RSC Advances
·
2016
·Vol. 6
·期 54
·48590-48598
·
IF 3.289
Yu Shang,Bo Jin,Rufang Peng,Zhicheng Guo,Qiangqiang Liu,Jun Zhao,Qingchun Zhang
A series of nitrogen-rich heterocyclic 1H,1′H-5,5′-bistetrazole-1,1′-diolate salts, namely, 1,2,4-triazolium (2), 3-amino-1,2,4-triazolium (3), 4-amino-1,2,4-triazolium (4), 3,5-diamino-1,2,4-triazolium (5), 2-methylimidazolium (6), imidazolium (7), pyrazolium (8), 3-amino-5-hydroxypyrazolium (9), dicyandiamidine (10), and 2,4-diamino-6-methyl-1,3,5-triazin (11), was synthesized with cations. These energetic salts were fully characterized through FT-IR, 1H NMR, 13C NMR, and elemental analysis. The structures of 2, 3·7H2O, 6·2H2O, 8, and 10·4H2O were further confirmed through single crystal X-ray diffraction. Their thermal stabilities were investigated through differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The results indicated that all of the salts possess excellent thermal stabilities with decomposition temperatures ranging from 225.7 °C to 314.0 °C. On the basis of the Kamlet–Jacobs formula, we carefully calculated their detonation velocities and detonation pressures. All of the salts, except 11, exhibit promising detonation performances with a detonation pressure of 20.23–28.69 GPa and a detonation velocity of 7050–8218 m s−1. These values are much higher than those of TNT. The impact sensitivities of the compounds were determined via a Fall hammer test. All of the compounds show excellent impact sensitivities of >50 J, and this finding is higher than that of TATB (50 J). Therefore, these ionic salts with excellent energetic properties could be applied as new energetic materials.
研究领域:
化学
·
材料科学
·
高能材料
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DOI
高影响因子
CARBOHYDRATE POLYMERS
·
2013
·
IF 3.479
Jie Chen,Cheng Peng,Jun Nie,John F. Kennedy,Guiping Ma
The hyaluronic acid (HA) fibers scaffold with an extracellular matrix mimic structure has been prepared via lyophilization. The morphology of the HA fibers varying the concentration from 0.05 wt% to 0.15 wt% was characterized by scanning electron microscope (SEM). The diameter of HA fibers increased and the morphology changed from fiber to sheet-like structure as the concentration of HA solution increased. To enhance the water-resistance, the pure HA fiber membranes were chemical cross-linked by 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC), and confirmed by fourier transform infrared (FT-IR) spectra. In vitro degradation behavior of cross-linked HA fiber membranes in both of water and PBS solutions was investigated, the physical properties were also studied by differential scanning calorimetry (DSC) and thermogravimetry (TG). The results showed that the bonding water capacity increased after crosslinking, and indicated that the crosslinked HA fibers could be used as scaffold in tissue engineering.
研究领域:
材料科学
·
生物医学工程
·
组织工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
FUEL
·
2022
·
IF 8.035
Xingxing Wang,Guancheng Jiang,Guoshuai Wang,Lili Yang,Yinbo He,Tengfei Dong,Xiangyang Chang,Haozhe Chen
Natural gas hydrate (NGH) in marine is usually reserved in the pores or cracks of weakly cemented argillaceous siltstones. Moreover, the hydrates are susceptible to variations in temperature and pressure conditions when water-based drilling fluids (WBDFs) are drilled into hydrate reservoirs, leading to the hydrate in-situ decomposition and severe sand production. In this work, an inexpensive and facilely prepared biomimetic wellbore stabilizer with strong adsorption of multiple hydrogen bonds was prepared by fusing catechol-rich tannic acid (TA) and polyvinyl alcohol (PVA) with polyol hydroxyl adsorption function, referred to as TA-PVA complex (TA-PVA). TA-PVA was added to WBDFs to strengthen the NGH reservoir wellbore for ensuring the safety of drilling process in a wide temperature range (2-60℃). The microscopic characterization of TA-PVA and its cohesion mechanism with argillaceous siltstone was investigated by Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), scanning electron microscopy (SEM) and atomic force microscopy (AFM). The mechanical properties of skeleton of the artificial hydrate cores were evaluated by compressive strength test, with maximum compressive strength reaching 0.45 MPa. And the adhesion force of TA-PVA to the probe modified by silica microsphere (PSM) was further studied by AFM. Meanwhile, the adhesion forces between TA-PVA and cyclopentane hydrate particles were measured at 1.5℃. Adhesion test results demonstrate that TA-PVA can bond clay particles, quartz sand and hydrate particles together. In detail, the adhesion force between TA-PVA and PSM reaches more than 164.46 mN/m, the adhesion force between TA-PVA droplet and cyclopentane hydrate particle reaches 43.19 mN/m. The differential scanning calorimetry (DSC)curves demonstrate that TA-PVA releases no heat between 0 and 60 °C, indicating that TA-PVA has no impact on the decomposition of NGH, showing the potential to maintain the integrity of NGH reservoir.
