Isotherms,kinetics, and thermodynamics of boron adsorption on fibrous polymeric chelator containing glycidol moiety optimized with response surface method

A fibrous boron chelator containing glycidol moiety (PE/PP-g-PVAm-G) was prepared by radiation induced grafting of N-vinylformamide (NVF) onto polyethylene/polypropylene (PE/PP) non-woven sheet followed by hydrolysis and immobilization of glycidol moiety. The glycidol density was controlled by optimization of the reaction parameters using the Box-Behnken design of response surface methodology (RSM). The properties of the PE/PP-g-PVAm-G were evaluated using Fourier transform infrared (FTIR) spectroscopy, field emission scanning electron microscopy (FESEM) and energy dispersive x-ray (EDX) analysis, X-ray diffraction (XRD) and thermal gravimetric analysis (TGA). A maximum glycidol density yield of 5.0 mmol·g⁻¹ was obtained with 11.8 vol%, 78.9 °C and 109.4 min for glycidol concentration, reaction temperature and time, respectively. The isotherms, kinetics, and thermodynamic behavior of boron adsorption on the optimized chelator were investigated. The boron adsorption was pH-dependent and attained a maximum adsorption capacity of 25.7 mg·g⁻¹. The equilibrium isotherm proceeded by Redlich–Peterson model whereas the kinetics was best expressed by the pseudo-second-order equation. The thermodynamic analysis revealed that boron adsorption is endothermic and spontaneous. The fibrous chelator demonstrated high boron selectivity and strong resistance to foreign ions with uncompromised regeneration efficiency after five adsorption/desorption cycles. The PE/PP-g-PVAm-G chelator seems to be very promising for boron removal from aqueous media.     

Fe(II) Spin Crossover/Polymer Hybrid Materials: Investigation of the SCO Behavior via Temperature-Dependent Raman Spectroscopy,Physicochemical Characterization and Migration Release Study

Polymeric composites constitute an appealing class of materials with applications in various fields. Spin crossover (SCO) coordination complexes are switchable materials with potential use in data storage and sensors. Their incorporation into polymers can be considered an effective method for their wider practical application. In this study, Fe(II) SCO/polylactic acid hybrid polymeric composites have been prepared by film casting. The mononuclear coordination complex [Fe{N(CN)₂}₂(abpt)₂] was incorporated into polylactic acid. The morphological, structural and thermoanalytical characterization of the composite films were performed via scanning electron microscopy (SEM), attenuated total reflectance (ATR/FTIR), Raman spectroscopy and differential scanning calorimetry (DSC). In addition, the migration release study (MRS) of the SCO compound from the polymeric matrix into the food simulant 50% v/v water/ethanol solution was also examined via UV/Vis absorption. Of particular interest was the investigation of the SCO behavior of the coordination complex after its incorporation into the polymer matrix; it was accomplished by temperature-dependent micro-Raman spectroscopy. The described attempt could be considered a preparatory step toward the development of SCO-based temperature sensors integrated into food packaging materials.     

Synthesis of linseed oil based biodegradable homo and copolymers: role as multifunctional greener additives in lube oil

Abstract

Homopolymer of linseed oil and its four copolymers with styrene, 1-decene, isodecyl acrylate and octyl acrylate, respectively, have been synthesized in this present context. The prepared polymers are characterized by NMR and FTIR spectroscopy. The molecular weights have been measured by gel permeation chromatography. Their effectiveness as pour point depressant (PPD), viscosity index improver (VII) and their shear stability in terms of permanent shear stability index have been evaluated in lube oil. The copolymers acted as better PPDs than the homopolymer whereas the homopolymer of linseed oil excelled as VII. Further it was observed that all the prepared polymers were stable enough under severe mechanical shear.     

