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•β-Cyclodextrin-functionalized mesoporous magnetic clusters (CD-MG) were synthesized.•The adsorption behaviors of CD-MG fitted well with the Langmuir isotherm model.•CD-MG had higher ...adsorption rate constant than other adsorbents.•CD-MG had higher maximum BPA adsorption capacity than other adsorbents.•The BPA recovery efficiency of CD-MG is 84.5% after four cycles of reuse.
To develop a novel magnetic adsorbent for the removal of endocrine-disrupting chemicals, mesoporous magnetic clusters (MMCs) functionalized with β-cyclodextrin (β-CD), henceforth denoted CD-MG, were prepared by a facile chemical strategy and were applied to bisphenol A (BPA) removal for the first time. Fourier-transform infrared spectroscopy and thermogravimetric analysis revealed that β-CD was successfully linked to the MMC surfaces. X-ray diffraction, field emission scanning electron microscopy, and high-resolution transmission electron microscopy confirmed that the morphologies and crystal structures of the MMCs were well preserved in CD-MG. A pseudo-second-order kinetic model and Langmuir isotherm model were used to describe the BPA adsorption behavior of CD-MG. The kinetic model yielded a BPA adsorption rate constant of 0.0367 g mg−1 min−1, while the isotherm model yielded a maximum BPA adsorption capacity of 52.7 mg g−1. Furthermore, CD-MG exhibited a good recovery efficiency of 84.5% in the reusability tests, even after four cycles. The fast adsorption kinetics, high adsorption capacity, and good recovery efficiency indicated that CD-MG could be an effective magnetic adsorbent for the removal of endocrine-disrupting chemicals.
The cellulose graft copolymer bearing a highly branched poly(ε-caprolactone) structure, upon blending with PLA induces an more ordered crystal phase resulted in significantly enhanced toughness of ...PLA bio-blends.
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•A series of PLA/cellulose graft copolymer (CghbP) bio-blends were fabricated.•The prepared PLA/CghbP blend series were found to be miscible at scale of 10–30 nm.•An optimal loading of CghbP induced a structurally robust PLA-based bio-blend.•The enhanced toughness was related to a hard/soft multi-phase system of PLA blend.•The prepared PLA/CghbP exhibited excellent migration stability and bio-degradability.
In this research, a series of PLA bio-blends with a highly-branched polycaprolactone (PCL)-grafted cellulose bio-toughener (CghbP) (i.e., PLA/CghbP series) were facilely fabricated and characterized to improve the tensile toughness of neat PLA. The prepared PLA/CghbP bio-blends were examined by attenuated total reflection Fourier-transform infrared (ATR FT-IR) spectroscopy and differential scanning calorimetry (DSC) analysis to be physically intact and partially miscible at the scale of ca.10∼30 nm. It was confirmed by the DSC and wide-angle X-ray diffraction (WXRD) analyses that the incorporation of CghbP into PLA matrix can induce a more disordered α′ crystalline phase of PLA in the prepared PLA/CghbP blends. The tensile properties of PLA/CghbP bio-blends investigated by universal testing machine (UTM) suggested that the mechanical behavior of highly-tough hard/soft multiphase polymeric system was realized with the incorporation of 5 wt% CghbP to PLA (i.e., PLA/CghbP5), resulting in a ∼215% increase in the tensile toughness (56.1 MJ m−3) compared to pristine PLA (17.8 MJ m−3). This research empirically identified that the improved tensile toughness of PLA/CghbP bearing 5 wt% CghbP are conjunctly correlated with the concurrent formation of more ordered hard PLA α crystalline and highly-branched soft phase induced by the loading of an appropriate CghbP into PLA. Furthermore, the PLA/CghbP5 bio-blend showed remarkably higher migration stability with the weight loss ∼0.1% CghbP after additive spillage test than those of other PLA/CghbP blends and PLA blends with conventional low molar mass plasticizers.
