Pyrolyzing soft template-containing poly(ionic liquid) into hierarchical N-doped porous carbon for electroreduction of carbon dioxide

Heteroatom-doped carbon materials have demonstrated great potential in the electrochemical reduction reaction of CO₂ (CO₂RR) due to their versatile structure and function. However, rational structure control remains one challenge. In this work, we reported a unique carbon precursor of soft template-containing porous poly(ionic liquid) (PIL) that was directly synthesized via free-radical self-polymerization of ionic liquid monomer in a soft template route. Variation of the carbonization temperature in a direct pyrolysis process without any additive yielded a series of carbon materials with facile adjustable textural properties and N species. Significantly, the integration of soft-template in the PIL precursor led to the formation of hierarchical porous carbon material with a higher surface area and larger pore size than that from the template-free precursor. In CO₂RR to CO, the champion catalyst gave a Faraday efficiency of 83.0% and a current density of 1.79 mA·cm^-2 at -0.9 V vs. reversible hydrogen electrode (vs. RHE). The abundant graphite N species and hierarchical pore structure, especially the unique hierarchical small-/ultra-micropores were revealed to enable better CO₂RR performance.     

Poly(styrene–maleic anhydride) functionalized graphene oxide

In this study, poly(styrene–maleic anhydride) functionalized graphene oxide (SMAFG) was fabricated with in situ polymerization. The sample was characterized with Raman spectroscopy, Fourier transform infrared spectroscopy, thermogravimetric analysis, transmission electron microscopy, and ultraviolet–visible absorption. The results of the experiments show that the thermal stability of SMAFG was improved significantly, and it also possessed a good dispersion in N,N‐dimethylformamide, N,N‐dimethylacetamide, aniline, and certain organic solvents. The calculated Hildebrand parameter of SMAFG was 23.8 MPa^1/2. This new method will broaden the applications of graphene, and the experiment showed that it could effectively improve the strength of polyamide 6 (PA6) compared with the pure PA6 fiber. The tensile strength of the SMAFG/PA6 composite fiber improved 29%, and the Young's modulus improved 33%, so this kind of functionalized graphene oxide can be used in the preparation of polymeric composites. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41987.     

1,2,3-Triazolium-based poly(acrylate ionic liquid)s

Nitroxide-mediated radical polymerization of a tailor-made acrylate carrying a 1,2,3-triazole group with an undecanoyl spacer affords a well-defined (M_n = 7860 g mol⁻¹ and D = 1.39) neutral polyacrylate precursor. A series of 1,2,3-triazolium-based poly(ionic liquid)s (TPILs) is then obtained by straightforward quaternization of the 1,2,3-triazole groups with methyl iodide and subsequent anion metathesis reactions. Among the prepared materials, TPIL with bis(trifluoromethane)sulfonimide anion exhibits low glass transition temperature (T_g = −40 °C), high thermal stability (T_d10 = 325 °C) and anhydrous ionic conductivity of 4 × 10⁻⁶ S cm⁻¹ at 30 °C, as measured by differential scanning calorimetry, thermogravimetric analysis and broadband dielectric spectroscopy, respectively.     

Thermal and mechanical properties of liquid silicone rubber composites filled with functionalized graphene oxide

To improve the thermal and mechanical properties of liquid silicone rubber (LSR) for application, the graphene oxide (GO) was proposed to reinforce the LSR. The GO was functionalized with triethoxyvinylsilane (TEVS) by dehydration reaction to improve the dispersion and compatibility in the matrix. The structure of the functionalized graphene oxide (TEVS‐GO) was evaluated by Thermogravimetric analysis (TGA), Fourier transform infrared (FTIR) spectra, X‐ray diffraction (XRD), and energy dispersive X‐ray spectroscopy (EDX). It was found that the TEVS was successfully grafted on the surface of GO. The TEVS‐GO/LSR composites were prepared via in situ polymerization. The structure of the composites was verified by FTIR, XRD, and scanning electron microscopy (SEM). The thermal properties of the composites were characterized by TGA and thermal conductivity. The results showed that the 10% weight loss temperature (T₁₀) increased 16.0°C with only 0.3 wt % addition of TEVS‐GO and the thermal conductivity possessed a two‐fold increase, compared to the pure LSR. Furthermore, the mechanical properties were studied and results revealed that the TEVS‐GO/LSR composites with 0.3 wt % TEVS‐GO displayed a 2.3‐fold increase in tensile strength, a 2.79‐fold enhancement in tear strength, and a 1.97‐fold reinforcement in shear strength compared with the neat LSR. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42582.     

