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Nitrogen and oxygen co-doped hierarchical porous carbons (NOPCs) is prepared by the pyrolysis of polyethylene glycol-200 (PEG) and triazine carbon forming agent (CFA) using MgO as template. The PEG/CFA/MgO mixtures were compacted to form a consolidate solids, which play a key role for the formation of NOPCs. The morphology, microstructure, phase structure, textural property, surface element composition and thermal stability properties of NOPCs were investigated. It was demonstrated that the NOPCs exhibit hierarchical porous structure, high specific surface area (the largest SBET of 1244 m2/g), and abundant mesopore structures without any activation. Benefiting from the unique porous structure and rich heteroatom functional group (1.34 at % N and 20.33 at % O), the NOPC-900 electrode shows a specific capacitance of up to 347 F/g at 0.5 A/g and can keep 187 F/g even at 50 A/g. Moreover, the NOPC-900 electrode shows good cycle life with capacitance retention of 90% after 10,000 cycles. This paper provides a new, convenient way to construct hierarchical porous carbon materials for super capacitors.

Three-dimensional graphene-like materials can effectively prevent the restacking of graphene layers and show tremendous potential applications in practice. In the present work, foamed graphene flakes (FGs) were easily prepared by a one-step pyrolysis of polyethylene glycol-200 (PEG)/MgO composites, and they were successfully applied in supercapacitors and lithium-ion batteries (LIBs). The FGs consisted of a large number of foamed flakes, and each flake was made up of 3 to 10 graphene layers. By changing the weight ratio of PEG/MgO, the specific surface area, porosity, and graphitization of the FGs could be adjusted. As electrode materials of supercapacitors, FGs from the PEG/MgO at a weight ratio of 1 : 1.5 showed the highest areal capacitance of 29.5 μF cm−2 and a retention rate of 92%. As the anode materials of LIBs, FGs from PEG/MgO at a weight ratio of 4 : 1.5 had a reversible discharge capacity of 787 mA h g−1 at a current density of 0.2C, and showed excellent rate performance and cycling stability. These FGs have significant potential for practical application in electrochemical energy storage.

The Ni, Ni–Mo, Ni–Mg, and Ni–Mo–Mg catalysts were systematically explored for the one-step conversion of polystyrene (PS) into carbon nanotubes (CNTs). The catalysts were characterized in the phase structure, morphology, reducibility, and carbonization performance. It was found that the Mo contributed to the small catalyst particle growth by the formation of NiMoO4 phase. The addition of Mg had no effect on catalyst particle sizes but effectively controlled the carbon solubility and led to the growth of CNTs by the generation of NiMgO2. Finally, we demonstrated that the Ni–Mo–Mg catalysts showed the most efficient for the conversion of PS into CNTs owing to the individually synergetic effect of Mo and Mg elements. Besides catalysts, the degradation additives and the carbonization temperature were also discussed for their effects on the carbonization of PS. It is believed that the work provides potential for the conversion of PS waste into CNTs.

Fluorometric “turn-on” glucose detection is presented that is based on the Fenton reaction which can trigger the generation of Ag nanoclusters (Ag NCs). Oxidation of D-glucose by glucose oxidase generates H2O2. Reactive radicals are formed from the Fenton reaction of H2O2 and Fe2+. These radicals initiate the polymerization of methacrylic acid to form poly(methacrylic acid) which is used as a template to generate fluorescent Ag NCs in situ by illumination with UV light. The increase in Ag NCs fluorescence intensity can be used to quantify glucose concentration. The sensing approach employed here provides a new strategy for the determination of glucose selectively.

Plastics used as carbon source present a sustainable and environmentally benign route for the preparation of carbon nanotubes (CNTs); however, the current catalysts basically take effect on a certain type of plastics. Herein, a significantly universal carbonization performance of Ni-Mo-Mg catalysts has been created for polypropylene (PP), polyethylene (PE), polystyrene (PS), and their blends with the highest CNT yields of 26.24%, 28.36%, 18.39%, and 31.66%. With the further introduction of a universal synergistic agent (nanosized carbon black), the maximum CNT yields of 53.56%, 65.95%, 41.85%, and 59.83% from PP, PE, PS, and their blends were achieved, respectively. The morphology, microstructure, and the graphitization of above CNTs were measured by scanning electron microscopy, transmission electron microscopy, X-ray diffractometer, Raman spectroscopy, and high-resolution transmission electron microscope. Results demonstrated that the addition of carbon black could further improve the morphology of CNTs and enhance the graphitization of CNTs. Within three polyolefins, the PS offered the highest graphitization of CNTs. Finally, the highly universal carbonization performance of Ni-Mo-Mg catalysts and the universal synergistic effect were also discussed. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44647.

