanodroplet in three distinct steps was recorded at atomic resolution by in situ high resolution transmission electron microscopy. First, formation of a crystalline nucleus at the edge of the nanodroplet is induced by the liquid-state surface faceting, which initiates the formation of a prefreezing state with a distorted structure. Then, a periodic line pattern of the atomic columns with a periodicity of 0.49 nm that is relative to the interlayer spacing of the Bi crystal along the ⟨112⟩* direction (one-dimensional ordered structure) was formed by structure relaxation of the prefreezing nanoparticle, followed by a concerted growth and ordering process. Finally, the crystallization from the periodic structure was carried out by atom/atom interactions within and between the atomic layers to form the covalent Bi–Bi bonds that have the same arrangement as in the Bi crystal (crystallization along the ⟨110⟩ direction). Motivated by the experimental observation...

Removal of triclosan (TCS) in water has attracted increasing attention due to its high detection frequency and potential toxicity. In this study, porous TiO2 nanotube arrays (TiO2 NTA) was prepared as the reactive electrochemical membrane (REM) to adsorb aqueous TCS, and subsequently to degrade TCS in-situ (a regeneration process of TiO2 NTA). Adsorption kinetics and thermodynamic of TCS followed pseudo-second-order model and Langmuir model, respectively. Compared with adsorption at 0 mL min−1 (static adsorption), the initial adsorption rate and the maximum adsorption capacity increased 18.8-fold and 73.8-fold at 300 mL min−1, respectively. The optimal equilibrium absorption capacity (per projected area of TiO2 NTA) and the initial adsorption rate were 2042.92 mg m−2 and 108.51 mg m−2 min−1, respectively. In the subsequently electrochemical oxidation process, 99.8% of the adsorbed TCS was degraded in-situ and TiO2 NTA was regenerated simultaneously. TiO2 NTA electrode maintained the stable removal performance of TCS during four adsorption-degradation cycles. The adsorption process was a complex combination of the hydrophobic interaction and electrostatic interaction with/without applied voltage at different pH value. The electrochemical degradation pathways of TCS on TiO2 NTA were hydroxylation, disproportionation, dichlorination and cleavage of ether bond under the attack of electrochemical generated OH and O2 −. The flow-through sequential adsorption and electrochemical degradation (SAED) based on TiO2 NTA REM were proved to be effective method to removal TCS in waters, especially for the water with low conductivity.

The current study presents a comprehensive and novel attempt to degrade aqueous tri(2-chloroethyl) phosphate (TCEP) by metal-oxide-coated Ti anodes for the first time. Six metal-oxide-coated Ti electrodes (Ti/SnO2-Sb, Ti/SnO2-Sb/PbO2, Ti/SnO2-Sb/La-PbO2, Ti/SnO2-Sb/Ce-PbO2, Ti/SnO2-Sb/Ga-PbO2 and Ti/SnO2-Sb/Zr-PbO2) were prepared and characterized. Ti/SnO2-Sb/La-PbO2 showed the highest pseudo-first-order reaction rate constant (2.1 × 10−2 min−1) and lowest energy consumption (21.35 Wh L−1) in the degradation of 1 mg L−1 TCEP at 10 mA cm−2, mainly because of its highest oxygen evolution potential and OH production. Higher current density and neutral condition favored TCEP degradation, while the presence of Cl− or NO3− could suppress the degradation. In the electrochemical degradation of 10 mg L−1 TCEP, mineralization percentage of 48.0% (mineralization current efficiency of 0.30%) and PO43− release percentage of 72.7% were achieved at 150 min. By the attack of OH on the C O and C Cl bonds in TCEP molecular structure, products of chloroethanol, Cl− and PO43− were released, with the major electrocatalytic degradation pathways of dechlorination and hydroxylation. Based on the results of flow cytometry, the relative toxicity to Escherichia coli effectively decreased to 4.93% in TCEP degradation. Compared with the UV-AOPs, electrochemical oxidation process is proved to be feasible and effective for mineralization and detoxification of TCEP in water.

The utilization of photocatalytic technology to remove air pollutants has attracted global interest. However, it still suffers from low removal activities under visible light irradiation. In this study, we demonstrated that the switching of the semiconducting behavior from n-type to p-type can efficiently improve the photocatalytic activity of g-C3N4 for nitric oxide (NO) removal about 3.5 times. This is due to that such switching could change the majority of carriers in g-C3N4 from electrons to holes. Interestingly, the photocatalytic removal of NO in both n-type and p-type g-C3N4 is proceeded via hole oxidation. More importantly, p-type g-C3N4 displays strong stability in both photocatalytic performance and crystal structures. This study provides a new strategy to improve the photocatalytic activity of semiconductors for air pollution removal.

2, 4-dichlorophenol (2, 4-DCP) is considered to be a highly toxic, mutagenic, and possibly carcinogenic pollutant. This study is focused on the electrochemical oxidation of 2, 4-DCP on nanostructured 3D-porous Ti/Sb-SnO2-Gr anodes, with the aim of presenting a comprehensive elucidation of mineralization process through the investigation of influential kinetics, the reactivity of hydroxyl radical's and analysis of intermediates. High efficiency was achieved at pH of 3 using Na2SO4 electrolytes at a current density of 30 mA cm-2. Under the optimized conditions, a maximum removal of 2, 4-DCP of up to 99.9% was reached, whereas a TOC removal of 81% was recorded with the lowest ECTOC (0.49 kW h g-1) within 40 min of electrolysis. To explore the stability of the 3D-Ti/Sb-SnO2-Gr electrodes, a continuous electrochemical operation was established, and the consistent mineralization results indicated the effectiveness of the 3D-Ti/Sb-SnO2-Gr system concerning its durability and practical utilization. EPR studies demonstrated the abundant generation of OH radicals on 3D-Ti/Sb-SnO2-Gr, resulting in fast recalcitrant pollutant incineration. From dechlorination and the reactivity of the OH radicals, several intermediates including six cyclic byproducts and three aliphatic carboxylic acids were detected, and two possible degradation pathways were proposed that justify the complete mineralization of 2, 4-DCP.