功能化离子液体在二氧化碳吸收分离中的应用

吸收及分离二氧化碳是降低碳排放和应对全球气候变化的主要策略之一,这就必然要求全球科技工作者注重开发具有选择性高效吸收分离二氧化碳的新材料和新路线。作为近20多年来发展的一类代表性的新材料,离子液体（尤其是功能化离子液体）具有独特的物理化学性质,例如几乎没有蒸气压、液态温度范围大、热稳定性和化学稳定性好、电化学窗口宽、不可燃、结构-性质可调控等。这些性质使离子液体在二氧化碳吸收及分离领域受到广泛关注。重点综述了近5年（2015~2019）来功能化离子液体吸收分离二氧化碳的研究进展, 主要内容包括单位点离子液体、多位点离子液体、基于功能化离子液体的混合物、功能化离子液体杂化材料对二氧化碳的吸收分离。同时, 对目前该领域的发展所面临的主要问题和进一步的研究工作进行了分析讨论。     

Effects of raw and poly(propylene oxide) grafted nanosilica on the morphology and thermal and mechanical properties of polyurethane foam

Poly(propylene oxide) (PPO)‐grafted nanosilica (NS)/polyurethane foam (PUF) composites were synthesized by a ring‐opening polymerization catalytic process and reaction‐molding technology. The raw NS and PPO–NS were characterized by Fourier transform infrared spectroscopy, thermogravimetric analysis, and transmission electron microscopy. Scanning electron microscopy, dynamic mechanical analysis, and compressive strength tests were used to compare the morphology and thermal and mechanical properties of the PPO–NS/PUF and raw NS/PUF composites with a series of filler contents. The PPO–NS/PUF composites generally exhibited better morphology, thermal and mechanical properties than raw NS/PUF composites. Moreover, the PPO–NS/PUF composites with lower contents (0.5, 1 php) of filler showed even higher mechanical reinforcement than that with higher contents (1.5, 2 php) of filler, which was caused by the interaction between additives and PUF matrix. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42400.     

Simple route to prepare stable liquid marbles using poly(ionic liquid)s

Individual “liquid marbles” were prepared by encapsulation of water droplets using flocculated polymer latexes stabilized with poly(ionic liquid)s. At first, the emulsion polymerization of poly(styrene) and poly(methyl methacrylate) using different poly(ionic liquid)s as stabilizers was investigated. Stable latexes composed of spherical polymer particles with sizes ranging between 300 and 700 nm as characterized by dynamic light scattering and scanning electron microscopy were obtained. Subsequently, the polymer particles were flocculated by anion exchange precipitation of the poly(ionic liquid)s provoked by the addition of lithium bis(trifluoromethanesulfonyl)imide salt. After simple filtration and drying processes, the flocculated latexes led to hydrophobic powders with similar micrograin size compared to the original latexes. Very stable “liquid marbles” were prepared by gently shaking water droplets of different volumes onto the hydrophobic powders. The morphology and stability of the liquid marbles were characterized by optical and confocal microscopy.     

Composite blending of ionic liquid–poly(ether sulfone) polymeric membranes: Green materials with potential for carbon dioxide/methane separation

The incorporation of imidazolium‐based ionic liquids into a poly(ether sulfone) (PES) polymeric membrane resulted in a dense and void‐free polymeric membrane. As determined through the ideal gas permeation test, the carbon dioxide (CO₂) permeation increased about 22% compared to that of the pure PES polymeric membrane whereas the methane (CH₄) permeation decreased tremendously. This made the CO₂/CH₄ ideal separation increase substantially by more than 100%. This study highlighted the utilization of imidazolium‐based ionic liquids in the synthesis of ionic liquid polymeric membranes (ILPMs). Two different ionic liquids were used to compare the CO₂ separation performance through the membranes. The glass‐transition temperatures (T_gs) of ILPMs were found to be lower than the T_g of the pure PES polymeric membranes; this supported the high CO₂ permeation of the ILPMs due to the increase in PES flexibility caused by ionic liquid addition. The results also draw attention to new trends of ionic liquids as a potential green candidates for future membrane synthesis. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43999.     

CO2 sorption capacity of porous poly(ionic liquid)s

Porous poly(ionic liquid)s based on copolymer of 1-allyl-3-methyimidazolium tetrafluoroborate and acrylonitrile with 70:30 monomer ratio were prepared and characterized for CO₂ sorption. The well-developed pore structure are formed in all the poly(ionic liquid)s and the pore size distribution(PSD) mainly concentrates in 0.4 ~ 0.8 nm. The effects of different pore-forming agents and their amount on the porous structure and CO₂ sorption were also discussed. For example, porous poly(ionic liquid) treated with n-heptane as the pore-forming agent and the amount of n-heptane 16 mL has the highest CO₂ sorption capacity of 1.43 wt % at 273 K and 0.101 MPa.     

