POWDER TECHNOLOGY
·
2018
·
IF 3.23
Zhilin Xi,Liwei Jin,J.Y. Richard Liew,Ding Li
A foam sol clay (FSC) mixture, mainly composed of fly ash (FA), surfactant ( n -amylamine) and polyethylene oxide (PEO), was proposed for coal dust control. The FA surface, modified by a FSC solution, stability and foamability were investigated. It was found that the FA surface in alkaline solution was deprotonated to form a negative charge, which could be adsorbed by the polar head group of n -amylamine via electrostatic interactions . As a result, with increasing surfactant, the particles gradually converted from hydrophilic to hydrophobic and attached at gas-liquid interfaces so that the contact angle, zeta potential , froth stability and foamability increased. At a surfactant concentration (c a ) of 35 g/L, a monolayer three-dimensional network was formed and the maximum foamability and half-life were obtained. Upon further increasing c a , a bilayer and particle clusters were formed by surfactant chain-chain interaction, resulting in particles becoming hydrophilic again, and the FSC solution having stronger mechanical resistance against flowing, so that the viscosity rapidly increased and the diffusion of free surfactant molecules was hindered at the froth surfaces. Thus, the contact angle, froth stability and foamability decreased. PEO could bond sodium dodecyl sulfate and water to form a dual adsorption layer and hydrogen, respectively, which enhanced the wettability of the FSC on coal dust surfaces. PEO could adsorb and curl FA particles to form a thin layer of armor after froth air-drying. It was concluded that the froth generated by the FSC solution, including 200 g/L FA, 35 g/L c a and 1 g/L PEO, could control coal dust with a long-term effect.
研究领域:
环境工程
·
矿物加工
·
胶体与界面化学
·
粉尘防治
·
资源利用
✓ 已验证
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2019
·Vol. 43
·期 16
·6136-6145
·
IF 3.069
Tianlu Xu,Jinrui Zhang,Lijie Qu,Xueyan Dai,Peihong Li,Yanlong Sui,Chunling Zhang
A phenyl group was introduced into the polymeric network of polysiloxane foam for the improvement of its thermal insulation capacity and thermal stability. Phenyl-containing polysiloxane was prepared via ring-opening polymerization, and phenyl-containing polysiloxane foam was fabricated through simultaneous foaming and crosslinking reactions. With increasing phenyl content, the thermal conductivity of the polysiloxane foam decreased from 0.093 W m−1 K−1 to 0.079 W m−1 K−1. When the phenyl content was 6.15 mol%, the average cell diameter decreased from 384 μm to 165 μm and the cell density increased from 0.58 × 108 cells per cm3 to 4.67 × 108 cells per cm3. When the phenyl content was 8.5 mol%, the cell morphology became imperfect and the average cell diameter and cell density reached 259 μm and 1.29 × 108 cells per cm3, respectively. TGA results revealed the improved thermal stability of the polysiloxane foam. The TGA curves under nitrogen and air conditions could be divided into three stages. Under nitrogen conditions, the mass loss of the maximum decomposition stage decreased and the residue at 800 °C slightly increased. Under air conditions, the maximum decomposition temperatures of the three stages increased. The compressive strength and specific compressive strength were measured and showed a downward trend.
研究领域:
高分子材料科学
·
热功能材料
·
复合泡沫材料
·
材料化学
·
绝缘材料工程
✓ 已验证
DOI
高影响因子
FUEL
·
2022
·
IF 8.035
Jian Qiao,Xiang-Ming Hu,Yun-Tao Liang,Qian Zhang,Wei Wang,Yan-Yun Zhao,Shuang Ju,Fu-Chao Tian
In order to improve the stability time and foaming ratio of gel foam, and change the traditional preparation method of gel foam. In this paper, using super-hydrophobic nanoparticles , PVA, sodium tetraborate and sodium bicarbonate as the main raw materials, based on the self-assembly effect of super-hydrophobic nanoparticles and hydrophilic macromolecules, a high-foaming gel foam (PGF) without foaming agent was prepared. Through the test, the foaming volume of the 100 ml PGF can reach 329 ml without adding foaming agent, which is 1.4 times of the traditional gel foam (TGF) and 1.2 times of the viscous foam (VF). Even without foaming agent, the PGF has a half-life of more than 13 days and can retain water for more than 15 h at 100 °C. Response surface analysis showed that the foaming performance of the PGF was affected by nanoparticles, sodium tetraborate and sodium bicarbonate, among which the content of nanoparticles was the main factor. At the same time, sodium tetraborate and sodium bicarbonate also significantly affect the water retention performance of PGF. Fire prevention experiments show that the gel foam prepared by this method also has excellent fire prevention ability, which can effectively inhibit the consumption of hydroxyl group and the generation of methyl and methylene group in the process of coal oxidation. Moreover, it can still play an inhibiting ability at a high temperature of 400 °C, and can effectively prevent the recurrence of coal fire after extinguishing. The development of PGF provides a new method for the preparation of gel foam in the future. At the same time, the application of foaming agent is avoided, which reduces the pollution of surfactant to the environment.