Pectins are synthesized and secreted to the cell wall as highly methyl-esterified polymers and demethyl-esterified by pectin methylesterases (PMEs), which are regulated by pectin methylesterase inhibitors (PMEIs). PMEs and PMEIs are involved in pectin degradation during fruit softening; however, the roles of the PME and PMEI gene families during fruit softening remain unclear. Here, 71 PME and 30 PMEI genes were identified in the peach (Prunus persica) genome and shown to be unevenly distributed on all eight chromosomes. The 71 PME genes comprised 36 Type-1 PMEs and 35 Type-2 PMEs. Transcriptome analysis showed that 11 PME and 15 PMEI genes were expressed during fruit ripening in melting flesh (MF) and stony-hard (SH) peaches. Three PME and five PMEI genes were expressed at higher levels in MF than in SH fruit and exhibited softening-associated expression patterns. Upstream regulatory cis elements of these genes related to hormone response, especially naphthaleneacetic acid and ethylene, were investigated. One PME (Prupe.7G192800) and two PMEIs (Prupe.1G114500 and Prupe.2G279800), and their promoters were identified as potential targets for future studies on the biochemical metabolism and regulation of fruit ripening. The comprehensive data generated in this study will improve our understanding of the PME and PMEI gene families in peach. However, further detailed investigation is necessary to elucidate the biochemical function and regulation mechanism of the PME and PMEI genes during peach fruit ripening.

Heterojunction is recognized as an effective approach to improve photocatalytic performance, but a well-matched energy band alignment is critical therein. In this work, the shuriken-shaped BiVO 4 /TiO 2−x heterojunction is built by engineering the electronic structure of TiO 2 with Ti 3+ self-doping via a two-step hydrothermal process to achieve a high photocatalytic performance. The presence of Ti 3+ creates a defect energy level under the conduction band of TiO 2 , and thereby diminishes the interfacial energy barrier between BiVO 4 and TiO 2 . The Ti 3+ defect energy level promotes the electron transfer from BiVO 4 to conduction band of TiO 2−x . The test of phenol degradation under 300 W Xenon lamp equipped with UV cut-off filter (λ ≥ 420 nm) demonstrates that BiVO 4 /TiO 2−x heterojunction exhibits higher photocatalytic activity than its counter parts, pure BiVO 4 and the physic mixture of BiVO 4 and TiO 2−x . The improved photocatalytic performance is mainly attributed to the heterojunction formed between BiVO 4 and TiO 2−x , which improves the separation of photogenerated charge carriers as support by comparative photocurrent and time-resolved PL spectral measurements. In addition, Ti 3+ self-doping also narrows the bandgap of TiO 2 and enhances the visible-light activity of TiO 2 . The holes of TiO 2−x transfer to the valance band of BiVO 4 which further significantly improves the separation of photogenerated charge carriers, further. Additionally, the high surface area caused by TiO 2-x also contributes to the improved photocatalytic efficiency.

Nanostructured highly porous 3D-Ti/Sb–SnO2–Gr electrode, based on 3D porous graphene hydrogel was fabricated via a fast-evaporation technique through layer by layer (LBL) deposition. The 3D pores are uniformly distributed on the high fidelity of substrate with pore sizes of 7–12 nm, as confirmed by SEM analysis. Compared to Ti/Sb–SnO2 electrode, the fabricated 3D porous electrode possesses high oxygen evolution potential (2.40 V), smaller charge transfer resistance (29.40 Ω cm−2), higher porosity (0.90), enhanced roughness factor (181), and larger voltammetric charge value (57.4 mC cm−2). Electrocatalytic oxidation of Rhodamine B (RhB) was employed to evaluate the efficiency of the fabricated 3D-Ti/Sb–SnO2–Gr anode. The results show that the electrochemical reaction follows pseudo first order kinetics with rate constant (k) value of 4.93 × 10−2 min−1, which is about 3.91 times higher compared to flat Ti/Sb–SnO2. The fabricated electrode demonstrates better stability and low specific energy consumption signifying its potential usage in electrocatalysis.

The SrBi 2 Nb 2 O 9 platelets with a thickness of about 600 nm were synthesized by molten salt synthesis method. The treatment of the SrBi 2 Nb 2 O 9 platelets with hydrochloric acid resulted in the formation of the protonated H 1.78 Sr 0.78 Bi 0.22 Nb 2 O 7 platelets. Through a top–down approach in ethylamine solution, the H 1.78 Sr 0.78 Bi 0.22 Nb 2 O 7 platelets were exfoliated into H 1.78 Sr 0.78 Bi 0.22 Nb 2 O 7 nanosheets with a thickness of about 2.6 nm. The evolution of the structure, composition, morphology, optical, and photocatalytic properties of SrBi 2 Nb 2 O 9 platelets was studied as it is converted into H 1.78 Sr 0.78 Bi 0.22 Nb 2 O 7 platelets and subsequently exfoliated into H 1.78 Sr 0.78 Bi 0.22 Nb 2 O 7 nanosheets. The absorption edge shifts to a lower wavelength accompanied by the protonation and exfoliation. The photocatalytic H 2 evolution of the three samples were evaluated under the irradiation of a 300 W Xenon lamp from CH 3 OH/H 2 O solution, indicating that H 1.78 Sr 0.78 Bi 0.22 Nb 2 O 7 nanosheets Exhibit 5.5 and 26.2 times higher activity than that of the H 1.78 Sr 0.78 Bi 0.22 Nb 2 O 7 and SrBi 2 Nb 2 O 9 platelets, respectively. The enhanced activity for the H 1.78 Sr 0.78 Bi 0.22 Nb 2 O 7 nanosheets is mainly attributed to the higher separation efficiency of the photogenerated carriers and the larger specific surface area caused by the significant reduction in thickness.

