PEG-imbedded PEO membrane developed by a novel highly efficient strategy toward superior gas transport performance.

Low-molecular-weight poly(ethylene glycol) (PEG) is deliberately incorporated into synthesized swellable poly(ethylene oxide) (PEO) membranes via a facile post-treatment strategy. The membranes exhibit both larger fractional free volume (FFV) and a higher content of CO2-philic building units, resulting in significant increments in both CO2 permeability and CO2/H2 selectivity. The separation performance correlates nicely with the microstructure of the membranes. This study may provide useful insights in the formation and mass transport behavior of highly efficient polymeric membranes applicable to clean energy purification and CO2 capture, and possibly bridge the material-induced technology gap between academia and industry.

Improving astaxanthin-loaded chitosan/polyvinyl alcohol/graphene oxide nanofiber membranes and their application in periodontitis.

Periodontitis is a chronic inflammatory disease primarily driven by host inflammation and plaque-induced immune responses. Controlling the host inflammatory response and improving the periodontal inflammatory microenvironment are crucial to promoting periodontal tissue regeneration. In this study, the blended nanofiber membranes previously prepared by our research group were improved, and we developed multifunctional chitosan/polyvinyl alcohol/graphene oxide/astaxanthin coaxial nanofiber membranes. Scanning electron microscopy showed that the prepared nanofibers had a smooth surface and a uniform diameter distribution. The mechanical property test results showed that the coaxial nanofiber membranes exhibited higher tensile strength compared to the blended nanofiber membranes, which increased from 4.50 ± 0.32 and 3.70 ± 0.45 MPa to 7.12 ± 0.22 and 5.62 ± 0.79 MPa respectively. Drug release studies indicated that the "shell-core" structure of coaxial nanofibers significantly reduced the initial burst release of astaxanthin (ASTA), with only 13.49 % and 10.71 % release in the first 24 h, and drug release lasted for over a week. Animal experiments confirmed that the coaxial nanofiber membranes loaded with ASTA promoted periodontal bone defect repair while inhibiting periodontal inflammation. In conclusion, the prepared coaxial nanofiber membranes are a promising sustained-release drug system for treating periodontitis.

Mussel-inspired tannic acid/polyethyleneimine assembling positively-charged membranes with excellent cation permselectivity.

The extraction of valuable target ions through monovalent cation exchange membranes (MCEMs) has been increasingly attracting in modern energy and environmental fields. However, the separation performance of MCEMs in terms of the permselectivity and cation fluxes, is typically restricted by membrane architecture and applied materials. Recently, mussel-inspired surface modification methods have been deployed in new membrane fabrications with special surface characteristics and functions. Herein, a facile layer-by-layer assembly method was designed to construct a series of de novo positively-charged tannic acid/polyethyleneimine (TA/PEI) membranes containing a negatively-charged support membrane and a TA/PEI selective layer. Notably, the peculiar support membrane with a much dense structure and abundant cation exchange groups can enable our TA/PEI membranes to possess high total cation fluxes. The selective layer with vast positive charges ensures mussel-inspired TA/PEI assembled positively-charged membranes to have a high permselectivity. Most importantly, compared with the separation performance of the state-of-the-art MCEMs, the superior separation performance of our developed new MCEMs at 5 mA·cm-2 and 10 mA·cm-2 is beyond the current "Upper Bound" plot between Na+ flux and the permselectivity (Na+/Mg2+), which opens new avenues for the construction of MCEMs. Furthermore, high purity of Li+ (95.37%) can be obtained through deploying mussel-inspired TA/PEI assembled positively-charged membranes with high permselectivity of Li+/Mg2+ (13.72), proving its great potentials in the field of resource recovery towards sustainability.

Biomimetic Silicification on Membrane Surface for Highly Efficient Treatments of Both Oil-in-Water Emulsion and Protein Wastewater.

The worldwide water crisis and water pollution have put forward great challenges to the current membrane technology. Although poly(vinylidene fluoride) (PVDF) porous membranes can find diverse applications for water treatments, the inherent hydrophilicity must be tuned for an energy-/time-saving process. Herein, the surface wettability of PVDF membranes transforming from highly hydrophobicity to highly hydrophilicity was realized via one-step reaction of plant-derived phenol gallic acid and γ-aminopropyltriethoxysilane in aqueous solutions. The surface hydrophilicization can be achieved on porous PVDF membranes by virtue of integration of a mussel-inspired coating and in situ silicification via a "pyrogallol-amino covalent bridge" toward excellent antifouling performance and highly efficient infiltration ability for oily emulsion and protein wastewater treatment. The water flux of a surface-manipulated microfiltration membrane can reach ca. 9246 L m-2 h-1 (54-fold increment compared to that of pristine membrane), oil rejection >99.5% in a three-cycle emulsion separation; the modified ultrafiltration membrane demonstrated benign performance in bovine serum albumin protein interception (rejection as high as ca. 96.6% with water flux of ca. 278.2 L m-2 h-1) and antifouling potential (increase of ca. 70.8%). Our in situ biomimetic silicification under "green" conditions exhibits the great potential of the developed strategy in fabrication of similar multifunctional membranes toward environmental remediation.

Bio-inspired Ni2+-polyphenol hydrophilic network to achieve unconventional high-flux nanofiltration membranes for environmental remediation.

A novel Ni2+-polyphenol network was designed as an excellent bio-coating by a one-step strategy to obtain nanofiltration membranes, possessing unconventional high water flux up to 56.1 L m-2 h-1 bar-1 with rose bengal (RB) rejection above 95%. This study provides a facile approach to prepare highly-efficient nanofiltration membranes for wastewater remediation.

Organic Microporous Nanofillers with Unique Alcohol Affinity for Superior Ethanol Recovery toward Sustainable Biofuels.

To minimize energy consumption and carbon footprints, pervaporation membranes are fast becoming the preferred technology for alcohol recovery. However, this approach is confined to small-scale operations, as the flux of standard rubbery polymer membranes remain insufficient to process large solvent volumes, whereas membrane separations that use glassy polymer membranes are prone to physical aging. This study concerns how the alcohol affinity and intrinsic porosity of networked, organic, microporous polymers can simultaneously reduce physical aging and drastically enhance both flux and selectivity of a super glassy polymer, poly-[1-(trimethylsilyl)propyne] (PTMSP). Slight loss in alcohol transportation channels in PTMSP is compensated by the alcohol affinity of the microporous polymers. Even after continuous exposure to aqueous solutions of alcohols, PTMSP pervaporation membranes loaded with the microporous polymers outperform the state-of-the-art and commercial pervaporation membranes.

Phosphatase-triggered cell-selective release of a Pt(iv)-backboned prodrug-like polymer for an improved therapeutic index.

We describe here the synthesis and cell-selective delivery of a cationic Pt(iv)-backboned prodrug-like polymer P(DSP-DAEP). P(DSP-DAEP) features excellent aqueous solubility, unusually high (44.5%) drug loading, can be rapidly reduced to release the active cisplatin, and is more potent than its small molecular Pt(iv) precursor DSP. P(DSP-DAEP) can be formulated with an oppositely charged methoxyl poly(ethylene glycol)-block-poly(l-phosphotyrosine) (mPEG-b-PpY) to afford a polyion micelle (Pt-PIC) by taking advantage of polyelectrolyte coacervation. Preliminary in vitro cellular uptake and cytotoxicity assays indicate that Pt-PIC exhibits receptor (surface alkaline phosphatase)-dependent uptake and cytotoxicity. Overall, our results suggest a new approach to the improved therapeutic index of platinum-based anticancer drugs via cell-selective delivery.