This article presents a novel investigation on the Mo/Mg/Ni/O catalysts (Nmm-cats) with which the noncharring polyolefins are basically transferred to the charring polymers under forced flaming conditions and the flame retardancy of polyolefins is improved dramatically. The results of model charring experiments show that when appropriate Mo/Mg/Ni molar ratio is adopted and only 3% Nmm-cats is blended, the Nmm-cats belong to high-efficient charring catalysts that can deposit 56 and 64 wt % of volatile products in-situ from linear low-density polyethylene (LLDPE) and polypropylene (PP), respectively. The charring properties are characterized by scanning electron microscopy, transmission electron microscopy, and Raman spectroscopy; and the char-forming mechanisms are analyzed by wide-angle X-ray diffraction experiment. The improvement in flammability properties for LLDPE and PP is demonstrated by using a cone calorimeter. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

A novel silicone-containing flame retardant (HSOBA) synthesized from hydrogen-containing silicone oil and Bisphenol A via a simple approach has been incorporated into polycarbonate (PC) matrix to study its effects on the flame retardancy. The flame retardancy of PC/HSOBA composites is investigated by limiting oxygen index (LOI), vertical burning tests (UL-94), and cone calorimeter measurement. The LOI value of the composites is 31.7 and the UL-94 rating reaches V-0, when the content of HSOBA is 3 wt %. Cone calorimeter data confirm that the HSOBA acts as an effective additive functioning both as flame retardants and as smoke suppressant. Evolution of the thermal behaviors of the composites tested by TGA, the morphological structures, and the constituent of char residue after LOI tests characterized by scanning electronic microscopy-energy-dispersive X-ray analysis were used to explain the possible flame-retardant mode. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012

In a simple device, two kinds of zeolites were successfully used as synergistic additive to promote formation of the multi-walled carbon nanotubes (MWNTs) from polypropylene (PP) via combustion. More importantly, this kind of process may potentially act as a new approach for recycling plastic wastes, because it could effectively transfer polyolefin wastes into valuable carbon materials. Experimental results demonstrated that the higher quality of MWNTs can be obtained from the mixture (PP/H-Beta/Ni2O3) than that from the mixture (PP/H-ZSM-5/Ni2O3). At the same time, the yield of MWNTs from PP/H-ZSM-5/Ni2O3 system is much lower than that from PP/H-Beta/Ni2O3 under the same condition. The reason for the different effects of both types of zeolites on the morphology and the yield of the MWNTs was analyzed. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009

Combination of Ni2O3 and solid acid with Bronsted acid sites and Lewis acid sites (such as HZSM-5 and H-beta) could dramatically improve fire retardancy of polyolefin, including polypropylene and linear low-density polyethylene. This is mainly attributed to the formation of a large amount of residual char from degradation products of polyolefin in the intermediate stage of combustion. Thus, the amount of flammable components diffusing into the flame zone was small.

Three kinds of organically modified Na+-montmorillonites (OMMTs), including two kinds of octadecylammonium modified montmorillonite with different contents of octadecylammonium and a kind of sodium dodecylsulfonate (SDSo) modified montmorillonite, were used to prepare polyamide 12 (PA12)/OMMT nanocomposites. Effects of the modifiers on degradation and fire retardancy of PA12/OMMT nanocomposites were investigated. Acid sites formed in cationic surfactant modified MMT via Hoffman decomposition could accelerate degradation of PA12 at high temperature. However, catalytic effect of the acid sites on carbonization of the degradation products promoted char barrier formation, which reduced heat release rate (HRR). Higher content of cationic surfactant in OMMT is beneficial to fire retardancy of PA12 nanocomposites and the dispersion states of OMMT have assistant effects. In contrast, Na+-montmorillonite (Na-MMT) and anionic surfactant modified MMT (a-MMT) could not form acid sites on the MMT layers; in this case, fire retardancy of PA12/Na-MMT appears to have no improvement and PA12/a-MMT appears to have limited improvement.

The degradation and flame retardancy of polypropylene/organically modified montmorillonite (PP/OMMT) nanocomposite were studied by means of gas chromatography-mass spectrometry and cone calorimeter. The catalysis of hydrogen proton containing montmorillonite (H-MMT) derived from thermal decomposition of (alkyl) ammonium in the OMMT on degradation of PP strongly influence carbonization behavior of PP and then flame retardancy. Bronsted acid sites on the H-MMT could catalyze degradation reaction of PP via cationic mechanism, which leads to the formation of char during combustion of PP via hydride transfer reaction. A continuous carbonaceous MMT-rich char on the surface of the burned residues, which work as a protective barrier to heat and mass transfer, results from the homogeneous dispersion of OMMT in the PP matrix and appropriate char produced.