Polymer vesicles, also known as polymersomes, are finding increasing applications in biomedical field, including drug delivery, gene therapy, magnetic resonance imaging, theranostics, etc. This is due to their intrinsic hollow nanostructure and compartmentalized domains with diverse functionalities. This review describes recent advances in the design and synthesis of polymer vesicles, including the formation mechanisms, preparation methods, applications and responsive behaviors toward external stimuli. We first present the rational design and synthesis of polymer vesicles based on different polymeric building blocks, followed by an insight into the structure and formation mechanism of polymer vesicles, as well as the recently developed means to determine the exact thickness of the vesicle membrane. Except for responding to traditional stimuli such as pH, temperature and oxidation/reduction, polymer vesicles are becoming ‘smarter’ owing to the newly developed stimuli including electrical field, magnetic field, sugar molecules, gas, ultrasound, etc. Finally, the potential applications of polymer vesicles beyond biomedical field are highlighted as novel nanoreactors, water remediation materials, etc.

In the present study, a new type of montmorillonite/carbon (MMT/C) adsorbent has been prepared by a one-pot hydrothermal carbonization process. The MMT/C composite was further modified to obtain functionalized MMT/C, i.e., hydroxylated MMT/C, carboxylated MMT/C, and aminated MMT/C. The prepared MMT/C-based sorbents were systematically characterized by X-ray diffraction (XRD), specific surface area, zeta potential, and scanning electron microscopy (SEM). Their adsorption capacity was evaluated by the removal of aqueous Pb(II) ions, following the order carboxylated MMT/C > hydroxylated MMT/C > aminated MMT/C > MMT/C. Moreover, the influential factors for Pb(II) removal by carboxylated MMT/C composites, such as pH, temperature, and initial concentration, were thoroughly explored. The adsorption capacity increases significantly when the pH increases from 2.0 to 5.0 but with minor change beyond. The maximum adsorption capacities of MMT/C–COOH toward Pb(II) are 247.85 mg g–1. The complexation of surface groups ...

Phenol degradation with TiO2 has attracted a great deal of interest in recent years. However, its low efficiency under solar radiation and difficulty of recovery limit the potential use. Here we report a novel “silica support inducing oxygen vacancies” strategy to prepare visible-light-active TiO2 with mixed-phase, which show excellent photocatalytic performance for phenol degradation under visible light. Hydroxyl and superoxide radicals were the main oxidative species responsible for the degradation of phenol. Our work demonstrates that coupling with oxygen vacancy creation and silica nanosheets (SNSs) immobilization for TiO2 is a new approach to obtained efficient visible-light photocatalysts for practical application.

Precision functionalized polyesters, with defined monomer sequences, are prepared using an orthogonal post-polymerization strategy. These polyesters can be synthesized from bio-derived monomers and are targeted to degrade, by hydrolysis processes, to biocompatible diols and diacids; the new structures enabled by this methodology would be very difficult to synthesize by alternative strategies. A series of 9 well-defined highly alternating AB-type copolyesters, containing terminal and internal alkene functionalities, are synthesized in high conversions by the ring-opening copolymerization of epoxides and cyclic anhydrides. Firstly, the polyesters are functionalized by a selective hydroboration–oxidation reaction to exclusively and quantitatively hydroxylate the terminal alkenes, leaving the alternating internal alkenes unreacted. Subsequently, the internal alkenes are quantitatively transformed into carboxylic acid, amine, alkyl and oligo-ether groups, by thiol–ene reactions, to afford AB polyesters with alternating functional substituents. Three polyesters showing alternating hydrophilic/hydrophobic side-chain sequences self-assemble in solution to form nanostructures that are characterized using transmission electron microscopy and dynamic light scattering methods (Rh = 100–300 nm). The selective patterning methodology provides facile, efficient and orthogonal functionalization of alternating polyesters with near-quantitative (AB)n repeat sequences. The method is expected to be generalizable to other polymers and provides access to completely new AB alternating structures with the potential to exploit ligand multi-valency and adjacency to enhance properties.

A series of AB alternating polyesters are orthogonally patterned to install two different functionalities at regular intervals along the backbone and with high precision., Precision functionalized polyesters, with defined monomer sequences, are prepared using an orthogonal post-polymerization strategy. These polyesters can be synthesized from bio-derived monomers and are targeted to degrade, by hydrolysis processes, to biocompatible diols and diacids; the new structures enabled by this methodology would be very difficult to synthesize by alternative strategies. A series of 9 well-defined highly alternating AB-type copolyesters, containing terminal and internal alkene functionalities, are synthesized in high conversions by the ring-opening copolymerization of epoxides and cyclic anhydrides. Firstly, the polyesters are functionalized by a selective hydroboration–oxidation reaction to exclusively and quantitatively hydroxylate the terminal alkenes, leaving the alternating internal alkenes unreacted. Subsequently, the internal alkenes are quantitatively transformed into carboxylic acid, amine, alkyl and oligo-ether groups, by thiol–ene reactions, to afford AB polyesters with alternating functional substituents. Three polyesters showing alternating hydrophilic/hydrophobic side-chain sequences self-assemble in solution to form nanostructures that are characterized using transmission electron microscopy and dynamic light scattering methods (Rh = 100–300 nm). The selective patterning methodology provides facile, efficient and orthogonal functionalization of alternating polyesters with near-quantitative (AB)n repeat sequences. The method is expected to be generalizable to other polymers and provides access to completely new AB alternating structures with the potential to exploit ligand multi-valency and adjacency to enhance properties.

