Hubei Institute of Aerospace Chemotechnology
Hubei Institute of Aerospace Chemotechnology
Hou B.,Hubei Institute of Aerospace Chemotechnology |
Tang X.-B.,Hubei Institute of Aerospace Chemotechnology |
Cao Y.-L.,Hubei Institute of Aerospace Chemotechnology |
He J.-X.,Hubei Institute of Aerospace Chemotechnology
Huozhayao Xuebao/Chinese Journal of Explosives and Propellants | Year: 2017
The effect of replacing ammonium perchlorate(AP) in AP/Al/HTPB with 2, 3-bis(hydroxymethyl) -2, 3-dinitro-1, 4-butanediol tetranitrate(SMX)and HMX on the energy performance of formulation was calculated and compared by a propellant performance evaluation software. The energy of AP/Al/SMX/HTPB and AP/Al/HMX/HTPB composite solid propellants and standard motor working process were simulated and calculated by a high temperature chemical equilibrium code. The results show that compared with HMX, SMX can more effectively enhance the energy level of HTPB composite solid propellants in a much larger proportion. In the formulation containing 14% HTPB and 18%Al in mass fraction, SMX can increase the equilibrium specific impulse (Isp) up to 2622.5 N·s/kg, which is 27.5N·s/kg higher than the optimized HTPB/Al/AP tri-propellant. In the formulation containing 14% HTPB and 15%Al in mass fraction, after replacing HMX with SMX, the Isp can reach to 2634.2N·s/kg, which is 39. 2N·s/kg higher than the optimized HTPB/Al/AP tri-propellant. In the formulation of 15%Al, 12%HTPB and 10%HTPB in mass fraction, the mass fraction of SMX can respectively reach 45% and 65%, and the maximum Isp can reach 2652.9 and 2679.3N·s/kg, which are 57.9 and 84.3N·s/kg higher than HTPB tri-propellants, respectively. In the formulation without Al or with a low content of Al, SMX can replace all of the AP. © 2017, Editorial Board of Journal of Explosives & Propellants. All right reserved.
Ao W.,Northwestern Polytechnical University |
Wang Y.,CIC Energigune |
Wu S.,Hubei Institute of Aerospace Chemotechnology
Acta Astronautica | Year: 2017
Study on the boron-based primary combustion products can bridge the gap between primary combustion and secondary combustion in solid rocket ramjets. To clarify the initial state and ignition characteristics of boron particles in the after-burning chamber of solid rocket ramjets, the elemental, composition and morphology of the primary combustion products collected under gas generator chamber pressure of 0.2 MPa and 6 MPa were investigated by energy dispersive (EDS), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy with energy dispersive (SEM-EDS) individually. The ignition times of boron particles among the primary combustion products were determined using a high temperature tube furnace system. The BD model was adopted for numerical verification. The numerical solution procedure of boron ignition model in a real afterburner chamber was modified. The results show that the sum of B, C, O elements in the primary combustion products reaches approximately 90%. The primary combustion products are mainly consisted of B, C, and B2O3. Images of the primary combustion products present highly agglomeration, indicating an oxidation of boron surface. Numerous spherical carbon particles with a diameter around 100 nm are observed in the products. Three features of the boron in the primary combustion products are obtained, compared to virgin boron. First most of the boron lumps are covered by carbon particles on the surface. Second the mean particle size is five times larger than that of virgin boron. Third the overall initial oxide layer covered on boron surface increases its thickness by above 0.1 µm. The ignition time of boron in the primary combustion products reaches 20–30 ms under 1673–1873 K, which is quite different from virgin boron of ~4 ms. Numerical calculation results show the key reason leading to such a long ignition time is the variation of the initial oxide layer thickness. In conclusion, the physicochemical properties of boron particles are found to differ with virgin boron after primary combustion process. The accurate evaluation of the initial oxide layer thickness and initial particle radius is a crucial procedure before the numerical calculation of boron ignition kinetics. Results of our study are expected to provide better insight in the simulation of solid rocket ramjets working process. © 2017 IAA
Hu J.,Hubei Institute of Aerospace Chemotechnology |
Hu J.,Karlsruhe Institute of Technology |
Fichtner M.,Karlsruhe Institute of Technology |
Baricco M.,University of Turin
International Journal of Hydrogen Energy | Year: 2017
Solid hydrogen storage materials as H2 supply for PEM fuel cells have been attempted over the past decades because of their high efficiencies in H2 storage. However, most investigations were focused on the stage of tank design for the storage materials. The Li-Mg-N-H hydrogen storage system was for the first time integrated into a HT-PEM fuel cell stack for a prototype auxiliary power unit, the maximum working temperature being 200 °C. With a designed output of 1 kW, a few kilograms of storage materials are needed. By using commercially available raw materials, an up-scaled preparation of the storage material was performed using laboratory facilities. Preparation conditions were established with the aid of FTIR, TG-DSC and x-ray diffraction to ensure the desired quality of materials. Prior to power the fuel cell stack, the storage materials need to go through an exothermic metathesis, and severe temperature overshooting is expected, which may cause deterioration in material performance and safety issue. Operation conditions were tested and the temperature overshooting could be effectively prevented under adequate conditions. © 2017 Hydrogen Energy Publications LLC
Wang N.,Nanjing University of Science and Technology |
Peng J.,Nanjing University of Science and Technology |
Pang A.,Hubei Institute of Aerospace Chemotechnology |
He T.,Hubei Institute of Aerospace Chemotechnology |
And 2 more authors.
