Synthesis and Thermal Properties of Acrylonitrile/Butyl Acrylate/Fumaronitrile and Acrylonitrile/Ethyl Hexyl Acrylate/Fumaronitrile Terpolymers as a Potential Precursor for Carbon Fiber

Insights into the p-nitrophenol adsorption by amidoxime-modified poly(acrylonitrile-co-acrylic acid): characterization, kinetics, isotherm, thermodynamic, regeneration and mechanism study

This study performs an appraisal of the adsorptive capacity of amidoxime-modified poly(acrylonitrile-co-acrylic acid) or abbreviated as (AO-modified poly(AN-co-AA)) for the p-nitrophenol (PNP) adsorption, from aquatic environments via batch system. The AO-modified poly(AN-co-AA) polymer was developed with redox polymerization, and then altered by using hydroxylamine hydrochloride (HH). Tools used to describe the physicochemical and morphological characteristics of the AO-modified poly(AN-co-AA) were Fourier transform infrared (FTIR) spectroscopy, CHN elemental analysis, X-ray diffraction analysis (XRD) and scanning electron microscopy (SEM). The adsorption kinetics were examined by pseudo-first order, pseudo-second order, Elovich and intraparticle diffusion kinetic models. Meanwhile, the isotherms were investigated by Langmuir, Freundlich, Temkin and Redlich-Peterson models. It was found that the adsorption was best fitted with pseudo-second order, and agreed with both Langmuir and Freundlich isotherm models. It was described best with the Freundlich isotherm due to highest R 2 (0.999). The maximum adsorption capacity was 143.06 mg g-1 at 298 K, and thermodynamic functions showed that the adsorption process was exothermic. Also, following five regeneration cycles, the adsorbent recorded 71.7% regeneration efficiency. The finding in this study indicates that the AO-modified poly(AN-co-AA) is an effective adsorbent to remove PNP from an aqueous solution.

Unravelling the nature of a toluene-fumaronitrile complex

In this research, the occurrence and anomalous increase of an additional absorption band observed in the spectrum of fumaronitrile dissolved in toluene are explained and characterized. The formation of a stable ground-state complex between these two molecules is evidenced by both experimental and theoretical studies. TD-DFT calculations show that the presence of an unexpected signal in the absorption spectra originates from the photoinduced intermolecular charge-transfer process occurring within this system. The mechanism and the efficiency of the adduct formation were investigated using both spectral measurements (UV-Vis, IR) and quantum-mechanical calculations (DFT). The influence of the solvent polarity on the complex stability was also evaluated. Since the forces responsible for the adduct formation turn out to be of a rather weak, dispersive character, the related equilibrium stability constant is relatively low and becomes even lower with the increase in solvent polarity. Finally, the system was analyzed for the expected fluorescence emission of the resulting complex, but none was observed.

Sequential and alternating RAFT single unit monomer insertion: model trimers as the guide for discrete oligomer synthesis

A complete set of model trimers and their synthetic kinetics are established to guide the synthesis of diverse sequence-defined polymers.

A facile method to fabricate carbon nanostructures via the self-assembly of polyacrylonitrile/poly(methyl methacrylate-b-polyacrylonitrile) AB/B′ type block copolymer/homopolymer blends

The self-assembly and high temperature behavior of AB/B′ type block copolymer/homopolymer blends containing polyacrylonitrile (PAN) polymers were studied for the first time.