研究领域:
石油工程
·
材料科学
·
化学工程
·
地质学
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Polymer Materials
·
2023
·
IF 5
Zhiping Fang,Shaoyue Zhang,Han Wang,Xue Geng,Lin Ye,Ai-ying Zhang,Zeng-guo Feng
The core–shell structured nanofibers are routinely fabricated by coaxial solution and single-nozzle emulsion electrospinning of two polymers. Herein, the core–shell structured polymeric nanofibers were electrospun from mixed solutions of poly(ether urethane) (PEU) with poly(ε-caprolactone) (PCL) or other biodegradable aliphatic polyesters via a single-nozzle spinneret. For comparison, the mixed solutions electrospinning of poly(carbonate urethane) (PCU) with these polyesters including PCL was also conducted. The morphologies and hierarchical structures of the as-spun nanofibers were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), in vitro lipase degradation, differential scanning calorimeter (DSC), and Fourier-transform infrared (FTIR) analyses. It was shown that the blends of PEU with PCL or other biodegradable aliphatic polyesters were solely electrospun into the core–shell structured nanofibers with PEU as a shell and PCL or other biodegradable aliphatic polyesters as a core. The thickness of core/shell layers from 833/606 to 193.3/54.2 μm was adjustable by varying the feeding mass ratio from 1:3 to 3:1 of PEU to PCL or other biodegradable aliphatic polyesters. In DSC analysis, the Tonset of PEU@PCL core–shell fiber was 1.31 °C higher than that of the PCL fiber, while Tm was approximate. Furthermore, changing the electrospinning solvents of PEU with PCL or other biodegradable aliphatic polyesters retained the formation of core–shell nanofibers. In contrast, the blends of PCU with these polyesters tended to form co-continuous structured nanofibers. The effects of the physicochemical properties of mixed solutions on the charged liquid droplets, whipped jets, and morphology of the electrospun nanofibers were also inspected. The creation of core–shell nanofibers from the blends of PEU with PCL or other biodegradable aliphatic polyesters was most likely due to the interaction between the inherent thermodynamic phase separation of the polymers and their external stretching kinetic phase separation during electrospinning.
研究领域:
材料科学
·
纳米技术
·
高分子科学
·
生物医学工程
✓ 已验证
产品关联
DOI
高影响因子
ENERGY & FUELS
·
2024
·
IF 5.2
Lexin Zhang,Zhen Long,Yong He,Jinhang Wang,Xuebing Zhou,Lingli Shi,Deqing Liang
Wax deposition and hydrate formation are two unwelcome problems that can threaten the safety of pipeline transportation in the oil and gas industry. The existing prevention methods mainly aim at the flow blockage resulting from single solid phase, but rarely take into account multi-solid-phase systems, such as hydrate-wax, hydrate-sand, etc. Recently, it has been proposed that adding pour point depressants (PPDs) can not only improve the rheological property of waxy oil but also have potential to inhibit hydrate formation. In this study, a series of PPD polymethylsilsesquioxane (PMSQ) microspheres were synthesized by a two-step sol–gel method. First, the effect of PMSQ microspheres on wax deposition in waxy mineral oil was tested by differential scanning calorimetry (DSC). Then, the influence of PMSQ microspheres on the cyclopentane (CP) hydrate formation in waxy oil–water systems at the atmospheric pressure and temperature of −3 °C was investigated by using a self-assembly high-pressure reactor. The experimental results showed that the addition of PMSQ microspheres could reduce the wax appearance temperature (WAT) of waxy oil and prolong the nucleation time of the CP hydrate. Powder X-ray diffraction and laser confocal micro-Raman data indicated that the presence of PMSQ did not affect the sII crystal structure of the CP hydrates. A possible inhibition mechanism of PMSQ microspheres by the steric hindrance effect was proposed.