Journal of Physical Chemistry C | Year: 2017
We use reactive molecular dynamics (RMD) simulations to study the interface between cyclotrimethylene trinitramine (RDX) and aluminum (Al) with different oxide layers to elucidate the effect of nanosized Al on thermal decomposition of RDX. A published ReaxFF force field for C/H/N/O elements was retrained to incorporate Al interactions and then used in RMD simulations to characterize compound energetic materials. We find that the predicted adsorption energies for RDX on the Al(111) surface and the apparent activation energies of RDX and RDX/Al are in agreement with ab initio calculations. The Al(111) surface-assisted decomposition of RDX occurs spontaneously without potential barriers, but the decomposition rate becomes slow when compared with that for RDX powder. We also find that the Al(111) surface with an oxide layer (Al oxide) slightly increases the potential barriers for decomposition of RDX molecules, while α-Al2O3(0001) retards thermal decomposition of RDX, due to the changes in thermal decomposition kinetics. The most likely mechanism for the thermal decomposition of RDX powder is described by the Avrami-Erofeev equation, with n = 3/4, as random nucleation and subsequent growth model. Although the decomposition mechanism of RDX molecules in the RDX/Al matrix complies with three-dimensional diffusion, Jander's equation for RDX(210)/Al oxide and the Zhuralev-Lesokin-Tempelman (Z-L-T) equation for RDX(210)/Al2O3(0001) provide a more accurate description. We conclude that the origin of these differences in dynamic behavior is due to the variations in the oxide layer morphologies. © 2017 American Chemical Society.
Gong S.,York University |
Zhu Z.H.,York University |
Li J.,York University |
Li J.,Hubei Institute of Aerospace Chemotechnology |
Meguid S.A.,King's College
Journal of Applied Physics | Year: 2014
This paper investigated the effect of carbon nanotube (CNT) agglomeration on the electrical conductivity of CNT-polymer composites by experimental characterization and theoretical modeling. The present experimental results show that the acid treatment of CNTs has significantly alleviated the CNT agglomeration in CNT-polymer composites and improved the electrical conductivity of the composites compared with CNT-polymer composites made from the same pristine CNTs. The improvement by the acid treatment is further studied by a multiscale CNT percolation network model that considers the CNT agglomeration based on experimental observation. Numerical results are in good agreement with the experimental data. The smaller the size of CNT agglomerates is in the experiments, the closer the measured electrical conductivity of CNT-polymer composites is to its theoretical limit. The current study verifies that (i) the CNT agglomeration is the main cause that leads to a lower electrical conductivity of CNT-polymer composites than their theoretical limit, and (ii) the current multiscale percolation network model can quantitatively predict the electrical conductivity of CNT-polymer composites with CNT agglomeration. The comprehensiveness of the developed modeling approach enables an evaluation of results in conjunction with experimental data in future works. © 2014 AIP Publishing LLC.
Tang G.,Huazhong University of Science and Technology |
Tang G.,HuBei Institute of Aerospace Chemotechnology |
Tian S.,Huazhong University of Science and Technology |
Tian S.,Wuhan University of Technology |
And 8 more authors.
Journal of Physical Chemistry C | Year: 2014
ZnO micro/nanocrystals with different percentages of the exposed (0001) facets were synthesized by a facile chemical bath deposition method. Various characterizations were carried out to understand the relationship between particle shape, exposed (0001) facets, and catalytic activity of ZnO nanocrystals for the thermal decomposition of ammonium perchlorate (AP). An enhancement in the catalytic activity was observed for the ZnO micro/nanocrystals with a higher percentage of the exposed (0001) facets, in which the activation energy Ea of AP decomposition was lowered from 154.0 ± 13.9 kJ/mol to 90.8 ± 11.4 kJ/mol, 83.7 ± 15.1 kJ/mol, and 63.3 ± 3.7 kJ/mol for ZnO micro/nanocrystals with ca. 18.6%, 20.3%, and 39.3% of the exposed (0001) facets. Theoretically evidenced by density functional theory calculations, such highly exposed (0001) facets can be favorable for the adsorption and diffusion of perchloric acid, and also facilitate the formation of active oxygen which can lead to the oxidation reaction of ammonia more completely in the catalytic decomposition of AP. © 2014 American Chemical Society.