The reactions between alcohols and the tetranuclear ethyl-Zn complexes of an ortho-phenylene-bridged polypyrrole macrocycle, Zn4Et4(L1) 1 and the related anthracenyl-bridged macrocyclic complex, Zn4Et4(THF)4(L2) 2 have been studied. With long-chain alcohols such as n-hexanol, the clean formation of the tetranuclear hexoxide complex Zn4(OC6H13)4(L1) 3 occurs. In contrast, the use of shorter-chain alcohols such as i-propanol results in the trinuclear complex Zn3(μ2-OiPr)2(μ3-OiPr)(HL1) 4 that arises from demetalation; this complex was characterised by X-ray crystallography. The clean formation of these polynuclear zinc clusters allowed a study of their use as catalysts in the ring-opening copolymerisation (ROCOP) reaction between cyclohexene oxide and CO2. In situ reactions involving the pre-catalyst 1 and n-hexanol formed the desired polymer with the best selectivity for polycarbonate (90%) at 30 atm CO2, whilst the activity and performance of pre-catalyst 2 was poor in comparison.

The reactions between alcohols and the tetranuclear ethyl-Zn complexes of an ortho-phenylene-bridged polypyrrole macrocycle, Zn4Et4(L1) 1 and the related anthracenyl-bridged macrocyclic complex, Zn4Et4(THF)4(L2) 2 have been studied. With long-chain alcohols such as n-hexanol, the clean formation of the tetranuclear hexoxide complex Zn4(OC6H13)4(L1) 3 occurs. In contrast, the use of shorter-chain alcohols such as i-propanol results in the trinuclear complex Zn3(μ2-OiPr)2(μ3-OiPr)(HL1) 4 that arises from demetalation; this complex was characterised by X-ray crystallography. The clean formation of these polynuclear zinc clusters allowed a study of their use as catalysts in the ring-opening copolymerisation (ROCOP) reaction between cyclohexene oxide and CO2. In situ reactions involving the pre-catalyst 1 and n-hexanol formed the desired polymer with the best selectivity for polycarbonate (90%) at 30 atm CO2, whilst the activity and performance of pre-catalyst 2 was poor in comparison.

International audience; Contamination of waters by pharmaceuticals is a major health issue. Therefore, there is a need for efficient techniques to remove pharmaceutical pollutants. Here, a photo-assisted fenton-like method based on sulfate radicals was tested using CaCu3Ti4O12 with different morphologies as catalyst. Sintering of CaCu3Ti4O12 at 775 °C for 6 h produced cubic structures with sizes from 2 to 5 μm, whereas sintering for 14 h produced microfibers, according to scanning electron microscopy. The highest electron paramagnetic resonance signal was observed for 6-h sintering. We evaluated the catalytic efficiency of CaCu3Ti4O12 for ibuprofen degradation with peroxymonosulfate under visible light. Results show that CaCu3Ti4O12 and 0.5 mM peroxymonosulfate under visible-light irradiation induced 91.8% removal of ibuprofen in 60 min. The Cu + vacancy on the surface of CaCu3Ti4O12 is essential to activate the sulfate radicals by forming a Cu +-Cu 2+ redox couple, which led to the rapid and efficient removal of ibuprofen.

This work presented a three-dimensional (3D) hierarchically microporous biochar (HMB) via molten alkali treatment that achieved efficient adsorption of perfluorinated carboxylic acids (PFCAs), which was a significant environment concern due to the global distribution and potential health risks. The systematic optimization of fabrication process rendered the HMB large surface area and uniform microporous structure, leading to a high adsorption capacity and adsorption rate of 1269 mg/g and 197 mg/(g·min), respectively, when perfluorooctanoic acid (PFOA) was as a representative. The adsorption mechanisms were explored via controlling the interaction between PFCAs and the HMB900-2.4. Specifically, hydrophobic effect was verified by the enhanced adsorption performance with the increase of the PFCAs homologues hydrophobicity. The observed highly pH-dependent adsorption capacity additionally suggested the dominant contribution of electrostatic interaction. For long-chain PFCAs (CnF2n+1COOH, n > 5), the HMB900-2.4 presented a high removal efficiency (> 90%) within 30 min. Even for short-chain PFCAs (CnF2n+1COOH, n = 4–5), the removal efficiency reached to over 60%. The synthesized HMB900-2.4 exhibited high stability during recycling experiments and superior performance over commercial adsorbents, suggested a promise of utilizing it to remove PFCAs from wastewater.

The effective electrochemical oxidation of aqueous carbamazepine (CBZ) using a novel blue-colored TiO2 nanotube arrays (BC-TiO2NTA) membrane filter anode was studied. The BC-TiO2NTA was characterized using SEM, TEM, BET, mercury intrusion porosimetry, XPS, XRD, CV, and LSV. The BC-TiO2NTA had reserved pore structure, formed mesopores, specific and electroactive surface areas of 2.01 m2 g-1 and 9.32 cm2 cm-2, respectively. The oxygen evolution potential was 2.61 V vs. SCE. CBZ could be degraded by OH, SO4- and O2- on BC-TiO2NTA in accordance to pseudo-first-order kinetic, which was greatly enhanced in flow-through mode. The optimal kinetic rate constant of CBZ degradation of 0.403 min-1 was achieved at 3 mA cm-2, while energy consumption per order was 0.086 kW h m-3. The mineralization efficiency and mineralization current efficiency were 50.8 % and 9.5 % at 180 min, respectively. The presence of Cl- (0.3-3 mM) accelerated electrochemical degradation of CBZ, while NO3- (0.1-2 mM) inhibited the reaction. Based on density functional theory calculation and UPLC-Orbitrap-MS/MS measurement, we found that electrochemical degradation of CBZ was initialized by cleavage of -CONH2 group and attack of OH on the olefinic double bond of the central heterocyclic ring.