研究领域:
材料科学
·
消防工程
·
能源安全
·
高分子化学
·
界面科学
✓ 已验证
DOI
高影响因子
JOURNAL OF SOLID STATE CHEMISTRY
·
2017
·
IF 2.299
Yuan-Zi Xu,Cheng-Zong Yuan,Xue-Ping Chen
To design highly efficient and low-cost electrocatalysts for oxygen evolution reaction (OER) is a great challenge for electrochemical water splitting. Here we introduce a simple and cost-effective strategy for one-step synthesis of a three-dimensional Ni 3 S 2 /MoS X (x is close to 3) nanosheets on Ni foam (NF) via a sovelthermal reaction. The electrochemical performance of the Ni 3 S 2 /MoS X nanosheets on NF has been investigated and exhibits superior OER electrocatalytic activity as well as excellent electrochemical durability. As a novel non-noble-metal OER catalyst operating in basic electrolytes, this 3D cathode exhibits an onset overpotential of as low as 165 mV, a Tafel slope of 67.5 mV dec −1 and remarkable long-term stability. This catalyst maintains its catalytic activity for at least 14 h and only affords 50, 100, and 150 mA cm −2 OER current densities at overpotentials of 215 mV, 265 mV and 305 mV respectively.
研究领域:
材料科学
·
电化学
·
能源化学
·
纳米科技
·
催化化学
✓ 已验证
DOI
高影响因子
APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
·
2016
·Vol. 122
·期 5
·515
·
IF 1.444
Huang Liang,Zhu Pengli,Li Gang,Sun Rong
The partial reduced graphene oxide (P-rGO) sheets-wrapped nickel foams (NF@P-rGO) were prepared by hydrothermal method, and then their epoxy composites were fabricated via a simple drop-wetting process. The P-rGO sheets on the metal networks could effectively improve the compatibility between nickel foam and epoxy resin, thus greatly accelerate the wetting of epoxy resin on the foams and avoid cracks in the network–polymer interface. Owing to the existence of high-efficiency conductive metal networks, the NF@P-rGO/epoxy composite has a high thermal conductivity of 0.584 W m −1 K −1 , which is 2.6 times higher than that of neat epoxy resin. Additionally, owing to the improved wetting ability, NF@P-rGO-10 wt% boron nitride (BN) microsheets/epoxy composites could be fabricated and have a further higher thermal conductivity of 0.71 W m −1 K −1 . We believe the use of P-rGO as a novel surface modifier and the following liquid polymer drop-wetting could be an effective method to obtain novel and outstanding metal foam/polymer composites.
研究领域:
材料科学
·
高分子复合材料
·
热管理材料
·
表面与界面工程
✓ 已验证
DOI
高影响因子
RSC Advances
·
2016
·Vol. 6
·期 16
·13418-13425
·
IF 3.289
Fubin Luo,Kun Wu,Mangeng Lu
The influence of polybenzoxazine modified ammonium polyphosphate (BMAPP) on the thermal behavior and flame retardancy of a rigid polyurethane foam (PU) are investigated via thermogravimetric analysis (TG), TG coupled with infrared spectroscopy (TG-FTIR), UL-94 vertical burning testing and limit oxygen index (LOI). The TG testing results indicate that BMAPP can enhance the thermal stability of PU, both under air and nitrogen conditions. The initial degradation temperature of the BMAPP/PU composites is 264 °C in air, which is 22 °C and 30 °C higher than that of ammonium polyphosphate (APP)/PU composites and neat PU, respectively. The reason might be attributed to the better dispersion and compatibility of BMAPP particles in PU compared with APP, which can prevent the PU chain from degrading at low temperatures. The LOI value results demonstrate that BMAPP has higher flame retardancy in PU than APP. Residue analysis implies that polybenzoxazine is partially converted into Si–O as char residue during combustion.
