Porous polymer membranes with highly interconnected open-cellular structure and high toughness are crucial for various application fields. Polymerized high internal phase emulsions (polyHIPEs), which usually exist as monoliths, possess the advantages of high porosity and good connectivity. However, it is difficult to prepare membranes due to brittleness and easy pulverization.
View Article and Find Full Text PDFDynamic hydrogels have attracted considerable attention in the application of flexible electronics, as they possess injectable and self-healing abilities. However, it is still a challenge to combine high conductivity and antibacterial properties into dynamic hydrogels. In this work, we fabricated a type of dynamic hydrogel based on acylhydrazone bonds between thermo-responsive copolymer and silver nanoparticles (AgNPs) functionalized with hydrazide groups.
View Article and Find Full Text PDFDynamic 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 RAFT polymerization, where the A block consisted of thermo-sensitive poly(-isopropylacrylamide--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).
View Article and Find Full Text PDFThe photoactive metal-organic frameworks (MOFs) were controllably coated on the surface plasmon resonance-excited Ag nanowires in a layer manner to adjust the photocatalytic activity. The influence of the thickness of the MOF coating layer on the photocatalytic activity was investigated. A thicker MOF coating layer not only facilitated the photogenerated electron-hole separation efficiency but also provided a larger Brunauer-Emmett-Teller surface area, thus enhancing the photocatalytic activity.
View Article and Find Full Text PDFSingle-layered, double-layered, and triple-layered Pt nanoparticles with a well-defined arrangement were encapsulated inside metal-organic frameworks (MOFs) to investigate the catalytic performance influenced by the progressive increasing of Pt nanoparticles inside MOFs; the results show that the catalytic activity of the Pt-MOF hybrid catalysts increases progressively with the progressive increasing of the Pt nanoparticles inside MOFs. Progressive increasing of Pt nanoparticles with a multiple-layered manner inside MOFs provides a new route for designing well-organized hybrid catalysts of noble metal nanoparticles and MOFs with enhanced catalytic activity.
View Article and Find Full Text PDFAg/MIL-100(Fe) core/sheath nanowire with controllable thickness of the MIL-100(Fe) sheath was prepared by controlling the crystal growth of MIL-100(Fe) on the Ag nanowire surface. The evolution of the MIL-100(Fe) sheath monitored by transmission electron microscopy (TEM), scanning electron microscopy (SEM), powder X-ray diffraction (XRD), thermogravimetric analyses (TGA), X-ray photoelectron spectroscopy (XPS), fourier transform infrared spectroscopy (FT-IR), and N adsorption-desorption analysis indicates that the thickness of the MIL-100(Fe) sheath increases with the increasing number of crystal growth cycles of MIL-100(Fe) on the Ag nanowire surface. Catalytic reaction over Ag/MIL-100(Fe) core/sheath nanowire suggests that the thickness of the MIL-100(Fe) sheath largely influences the catalytic performance and it is quite important to control the crystal growth of MIL-100(Fe) on the Ag nanowire surface for optimizing catalytic performance.
View Article and Find Full Text PDFMetal-organic frameworks (MOFs)-supported noble metal nanoparticles (NMNPs) catalysts attract increasing attention due to their high durability and efficiency in catalytic reactions. In this work, Pt nanoparticles are inserted at the designated location inside MIL-100(Fe) to investigate the location-effect of NMNPs inside MOFs on the catalytic reaction. The comparison test on the reduction of -nitrophenol suggests that the location of the Pt nanoparticles inside MIL-100(Fe) largely influences the catalytic performance and the Pt nanoparticles inside MIL-100(Fe) locate closer to the outer surface of the MIL-100(Fe), providing higher catalytic efficiency.
View Article and Find Full Text PDFA TiWO/TiO nanocomposite interfacial photocatalyst was designed and prepared for the photocatalytic degradation of phenol pollutants in wastewater. The detailed properties of the TiWO/TiO nanocomposite interface (NCI) were analyzed by XRD, SEM, EDX, DRS, UPS and XPS technologies, showing that anatase TiO nanospheres (NSs) were uniformly dispersed on the surface of rutile TiWO nanoparticles (NPs) and formed the nanocomposite interface. The DRS and UPS results of 5 wt% TiWO/TiO NCI indicated a greatly broadened light response range with a wavelength shorter than 527 nm and a shorter band gap energy of 2.
View Article and Find Full Text PDFMetal-organic framework (MOF)-based magnetic Pt catalyst FeO@Pt@MIL-100(Fe) core-shell heterostructures were prepared through transforming FeO into MIL-100(Fe) in benzene-1,3,5-tricarboxylic acid solution along with encapsulating the Pt nanoparticles successively adsorbed onto the surface of the FeO nanosphere and the continuously forming surfaces of the growing MIL-100(Fe) crystals. This method circumvented the obstacles, controlling the formation of metal nanoparticles (MNPs) inside MOFs or regulating growth of MOFs around the MNPs, for preparing an MNP-MOF composite catalyst. The obtained well-defined FeO@Pt@MIL-100(Fe) core-shell heterostructure was shown promoting catalytic activity on the reduction of 4-nitrophenol due to the synergistic effect between the Pt nanoparticles and the MIL-100(Fe) shell and recycling convenience due to the rapid separation of the FeO core under an external magnetic field.
