Fabrication of porous Mn₂O₃ microsheet arrays on nickel foam as high–rate electrodes for supercapacitors

Xu, Jiasheng,Sun, Yudong,Lu, Mingjun,Wang, Lin,Zhang, Jie,Qian, Jianhua,Kim, Eui Jung ELSEVIER SCIENCE 2017 JOURNAL OF ALLOYS AND COMPOUNDS Vol.717 No.-

<P><B>Abstract</B></P> <P>Porous Mn<SUB>2</SUB>O<SUB>3</SUB> microsheet arrays on nickel foam have been prepared by a mild chemical reaction combined with a calcination process. The porous Mn<SUB>2</SUB>O<SUB>3</SUB> microsheet arrays are directly grown on the surface of the conductive nickel foam. The porous Mn<SUB>2</SUB>O<SUB>3</SUB> microsheet arrays are composed of numerous interconnected nanopores with an average size of about 16 nm. The specific surface area of the porous Mn<SUB>2</SUB>O<SUB>3</SUB> materials is 36.34 m<SUP>2</SUP> g<SUP>−1</SUP>. The fabricated electrode materials exhibit a high specific capacitance of 566.6 F g<SUP>−1</SUP> at a current density of 0.5 A g<SUP>−1</SUP> and 294.4 F g<SUP>−1</SUP> at a current density of 20 A g<SUP>−1</SUP>. The energy density of the porous Mn<SUB>2</SUB>O<SUB>3</SUB> microsheet was 19.65 Wh kg<SUP>−1</SUP> at a power density of 124.85 W kg<SUP>−1</SUP> and it was reduced to 10.22 Wh kg<SUP>−1</SUP> at a power of density of 5.00 kW kg<SUP>−1</SUP>. The good electrochemical capacitance is ascribed to the interconnected porous structure of the Mn<SUB>2</SUB>O<SUB>3</SUB> microsheet, which facilitates electrolyte diffusion and enhances electron transport. The porous Mn<SUB>2</SUB>O<SUB>3</SUB> microsheet arrays on nickel foam are a promising electrode material for supercapacitors.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Porous Mn<SUB>2</SUB>O<SUB>3</SUB> microsheet arrays on nickel foam are synthesized via solution process followed with an annealing treatment. </LI> <LI> It directly utilizes as electrode materials for pseudocapacitors. </LI> <LI> A specific capacitance of 566.6 F g<SUP>−1</SUP> is achieved at a current density of 0.5 A g<SUP>−1</SUP>. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

EFFECT OF MACROMOLECULAR COUPLING AGENT PMMA-b-PVTES ON STABILIZING NANO-Si3N4

HUI ZHU,Jiasheng Qian,Peng Chen,JIBIN MIAO,RU XIA,Bin Yang,LIFEN SU 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2014 NANO Vol.9 No.8

Poly(methyl methacrylate)-b-poly(vinyltriethoxysilane) (PMMA-b-PVTES) are synthesized using atom transfer radical polymerization (ATRP) and used as macromolecular coupling agents to modify silicon nitride nanoparticles (nano-Si3N4). The chemical composition of copolymers PMMA-b-PVTES and modified nano-Si3N4 are confirmed by various characterization techniques. The modified nano-Si3N4 shows excellent hydrophobic nature, which make nanoparticles (NPs) stably disperse in organic solvent. Transmission electron microscope (TEM), particle size testing, contact angle measuring and sedimentation experiment are employed to examine the dispersion of modified nano-Si3N4 in chloroform. By comparing the effects of copolymers with varied number-average molecular weight (Mn) and block length ratio on stabilizing nano-Si3N4, we discussed the mechanism of macromolecular coupling agent stabilizing NPs. In our experiments, the copolymer PMMA88-b-PVTES17 is found to be the most effective macromolecular coupling agent for stabilizing nano-Si3N4.