In this research, Methylene blue (MB), a type of environmental pollutants (dye), was initially adopted as a carbonaceous precursor to synthesize activated carbons (ACs) with the activation of ZnCl2 at high temperatures. Varieties of techniques have been used to characterize the MB-derived ACs. The pore structures and surface functional groups were fully studied by N2 adsorption-desorption analysis, XPS, IR, SEM and TEM, respectively. The MB-derived ACs have as large specific surface area as up to 2151.92 m2g−1 and the pore size distribution concentrates on 2–5 nm. Moreover, electrochemical techniques such as cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and galvanostatic charge/discharge (GCD) were employed to assess AC’s capacitive behavior and rate performance. It demonstrated that MB-derived ACs possessed as high specific capacitance as 265 Fg−1 at a scan rate of 5 mV s−1 in 1 M H2SO4. In addition, the MB-derived ACs exhibited long-term cycling stability and more than 90% original capacity have been maintained after first 1000 cycles (the total cycles of 10000 were carried out.) at a high current density of 1 A g−1.

Simonkolleite aerogel is fabricated by assembling its two-dimensional nanoplatelets with the aid of hydrogen bonding. Water plays key roles during the aging and solvent exchange progresses where hydrogen bondings inside and between the nanoplatelets are formed. The freeze-dried aerogel exhibits a pore size distribution around 17–19 nm, a compressive modulus up to 2–4 MPa comparable to carbon nanotube arrays, and strong photoluminescence in a blue band around 416–437 nm. This study demonstrates a new metal-based inorganic aerogel and the sol–gel technique can be developed for industrial applications. Keywords: Simonkolleite aerogel, Hydrogen bonding, Sol–gel approach, Photoluminescence

Charge separation is crucial for increasing the activity of semiconductor-based photocatalysts. In this work, a series of non-centric structure materials: K 3 ZnB 5 O 10 (KZBO), K 2 NaZnB 5 O 10 (KNZBO) and Na 3 ZnB 5 O 10 (NZBO), called nonlinear optical materials, show high activity in the chlorophenols dechlorination under UV–vis light irradiation ( λ > 254 nm). The obtained dechlorination efficiency is one order of magnitude higher than that of commercial P25 TiO 2 catalyst under same reaction conditions. Such materials possess a spontaneous polarization arising from the displacement of the center of the positive and negative charges, providing a driving force for the separation of photogenerated electrons and holes and thereby mitigating the effect of charge recombination as confirmed by Kelvin probe force microscopy. The present work implies that the nonlinear optical materials hold promise in degradation of organic chlorinated pollutants.

Because of the lack of experimental evidence, much confusion still exists on the nucleation and growth dynamics of a nanostructure, particularly of metal. The situation is even worse for nanodroplets because it is more difficult to induce the formation of a nanodroplet while imaging the dynamic process with atomic resolution. Here, taking advantage of an electron beam to induce the growth of Bi nanodroplets on a SrBi2Ta2O9 platelet under a high resolution transmission electron microscope (HRTEM), we directly observed the detailed growth pathways of Bi nanodroplets from the earliest stage of nucleation that were previously inaccessible. Atomic scale imaging reveals that the dynamics of nucleation involves a much more complex trajectory than previously predicted based on classical nucleation theory (CNT). The monatomic Bi layer was first formed in the nucleation process, which induced the formation of the prenucleated clusters. Following that, critical nuclei for the nanodroplets formed both directly from the addition of atoms to the prenucleated clusters by the classical growth process and indirectly through transformation of an intermediate liquid film based on the Stranski-Krastanov growth mode, in which the liquid film was induced by the self-assembly of the prenucleated clusters. Finally, the growth of the Bi nanodroplets advanced through the classical pathway and sudden droplet coalescence. This study allows us to visualize the critical steps in the nucleation process of an interfacial nanodroplet, which suggests a revision of the perspective of CNT.

Nanosized metallic copper could be a replacement of noble metals for improving photoactivity of TiO2-based photocatalysts, but it tends to be oxidized by oxygen in surroundings. To avoid this, black TiO2−coated Cu nanoparticles (denoted as Cu@TiO2) were constructed in the present work, and their photoactivity for the photoreaction of CO2 with H2O vapor under visible-light irradiation was explored. X-ray diffraction, transmission electron microscopy and selected area electron diffraction analysis for the used Cu@TiO2 confirm the hierarchical structure of Cu@TiO2 and oxygen resistance of metallic Cu. The photocatalytic activity for Cu@TiO2 (∼4%Cu) reaches 1.7 times of that for its counterpart, bared black TiO2. The improved photoactivity is attributed to the embedded metallic Cu, which promotes the formation of oxygen vacancies in TiO2 through the metal-oxide interaction, thus increasing the visible-light absorption of Cu@TiO2 and the adsorption of CO2 on their surface. Furthermore, the metallic Cu increases photoinduced charge-separation of TiO2 through trapping electrons as evidenced by transient photocurrent measurements. The present work sheds light on developing new type of metal-oxide based visible-light-driven photocatalysts.