A highly self‐plasticized poly(vinyl chloride) (PVC) is demonstrated for the first time via click grafting of hyperbranched polyglycerol (HPG). The plasticizing effect of the grafted HPG on PVC is ...systematically investigated by various analytical methods. The amorphous and bulky dendritic structure of HPG efficiently increases the free volume of the grafted PVC, which leads to a remarkably lower glass transition temperature comparable to that of the conventional plasticized PVC. Viscoelastic analysis reveals that HPG considerably improves the softness of the grafted PVC at room temperature and promotes the segmental motion in the system. The HPG‐grafted PVC films exhibit an exceptional stretchability unlike the mixture of PVC and HPG because the covalent attachment of HPG to PVC allows it to maintain its homogeneous and well‐organized architecture under tensile stretching. The work provides valuable insights into the design of highly flexible and stretchable polymeric materials by means of introducing hyperbranched side chains.
Highly self‐plasticized and migration‐free poly(vinyl chloride) (PVC) is realized via click grafting of hyperbranched polyglycerol. Introducing highly branched polyether side chains provides the PVC with a structurally enhanced self‐plasticization ability, which leads to a remarkably lower glass transition temperature of −28.9 °C and an exceptional elongation at break of 912%.
•AMH-3 has unique framework and abundant exchangeable cations.•The removal of metal ions was governed by ion exchange rather than surface adsorption.•AMH-3 exhibited a high sorption capacities for ...metal ions.•Metal ions were selectively removed by AMH-3 pore size.
AMH-3 is a zeolite-like material with a three-dimensional uniform porous structure, layered structure, and abundant exchangeable cations. Herein, the use of AMH-3 to remove heavy metals present in aqueous solutions is investigated for the first time. Pristine AMH-3 and metal-sorbed AMH-3 were characterized with inductively coupled plasma atomic emission spectroscopy (ICP-AES), field emission scanning electron microscopy (FE-SEM), 29Si cross polarization magic angle spinning nuclear magnetic resonance spectroscopy (CP MAS NMR) and X-ray diffraction (XRD). The removal of heavy metals by AMH-3 was found to be governed by ion exchange rather than surface adsorption, and no significant change occurred in the structure of the AMH-3 during the ion exchange. The removal of various heavy metal ions (Pb2+, Cu2+, Cd2+, and Zn2+) onto AMH-3 from aqueous solutions was conducted using a batch method. The effects of influential parameters, such as the initial metal ion concentration and contact time, on the sorption process were studied. The metal ion sorption capacity and removal efficiency were mainly dependent on the difference between the effective pore size of the AMH-3 and the hydrated radius of the metal ion. The sorption isotherm data were well fitted by Langmuir (for Pb2+, Cu2+, and Zn2+) and Freundlich (for Cd2+) models. The sorption kinetics data were well fitted by a pseudo-secondorder kinetic model. Competitive sorption experiments revealed an order of metal ion affinity of Pb2+>Cu2+>Zn2+>Cd2+. These findings indicate that AMH-3 is suitable for the efficient and selective removal of heavy metals from aqueous solutions.
An acid-recovering nanofiltration (NF) membrane with both acid resistance and selective acid permeability was fabricated via a water-based coating process for the recovery of hydrochloric acid. To ...achieve this, a thermally cross-linked branched-polyethyleneimine (b-PEI) layer was introduced to a loose polyethersulfone NF membrane by dip-coating of b-PEI and an epoxy linker and heat treatment in a sealed oven with a high-humidity atmosphere. The resulting membrane displayed a positive surface charge with a zeta potential, and exhibited a rejection performance order of MgCl2> MgSO4> NaCl > Na2SO4 characteristic of positive-charge-separation membranes. Mg rejection and Cl permeation experiments showed that the selective permeation of hydrochloric acid was achieved with Mg rejection above 95% and Cl permeation above 70%, and this allowed the acid to be recovered by obtaining permeate at the same pH as the feed. Moreover, the NF membrane maintained selective separation performance and flow rate for a month.