Innovative polyelectrolytes/poly(ionic liquid)s for energy and the environment

This paper presents the work carried out within the European project RENAISSANCE‐ITN, which was dedicated to the development of innovative polyelectrolytes for energy and environmental applications. Within the project different types of innovative polyelectrolytes were synthesized such as poly(ionic liquid)s coming from renewable or natural ions, thiazolium cations, catechol functionalities or from a new generation of cheap deep eutectic monomers. Further, macromolecular architectures such as new poly(ionic liquid) block copolymers and new (semi)conducting polymer/polyelectrolyte complexes were also developed. As the final goal, the application of these innovative polymers in energy and the environment was investigated. Important advances in energy storage technologies included the development of new carbonaceous materials, new lignin/conducting polymer biopolymer electrodes, new iongels and single‐ion conducting polymer electrolytes for supercapacitors and batteries and new poly(ionic liquid) binders for batteries. On the other hand, the use of innovative polyelectrolytes in sustainable environmental technologies led to the development of new liquid and dry water, new materials for water cleaning technologies such as flocculants, oil absorbers, new recyclable organocatalyst platforms and new multifunctional polymer coatings with antifouling and antimicrobial properties. All in all this paper demonstrates the potential of poly(ionic liquid)s for high‐value applications in energy and enviromental areas. © 2017 Society of Chemical Industry     

Polyurethane-based poly (ionic liquid)s for CO2 removal from natural gas

Carbon dioxide separation from CH₄ is important to the environment and natural gas processing. Poly (ionic liquid)s (PILs) based on polyurethane structures are considered as potential materials for CO₂ capture. Thus, a series of anionic PILs based on polyurethane were synthesized. The effects of polyol chemical structure and counter-cations (imidazolium, phosphonium, ammonium, and pyridinium) in CO₂ sorption capacity and CO₂/CH₄ separation performance were evaluated. The synthesized PILs were characterized by NMR, DSC, TGA, dinamical mechanical thermo analysis (DMTA), SEM, and AFM. CO₂ sorption, reusability, and CO₂/CH₄ selectivity were assessed by the pressure-decay technique. The counter-cation and polyol chemical structure play an important role in CO₂ sorption and CO₂/CH₄ selectivity. PILs exhibited competitive thermal mechanical properties. Results showed that PILPC-TBP was the best poly (ionic liquid) for CO₂/CH₄ separation. Moreover, poly (liquid ionic) base polyol (polycarbonate) with phosphonium (PILPC-TBP) demonstrated higher CO₂ sorption capacity (21.4 mgCO₂/g at 303.15 K and 0.08 MPa) as compared to other reported poly (ionic liquids). © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47536.     

Clickable poly(ionic liquid)s for modification of glass and silicon surfaces

Covalent attachment of poly(ionic liquid)s (PILs) by click chemistry on glass or silicon (Si) surfaces was performed. Poly[1-(4-vinylbenzyl)-3-butylimidazolium bis(trifluoromethylsulfonyl)imide] (polyVBBI⁺Tf₂N⁻), and copolymers of polyVBBI⁺Tf₂N⁻ with fluorescein O-methacrylate were synthesized by conducting an atom transfer radical polymerization (ATRP) from initiators containing azide or thioacetate groups. The azide- and thiol-terminated PILs were then successfully grafted onto alkyne and alkene modified glass/Si wafers by thermal azide–alkyne cycloaddition and photoinitiated thiol-ene click reactions, respectively. The modified surfaces were characterized by contact angle measurements and ellipsometry. The fluorescent PIL functionalized surfaces showed strong fluorescence under UV irradiation. This procedure of tethering PILs to substrates also provides an easy way to change the surface hydrophilicity by replacing the anions in the grafted PILs. The present approach could be readily applied for surface modifications with other types of PILs or their copolymers to achieve different functionalities on various surfaces.     

燃烧后CO_2捕集技术研究

对燃烧前、燃烧后CO2捕集以及富氧燃烧3种CO2捕集技术的特点,以及适用于燃煤电厂的燃烧后CO2捕集技术进行了介绍,分析了吸收分离法、吸附分离法和膜分离法的原理及优缺点。其中,化学吸收法应用最广,但再生能耗大,运行成本高;吸附法虽再生能耗小,但对CO2选择性低,吸附能力有限;膜分离法目前仍处于实验室研究阶段,但应用前景巨大。对上述技术整合形成复合技术以及对新材料进行开发将有助于克服现有CCS技术面临的困难。     

Improving the thermal and mechanical properties of poly(propylene carbonate) by incorporating functionalized graphite oxide