Presented in this article is the template-free fabrication of nitrogen-doped hollow carbon spheres (N-HCSs) as electrode materials for high-performance supercapacitors based on scalable homopolymer vesicles, which are self-assembled from an amphiphilic homopolymer, poly(amic acid) (PAA). This homopolymer can be massively produced by simple stepwise polymerization at room temperature with a fast polymerization rate. For the first time, PAA homopolymer vesicles are carbonized to form N-HCSs with tunable porous structures and nitrogen contents (from 1.3% to 7.4%) by controlling the content of the cross-linker (melamine). This template-free method for fabricating N-HCSs is more environmentally friendly and does not involve tedious synthetic procedures compared to traditional template-based methods. More importantly, the N-HCSs exhibit excellent electrochemical performance with a very high specific capacitance (266.9 F g−1) after more than 1000 cycles when used as the active electrode material for the supercapacitor. The N-HCSs presented in this paper retain its specific capacitance as high as 84% at a very high current density (20 A g−1). Given the potential massive production and excellent electrochemical properties, the N-HCSs based on the carbonization of scalable PAA homopolymer vesicles are promising candidate electrode materials for energy storage devices.

钽酸盐光催化材料往往具有较高的光催化活性.近年报道的钽酸盐光催化剂主要采用传统高温固相法制备,该方法不可避免地导致高温烧结,使合成的钽酸盐颗粒较大,比表面积较小,而且该方法具有不可克服的晶体转变、结晶度差、分解、挥发和纯度低等缺点,使制备的光催化剂活性较低.而纳米材料由于粒径小,提高了电子和空穴的扩散速度,大大降低了电子和空穴在材料内的复合几率,从而使光催化材料活性大幅提高.此外,粒径减小也使表面原子迅速增多,减小了光的漫反射,同时也使光吸收不易达到饱和,有利于提高光吸收效率.因此,制备纳米材料是提高半导体光催化剂活性的有效手段.目前,采用湿化学的溶液合成方法能在较低温度下获得粒度小且均匀、计量比准确的光催化剂粉末,但是合成钽酸盐光催化剂的水溶性钽前体即乙醇钽(或氯化钽)价格昂贵,而且对潮湿极端敏感易水解,使产物纯度降低,不适合工业化生产.近年来,尽管有文献报道以Ta2O5为原料利用水热、溶胶-凝胶和共沉淀等方法制备钽酸盐,但其合成条件苛刻,合成步骤复杂,合成周期较长,耗能大,产物产量较低且不均匀,很难实现产物的形貌控制来筛选出适合光催化反应的材料.目前关于纳米钽酸盐光催化材料形貌控制方面的研究鲜有报道,主要是由于Ta2O5极难溶解,很难实现液相合成.因此,纳米钽酸盐光催化材料的可控制备是研究的难点.我们发展了熔盐-水热制备钽酸盐新方法,实现了K1.9Na0.1Ta2O6m2H2O的可控制备.利用熔盐法制备一种可溶性钽酸盐前驱体,再通过水热法在液相进一步反应制得纳米钽酸盐光催化材料K1.9Na0.1Ta2O6m2H2O,通过控制反应条件实现了纳米钽酸盐K1.9Na0.1Ta2O6m2H2O的形貌调控,得到了纳米球、微球、去顶八面体形貌和类似榴莲形貌等不同形貌,而利用其它制备方法很难控制钽酸盐的形貌.另外,研究了制备材料吸附和光催化降解罗丹明B的性能,发现该材料光催化活性与形貌直接相关.表征结果表明,制备样品的X射线衍射(XRD)谱图尖锐,结晶较好,其各衍射峰位置均与K2Ta2O6一致,为纯相烧绿石结构,属于立方晶系,空间群为Fd3m.通过分析合成材料的元素组成及含量,确定K:Na:Ta比例近似为1.9:0.1:2.为了进一步研究属于烧绿石型化合物K1.9Na0.1Ta2O6m2H2O的结构,对不同形貌材料进行了红外光谱测试,所有样品在450n1000 cmn1的谱峰可归属于(K,Na)nO和TanO键的振动,3300 cmn1左右为晶体结构中水的羟基伸缩振动峰,1720 cmn1左右是晶体结构中水的弯曲振动峰.可以看出,不同形貌材料的红外谱图吸收带宽度和位置十分相似,只存在小的偏移和变化,进一步表明不同形貌的材料具有相似的晶体结构,与XRD结果一致.差热-热重分析确定了结构中所含结晶水数量近似为2.光催化性能测试结果表明,具有纳米球形貌的材料比表面积较大,因而光催化活性最高.

Solidification microstructure of Cu–Cr and Cu–Cr-In alloys has been characterized using scanning electron microscopy in the present work. Thermodynamic database has been established for the Cu–Cr binary system and Cu–Cr-In ternary system. Solidification behaviors of the two alloys have been simulated using the thermodynamic parameters based on Scheil model. The results show that the primary Cr phases with long and thin dendrites can be observed between Cu matrix grains for the Cu–Cr alloy, and the ‘flower-like’ coarsen dendrites primary Cr phases of the Cu–Cr-In alloy exist in the triangular grain boundary areas. The weight percent of indium element in the liquid phase of the Cu–Cr-In alloy during solidification continuously increases up. This will enlarge the solidification temperature range from 6 °C to 214 °C resulting in longer time for the dendrite growth and the alloying element indium with low melting point tends to segregate to the grain boundary region.

Combining the smart library management plan, recognize the importance of modern smart library construction, summarize the technology in the construction of smart libraries, aiming to demonstrate the innovative value of smart library construction through the innovation of construction programs, and to provide guarantee for the design of modern libraries.