研究领域:
化学工程
·
材料科学
·
石油工程
✓ 已验证
产品关联
DOI
高影响因子
COMPOSITES SCIENCE AND TECHNOLOGY
·
2020
·
IF 7.094
Xiaogang Guo,Cheng-Hsin Lu,Huisheng Huang,Xun Cui,Taotao Liang,Binfang Yuan,Jing Wang,Xueming Li
This study firstly proposed the fabrication and characterization of novel multifunctional aluminum/nickel/perfluorosilane composites with stable thermal energy release capability and anti-wetting properties via a controllable electrophoretic assembly deposition (EAD) method through co-assembly of aluminum and nickel nanoparticles and further surface functionalization with natural drying. Products exhibited promising reticulate-like microstructures with uniform distribution and high degree of crystallinity . The controllable fabrication of composites can be realized conveniently by deeply analyzing the assembly dynamics of EAD process of different nanoparticles in an optimal suspension ( V isopropyl alcohol :V polyethyleneimine :V perhydrobisphenol A = 50:1:1.5 ). The differential scanning calorimetry (DSC) results demonstrated a violent energy release ( Q = 3.12 × 10 5 J/kg ) of composite that confirmed by the ignition tests, and the corresponding output of heat ( Q ) kept stable with low fluctuation degrees ( F d = ~2% ) in different real environments. Moreover, products turned out to possess outstanding anti-wetting properties for various droplets with different surface tensions under changeable environments (e.g. hydrogen, oxygen, humidity, etc.) after extra-long (2 years) exposure experiments, and their contact angle still exceeded 150° even for hexadecane with a low surface tension of 27.5 mN/m. Over all, the feasibility of the concept for designing multifunctional aluminum/nickel/perfluorosilane composites demonstrated in this study has great potentials to be generally applied to facilitate the efficient design of a myriad of metal(s)@polymers composites with wide applications.
研究领域:
材料科学
·
化学工程
·
表面化学
·
热能工程
✓ 已验证
产品关联
DOI
高影响因子
POLYMER BULLETIN
·
2022
·Vol. 80
·期 1
·725-738
·
IF 2.843
Zhang Huadong,Yan Zhongyi,Yang Zhizhou,Mu Qiuhong,Peng Dan,Zhao Hui
Two low melting point phthalonitrile monomers (EPN and EEPN) containing flexible glycidyl groups were synthesized using hydroxyl-containing phthalonitrile and epichlorohydrin as raw materials. The structures of the synthesized monomers were characterized by Fourier transform infrared (FT-IR), nuclear magnetic resonance ( 1 H-NMR and 13 C-NMR) spectra and elemental analysis. Then each of them was blended with 4-(4-aminophenoxy)-phthalonitrile (APPN) and cured to obtain two kinds of amine-catalytic phthalonitrile-based crosslinked polymers. DSC results showed that two blending systems underwent a two-stage polymerization process with the increase of curing temperature. Rheological measurements exhibited that the introduction of glycidyl groups to phthalonitrile resin could greatly improve its processability. Moreover, after thermal cured at 300 ℃, the resulting phthalonitrile resins exhibited excellent mechanical performance, thermal and thermo-oxidative stability.