Poly(propylene carbonate) (PPC) is a new biodegradable aliphatic polycarbonate. However, the poor thermal stability, low glass transition temperatures (T_g), and relatively low mechanical property have limited its applications. To improve the thermal and mechanical properties of PPC, functionalized graphite oxide (MGO) was synthesized and mixed with PPC by a solution intercalation method to produce MGO/PPC composites. A uniform structure of MGO/PPC composites was confirmed by X‐ray diffraction and scanning electron microscope. The thermal and mechanical properties of MGO/PPC composites were investigated by thermal gravimetric analysis, differential scanning calorimetric, dynamic mechanical analysis, and electronic tensile tester. Due to the nanometer‐sized dispersion of layered graphite in polymer matrix, MGO/PPC composites exhibit improved thermal and mechanical properties than pure PPC. When the MGO content is 3.0 wt %, the MGO/PPC composites shows the best thermal and mechanical properties. These results indicate that nanocomposition is an efficient and convenient method to improve the properties of PPC. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Preparation of cellulose–tungsten carbide composite beads with ionic liquid for expanded bed application

Expanded bed adsorption (EBA) is an integrated technology for capturing target biomolecules directly from unclarified feedstock. The adsorbents should be designed specially to ensure the perfect performance of the expanded bed. In this study, an ionic liquid (IL), 1‐butyl‐3‐methylimidazolium chloride, was used to dissolve cellulose directly to prepare cellulose–tungsten carbide composite beads with water‐in‐oil suspension and cooling/ethanol regeneration. The preparation conditions were optimized, especially for four key factors, the cellulose concentration, ratio of the oil phase to the cellulose solution, stirring speed, and addition of tungsten carbide powder. The results showed that the tungsten carbide powder emerged well in the cellulose matrix as an inert densifier. The composite beads had a spherical appearance, a suitable size and size distribution, an appropriate wet density of 1.32–1.68 g/mL, a porosity of 90–96%, a pore radius of 45–65 nm, and a specific surface area of 30–42 m²/mL. These results show the potential application for this EBA process. Compared to the traditional technology with cellulose xanthate viscose, the new method with the IL as the nonderivatizing dissolution solvent is technically feasible, has concise processing, and is environmentally friendly. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

变压吸附分离工业废气二氧化碳的研究进展

概述了未来人类对过量二氧化碳排放的处理办法,即碳的捕获和存储(CCS).简介了4种二氧化碳的分离工艺及特点和工业中二氧化碳的捕获系统.阐述了变压吸附工艺的基本原理和其在捕获工业废气中二氧化碳上的应用,以及变压吸附分离二氧化碳的工艺在循环结构设计、吸附剂材料和数值模拟等方面的研究进展和国内外的工业化应用.分析了目前该工艺仍存在的问题,指出该技术具有广阔的应用前景.     

PEG基功能化离子液体的脱硫性能

合成一系列含有长醚链的PEG基咪唑对甲苯磺酸盐(PEG基功能化离子液体), 检测其脱硫与再生性能, 并测定其脱硫过程中物性(密度、黏度和表面张力)变化。结果表明, PEG基功能化离子液体具有良好的脱硫与再生性能, 而且该离子液体的脱硫性能随醚链增长而增强, 20℃时SO₂与离子液体摩尔比达到5.51以上, 吸收的SO₂在80℃条件下可彻底解吸。由¹H NMR图谱和Raman光谱分析结果表明, PEG基咪唑功能化离子液体对SO₂的吸收为物理吸收。脱硫后的PEG基功能化离子液体密度增大, 表面张力减小, 黏度较脱硫之前显著降低。     

Reusable poly(allylamine)-based solid materials for carbon dioxide capture under continuous flow of ambient air

Poly(allylamine) (PAA) is prepared via free-radical polymerization and physically impregnated on fumed silica at various amine loadings. The PAA-silica composites were found to have significant potential as trace carbon dioxide adsorbents under ambient conditions. The sorbent materials are shown to have high adsorption capacities with desirable adsorption-desorption characteristics. The effects of temperature and humidity on adsorption capacity and kinetics were studied at near-ambient conditions. Sorbent regenerative ability was confirmed within around 8% change following subsequent adsorption-desorption cycles and thermogravimetric analysis.     

CO_2/环氧丙烷共聚合成聚碳酸亚丙酯多元醇

利用双金属氰化物作为催化剂,催化CO2/环氧丙烷调节共聚制备聚碳酸亚丙酯多元醇(PPC),详细考察了催化剂用量、相对分子质量调节剂及其用量、CO2用量等对聚合的影响.研究发现PPC的相对分子质量与相对分子质量调节剂的用量成线性关系,可以根据需要合成具有规定相对分子质量的PPC树脂.最后提出聚合过程中碳酸丙烯酯可能按照解拉链的方式生成.