Self-Propelling Hydrogel/Emulsion-Hydrogel Soft Motors for Water Purification

We fabricate a kind of catalytic self-propelling hydrogel soft motor (H-motor) via a facile injection loading method with low energy consumption. The factors influencing the practicability of H-motors, including locomotive ability and reusability, are investigated. The succession of rapid bubble evolution and propulsion endows the millimeter-sized columnar H-motors with length/diameter of 1 a remarkable speed of 3.84 mm s^–1 in 10% (w/w) hydrogen peroxide (H₂O₂) solution. Moreover, the H-motors maintain undiminished propulsion capability and functionality even after repeated loading for 6 times. Additionally, we also fabricate emulsion-hydrogel soft motors (E-H-motors) templated from the oil/water (O/W) emulsion for the first time, which exhibit a faster speed of 4.33 mm s^–1 under the same conditions. It can be ascribed to the additional liberation of low-boiling oil phase stored in the emulsion-hydrogels caused by catalytic reaction heat, which is appropriate for larger propulsive situations. The stabilized, efficient, and reusable H-motors are selected for industrial effluents purification to fit the imperious demands about the disposal of organic pollutants in water. The synergy effect between catalytic degradation and enhanced intermixing of the fluid flow around the miniaturized soft motors gives rise to an effective and exhaustive removal of organic contaminants

Self-Propelling Hydrogel/Emulsion-Hydrogel Soft Motors for Water Purification

We fabricate a kind of catalytic self-propelling hydrogel soft motor (H-motor) via a facile injection loading method with low energy consumption. The factors influencing the practicability of H-motors, including locomotive ability and reusability, are investigated. The succession of rapid bubble evolution and propulsion endows the millimeter-sized columnar H-motors with length/diameter of 1 a remarkable speed of 3.84 mm s^–1 in 10% (w/w) hydrogen peroxide (H₂O₂) solution. Moreover, the H-motors maintain undiminished propulsion capability and functionality even after repeated loading for 6 times. Additionally, we also fabricate emulsion-hydrogel soft motors (E-H-motors) templated from the oil/water (O/W) emulsion for the first time, which exhibit a faster speed of 4.33 mm s^–1 under the same conditions. It can be ascribed to the additional liberation of low-boiling oil phase stored in the emulsion-hydrogels caused by catalytic reaction heat, which is appropriate for larger propulsive situations. The stabilized, efficient, and reusable H-motors are selected for industrial effluents purification to fit the imperious demands about the disposal of organic pollutants in water. The synergy effect between catalytic degradation and enhanced intermixing of the fluid flow around the miniaturized soft motors gives rise to an effective and exhaustive removal of organic contaminants

Fabrication of Anion-Exchange Polymer Layered Graphene–Melamine Electrodes for Membrane Capacitive Deionization

A novel nitrogen-doped reduced graphene sponge composite (NRGS) is fabricated by using melamine sponge to restrain the aggregation of graphene sheets during reduction. The anion-exchange polymer layered graphene composites (A-NRGS) are prepared by coating the surface of the NRGS electrode with cross-linked poly­(vinyl alcohol) with quaternization modification (C-qPVA). With the help of a melamine sponge to suppress the agglomerate of graphene sheets, the NRGS exhibits a unique three-dimensional (3D) interconnected porous structure with abundant nitrogen doping of 5.2%. Its specific surface area is up to 241 m²/g. In addition, the enhanced wettability of A-NRGS composites favors the diffusion of ion from the electrolyte to electrode. Therefore, A-NRGS composites have excellent electrochemical capacity (184 F/g). The membrane capacitive deionization (MCDI) performance for A-NRGS electrode (11.3 mg/g) is higher than that of pristine reduced graphene oxide (RGO) (6.2 mg/g) and NRGS (8.6 mg/g) electrodes. All the results demonstrate that A-NRGS composites can be a promising candidate for CDI and other electrochemical applications

Fabrication of Graphene-Based Xerogels for Removal of Heavy Metal Ions and Capacitive Deionization

With a rapid increase of population, delivering clean and potable water to humans has been an impending challenge. Here, we report a green method for the preparation of graphene–chitosan–Mn₃O₄ (Gr–Cs–Mn₃O₄) composites, where Gr–Cs hydrogels are first prepared from the self-assembly of chitosan with graphene oxide (GO) nanosheets; then Gr–Cs–Mn₃O₄ composites are obtained by oxidizing Mn­(II) ions which are adsorbed by Gr–Cs hydrogels. The effects of pH and mass ratio of GO to Cs on sorption of different ions are investigated. Enhanced capacitive deionization performance of Gr–Cs–Mn₃O₄ composites was also demonstrated. The resultant Gr–Cs–Mn₃O₄ composites exhibit a hierarchical porous structure with a specific surface area of 240 m²/g and excellent specific capacity of 190 F/g, much higher than those of pristine reduced graphene oxide electrodes. Distinguished electrochemical capacity and low inner resistance endow Gr–Cs–Mn₃O₄ composites with outstanding specific electrosorptive capacity of 12.7 mg/g