The effects of both organically modified montmorillonite (OMMT) and Ni(2)O(3) on the carbonization of polypropylene (PP) during pyrolysis were investigated. The results from TEM and Raman spectroscopy showed that the carbonized products of PP were mainly multiwalled carbon nanotubes (MWNTs). Surprisingly, a combination of OMMT and Ni(2)O(3) led to high-yield formation of MWNTs. X-ray powder diffraction (XRD) and GC-MS were used to investigate the mechanism of this combination for the high-yield formation of MWNTs from PP. Brønsted acid sites were created in degraded OMMT layers by thermal decomposition of the modifiers. The resultant carbenium ions play an important role in the carbonization of PP and the formation of MWNTs. The degradation of PP was induced by the presence of carbenium ions to form predominantly products with lower carbon numbers that could be easily catalyzed by the nickel catalyst for the growth of MWNTs. Furthermore, carbenium ions are active intermediates that promote the growth of MWNTs from the degradation products with higher carbon numbers through hydride-transfer reactions. The XRD measurements showed that Ni(2)O(3) was reduced into metallic nickel (Ni) in situ to afford the active sites for the growth of MWNTs.

Multi-walled carbon nanotubes (MWCNTs) were efficiently synthesized by catalytic combustion of polypropylene (PP) using nickel compounds (such as Ni2O3, NiO, Ni(OH)2 and NiCO3 · 2Ni(OH)2) as catalysts in the presence of organic-modified montmorillonite (OMMT) at 630–830 °C. Morphologies of the sample undergoing different combustion times were observed to investigate actual process producing MWCNTs by this method. The obtained MWCNTs were characterized by X-ray diffraction (XRD), transmission electron microscope and Raman spectroscopy. The yield of MWCNTs was affected by the composition of PP mixtures with OMMT and nickel compounds and the combustion temperature. The proton acidic sites from the degraded OMMT layers due to the Hoffman reaction of the modifiers at high temperature played an important role in the catalytic degradation of PP to supply carbon sources that are easy to be catalyzed by nickel catalyst for the growth of MWCNTs. The XRD measurements demonstrated that the nickel compounds were in situ reduced into the Ni(0) state with the aid of hydrogen gas and/or hydrocarbons in the degradation products of PP, and the Ni(0) was really the active site for the growth of MWCNTs. The combination of nickel compounds with OMMT was a key factor to efficiently synthesize MWCNTs via catalytic combustion of PP.

Carbon black particles were incorporated into the polypropylene (PP) in combination with Ni–Mo–Mg catalysts to investigate their influences on the carbonization and flame retardancy of PP. The results demonstrate that the carbon black exhibited a very positive effect on the char yield of PP in a pyrolyzation experiment with different temperatures. For pyrolyzation at 750 and 550°C, the PP/5% Ni–Mo–Mg/5% carbon black blends gave 56 and 37.1% char yields, respectively. Scanning electron microscopy, transmission electron microscopy results, and direct optical observations from designed experiments all demonstrated a combination of carbon black with growing carbon nanotubes (CNTs) for the generation of char with integrated and compact structures. Cone calorimeter and limited oxygen index tests confirmed that the integration of carbon black particles and CNTs led to a significant improvement in the flame retardancy of PP. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43034.

In the experiment, the furfural added compound agent was applied to treat catalytic cracking slurry oil in order to utilize the saturated hydrocarbon and condensed-nuclei aromatics reasonably and soundly. The added agent could improve the dissolubility and selectivity of furfural and enhance the recovery and quality of treated oil. The optimum condition was as follows: compound ratio was 0.5:1; the added quantities were 8% relative to furfural volume; the temperature was 50°C; the solvent/oil ratio was 0.5:1. Under the condition, compared with that of furfural extraction, the recovery of treated oil was increased 14.8 wt%, the quality of treated oil also had been improved to some extent, and thus, the treated oil could be used as good stockfeed of catalytic cracking. The extract oil contained abundant condensed-nuclei aromatics, which could be used as good stockfeed to produce a high value-added chemical engineering product.

Carboxyl-containing polysiloxane (LCCP) has been successfully applied in the flame retardancy of polycarbonate (PC). The LCCP was synthesized by hydrosilylation and condensation reaction. The presence of carboxyl groups has been demonstrated to be crucial to provide high flame retardant effectiveness. The flame retardancy of LCCP–PC composites is investigated by limiting oxygen index (LOI), vertical burning tests (UL-94). At the mole ratio of diethoxymethyl (1-propionyloxy) silane/diethoxydimethylsilane = 8/100 in LCCP(3), the best flame retardant performance of LCCP-PC composites was obtained. The LOI value of the composites is 38.5 and the UL-94 rating reaches V-0 when the content of LCCP(3) is as low as 0.5 wt %. Evolution of the thermal behaviors of the composites tested by thermogravimetric analysis shows that addition of LCCP(3) in PC can reduce the degradation speed of PC and induce a reduction of the initiated decomposition temperature of PC. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2014, 131, 39814.