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•An acid-recovering nanofiltration membrane was developed.•The cross-linked PEI layer was introduced via a water-based coating process.•The PEI-coated membrane displayed a positive surface charge.•PCM7.5–2:1 was achieved with Mg rejection above 95% and Cl permeation above 70%.•PCM7.5–2:1 maintained selective separation performance for a month.
A series of ion-exchange membranes for vanadium redox flow batteries (VRBs) are prepared by filling the pores of a poly(tetrafluoroethylene) (PTFE) substrate with sulfonated poly(ether ether ketone) ...(SPEEK) and microporous Engelhard titanosilicate-10 (ETS-10). The effects of ETS-10 incorporation and PTFE reinforcement on membrane properties and VRB single-cell performance are investigated using various characterization tools. The results show that these composite membranes exhibit improved mechanical properties and reduced vanadium-ion permeabilities owing to the interactions between ETS-10 and SPEEK, the suppressed swelling of PTFE, and the unique ETS-10 framework. The composite membrane with 3 wt% ETS-10 (referred to as “SE3/P”) exhibits the best membrane properties and highest ion selectivity. The VRB system with the SE3/P membrane exhibits higher cell capacity, higher cell efficiency, and lower capacity decay than that with a Nafion membrane. These results indicate that this composite membrane has potential as an alternative to Nafion in VRB systems.
•Pores of PTFE membrane were filled with SPEEK and ETS-10.•The composite membranes showed enhanced membrane stability.•ETS-10 acted as a permselective barrier to reduce vanadium permeability.•The composite membranes exhibited better VRB cell performance than Nafion.
The effect of the anion type, in an ionic liquid, on the transition of the crystalline structure when lignocellulose was pretreated in 1-ethyl-3-methylimidazolium acetate (EmimOAC) or ...1-ethyl-3-methylimidazolium chloride (EmimCl) was studied. The influence of the pretreatment on the composition, the molecular structure, and the crystalline structure was observed using Fourier-transform infrared (FT-IR) compositional analysis, thermogravimetric analysis (TGA), rheological behavior, and X-ray diffraction (XRD). Compared to EmimCl, EmimOAC pretreatment substantially decreased the lignin and hemicellulose contents. The pretreatment also significantly changed the entanglement or crosslinking state of polymer chains in the lignocellulose solution. The changes in lignin content and the transformation from cellulose I to II were dependent on the anion type of the ionic liquid. The pretreated samples were recrystallized to cellulose II only in EmimOAC, whereas the samples pretreated with EmimCl had both cellulose I and II structures present at the same time.
•Two types of ionic liquids were applied to lignocellulosic biomass pretreatment.•Different ionic liquids significantly influenced the characteristics of biomass.•The removal efficiency of non-cellulosic components depended on type of ionic liquid and temperature.•Well-dissolved biomass was more hydrolyzed than heterogeneous dissolution.•Improvement of molecular mobility dramatically changed the crystalline structure.
Several billion tons of plastic waste were discarded in landfills, specifically in marine environments. Remediation of plastic waste is vital for ensuring a clean marine environment. Photocatalyst ...such as titanium oxide (TiO
2
) is a promising and environmental friendly approach for plastic waste degradation, compared to other waste management methods. In this study, switchable degradation of a cellulose acetate (CA) was carried out through composite preparation with a seawater-activated TiO
2
(SA-TiO
2
) photocatalyst. The successful preparation of CA/SA-TiO
2
composite was confirmed using Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction, thermogravimetric analysis, and field-emission scanning electron microscopy (FE-SEM) results. The degradation of CA through SA-TiO
2
in marine environments was confirmed by
1
H nuclear magnetic resonance spectroscopy, size exclusion chromatography, and FE-SEM results. The seawater-activated degradation makes switchable and degradable polymer-photocatalyst composites an efficient and eco-friendly solution for plastic waste remediation in marine environments.