PubMed | Beijing Institute of Technology, Harbin Institute of Technology and Hubei Institute of Aerospace Chemotechnology
Type: | Journal: Scientific reports | Year: 2016
Lithium-sulfur (Li-S) batteries are a promising candidate of next generation energy storage systems owing to its high theoretical capacity and energy density. However, to date, its commercial application was hindered by the inherent problems of sulfur cathode. Additionally, with the rapid decline of non-renewable resources and active appeal of green chemistry, the intensive research of new electrode materials was conducted worldwide. We have obtained a sheet-like carbon material (shaddock peel carbon sheets SPCS) from organic waste shaddock peel, which can be used as the conductive carbon matrix for sulfur-based cathodes. Furthermore, the raw materials are low-cost, truly green and recyclable. As a result, the sulfur cathode made with SPCS (SPCS-S), can deliver a high reversible capacity of 722.5mAh g(-1) at 0.2C after 100 cycles with capacity recuperability of ~90%, demonstrating that the SPCS-S hybrid is of great potential as the cathode for rechargeable Li-S batteries. The high electrochemical performance of SPCS-S hybrid could be attributed to the sheet-like carbon network with large surface area and high conductivity of the SPCS, in which the carbon sheets enable the uniform distribution of sulfur, better ability to trap the soluble polysulfides and accommodate volume expansion/shrinkage of sulfur during repeated charge/discharge cycles.
Gu J.,University of Western Ontario |
Gu J.,Hubei Institute of Aerospace Chemotechnology |
Hu M.J.,University of Western Ontario |
Guo Q.Q.,University of Western Ontario |
And 3 more authors.
RSC Advances | Year: 2014
A facile and high-yielding hydrothermal method for synthesizing graphene quantum dots (GQDs) from glucose is presented. The GQDs, with fluorescence quantum yield (FL QY) of 44.3%, demonstrate strong green photoluminescence (PL) and excitation-independent PL emission characteristics. This journal is © the Partner Organisations 2014.
PubMed | Hubei Institute of Aerospace Chemotechnology and Huazhong University of Science and Technology
Type: | Journal: Scientific reports | Year: 2016
Recently, graphene nanomesh (GNM) has attracted great attentions due to its unique porous structure, abundant active sites, finite band gap and possesses potential applications in the fields of electronics, gas sensor/storage, catalysis, etc. Therefore, diverse GNMs with different physical and chemical properties are required urgently to meet different applications. Herein we demonstrate a facile synthetic method based on the famous Fenton reaction to prepare GNM, by using economically fabricated graphene oxide (GO) as a starting material. By precisely controlling the reaction time, simultaneous regulation of pore size from 2.9 to 11.1nm and surface structure can be realized. Ultimately, diverse GNMs with tunable band gap and work function can be obtained. Specially, the band gap decreases from 4.5-2.3eV for GO, which is an insulator, to 3.9-1.24eV for GNM-5h, which approaches to a semiconductor. The dual nature of electrophilic addition and oxidizability of HO() is responsible for this controllable synthesis. This efficient, low-cost, inherently scalable synthetic method is suitable for provide diverse and optional GNMs, and may be generalized to a universal technique.
Lu S.,Hubei Institute of Aerospace Chemotechnology
Fuhe Cailiao Xuebao/Acta Materiae Compositae Sinica | Year: 2015
Strain invariant failure theory (SIFT) is a new type of strength theory for composites based on physical failure mode, which is applied to the failure analysis of composite structures widely. In order to improve the accuracy of theoretical analysis, SIFT was extended to be used to analyze the static loading compressive progressive failure mechanism and strength for carbon fiber reinforced polymer (CFRP) composite laminate open-hole structures firstly. The implementation methods of developed SIFT include two parts of material strength characterization and structure strength prediction. The structure strength prediction based on the ABAQUS platform and was realized by using the user defined material subroutine (UMAT) wrote by Fortran scripts. Then, the predicted values of SIFT as well as the predicted results of classical composites strength theories such as Tsai-Wu and Hashin theories were compared with the testing results, and the results showed that the accuracy of SIFT prediction was the best. Meanwhile, based on SIFT, the failure mechanisms evolution from initial failure to final failure of AS4/3501-6 laminate open-hole structures under static loading compression were analyzed in details. Finally, the static loading compressive failure mechanisms of AS4/3501-6 laminate open-hole structures predicted by SIFT were compared with testing results. The results show that the progressive failure mechanisms predicted by SIFT agree well with the testing results. The obtained conclusions provide new thoughts for the strength prediction of CFRP structures. © 2015, BUAA Culture Media Group Ltd.. All right reserved.