DataSheet_1_Histone lysine-specific demethylase 1 regulates the proliferation of hemocytes in the oyster Crassostrea gigas.docx

BackgroundLysine-specific demethylase 1 (LSD1) is an essential epigenetic regulator of hematopoietic differentiation, which can specifically mono-methylate H3K4 (H3K4me1) and di-methylate H3K4 (H3K4me2) as a transcriptional corepressor. Previous reports have been suggested that it participated in hematopoiesis and embryonic development process. Here, a conserved LSD1 (CgLSD1) with a SWIRM domain and an amino oxidase (AO) domain was identified from the Pacific oyster Crassostrea gigas.MethodsWe conducted a comprehensive analysis by various means to verify the function of CgLSD1 in hematopoietic process, including quantitative real-time PCR (qRT-PCR) analysis, western blot analysis, immunofluorescence assay, RNA interference (RNAi) and flow cytometry.ResultsThe qRT-PCR analysis revealed that the transcripts of CgLSD1 were widely expressed in oyster tissues with the highest level in the mantle. And the transcripts of CgLSD1 were ubiquitously expressed during larval development with the highest expression level at the early D-veliger larvae stage. In hemocytes after Vibrio splendidus stimulation, the transcripts of CgLSD1 were significantly downregulated at 3, 6, 24, and 48 h with the lowest level at 3 h compared to that in the Seawater group (SW group). Immunocytochemical analysis showed that CgLSD1 was mainly distributed in the nucleus of hemocytes. After the CgLSD1 was knocked down by RNAi, the H3K4me1 and H3K4me2 methylation level significantly increased in hemocyte protein. Besides, the percentage of hemocytes with EdU-positive signals in the total circulating hemocytes significantly increased after V. splendidus stimulation. After RNAi of CgLSD1, the expression of potential granulocyte markers CgSOX11 and CgAATase as well as oyster cytokine-like factor CgAstakine were increased significantly in mRNA level, while the transcripts of potential agranulocyte marker CgCD9 was decreased significantly after V. splendidus stimulation.ConclusionThe above results demonstrated that CgLSD1 was a conserved member of lysine demethylate enzymes that regulate hemocyte proliferation during the hematopoietic process.</p

Synthesis, Characterization, and Utilization of a Novel Phosphorus/Nitrogen-Containing Flame Retardant

The novel phosphorus/nitrogen-containing flame retardant hexa­(phosphaphenanthrene aminophenoxyl)­cyclotriphosphazene (HPAPC), which contains phosphaphenanthrene [9,10-dihydro-9-oxa-10-phosphaphenanthrene 10-oxide (DOPO)] and phosphazene (hexachlorocyclotriphosphazene) groups, was synthesized by the classic Atherton–Todd reaction, and its chemical structure was characterized by Fourier transform infrared (FTIR) and nuclear magnetic resonance (NMR) spectroscopies. Poly­(lactic acid) (PLA) composites containing HPAPC were prepared by melt blending, and their fire performance and thermal behaviors were investigated in terms of limiting oxygen index (LOI), vertical burning (UL-94), cone calorimeter tests, and thermogravimetric analysis (TGA). The LOI value could reach up to 34.7%, and UL-94 could pass V-0 for the PLA composite containing only 5 wt % HPAPC. TGA results showed that the char formation of PLA could be significantly improved by the presence of HPAPC. The evolved gas of the composite was analyzed by FTIR-TGA and pyrolysis–gas chromatography/mass spectrometry (Py–GC/MS). The dispersion of fillers in PLA was observed by back-scattered electron (BSE). The char morphology was characterized by FTIR spectroscopy and scanning electronic microscopy (SEM). It was suggested that the presence of HPAPC could release ammonia gas during combustion, which was beneficial to the formation of an intumescent char structure

Low Chemically Cross-Linked PAM/C-Dot Hydrogel with Robustness and Superstretchability in Both As-Prepared and Swelling Equilibrium States

Superior mechanical, recoverable, and swelling properties are important for the application practice of hydrogel. However, most of the hydrogels do not possess those three features at the same time. Herein, we have prepared a novel low chemical cross-linked polyacrylamide (PAM)/carbon nanodot (C-dot) hydrogel by introducing the C-dot into low chemically cross-linked PAM network. C-dot acts as both a physical cross-linker and lubricant in the low chemical cross-linked PAM network, and the synergistic effect between C-dot and PAM chains endows the hydrogel with extraordinary mechanical, recoverable, and swelling properties. The as-prepared hydrogel can be stretched over 3700% with fracture strength as high as 166 kPa, and it can keep high recoverability even when it is stretched up to 500% (more than 97% recovery ratio). Furthermore, the highest swelling ratio of the hydrogel is up to 235 times, which is much higher than that of the conventional PAM hydrogel. Moreover, even in the swelling equilibrium state, the hydrogel can be stretched up to 650% and almost completely recover once the stress is removed. The hydrogel with such an excellent mechanical property in both as-prepared and swollen states is barely reported and can greatly extend its potential application in biomedical fields