View Article and Find Full Text PDFACS Appl Mater Interfaces
November 2018
Adsorbents that are capable of controllable pollutants adsorption and release without secondary pollution are attractive in water treatment. Here, we propose eco-friendly CO as a trigger to switch the charge states and collapse-expansion transition of giant microgels consisting of hydrophilic acrylamide and hydrophobic 2-(diethylamino)ethyl methacrylate and demonstrated the on-off, selective, and recyclable adsorption of anionic dyes on microgels under CO stimulation. Apart from easy-handling separation from the water by a simple filtration process, the maximum adsorption capacity is as high as 821 mg g, and the adsorption isotherms and kinetics obeyed Langmuir isotherm and the pseudo-second-order kinetics models, respectively.
View Article and Find Full Text PDFJ Colloid Interface Sci
January 2019
Hypothesis: The effective separation and recovery of oils from water is important for the protections of ecosystems and the environment. Polymeric porous monoliths have been demonstrated as attractive absorbents for oil/water separation. However, the recyclability was mainly realized by squeezing, combustion, or centrifugation, which may restrict in elastic materials, destroy the adsorbates or need special apparatus.
View Article and Find Full Text PDFMultidrug resistance and the refractory character of bacterial biofilms are among the most difficult challenges in infection treatment. Current antimicrobial strategies typically are much more effective for prevention of biofilm formation than for eradication of established biofilms; these strategies also leave dead bacteria and endotoxin in the infection site, which impairs healing. We report a novel hydrogel that eradicates biofilm bacteria by non-leaching-based debridement followed by ex situ contact-killing (DESCK) away from the infection site.
View Article and Find Full Text PDFStimuli-responsive hydrogels using dynamic covalent bonds (DCBs) as cross-links may exhibit simultaneously the stimuli-responsibility of the physical gels and stability of the chemical gels. We prepared well-defined, ketone-based polymers based on commercially available diacetone acrylamide (DAAM) by a reversible addition-fragmentation chain transfer (RAFT) polymerization technique. The polymers could react with hexanedihydrazide yielding hydrogels.
View Article and Find Full Text PDFACS Appl Mater Interfaces
September 2016
A novel coordination replication of Cu2O redox-template strategy is reported to efficiently fabricate Au-HKUST-1 composite nanocapsule, with a HKUST-1 sandwich shell and an embedded Au nanoparticles layer. The novel synthesis procedure involves forming Au nanoparticles on the surface of Cu2O, transforming partial Cu2O into HKUST-1 shell via coordination replication, and removing the residual Cu2O by acid. The as-prepared Au-HKUST-1 composite nanocapsules displayed high catalytic activity on CO oxidation.
View Article and Find Full Text PDFWater disinfection materials should ideally be broad-spectrum-active, nonleachable, and noncontaminating to the liquid needing sterilization. Herein, we demonstrate a high-performance capacitive deionization disinfection (CDID) electrode made by coating an activated carbon (AC) electrode with cationic nanohybrids of graphene oxide-graft-quaternized chitosan (GO-QC). Our GO-QC/AC CDID electrode can achieve at least 99.
View Article and Find Full Text PDFA wormlike micellar system that undergoes a fully reversible, repeatable "sol-gel" transition upon alternative treatment with CO2 and N2 has been developed based on a C18-tailed polyamine surfactant.
View Article and Find Full Text PDFCovalently functionalized multi-walled carbon nanotubes (MWNTs) were prepared by grafting well-defined thermo-responsive poly(N-isopropylacrylamide) (PNIPAM) via click reactions. First, azide-terminated poly(N-isopropylacrylamide) (N3-PNIPAM) was synthesized by reversible addition fragmentation chain-transfer (RAFT) polymerization, and then the N₃-PNIPAM moiety was connected onto MWNTs by click chemistry. The products were characterized by means of FT-IR, TGA and TEM.
View Article and Find Full Text PDFA new type of "smart" single-walled carbon nanotubes is created by wrapping a pyrene-labeled CO(2) -responsive polymer via π-π stacking. The polymer/SWNT hybrids not only undergo a hydrophobic-hydrophilic transition upon CO(2) stimulus of CO(2) in a mixed solvent, but also exhibit switchable dispersion/aggregation states upon the alternate bubbling of CO(2) and N(2) in pure water.
View Article and Find Full Text PDFAn amidine-based polymer was prepared by combination of RAFT polymerization and "click" reaction, and the polymer undergoes a hydrophobic-hydrophilic transition upon the stimulus of CO(2).
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