Polyester block polymers containing polylactide have garnered significant attention as renewable, degradable alternatives to traditional elastomers. However, the low glass transition of the PLA blocks limits the upper-use temperatures of the resulting elastomers. To improve the thermal performance, we explore a series of multiblock polyesters composed of poly(ε-decalactone) (PDL) and poly(cyclohexene phthalate) (PCHPE). These materials are prepared using switchable polymerization catalysis followed by chain extension. The strategy involves (i) alternating ring-opening copolymerization (ROCOP) of cyclohexene oxide and phthalic anhydride, (ii) ε-decalactone ring-opening polymerization (ROP), and (iii) diisocyanate coupling of the telechelic triblocks to increase molar mass. The resulting multiblock polyesters are amorphous, and the blocks are phase separated; glass transition temperatures are ∼−45 and 100 °C. They show thermal resistance to mass loss with Td5% ∼ 285 °C and higher upper use temperatures compared to alternative aliphatic polyesters. The nanoscale phase behavior and correlated mechanical properties are highly sensitive to the block composition. The sample containing PCHPE = 26 wt % behaves as a thermoplastic elastomer with high elongation at break (εb > 2450%), moderate tensile strength (σb = 12 MPa), and low residual strain (εr ∼ 4%). It shows elastomeric behavior from −20 to 100 °C and has a processing temperature range of ∼170 °C. At higher PCHPE content (59 wt %), the material has shape memory character with high strain fixation (250%) and recovery (96%) over multiple (25) recovery cycles. The multiblock polyesters are straightforward to prepare, and the methods presented here can be extended to produce a wide range of new materials using a other epoxides, anhydrides, and lactones. This first report on the thermal and mechanical properties highlights the significant potential for this class of polyesters as elastomers, rigid plastics, and shape memory materials.

International audience; Water pollution caused by heavy metals has dramatically impacted ecosystems in recent years. For instance, 45.4% of lakes in China are in the category of moderate to high risk of toxic metal pollution, due to excessive mining. There is, therefore, a need for efficient techniques of metal decontamination. Hydrogels are gaining interest as heavy metal adsorbents because of their easy separation, but hydrogel applications are limited due to their poor mechanical property. Here we solve this problem by introducing natural attapulgite into the sodium alginate-poly(acrylic acid) semi-interpenetrating polymer network of the hydrogel. Results show that the compressive stress of the hydrogel with 10% attapulgite, of 1.230 Mpa, was 4.1 times higher than that of pure hydrogel, of 0.299 MPa. The adsorption capacity of hydrogel with 10% attapulgite was high, of 272.8 mg/g for Cu 2+ and 391.7 mg/g for Pb 2+. Even after five cycles of adsorption, the hydrogel with 10% attapulgite still adsorbs 261.7 mg/g Cu 2+ and 368.1 mg/g Pb 2+. Our findings thus reveal that network-structured sodium alginate-poly(acrylic acid)/attapulgite hydrogel holds great potential as an efficient and recyclable adsorbent for heavy metal removal.

NiCrAlY coating was plasma-sprayed on a Ni-based single crystal superalloy and then subjected to isothermal oxidation at 1100 C in air up to 50 h. Using scanning electron microscopy (SEM) and transmission electron microscopy (TEM), we investigate interfacial microstructure evolution of the coating induced by internal oxidation and nitridation. After 5 h oxidation, a-Al2O3 and Cr2O3 sub-layers form at the coating/substrate interface. Interestingly, after 10 h oxidation, pure Al phase is found at the coating/substrate interface owing to decomposition of substrate phase c 0 -Ni3Al. Although, after 25 h oxidation, hexagonal AlN and cubic TiN form in the substrate close to the coating/substrate interface, after 50 h oxidation, AlN transforms into a-Al2O3 owing to internal oxidation while TiN remains in the substrate because of its high stability. The findings of this work provide solid experimental evidence of microstructural evolution at the coating/substrate interface, especially demonstrate the conjecture that pure metal phases and nitrides could precipitate at coating/substrate interface after high temperature oxidation.

A simple template removal method has been developed for fabrication of hierarchically porous Sb doped SnO2 electrode with high porosity, effective electroactive sites, and enhanced electrocatalytic efficiency. Two different kinds of hierarchically porous architectures (Ti/Sb–SnO2-honeycomb and Ti/Sb–SnO2-network) with remarkable porosity and layer by layer arrangement in multiple directions are fabricated as observed by SEM measurements. EDS confirms the uniform distribution of Sb, Sn and O on substrate surface and the peaks of XRD at 33.9° and 51.8° proves the presences of rutile SnO2. Linear sweep voltammetry shows the Ti/Sb–SnO2-honeycomb and Ti/Sb–SnO2-network possess high OEP value upto 2.60 V, and 2.76 V. By analyzing CV curves, the recorded total voltammetric charge for hierarchically porous electrodes is boosted upto 7.46 mC cm−2 and 11.96 mC cm−2, compared to the conventional one (3.0 mC cm−2), which indicates the significant enhancement in electrochemical active sites. The electrocatalytic efficiency is explored by degradation of Rhodamine B under different parameters (pH, current density, and concentration). The reaction rates for Ti/Sb–SnO2-honeycomb and Ti/Sb–SnO2-network are 9.2 × 10−2 min−1 and 19.7 × 10−2 min−1, respectively, which are 2.2 and 4.7 times higher than conventional one (k = 4.2 × 10−2 min−1). Further mechanistic study suggests that more electroactive sites provided by hierarchically porous electrodes lead to accelerate HO˙ generation and the channels of porous structure significantly promotes the adsorption and diffusion of pollutant molecules.