Adaptation of electrodes and printable gel polymer electrolytes for optimized fully organic batteries

Despite intensive scientific efforts on the development of organic batteries, their full potential is still not being realized. The individual components, such as electrode materials and electrolytes, are in most cases developed independently and are not adjusted to each other. In this context, we report on the performance optimization of a full-organic solid-state battery system by the mutual adaptation of the electrode materials and an ionic liquid (IL)-based gel polymer electrolyte (GPE). The formulation of the latter was designed for a one-step manufacturing approach and can be applied directly to the electrode surface, where it is UV-cured to yield the GPE without further post-treatment steps. Herein, a special focus was placed on the applicability in industrial processes. A first significant capacity increase was achieved by the incorporation of the IL into the electrode composite. Furthermore, the GPE composition was adapted applying acrylate- and methacrylate-based monomers and combinations thereof with the premise of a fast curing step. Furthermore, the amount of IL was varied, and all combinations were evaluated for their final performance in cells. The latter variation revealed that a high ionic conductivity is not the only determining factor for a good cell performance. Next to a sufficient conductivity, the interaction between electrode and electrolyte plays a key role for the cell performance as it enhances the accessibility of the counter ions to the redox-active sites.     

Ordered Large-Pore MesoMOFs Based on Synergistic Effects of TriBlock Polymer and Hofmeister Ion

Ordered mesoporous metal–organic frameworks (mesoMOFs) were constructed with a uniform pore size up to about 10 nm and thick microporous walls, opening up the possibility for the mass diffusion of large-size molecules through crystalline MOFs. The synergistic effects based on triblock copolymer templates and the Hofmeister salting-in anions promote the nucleation of stable MOFs in aqueous phase and the in situ crystallization of MOFs around templates, rendering the generation of a microcrystal with periodically arranged large mesopores. The improved mass transfer benefiting from large-pore channels, together with robust microporous crystalline structure, endows them as an ideal nanoreactor for the highly efficient digestion of various biogenic proteins. This strategy could set a guideline for the rational design of new ordered large-pore mesoMOFs with a variety of compositions and functionalities and pave a way for their potential applications with biomacromolecules.     

对苯二胺缩对苯二甲醛席夫碱及其配合物的制备和电化学性能

以对苯二胺和对苯二甲醛为原料缩合制备出对苯二胺缩对苯二甲醛席夫碱聚合物（PT）,研究了采用不同物质的量之比的单体所制备的聚合物的电化学性能。利用席夫碱聚合物中N原子上的孤对电子与不同金属离子配位形成席夫碱配位聚合物（PT-M）,并对所形成聚合物的电化学性能进行了研究。采用X射线衍射（XRD）、红外（IR）、热重-差示扫描量热法（TG-DSC）、扫描电子显微镜（SEM）和能谱（EDS）对产物进行了表征,PT-M的XRD峰强度相比于PT明显降低,表明金属离子配位进入分子链骨架中引起的空间位阻减少了分子链排列的有序性。采用循环伏安、恒电流充放电和交流阻抗评价了所制备的配位聚合物材料的电化学性能。研究发现,聚席夫碱铝配合物（PT-Al）表现出较优的电化学性能,在0.5 A·g^-1的电流密度下其电容值为649.6 F·g^-1,并且具有较好的循环稳定性,在8 A·g^-1的电流密度下循环1 000次后仍有80.9%的电容保持率。     

分子凝胶:从结构调控到功能应用

作为一类典型软物质材料,近年来分子凝胶在生物医学、柔性电子设备、晶体控制生长、水体净化,以及3D打印材料、微纳米材料和高能量密度材料制备等领域表现出巨大的应用潜力,受到人们越来越多的关注。如何提高分子凝胶结构调控效率,拓展分子凝胶功能,促进分子凝胶实际应用已经成为新阶段分子凝胶研究的主要内容。本文结合本课题组的研究工作,从动态共价键调控分子凝胶力学性能、分子凝胶促进高品质有机晶体制备和高性能多孔高分子材料的分子凝胶(凝胶乳液)软膜板制备三个方面阐述分子凝胶的结构调控和功能化应用研究。在此基础上,简要展望分子凝胶研究的发展趋势。