Preparation and Study on Thermal Conductive Composites of Chlorinated Polyethylene Rubber Reinforced by Boron Nitride Particles

Junjie Shu,Ru Xia,Jiasheng Qian,JIBIN MIAO,LIFEN SU,Ming Cao,Hongyun Lin,Peng Chen,Jinyang Chen 한국고분자학회 2016 Macromolecular Research Vol.24 No.7

The composites of chlorinated polyethylene rubber (CM) filled with boron nitride (BN) were prepared and examined systematically. Scanning electron microscopy (SEM) was used to observe microscopic morphology of composites. Mechanical properties of composites were analyzed by a rubber process analyzer (RPA) and dynamic mechanical thermal analyzer (DMTA). Thermal conductivity as well as thermo stability of composites was improved by adding BN particles into the CM rubber. It was found that BN particles can reinforce the rubber matrix while they also break down the network of polymer chains and ruin the physical properties of the rubber matrix. During the dynamic compressing process, BN particles can transfer heat from the matrix and alleviate the heat build-up phenomenon. The BN/CM composites (volume content CBN=18%) with thermal conductivity 1.179 W/(m·K) and good flexibility (Elongation at break=320%) were prepared, which may be used as thermal interface materials in a dynamic compressing process.

Morphology, Thermal and Crystallization Properties of Polyamide-6/Boron Nitride (BN) Thermal Conductive Composites

Ru Xia,Manman Sun,Bin Yang,Jiasheng Qian,Peng Chen,Ming Cao,JIBIN MIAO,LIFEN SU 한국고분자학회 2018 폴리머 Vol.42 No.2

A series of the thermal conductive polyamide-6 (PA6) composites filled with boron nitride (BN) were prepared by two methods, including melting method (MM) and solution method (SM). The thermal conductivity, morphology, crystallization behavior, thermal stability, and rheological properties of PA6 composites were investigated. The results showed that the thermal conductivity of two methods increased with increase in the filler content, the thermal conductivity of PA6/BN composites containing 40 wt% BN prepared by melting method was up to 1.02W·m-1·K-1, while the thermal conductivity of PA6/BN composites prepared by solution method was up to 1.44 W·m-1·K-1 at the same filler content.

Effect of Microstructure on Thermal Conductivity of Polymer Composites

Yue Yang,Junjie Shu,Peng Chen,Ru Xia,Jiasheng Qian,Bin Yang,JIBIN MIAO,LIFEN SU,Zhengzhi Zheng,Ming Cao 한국고분자학회 2017 Macromolecular Research Vol.25 No.4

Thermal conductivity (TC) of polymer composites is strongly depended on thermal conductive fillers as well as heat conduction pathways formed by these fillers. In this work, we examined effects of morphology, size and arrangement of fillers on TC of polymer composites by using energy-conserving dissipative particle dynamic (e-DPD) simulation. Theoretically, we explored effects of ideal and “pseudo” thermal conductive pathways on composites’ TC and investigated heat conduction of filler particles with cubic-center and lamellar morphology. To confirm orientation and size effects of lamellar filler particles on composites’ TC, we prepared a series of Boron Nitride/Silicon rubber composites (BN/SiR). Being same with those observed in e-DPD simulation, orientation could efficiently improve TC of BN/SiR composites. The TC of composites with filled diameters about 10 micrometer of BN flats is 11 times higher than that of SiR matrix. Our researching results show that heat conduction pathways are essential to transportation of heat flux in polymer composites and even “pseudo” pathways by disconnected filler particles along temperature gradient can accelerate heat conduction.

