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ÖgeSupramolecular alternating polymers based on calix[4]pyrrole and pillar[5]arene molecular recognition(American Chemical Society, 2024)Supramolecular alternating polymers (SAPs) were constructed based on orthogonal interactions between an alkylnitrile-tethered calix[4]pyrrole and two different carboxylate-functionalized pillar[5]arene monomers possessing different chain lengths. Concurrent anion complexation and host–guest interactions were utilized by means of calix[4]pyrrole- and pillar[5]arene-based molecular recognitions. Characterization and multiresponsive behaviors of the resulting SAPs were characterized by means of a series of analyses, including various nuclear magnetic resonance techniques, viscosity measurements, and scanning electron microscopy. The resulting polymers were also applied to the fabrication of hierarchical materials with different dimensionalities. These materials include spherical aggregates with zero-dimensionality, fibers with one-dimensionality, two-dimensional microporous films, and finally three-dimensional materials. Current work represents the first example of SAPs based on calix[4]pyrrole and pillar[5]arene molecular recognition and is expected to be useful for designing and preparation of advanced, multicomponent synthetic self-assembled systems.
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ÖgeCombination of polyethylenimine and vanillin-based benzoxazine as a straightforward self-healable system with excellent film-forming ability(American Chemical Society, 2024)This study introduces a straightforward and efficient route for synthesizing self-healable polybenzoxazine networks by utilizing dynamic imine bond exchanges under mild conditions. The process involves combining polyethylenimines with aldehyde-functional bisbenzoxazine, which was produced from vanillin, using a Sc(OTf)3 catalyst and subjecting them to moderate heating at 150 °C. Remarkably, the resulting polybenzoxazine films exhibit good self-healing capabilities at low temperatures and pressures, without requiring any additional additives to facilitate the healing process. The degree of recovery was assessed through tensile tests, while rheologic measurements were utilized to analyze stress relaxation and activation energy of dynamic bonding, providing insights into the self-healing process. Additionally, comprehensive spectral characterizations and investigations of thermal behaviors were conducted to gain a deeper understanding of the material’s properties and performance. Moreover, the polybenzoxazine networks demonstrated enhanced hydrolysis stability compared to conventional imine-based systems, benefiting from the specific Mannich linkages and inherent hydrophobic nature of polybenzoxazines.
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ÖgeHigh-performance thienothiophene and single wall carbon nanotube-based supercapacitor as a free-standing and flexible hybrid energy storage material(American Chemical Society, 2024)Long cycle life and high energy/power density are imperative for energy storage systems. Similarly, flexible and free-standing electrodes are important for supercapacitor applications. Herein, we report, for the first time, use of thienothiophene (TT) and a single-walled carbon nanotube (SWCNT)-based free-standing and flexible hybrid material (TT-TPA-SWCNT) as a high-performance supercapacitor. The synthesized TT derivative, TT-TPA, was directly attached to SWCNT through noncovalent interactions to obtain the TT-based SWCNT hybrid, TT-TPA-SWCNT, as a flexible film. The hybrid film was clarified by surface analysis methods of scanning electron microscopy and atomic force microscopy. TT-TPA-SWCNT was used as a flexible and free-standing electrode in a two-electrode system for supercapacitor and energy storage applications. It displayed a high energy storage capacity of 83.2 F g–1 at 5 mV s–1 scan rate, an excellent cyclic stability with 110% retention of its initial specific capacitance after 7000 cycles and a long power density ranged from 100 to 3000 W·kg–1, demonstrating that TT-TPA-SWCNT is a promising hybrid nanomaterial for high-performance energy storage applications.
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ÖgeComparison of dye adsorption of chitosan and polyethylenimine modified bentonite clays : optimization, isotherm, and kinetic studies(American Chemical Society, 2024)The aim of this study was to compare the effect of modifying calcium bentonite (Bent-Ca) clay with two cationic polymers, chitosan (Chi) and polyethylenimine (PEI), on the removal of remazol black B (RB-B) dye from an aqueous solution. The samples were characterized by using scanning electron microscopy, X-ray diffraction, and Fourier-transform infrared spectroscopy. The fractional factorial design of 2(6–1) was applied to investigate the effects of pH, temperature, amount of adsorbent, initial dye concentration, contact time, and shaking rate on the adsorption process. To further optimize RB-B removal from an aqueous solution, a Box–Behnken design with three factors and a response surface methodology was used. The optimum conditions were a pH of 3.77, a temperature of 40.45 °C, and an initial RB-B concentration of 77.27 mg L–1 for Bent-Ca-Chi, whereas for Bent-Ca-PEI, the optimum conditions were a pH of 5.53, a temperature of 41.06 °C, and an initial dye concentration of 238.89 mg L–1. To understand the adsorption behavior, the Langmuir and Freundlich isotherms were fitted to the experimental data. It was found that the Langmuir isotherm model matched well with the dye adsorption by Bent-Ca-Chi and Bent-Ca-PEI. The kinetics study was performed using three kinetic models: pseudo-first-order, pseudo-second-order, and intraparticle diffusion models. Among these models, the RB-B dye kinetics were best represented by the pseudo-second-order model equation for the adsorbents.
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ÖgeElemental composition of household dusts extracted in simulated body fluids and their impact on culturable pathogenic bacteria responses(Springer, 2024)In the last decade, a great deal of research has focused on the determination of potential toxic elements by total concentration and identification the microorganisms in dust. However, determining bio-relevant (e.g., inhalable) forms of elements instead of total contents in acids is necessary for human health. Moreover, examination of the behavior of microorganism under these bio-relevant conditions and revealing the interaction between elements and pathogens is vital and necessary for deeper understanding. However, previous studies have ignored these topics. Therefore, the present study aimed to (i) investigate elements in household dusts extracted in simulated lung fluids, (ii) examine the total concentration of culturable bacteria and their biochemical responses with exposure to bio-fractions of household dusts, and (iii) assess their relations and risks using the model approaches by inhalation. Here, settled dusts were collected in 25 houses, and extracted in four simulated body fluids to determine bio-fractions of elements. Moreover, total count of potentially pathogenic and heterotrophic bacteria, and four clinically important culturable pathogens were incubated in the presence of household-dusts extracted in simulated body fluids. The activity, biofilm, biochemical and oxidative responses of pathogens were measured following household-dust exposures. Afterward, the relationship between elements and pathogen responses were evaluated, and model and derived approaches were used for risk assessments of elements and pathogens. The higher daily intake of elements obtained in artificial lysosomal fluid fraction of household dust mimicking the inflammatory condition compared to other body fluids. Moreover, bacterial responses were mainly influenced from bio-fractions of household dusts and their elemental contents.