2, 4-dichlorophenol (2, 4-DCP) is considered to be a highly toxic, mutagenic, and possibly carcinogenic pollutant. This study is focused on the electrochemical oxidation of 2, 4-DCP on nanostructured 3D-porous Ti/Sb-SnO

Renewable resources are used increasingly in the production of polymers. In particular, monomers such as carbon dioxide, terpenes, vegetable oils and carbohydrates can be used as feedstocks for the manufacture of a variety of sustainable materials and products, including elastomers, plastics, hydrogels, flexible electronics, resins, engineering polymers and composites. Efficient catalysis is required to produce monomers, to facilitate selective polymerizations and to enable recycling or upcycling of waste materials. There are opportunities to use such sustainable polymers in both high-value areas and in basic applications such as packaging. Life-cycle assessment can be used to quantify the environmental benefits of sustainable polymers.

Piezoelectric generators based on zinc oxide (ZnO) nanowires/nanorods require not only an aligned assembly morphology but also Schottky contacts between ZnO and electrodes to rectify the piezoelectric signals. Here we demonstrate that two-dimensional carbon nanotube (CNT) assembly films can serve as highly efficient electrode materials to meet these two requirements. The flexibility, porosity and pore size distribution, and intimate contact with ZnO of CNT films have advantages in controllable hydrothermal deposition to generate highly aligned ZnO nanorods with high crystallinity at a high density. Due to the Schottky characteristics between ZnO and CNT, aluminum and titanium are suggested to serve as the negative electrode of a piezoelectric energy supply, by using their ohmic contacts with ZnO. The three-layered piezoelectric generator outputs a signal of 50–60 mV by using bending deformations, one order of magnitude larger than the signal generated by fast pressing deformations. This study presents a method to design ZnO-based piezoelectric generators without using precious metals or rare earth elements.

N-TiO2/Bi2O3 composites have been successfully prepared by a simple coupling method and evaluated in detail. These composites represent a potential new class of heterojunction-structured photocatalysts wherein the enhanced light absorption properties of N-TiO2 are anticipated to couple with the observed benefits of composite TiO2/Bi2O3 systems. The composites were characterized by powder X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), photoluminescence (PL), N-2-adsorption desorption, diffuse reflectance spectroscopy (DRS), and scanning electron microscopy (SEM). It was found that composites with low Bi2O3 content display enhanced photocatalytic activity for decomposition of 2,4-dichlorophenol (2,4-DCP) under visible light irradiation, which is attributed to a synergistic effect between the two composite components and the flow of holes and electrons through the heterojunction. The PL spectroscopy was adopted to analyze the physical properties of the photogenerated carriers and it was found that the separation of photogenerated carriers of Bi2O3 has been largely promoted after being coupled with N-TiO2. Significantly, the enhanced performance demonstrated the importance of evaluating new composite photocatalysts. It would be helpful in designing and constructing high efficiency heterogeneous semiconductor photocatalyst with the purpose of enhancing activity by coupling suitable wide and narrow band-gap semiconductors, which is inspiring for the practical environmental purification.

In recent years, methicillin-resistant Staphylococcus aureus (MRSA) has become one of the most common multi-drug resistant bacteria in both hospital and community. The aim of this study is to investigate the selective inhibition of MRSA by a modified photosensitizer (LAEtNBS) in vitro and the efficacy of MRSA infection treatment by photodynamic therapy (PDT) with LAEtNBS in vivo. LAEtNBS was synthesized by adding a cationic photosensitizer molecule (EtNBS-COOH) and a quencher molecule to two side chains of cephalosporin, which was then shown to have similar absorption and emission wavelengths with EtNBS-COOH, but suppressed yields of fluorescence quantum and singlet oxygen. The selective inactivation and less phototoxicity of LAEtNBS, compared to that of EtNBS-COOH, were assessed and confirmed by conducting PDT to two Staphylococcus aureus strains and human skin cells at a fluence of 15 J/cm(2) with 640±10 nm LED light. Furthermore, using mouse skin wound model infected with 10(8) CFU of MRSA, we found that both LAEtNBS and EtNBS-COOH were able to treat MRSA infection and enhance wound repair. However, there was no significant difference in the two photosensitizers that might be due to the environment in vivo. Modification of the photosensitizer will be very beneficial for developing new strategies to treat drug resistant bacterial infection with less harm to host tissue.

It is a theoretical and technical challenge to construct well-defined nanostructures such as vesicles from fully hydrophilic homopolymers in pure water. In this paper, we incorporate one terminal alkynyl group into a fully hydrophilic linear or non-linear homopolymer to drive its unusual self-assembly in aqueous solution to form multicompartment vesicles, spherical compound micelles, flower-like complex particles, etc., which have been confirmed by transmission electron microscopy (TEM), atomic force microscopy (AFM), dynamic/static light scattering (DLS/SLS) and drug encapsulation experiments. The formation of poly(N-isopropyl acrylamide) (NIPAM) and poly[oligo(ethylene glycol) methacrylate] (POEGMA475) self-assemblies is mainly determined by the terminal alkynyl group itself (typically 1–3 wt%) while it is independent of other factors such as traditional hydrophobic–hydrophilic balance. Moreover, upon increasing the chain length of PNIPAM homopolymers, multicompartment vesicles, spherical micelles, and large flower-like complex particles can be obtained during the self-assembly process. In contrast, smaller micelles were formed when the kind of terminal alkynyl group attached to the PNIPAM chain was changed from a propargyl isobutyrate group to a (di)propargyl 2-methylpropionamide group. Particularly, a long chain hyperbranched structure with lots of terminal alkynyl groups induces the formation of vesicles. Also, the encapsulation experiment of doxorubicin hydrochloride was employed to further distinguish vesicular and micellar nanostructures. Additionally, the terminal alkynyl group-driven self-assembly has been applied to hydrophilic POEGMA475 homopolymers to afford similar nanostructures to PNIPAM homopolymers such as multicompartment vesicles and spherical compound micelles. Our study has opened up a new way to prepare hydrophilic homopolymer self-assemblies with tunable morphology.