研究领域:
高分子材料科学
·
阻燃材料
·
热功能材料
·
复合材料学
·
材料化学
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry A
·
2014
·Vol. 2
·期 34
·13859-13867
·
IF 0
Chengxin Peng,Huixin Chen,Qiongyu Li,Weiwei Cai,Qin Yao,Qingsheng Wu,Jinhu Yang,Yong Yang
The silicon material is the most promising candidate for developing new-generation lithium-ion batteries with high energy and power output. However, there remains a significant challenge due to poor electrical conductivity and pulverization of the silicon based anode during cycles. Aiming to solve these problems, in this work we fabricate a novel 3D composite architecture made of a Si@SiOx core–shell nanowire array grown on a 3D graphitic foam (Si CNW–3D GF) substrate by a well-designed multiple-step approach. The prepared Si CNW–3D GF composite shows the integrated advantages for high-performance lithium ion batteries, including its light weight, open macroporosity, high conductivity, high Si NW loading, excellent flexibility as well as SiOx buffer layers. As a result, the Si CNW–3D GF composite exhibits excellent performance such as high reversible lithium storage capacity (3603 mA h g−1 at a current density of 840 mA g−1), excellent cycling performance (up to 100 cycles) and superior rate capability (2299 mA h g−1 at 4200 mA g−1 and 1206 mA h g−1 at 8400 mA g−1), which is 2 times that of the Si CNW electrode where Si CNWs were grown directly on a stainless steel current collector without the presence of 3D GF.
研究领域:
材料科学
·
电化学
·
纳米科技
·
能源存储
·
功能材料
·
电池技术
✓ 已验证
DOI
JOURNAL OF ALLOYS AND COMPOUNDS
·
2018
·
IF 3.779
Hui Wang,Houzhen Chen,Hongjiao Wang,Lei Wu,Qixing Wu,Zhongkuan Luo,Fang Wang
The electrochemical performance of the lithium−oxygen (Li−O 2 ) batteries largely depends on the material and architecture of the catalytic cathode. In this paper, to avoid the parasitic reactions of carbon and binder with discharge products and reaction intermediates, we proposed an effective design of a free-standing catalytic cathode for Li−O 2 batteries. The FeCo 2 O 4 @Ni electrode consists of FeCo 2 O 4 nanosheets grown directly on nickel (Ni) foam. The resultant hierarchical macroporous/mesoporous structure provides sufficient space for the insoluble discharge product Li 2 O 2 and catalytically active sites for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). Consequently, the carbon- and binder-free self-supporting electrode has demonstrated a high discharge capacity with relatively low charge overvoltage and a better cycle performance than the corresponding carbon-based electrodes.
研究领域:
电化学
·
能源材料
·
纳米材料
·
电催化
·
储能技术
✓ 已验证
DOI
高影响因子
POLYMERS FOR ADVANCED TECHNOLOGIES
·
2018
·Vol. 29
·期 12
·2982-2991
·
IF 2.137
Zhiyong Zhang,Miaojun Xu,Bin Li
The polymethacrylimide/silicate (PMI/silicate) composites were successfully prepared from the monomers of acrylonitrile (AN) and methacrylic acid (MAA) via the monomer in situ intercalation polymerization and free foaming. The formation of imide groups was monitored by Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). The results of FTIR and XPS indicated that the imide groups were gradually formed and cyano groups were dwindling but still existed during foaming and thermal treatment. The thermogravimetric analysis results revealed that the thermal stability of the PMI/silicate composites was improved, the rate of thermal degradation was reduced, and the residue was increased because of the addition of silicates. The results of dynamic mechanical analysis revealed that the rigidity and the glass transition temperature of the composites were improved. The limit oxygen index (LOI) and cone calorimeter (CONE) test showed that the fire-retardant properties were improved because of the barrier effect of silicates. The cell morphologies of the PMI/silicate composites were characterized by scanning electron microscopy (SEM), and the results showed that the silicate particles were distributed on the cell walls, but the cells slightly cracked. The mechanical properties were measured by tensile, flexural, and compressive strength. The mechanical strength, especially flexural strength, was significantly improved. The flexural strength of PMI/MMT, PMI/kaolin, and PMI/talc containing 8 wt% silicates was improved to 172%, 240%, and 233%.
