Well-designed chitosan-based cationic porous polymer: A robust material for effective adsorption of endocrine disrupting chemicals

There is an immediate need for meticulous design of easily accessible, cost-effective, chemically stable and eco-friendly materials for effectively removal of water contaminant. Herein, targeting typical water contaminants, endocrine disrupting chemicals (EDCs), three cationic hyper-cross-linked porous polymers (ciHCP-1, ciHCP-2, ciHCP-3) with multiple adsorption sites were designed with 2-hydroxypropyltrimethyl ammonium chloride chitosan (HACC) as precursor. The ciHCP-3 with large surface area (806 m2 g-1) exhibited high sorption capacity (137-366 mg g-1), and fast adsorption kinetics (5 min) for the EDCs, which is superior to the reported sorbents. The adsorption mechanisms can be attributed to the synergistic effect of physisorption and chemisorption. The high preparation reproducibility, physicochemical stability, and reuse capability of ciHCP highlights its great potential in practical water remediation applications.

Recent Progress of Polymeric Corrosion Inhibitor: Structure and Application

An anti-corrosion inhibitor is one of the most useful methods to prevent metal corrosion toward different media. In comparison with small molecular inhibitors, a polymeric inhibitor can integrate more adsorption groups and generate a synergetic effect, which has been widely used in industry and become a hot topic in academic research. Generally, both natural polymer-based inhibitors and synthetic polymeric inhibitors have been developed. Herein, we summarize the recent progress of polymeric inhibitors during the last decade, especially the structure design and application of synthetic polymeric inhibitor and related hybrid/composite.

PMMA-Grafted Calcium Sulfate Whiskers for Applications as Fillers in PVC

Calcium sulfate whiskers (CSWs) were hydroxylated with a sodium hydroxide (NaOH) solution and isolated for subsequent treatment with an ethanolic 3-(methacryloxy)propyltrimethoxysilane (KH570) solution to introduce C=C double bonds on the CSWs' surfaces. Then, CSW-g-PMMA was prepared by grafting polymethyl methacrylate (PMMA) onto the surface of modified CSW using in situ dispersion polymerization. The CSW-g-PMMA was used as a filler and melt-blended with polyvinyl chloride (PVC) to prepare PVC-based composites. The surface chemical structure, PMMA grafting rate, and hydrophobic properties of CSW-g-PMMA were analyzed using X-ray diffraction, diffuse reflectance Fourier-transform infrared spectroscopy, thermogravimetric analysis, and water contact angle measurements, respectively. The effects of the CSW-g-PMMA filler on the mechanical properties of the CSW-PMMA/PVC composites were also investigated. The results showed that NaOH treatment significantly increased the number of hydroxyl groups on the surface of the CSWs, which facilitated the introduction of KH570. PMMA was successfully grafted onto the KH570 with a grafting rate of 14.48% onto the surface of the CSWs. The CSW-g-PMMA had good interfacial compatibility and adhesion properties with the PVC matrix. The tensile, flexural, and impact strengths of the CSW-g-PMMA/PVC composite reached 39.28 MPa, 45.69 MPa, and 7.05 kJ/m², respectively, which were 38.55%, 30.99%, and 20.10% higher than those of the CSW/PVC composite and 54.52%, 40.80%, and 32.52% higher than those of pure PVC, respectively. This work provides a new method for surface modification of inorganic fillers, resource utilization, and high value-added application of CSWs from phosphogypsum.

Zwitterionic Polymers toward the Development of Orientation-Sensitive Bioprobes

Dynamics with an orientational degree of freedom are fundamental in biological events. Probes with polarized luminescence enable a determination of the orientation. Lanthanide-doped nanocrystals can provide more precise analysis than quantum dots due to the nonphotoblinking/bleaching nature and the multiple line-shaped emission. However, the intrinsic polarization property of the original nanocrystals often deteriorates in complex physiological environments because the colloidal stability easily breaks and the probes aggregate in the media with abundant salts and macromolecules. Engineering the surface chemistry of the probes is thus essential to be compatible with biosystems, which has remained a challenging task that should be exclusively addressed for each specific probe. Here, we demonstrate a facile and efficient surface functionalization of lanthanide-doped nanorods by zwitterionic block copolymers. Due to the steric interaction and the intrinsic zwitterionic nature of the polymers, high colloidal stability of the zwitterionic nanorod suspension is achieved over wide ranges of pH and concentration of salts, even giving rise to the lyotropic liquid crystalline behavior of the nanorods in physiological media. The shear-aligned ability is shown to be unaltered by the coated polymers, and thus, the strongly polarized emission of Eu³⁺ is preserved. Besides, biological experiments reveal good biocompatibility of the zwitterionic nanorods with negligible nonspecific binding. This study is a stepping stone for the use of the nanorods as orientation probes in biofluids and validates the strategy of coupling zwitterions to lanthanide-doped nanocrystals for various bioapplications.

Efficient Radical C(sp3)-H α-Oxyamination of Carbonyls Adjacent to Carbon Chalcogen Bond

An efficient radical C(sp3)-H α-oxyamination of carbonyls adjacent to different chalcogen (e.g., S, O, and Se) at α-position is demonstrated. This radical oxyamination process conducts under solvent-free conditions without the...

Synthesis of fluorinated phosphorus-containing copolymers and their immobilization and properties on stainless steel

A series of fluorinated-phosphonic acid methacrylates were synthesized by free radical polymerization using heptadecafluorodecyl methacrylate (HDFDMA) and (dimethoxyphosphoryl) methyl methacrylate (DMPMM) monomers for potential application as anti-corrosion coatings. The dimethyl protecting groups were then hydrolyzed, giving phosphonic acid groups that are able to stably bind onto metal oxide surfaces. The copolymers were then immobilized as a monolayer film to the surface of 316L stainless steel by treatment of dilute solutions in trifluoroacetic acid for 30 minutes followed by rinsing. The surfaces were analyzed using various techniques and contact angles as high as 128° were recorded for some copolymer functionalized surfaces. Results also demonstrated that the polymer films proved stable to hydrolysis over several weeks of immersion in water.

A series of fluorinated-phosphonic acid methacrylates were synthesized by free radical polymerization using heptadecafluorodecyl methacrylate (HDFDMA) and (dimethoxyphosphoryl) methyl methacrylate (DMPMM) monomers for potential application as anti-corrosion coatings.