研究领域:
材料科学
·
高分子化学
·
热能工程
✓ 已验证
产品关联
DOI
高影响因子
CONSTRUCTION AND BUILDING MATERIALS
·
2023
·
IF 7.4
Tao Liu,Naisheng Guo,Xin Jin,Yiqiu Tan,Zhanping You,Shichao Cui,Zhaoyang Chu,Chenze Fang
Phase change materials (PCMs) can regulate asphalt temperature through thermal storage properties to prevent thermal damage in asphalt pavements. However, the effects of PCMs on the thermoregulation and rheological properties of asphalt require further study. In this study, polyurethane solid–solid phase change materials (PUSSPCMs) were prepared to impart thermoregulation properties to asphalt, and the effects of PUSSPCMs on the rheological properties and microscopic characterization of asphalt were investigated. The PUSSPCMs were produced by different soft segment mass fractions (70 %, 80 %, and 90 %), and they were used to prepare modified asphalt with varying contents (3 %, 5 %, and 7 %). Thermoregulation testing system, dynamic shear rheology (DSR), bending beam rheology (BBR) tests, differential scanning calorimetry (DSC), infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and atomic force microscopy (AFM) were conducted to determine the thermoregulation, rheological properties, and modification mechanism of PUSSPCM-modified asphalt, respectively. The results show that the thermoregulation property of PUSSPCM-modified asphalt improves with the increase of soft segment mass fraction and content, 7 % P90 asphalt exhibits the best thermoregulation property with the excellent delayed time (1105 s) and temperature difference (7.1 ℃). The high-temperature rutting resistance of the modified asphalt is enhanced by decreasing the soft segment mass fraction and increasing the content of PUSSPCMs, with the 7 % P70 being the best asphalt type. The 7 % P90 asphalt exhibits the optimum low-temperature creep performance due to a higher soft segment mass fraction. The modified asphalt may be a physical modification since no new characteristic peaks appear. With the increase of soft segment mass fraction, the PUSSPCMs in asphalt transform from elastomer to a ribbon-like structure. Furthermore, the microscopic roughness ( S q ) and Young's modulus of the modified asphalt decline with the increase in soft segment mass fraction and content of PUSSPCMs, implying an increase in microscopic crack resistance and a decrease in elasticity.
研究领域:
土木工程
·
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2023
·
IF 4.2
Weizhen Zhang,Zhilong Yang,Yuan Li,Qi Zhang,Shijun Zhang,Liqun Zhang
Epoxidized silicone rubber with an epoxy content of 5% (ESR-5) was introduced to improve the compatibility of the polyamide 6 (PA6)/poly(dimethylsiloxane) (PDMS) composite. The effects of the ESR-5 on the molecular structure, interfacial morphology, and toughness and thermal properties of the PA6/PDMS composite were investigated using nuclear magnetic resonance (NMR) spectroscopy, Fourier transform infrared (FT-IR) spectroscopy, differential scanning calorimetry (DSC), scanning electron microscopy (SEM), atomic force microscopy (AFM), and dynamic thermomechanical analysis (DMA). The FT-IR spectra and torque rheological testing confirmed the reaction between the epoxy group of ESR-5 and the carboxyl group at the end of PA6. The AFM and SEM images confirmed that the ESR-5 altered the interfacial thickness and remarkably decreased the average size of the dispersed rubber particles, which enhanced the interfacial compatibility. At a rubber content of 20% by weight in PA6/PDMS composites, the optimum impact strength at −60 °C, which is 469% higher than pure PA6, was obtained with an ESR-5 content of 50% in rubber phase.
研究领域:
材料科学
·
高分子科学
·
复合材料
✓ 已验证
产品关联
DOI
高影响因子
LWT-FOOD SCIENCE AND TECHNOLOGY
·
2021
·
IF 4.952
Xizhe Fu,Di Wang,Tarun Belwal,Jing Xie,Yanqun Xu,Li Li,Ligen Zou,Lixia Zhang,Zisheng Luo
A deep understanding upon the relation between anthocyanin extraction performance and physicochemical properties of natural deep eutectic solvents (NADESs) was obtained, and a high-efficiency NADES (Choline chloride-Oxalic acid (ChOa)) was selected and coupled with pulse-ultrasonication for anthocyanin extraction from blueberry pomace . Response surface methodology was adopted to analyzed the significant factors’ influence, interactive effects on extraction yield and optimize the extraction conditions. The theoretical optimal conditions with highest yield of total anthocyanins content (TAC) were 3.2 min of ultrasonic time, 325 W of ultrasonic power, 349.15 K of temperature, 60 mL/g of solvent to solid ratio, under which the experimental TAC value (24.27 ± 0.05 mg C3GE/g DW) was highly correlated with theoretical result (24.28 mg C3GE/g DW). Multi-stability protective effect of ChOa on anthocyanin over acidified ethanol was revealed by stability assays in high temperature, varying pH and light exposure conditions. FT-IR and DSC analysis further characterized the influence of ChOa over acidic ethanol on typical anthocyanins functional groups and thermal behavior of anthocyanin extracts. UPLC-Triple-TOF/MS analysis identified 10 anthocyanins that mainly consisted of delphinidin , petunidin , and malvidin compounds. Overall, this study provided a green, high-efficiency and multi-stability protective strategy for the recovery of anthocyanins from plant source by-products.
