Controlled Synthesis of Polyelectrolytes by 4-Cyanopentanoic Acid Dithiobenzoate Mediated RAFT Polymerization

Brush-like Polyaniline with Optical and Electroactive Properties at Neutral pH and High Temperature

In this research, a brush-like polyaniline (poly(2-acrylamide-2-methyl-1-propanesulfonate)-g-polyaniline)-b-poly(N-vinylcarbazole) (BL PAni) was developed as a strategy to overcome the limited processability and dedoping above pH 4 of conventional polyaniline (PAni). For the BL PAni synthesis, RAFT polymerization (homopolymer), RAFT-mediated surfactant-free emulsion polymerization (block copolymer), and interfacial oxidative polymerization were applied to graft the PAni chains. NMR and FT-IR spectroscopies were performed to confirm the structural elucidation of the reaction pathways, while the thermal properties were analyzed by TGA and DSC. Notably, the BL PAni presents absorption throughout the visible region and up to the near-infrared, showing dedoping resistance at up to 80 °C and at a neutral pH. The absorption range of the BL PAni, block copolymer, and homopolymer were studied by UV–Vis spectroscopy in solid-state and dispersion/solution, highlighting BL PAni and poly(anilinium 2-acrylamide-2-methyl-1-propanesulfonate)-b-poly(N-vinylcarbazole) (PAAMP-b-PVK) due to the π-stacking between the anilinium and carbazole groups. The cyclic voltammetry confirmed the persistence of electroactivity at a pH near 7.

HPW/PDMAEMA-b-PMAA/ZIF-8 Ternary Lamellar Composite and the Photocatalytic Degradation of Methylene Blue

PDMAEMA-b-PMAA block copolymers were prepared by the sequential RAFT polymerization of DMAEMA and tBMA, followed by hydrolysis. Phosphotungstic acid (HPW) was anchored to the PDMAEMA blocks through electrostatic interactions and the as-obtained HPW/PDMAEMA-b-PMAA was added to the synthesis of ZIF-8. During the formation of ZIF-8, the PMAA blocks coordinated to the Zn²⁺ ions through their carboxy groups, along with the HPW groups that were anchored to the PDMAEMA blocks. In this way, the block copolymer could consolidate the interactions between HPW and ZIF-8 and prevent the leakage of HPW. Finally, the HPW/PDMAEMA-b-PMAA/ZIF-8 ternary lamellar composite was obtained and the structure of the HPW/PDMAEMA-b-PMAA/ZIF-8 hybrid material was characterized by using powder X-ray diffraction (PXRD), X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM). As a photocatalyst, the HPW/PDMAEMA-b-PMAA/ZIF-8 ternary lamellar composite showed excellent photoactivity for the degradation of methylene blue (MB). The rate of degradation of MB was 0.0240 min^-1 , which was 7.5-times higher than that of commercially available P25 (0.0032 min^-1 ). In the presence of H₂ O₂ , the kinetic degradation parameters of the composite reached 0.0634 min^-1 , which was about 19.8-times higher than that of P25.

PVBA-UiO-66 using a flexible PVBA with multi-coordination groups as mixed ligands and their super adsorption towards methylene blue

A series of poly-vinyl benzoic acid (PVBA) and UiO-66 materials (PVBA-UiO-66) were prepared by a mixed-linker approach. Using a flexible PVBA with multi-coordination groups as mixed ligands, mesopores and uncoordinated benzoic groups were introduced into the UiO-66 crystal structures, thus leading to a special structure and functionality. The structure of the PVBA-UiO-66 was characterized by powder X-ray diffraction (PXRD), scanning electron microscopy (SEM) and nitrogen gas adsorption measurements. The adsorption property toward methylene blue (MB) of PVBA-UiO-66 was studied. The adsorption of MB by UiO-66 and PVBA (43%)-UiO-66 fit the Langmuir model and Freundlich model well. The result showed that PVBA (43%)-UiO-66 has super adsorption capacity as high as 909 mg g-1 for MB owing to the mesopores and the uncomplexed carboxyl groups which were caused by the long PVBA involved in coordination. The adsorption kinetics of MB onto PVBA (43%)-UiO-66 can be well fitted to the pseudo-second-order model. The process of adsorption MB onto PVBA-UiO-66 is spontaneous and thermodynamically favorable at 303, 313 and 323 K.

Effect of nanoporous structure and polymer brushes on the ionic conductivity of poly(methacrylic acid)/anode aluminum oxide hybrid membranes

Anode aluminum oxide (AAO) porous materials have been widely used in ionic translocation for many biological and chemical studies.

Polyelectrolyte/mesoporous silica hybrid materials for the high performance multiple-detection of pH value and temperature

Mesoporous silica nanoparticles are modified by electrolyte polymer, giving significant ionic permselectivity under pH and/or temperature switches.