研究领域:
高分子材料
·
复合材料科学
·
材料化学
·
防火材料
·
多孔材料
✓ 已验证
DOI
高影响因子
POWDER TECHNOLOGY
·
2019
·
IF 3.413
Zhilin Xi,Shuhui Zhou,Longzhe Jin
In this work, a self-hardening foam-sol (SHF) is proposed to control the diffusion of static coal dust. The SHF was mainly synthesized by a foaming solution (composed of 1 g/L polyethylene oxide (PEO), 25 g/L sodium dodecyl sulfate (SDS), 100 g/L sodium silicate and 874 g/L water) and organic acid with a concentration range of 10 to 13 g/L. Based on fluorescence spectrophotometry , drop shape analysis, X-ray photoelectron spectroscopy and scanning electron microscopy, several conclusions could be found. The critical micelle concentration of SDS was 25 g/L, when most of the pyrene pendants were solubilized into the SDS micelles to form the hydrophobic mixed micelles, and excimer formation began to reach a maximum. The SHF had optimal wetting ability with the smallest contact angle of 17 o , due to PEO-bonded water and SDS forming hydrogen and a dual adsorption layer, which could enhance the wetting ability of the SHF on coal dust surfaces. The SHF had the best accepted loss of liquidity time (180–86 s) and self-hardening time (236–121 s) via the reaction of sodium silicate and organic acid. The pores and cracks among dust particles could be linked closely by SHF via the solid bridge force. The primary components were silica and sodium carbonate with crystal water and hydrophilic C O and C O or O–C–O functional groups. Based on the dust suppression experiment, the dust suppression efficiency was almost 100% at airflow speeds below 12 m/s. Obviously, the dust particles could be controlled via their surfaces being covered by a layer of SHF, since the SHF has strong hydrophilic properties and the solid bridge force. In addition, vehicle-mounted SHF preparation equipment was designed.
研究领域:
环境工程
·
矿业安全
·
胶体与界面化学
·
职业健康
·
颗粒物控制
✓ 已验证
DOI
高影响因子
RSC Advances
·
2015
·Vol. 5
·期 60
·48946-48953
·
IF 3.84
Tingting Yu,Lifen Liu,Qiao Yang,Jing Song,Fenglin Yang
Using the flat module membrane electrodes based on polyester filter modified with polyaniline (PANI)–phytic acid (PA), a new type of membrane bio-reactor (MBR) system is developed for both bio-electrochemical electricity generation and effluent filtration. A specifically prepared carbon foam–Fe–Co catalyst was coated on the conductive, filterable cathode membrane which makes it catalytic for enhancing cathodic oxygen reduction reaction and electricity generation. The cell voltage (with carbon foam–Fe–Co, 0.5–0.4 V) is superior to control test 1 (without any catalyst, 0.2 V), moreover, it is even better than control test 2 (with Pt–C catalyst, 0.5–0.3 V). The corresponding maximum power density of carbon foam–Fe–Co is 38.5 and 2.4 times higher than control test 1 and 2, respectively. More importantly, the base electrode materials and catalyst were both low-cost. The overall removal efficiency of COD and NH4+–N are satisfactory, at 95% ± 2.5% and 85% ± 2.5%, respectively. This integrated system is easy to scale up for practical application in waste-water treatment and offers a better option in operating and coupling MBR with bio-electricity generation.
研究领域:
环境工程
·
环境微生物学
·
电化学工程
·
水处理技术
·
生物电化学系统
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry A
·
2015
·Vol. 3
·期 43
·21569-21577
·
IF 7.443
Zhaoqiang Li,Longwei Yin
A sandwich-like structure with reduced graphene oxide (RGO) wrapped MOF-derived ZnCo2O4–ZnO–C polyhedrons on nickel foam as an anode for high performance lithium ion batteries (LIBs) is for the first time reported via simply growing MOFs on Ni foam, and wrapping graphene oxide nanosheets on MOFs, and then annealing under a N2 atmosphere. It should be noted that the MOF-derived porous products are composed of carbon-coated spinel ZnCo2O4–ZnO nanoparticle polyhedrons. When tested as anodes for LIBs, the unique RGO/ZnCo2O4–ZnO–C/Ni sandwich-structured LIB anodes exhibit superior coulombic efficiency, excellent cycling stability and rate capability. The in situ formed carbon layers outside the ZnCo2O4–ZnO act as not only a conductive substrate but also a buffer layer for volume changes. The open pores in ZnCo2O4–ZnO–C polyhedrons provide sufficient electrolyte as well as serve as cushion space to further alleviate volume changes. The RGO nanosheets act as a flexible protector to firmly fix polyhedrons on the Ni foam, as well as a conductive substrate to wire up all the polyhedrons. The interconnected carbon layers and two high conductive substrates (RGO and Ni foam) together form an unhindered highway for charge transfer during discharge/charge processes, promising good electrochemical performance.
研究领域:
材料科学
·
电化学
·
纳米材料
·
能源存储
·
功能材料
·
固态化学
·
电极工程
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）