研究领域:
食品科学
·
化学工程
·
分析化学
·
植物科学
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2019
·
IF 8.355
Renjie Chen,Xinyu Huang,Ruizhi Zheng,Delong Xie,Yi Mei,Ruqiang Zou
Organic phase change materials are flammable, which limits their applications in heat storage and conversion. In the presented study, a phosphorus-grafted hexadecanol was blended with pentaerythritol phosphate (PEPA) to prepare flame-retardant phase change material (FRPCM). The thermal properties of FRPCM were evaluated by means of differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and cone calorimetry. The flame-retardant mechanism was examined by thermogravimetric analysis-Fourier transform infrared spectrometry (TG-FTIR) and scanning electron microscopy (SEM) tests. The FRPCM maintains a promising heat storage capacity (186.9 J/g) and thermal stability after grafting and blending. The flame retardance analysis reveals that the grafted phosphorus group helps to promote char formation. PEPA extends the time before exposed combustible material ignites. The cone calorimeter test demonstrated that the peak heat release rate and total heat release are further decreased by more than 50%, owing to the synergistic effect between the phosphorus group and PEPA. The SEM results showed that a porous structure is formed during combustion. Self-extinguishment testing indicates that the FRPCM is extinguished in a much shorter time than is hexadecanol.
研究领域:
材料科学
·
热能工程
·
能源存储
✓ 已验证
产品关联
DOI
高影响因子
Sustainability
·
2024
·Vol. 16
·期 19
·8568
·
IF 3.3
Yuan-Yuan Wang,Dan-Feng Zhang,Hong-Rui Zhang,Wen-Jun Liu,Zhi-Quan Chen,Jun-Cheng Jiang,Lei Ni
In this study, sodium dodecylbenzene sulfonate was used as a stabilizer, and NaOH, TBHP, and benzoyl chloride were used as reactants in the preparation of tert–butyl peroxybenzoate (TBPB) using a two–step process. The process conditions were optimized by a three–factor, three–level Box–Behnken design approach. The results showed that the yield of TBPB achieved 88.93% under the optimum conditions of temperature of 31.50 °C, feeding time of 22.00 min, and NaOH concentration of 15%. The exothermic properties of the synthesis of TBPB were investigated using reaction calorimetry. The thermal decomposition characteristics of reactants and products were analyzed by differential scanning calorimetry (DSC) and accelerating rate calorimetry (ARC), and the changes in substance types, characteristic peaks, and exothermic quantities during the reaction were analyzed before and after the reaction by FTIR. The reaction mechanism was proposed by combining EasyMax 102, RC1e, gas chromatography (GC), and Fourier transform infrared spectrometry (FTIR). A comprehensive study of the reaction mechanism and reaction exotherm was carried out using density functional theory (DFT) to predict the reaction energy change and the direction of the reaction and to determine whether the reaction was reversible or not. The risk level for the synthesis of TBPB in semi–batch mode was evaluated using a risk matrix and the Stoessel criticality diagram. The optimal conditions for the TBPB synthesis process in a plate microreactor were explored. Both microreactors and semi–batch modes were comparatively analyzed using the m–ITHI quantitative assessment method. The results indicated a hazard class 2 in semi–batch mode and a hazard class 1 in the microreactor. The results of the study may provide a reference for the further improvement of the intrinsically safe design of the synthetic TBPB process.
研究领域:
化学工程
·
过程安全
·
热分析
·
反应工程
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）