Synthesis, Characterization, and Utilization of a Novel Phosphorus/Nitrogen-Containing Flame Retardant

The novel phosphorus/nitrogen-containing flame retardant hexa­(phosphaphenanthrene aminophenoxyl)­cyclotriphosphazene (HPAPC), which contains phosphaphenanthrene [9,10-dihydro-9-oxa-10-phosphaphenanthrene 10-oxide (DOPO)] and phosphazene (hexachlorocyclotriphosphazene) groups, was synthesized by the classic Atherton–Todd reaction, and its chemical structure was characterized by Fourier transform infrared (FTIR) and nuclear magnetic resonance (NMR) spectroscopies. Poly­(lactic acid) (PLA) composites containing HPAPC were prepared by melt blending, and their fire performance and thermal behaviors were investigated in terms of limiting oxygen index (LOI), vertical burning (UL-94), cone calorimeter tests, and thermogravimetric analysis (TGA). The LOI value could reach up to 34.7%, and UL-94 could pass V-0 for the PLA composite containing only 5 wt % HPAPC. TGA results showed that the char formation of PLA could be significantly improved by the presence of HPAPC. The evolved gas of the composite was analyzed by FTIR-TGA and pyrolysis–gas chromatography/mass spectrometry (Py–GC/MS). The dispersion of fillers in PLA was observed by back-scattered electron (BSE). The char morphology was characterized by FTIR spectroscopy and scanning electronic microscopy (SEM). It was suggested that the presence of HPAPC could release ammonia gas during combustion, which was beneficial to the formation of an intumescent char structure

Improving the Fire Performance of Nylon 6,6 Fabric by Chemical Grafting with Acrylamide

Our previous study has demonstrated that photografting can enhance the flame retardancy of both polyamide and polyester fabric. In this work, efforts to use chemical grafting with acrylamide (AM) as the monomer and dibenzoyl peroxide (BPO) as the initiator were made to improve the homogeneity of the grafting chains and the flame retardancy of nylon 6,6 fabric. The effects of reaction time, reaction temperature, and monomer concentration on the percentage of grafting (PG) were investigated. The effect of PG on the fire performance of AM-<i>g</i>-nylon 6,6 fabric was also studied. The flame retardancy and thermal behavior were characterized in terms of the limiting oxygen index (LOI), UL 94 test, cone calorimetry, thermogravimetric analysis (TGA), and differential thermal analysis (DTA). The results showed that the after-flame time and char length were significantly reduced after grafting. The heat release rate (HRR) of grafted sample was decreased by 28% compared to that of the ungrafted sample. The optimal grafting conditions were obtained as follows: reaction time, 1.5 h; reaction temperature, 70 °C; and concentration of total monomer, 15 wt %. The chemical structure and microstructure of AM-<i>g</i>-nylon 6,6 fabric were analyzed by attenuated-total-reflection Fourier transform infrared (ATR-FTIR) spectroscopy and scanning electron microscopy (SEM), respectively. A possible grafting mechanism is proposed and discussed

Facile Fabrication of Poly(l‑lactic Acid)-Grafted Hydroxyapatite/Poly(lactic-<i>co</i>-glycolic Acid) Scaffolds by Pickering High Internal Phase Emulsion Templates

Porous scaffolds consisting of bioactive inorganic nanoparticles and biodegradable polymers have gained much interest in bone tissue engineering. We report here a facile approach to fabricating poly­(l-lactic acid)-grafted hydroxyapatite (g-HAp)/poly­(lactide-<i>co</i>-glycolide) (PLGA) nanocomposite (NC) porous scaffolds by solvent evaporation of Pickering high internal phase emulsion (HIPE) templates, where g-HAp nanoparticles act as particulate stabilizers. The resultant porous scaffolds exhibit an open and rough pore structure. The pore structure and mechanical properties of the scaffolds can be tuned readily by varying the g-HAp nanoparticle concentration and internal phase volume fraction of the emulsion templates. With increasing the g-HAp concentration or decreasing the internal phase volume fraction, the pore size and the porosity decrease, while the Young’s modulus and the compressive stress enhance. Moreover, the in vitro mineralization tests show that the bioactivity of the scaffolds increases with increasing the g-HAp concentration. Furthermore, the anti-inflammatory drug ibuprofen (IBU) is loaded into the scaffolds, and the drug release studies indicate that the loaded-IBU exhibits a sustained release profile. Finally, in vitro cell culture assays prove that the scaffolds are biocompatible because of supporting adhesion, spreading, and proliferation of mouse bone mesenchymal stem cells. All the results indicate that the solvent evaporation based on Pickering HIPE templates is a promising alternative method to fabricate NC porous scaffolds for potential bone tissue engineering applications