The detection of p-nitrophenol (PNP) is of great significance for assessment of environment pollution and potential health risks. In this study, based on inverse opal polymeric photonic crystals (IOPPCs), a selective and visual sensor for high-performance PNP detection is developed. Due to their unique optical properties, IOPPCs report events by change of color, which can easily be observed by the naked eye. Hydroxyethyl methacrylate (HEMA) was selected as the functional monomer with which to fabricate the IOPPCs. By precisely adjusting the molar ratio between the functional monomer and the crosslinker, the sensors were only able to be sensitive to a specific solution, thus realizing the visual, selective, and semi-quantitative detection of PNP. When the sensors were immersed in different concentrations of PNP solution, their Bragg diffraction wavelengths showed different redshifts. The color of the IOPPCs changed from green to red as the peak shift of Bragg diffraction occurred. In addition, the IOPPCs displayed good interference immunity and reusability.
A novel nitroxyl radical polymer poly(TEMPO-acrylamide-co-sodium styrene sulfonate) (abbreviated as poly(TAm-co-SSS)) was synthesized using 4-acrylamido-2,2,6,6- tetramethylpiperidine (AATP) copolymerized with styrene sulfonate sodium (SSS). AATP was synthesized through a substitution reaction of acryloyl chloride. Meanwhile, poly(4-acrylamido-2,2,6,6-tetramethylpiperidine-1-nitroxyl radical) (PTAm) was prepared as a control sample. Then, the structures of products were characterized by nuclear magnetic resonance spectroscopy (1H-NMR), Fourier transform infrared spectroscopy (FT-IR), high performance liquid chromatography-mass spectrometry (HPLC-MS), differential scanning calorimetry (DSC), X-Ray photoelectron spectroscopy (XPS), and electron paramagnetic resonance (EPR), respectively. Additionally, the electrochemical impedance spectra (EIS) and the charge-discharge cycling properties were studied. The results demonstrated that the poly(TAm-co-SSS) with the side group of sodium sulfonate adjacent to TEMPO group exhibits a better charge-discharge cycling stability than that of the PTAm. Moreover, the charge specific capacity of the poly(TAm-co-SSS) is larger than that of the PTAm. Besides, the first coulombic efficiency of poly(TAm-co-SSS) is higher in comparison with that of PTAm. These superior electrochemical performances were ascribed to the synergistic effect of sulfonate ions group and nitroxyl radical structure, which benefits the improvement of charge carrier transportation of the nitroxyl radical polymers. Consequently, the nitroxyl radical poly(TAm-co-SSS) is promising for use in organic radical battery materials, based on the good electrochemical properties.
17 July 2025 in International Journal of Biological Macromolecules
In recent years, a great deal of work has been devoted to the development of thermoresponsive polymers that can be made into new types of smart materials. In this paper, a branched polymer, HTPB-g-(PNIPAM/PEG), with polyolefin chain segments as the backbone and having polyethylene glycol (PEG) and poly(N-isopropylacrylamide) (PNIPAM) as side chains was synthesized by ATRP and click reactions using N3-HTPB-Br as the macroinitiator. This initiator was designed and synthesized using hydroxyl-terminated polybutadiene (HTPB) as the substrate. The temperature-responsive behavior of the branched polymer was investigated. The lower critical solution temperature (LCST) of the branched polymer was determined by ultraviolet and visible spectrophotometry (UV-vis) and was found to be 35.2 °C. The relationship between the diameter size of micelles and temperature was determined by dynamic light scattering (DLS). It was found that the diameter size changed at 36 °C, which was nearly consistent with the result obtained by UV-vis. The results of the study indicate that HTPB-g-(PNIPAM/PEG) is a temperature-responsive polymer. At room temperature, the polymer can self-assemble into composite micelles, with the main chain as the core and the branched chain as the shell. When the temperature was increased beyond LCST, the polyolefin main chain along with the PNIPAM branched chain assembled to form the nucleus, and the PEG branched chain constituted the shell.
This study introduces a novel water-insoluble dispersant for coal water slurry (CWS), namely, a poly(sodium styrene sulfonate)-grafted SiO2 nanoparticle (SiO2-g-PSSNa). SiO2-g-PSSNa was synthesized by combining the surface acylation reaction with surface-initiated atom transfer radical polymerization (SI-ATRP). Fourier transform infrared spectrometry (FTIR), X-ray photoelectron spectroscopy (XPS), energy dispersive spectrometer (EDS), nuclear magnetic resonance spectroscopy (NMR) and thermogravimetric analysis (TGA) verified that SiO2-g-PSSNa with the desired structure was successfully obtained. Afterwards, the performance of SiO2-g-PSSNa as a dispersant in CWS preparation was evaluated. The results indicated that the optimal dosage of SiO2-g-PSSNa was 0.3%. Compared to the famous commercial products, PSSNa and lignosulfonate (LS), SiO2-g-PSSNa exhibits improved viscosity reduction performance. When SiO2-g-PSSNa was used as the dispersant, the maximum coal loading of CWS was 64.2%, which was higher than LS (63.4%) and PSSNa (63.9%). All CWSs obtained in this study were pseudoplastic fluids and more consistent with the Herschel–Bulkley rheological model. The turbiscan stability index (TSI) of CWS prepared with SiO2-g-PSSNa was 0.05, which was significantly lower than CWSs obtained from PSSNa (0.30) and LS (0.36). Therefore, SiO2-g-PSSNa also exhibits excellent stability performance. This result was confirmed by rod penetration tests. The underlying mechanism was also clarified by various measurements, such as contact angle, zeta potential, EDS and low-field nuclear magnetic resonance spectra (low-field NMR). The results reveal that SiO2-g-PSSNa can adsorbed onto the coal surface. SiO2-g-PSSNa possesses a special branched structure, which bears a higher charge density as compared to linear ones with approximate chemical composition. As a result, coal particles adsorbed with SiO2-g-PSSNa exhibit more electronegativity. With the enhancement of the electrostatic repulsive between coal particles, the apparent viscosity was lowered and the static stability was improved. This study demonstrated that solubility in water is not an essential factor in engineering the dispersant. Densely charged groups are probably more important.
In this paper, the effects of HTPBs with different main-chain microstructures on their triblock copolymers and polyurethane properties were investigated. Three polyether-modified HTPB triblock copolymers were successfully synthesized via a cationic ring-opening copolymerization reaction using three HTPBs with different microstructures prepared via three different polymerization methods as the macromolecular chain transfer agents and tetrahydrofuran (THF) and propylene oxide (PO) as the copolymerization monomers. Finally, the corresponding polyurethane elastomers were prepared using the three triblock copolymers as soft segments and toluene diisocyanate (TDI) as hard segments. The results of an analysis of the triblock copolymers showed that the triblock copolymers had lower viscosity and glass transition temperature (Tg) values as the HTPB 1,2 structure content decreased, although the effect on the thermal decomposition temperature was not significant. An analysis of the polyurethane elastomers revealed that as the content of the 1,2 structure in HTPB increased, its corresponding polyurethane elastomers showed a gradual increase in breaking strength and a gradual decrease in elongation at break. In addition, PU-1 had stronger crystallization properties compared to PU-2 and PU-3. However, the differences in the microstructures of the HTPBs did not seem to have much effect on the surface properties of the polyurethane elastomers.