POLYMERS FOR ADVANCED TECHNOLOGIES
·
2020
·Vol. 31
·期 11
·2480-2491
·
IF 2.578
Po Hu,Xinyu Zheng,Jiwei Zhu,Baolin Wu
Chicken feather keratin (CK), a biomaterial that contains a large amount of nitrogen is extracted from chicken feathers and has significant potential for use as a flame retardant. In this study, CK and 9,10-dihydro-9-oxa-10-phosphenanthrene-10-oxide (DOPO) were added in different amounts to an epoxy resin (EP), and their flame retardancy and smoke suppression effects were studied. The results showed that CK exhibits a good flame-retardancy effect and better smoke suppression characteristics than those of DOPO when added to EP. Furthermore, it greatly reduces the CO yield in smoke. While the EP samples with DOPO showed better flame-retardancy properties than those of the samples with CK, they also produced more smoke, which had a higher CO content. Furthermore, when CK and DOPO were added to EP together, the flame-retardancy characteristics of the samples varied with the CK/DOPO ratio. Then the pyrolysis of all samples was divided into two stages based on thermokinetics analysis and the activation energies of these samples in the two stages were investigated. Finally, the flame-retardancy mechanism was discussed. When samples burn, the PO· free radicals derived from DOPO combine with H· and OH· to induce a quenching effect. In addition, the phosphate resulting from the decomposition of DOPO promotes the formation of the char layer. At the same time, the noncombustible gases generated during the pyrolysis of CK cause the char layer to expand and remove some of the heat. Thus, CK and DOPO synergistically improved the flame retardancy of EP.
研究领域:
高分子材料科学
·
阻燃化学
·
热分析
·
环境友好材料
·
生物基添加剂
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DOI
高影响因子
CHIRALITY
·
2012
·Vol. 24
·期 5
·391-399
·
IF 2.35
Hui Yu,Chenghua Yin,Cunyu Jia,Yu Jin,Yanxiong Ke,Xinmiao Liang
Two “click” binaphthyl chiral stationary phases were synthesized and evaluated by liquid chromatography. Their structures incorporate S-(−)-1,1'-binaphthyl moiety as the chiral selector and 1,2,3-triazole ring as the spacer. These chiral stationary phases (CSPs) allowed the efficient resolution for a wide range of racemic BINOL derivatives, particularly for nonpolar diether derivatives and 3-phenyl indolin-2-one analogs. The chromatographic data showed that the π–π interaction was crucial for enantiorecognition of these CSPs. Loss of enantioselectivity observed on CSP3 , which are lacking the triazole ring linkage, indicated that the triazole ring linkage took part in the enantioseparation process, although it was remote from the chiral selector of the CSP. The substitution of the phenyl group at 6 and 6' positions can significantly improve the separation ability of the CSP. The chiral recognition mechanism was also investigated by tracking the elution orders and studying the thermodynamic parameters. Chirality 24:391–399, 2012 . Copyright © 2012 Wiley Periodicals, Inc.
研究领域:
分析化学
·
药物化学
·
色谱学
·
手性分离
·
有机合成
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DOI
高影响因子
Desalination and Water Treatment
·
2024
·
IF 1
Jian Wu,Dajun Ren,Shuqin Zhang,Wenting Liu,Xiaoqin Zhang,Xiangyi Gong
Organic pollutants in aqueous solutions may potentially be adsorbed on biochar. In this study, biochar was derived from the pyrolysis of chitosan at 800°C. The removal rate of 2,4-dichlorophenol (DCP) exceeded 80%. Investigations by Fourier transform infrared spectroscopy and Brunauer– Emmett–Teller indicated that the adsorption of organic pollutants on biochar tends to be a physical process. The optimized pH was 5. All three isotherm models involved (Freundlich, Koble–Corrigan, and Henry) could describe the adsorption process of 2,4-DCP well on chitosan-biochar, which was non-uniform surface adsorption in a diluted solution. The adsorption was an endothermic process. It took 40 min to reach the adsorption equilibrium, and kinetics of the Elovich equation and intraparticle diffusion (IPD) model indicated that the adsorption rate at the rapid adsorption stage was simultaneously controlled by surface diffusion and IPD and that at slow adsorption stage was controlled by surface diffusion. The ionic strengths suggested that electrostatic interaction was not the dominant mechanism during this process.