Monte Carlo Simulation on Kinetics of Batch and Semi-Batch Free Radical Polymerization

Jing Shao,Peng Chen,Wei Tang,Ru Xia,Xiaoshuang Feng,Jiasheng Qian,Changjiang Song 한국고분자학회 2015 Macromolecular Research Vol.23 No.11

Based on Monte Carlo simulation technology, we proposed a hybrid routine which combines reaction mechanism together with coarse-grained molecular simulation to study the kinetics of free radical polymerization. By comparing with previous experimental and simulation studies, we showed the capability of our Monte Carlo scheme on representing polymerization kinetics in batch and semi-batch processes. Various kinetics information, such as instant monomer conversion, molecular weight, and polydispersity etc. are readily calculated from Monte Carlo simulation. The kinetic constants such as polymerization rate kp is determined in the simulation without of “steady-state” hypothesis. We explored the mechanism for the variation of polymerization kinetics those observed in previous studies, as well as polymerization-induced phase separation. Our Monte Carlo simulation scheme is versatile on studying polymerization kinetics in batch and semi-batch processes.

Effect of Different Nanofillers on Non-Isothermal Crystallization Kinetics and Electric Conductivity of Dynamically-Vulcanized PP-EPDM Blends

Bin Yang,Lei Hu,Ru Xia,Fang Chen,Shu-Chun Zhao,Yan-Li Deng,Ming Cao,Jiasheng Qian,Peng Chen 한국고분자학회 2016 Macromolecular Research Vol.24 No.1

In this study, nanofillers composed of hydroxylated carbon nanotubes (h-CNT), carbon nanotubes (CNT) and graphene (GR) were separately added into the dynamically-vulcanized polypropylene (PP)/ethylene-propylenediene monomer (EPDM) blend. Differential scanning calorimetry (DSC), wide-angle X-ray diffraction (WAXD) and electrical resistivity measurements were employed to study the effect of nanofillers on the melt behavior, non-isothermal crystallization behavior and electrical conductivity of the prepared composites. WAXD results showed that h-CNT had a better induction effect of β-PP in the nanocomposites. The sequence of the activity in inducing the formation of β-PP was h-CNT>GR>CNT. However, the total crystallinity of the nanocomposites nearly remained constant. Non-isothermal crystallization kinetic analysis indicated that the presence of nanofillers improved the crystallization rate of the nanocomposites. The consequence of nucleation activity was as follows: CNT>GR>h-CNT. Although EPDM hindered the macromolecular motion of PP, interestingly it could increase the crystallization rate to an extent. Besides, the influence of nanofillers on enhancing the conductive property of the nanocomposites can be ranked as follow: CNT>GR>h-CNT.

Salt template-assisted construction of three-dimensional interconnected network in thermally conductive EP/PVDF/NiCo@GNP composites

Ning Jia,Bin Yang,Xiaohong Wang,Shishuang Cui,Peng Chen,Ru Xia,Zhengzhi Zheng,Jiasheng Qian,Yuchao Ke,Yang Pan 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.125 No.-

In this study, graphene nanoplatelets (GNP) and nickel–cobalt (NiCo) alloy were adopted as reinforcingmaterials to prepare epoxy (EP) resin-based composites. NiCo particles were able to achieve uniformanchoring on GNPs’ surface under the electrostatic force due to the successful introduction of oxygendefects on GNPs. With the synergistic effect of adhesive PVDF and salt particles, the system with threedimensionally(3D) interconnected network was successfully constructed. Benefit from the formation ofmechanically stable and efficient heat conduction paths, the thermal conductivity (TC) of the EP/PVDF/NiCo@GNP composite reached 1.077 Wm1K1 at a filler volume fraction of 6.82 vol%, while the counterpart’sstoragemodulus (E’) was up to 3.22 GPa. In addition, a scaling formula was quantitatively proposed tocorrelate TC with E’, and the perfect agreement between the theoretical prediction and experimental dataclarified the underlying mechanism of the relationship between phonons transport and stress transferwithin a systemwith 3D ordered structures. The establishment of relationship between AHR (average heatingrate) and TC made it possible to further predict TC of composites based upon the infrared thermal imaging(ITI) data. The as-prepared GNP composites show good application prospects as thermal managementmaterials which need to experience thermally mechanical deformation.