研究领域:
环境科学
·
环境工程
·
材料科学
·
污染控制化学
·
吸附技术
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DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
·
2020
·
IF 6.155
Yijie Hu,Hao Zhuo,Zehong Chen,Xinwen Peng,Linxin Zhong,Runcang Sun
Interfacial design is one of the most promising ways in improving mechanical properties of nanocomposites . In this work, a multifunctional aerogel with excellent mechanical performances, sensing sensitivity, and fire retardancy is fabricated by taking advantage of metal coordination between biopolymer and Fe 3+ . Montmorillonite (MMT) nanosheets are added to induce a ‘brick and mortar’ structure. The coordination remarkably reduces structural defects , leading to well-formed lamellas that can effectively distribute stress under sever compression without plastic deformation . The structural merits impart the aerogel highly reversible compressibility even at 99 % strain and superior durability. Besides, it demonstrates high sensing performance in wearable health monitoring devices, and shows fire resistance property that can maintain elasticity in a flame. The work offers a facile and effective method to create multifunctional aerogels from various polymers.
研究领域:
材料科学
·
高分子化学
·
纳米复合材料
·
生物医学工程
·
柔性电子器件
✓ 已验证
DOI
高影响因子
Alexandria Engineering Journal
·
2024
·
IF 6.2
Hong Zhang,Ming Chen,Tiantian Liang,Zanpeng Zhang,Changhui Yang
The use of nanocarbon materials to enhance the toughness of fragile cementitious materials has attracted increasing attention for investigation. This study examines the effects of incorporating graphene oxide (GO) into NaOH-activated slag (AAS) pastes and mortars, focusing on workability, phase composition, mechanical properties, and the local mechanical properties of the interfacial transition zone (ITZ) between sand and paste. The experimental results indicate that the addition of GO decreases the flowability of NaOH-AAS pastes, with noticeable aggregation at concentrations above 0.03 wt%. Furthermore, GO enhances the hydration degree of ground granulated blast furnace slag (GGBS), leading to an increased amount of C-A-S-H gel without introducing new phases. In terms of macro performance, incorporating 0.03 wt% GO significantly improves the compressive and flexural strengths of NaOH-AAS mortars by 10.6 % and 17.9 %, respectively. Additionally, the presence of GO reduces the ITZ thickness from 30 to 15 micrometres in NaOH-AAS mortars, which likely contributes to the enhanced mechanical performance.
研究领域:
材料科学
·
水泥基材料
·
纳米复合材料
·
建筑材料化学
·
界面工程
✓ 已验证
DOI
高影响因子
INTERNATIONAL JOURNAL OF REFRACTORY METALS & HARD MATERIALS
·
2020
·
IF 3.407
Weiqiang Hu,Zhi Dong,Hui Wang,Tansir Ahamad,Zongqing Ma
Oxide-dispersion-strengthened (ODS) tungsten based alloys with high performance were synthesized by optimized freeze-drying with PVP and PEG polymer dispersant additives and subsequent low temperature sintering . The pre-freezing principle developed firstly in our work shows that fast cooling rate and polymer dispersant additives contribute to the refinement and uniformity of precursor powders. The optimized freeze-dried W-Y 2 O 3 composite powders possess an average grain size of 9 nm, which can be attributed to the steric hindrance provided by polymer dispersants during freeze-drying and voids left by the decomposition of polymer dispersants during calcination . After sintering at low temperature, the W-Y 2 O 3 alloys have ultrafine W grain (210 nm) and nano second phase particles (<50 nm) dispersed in W matrix while maintaining a high relative density of 97.8%. These factors mentioned above lead to the microhardness and compressive strength as high as 721 ± 31 HV 0.2 , 814 MPa respectively, accompanied by a high total deformation plasticity of above 50%. These results indicate that the optimized freeze-drying and subsequent low temperature sintering is a promising way to fabricate ODS tungsten based alloys with high performance.
研究领域:
材料科学
·
金属学与冶金工程
·
纳米材料
·
复合材料
·
结构材料
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DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2017
·Vol. 134
·期 35
·45258
·
IF 1.86
Jie Shen,Jian-wu Sun,Yang Hu,Cheng-you Kan
Polysiloxane/polyacrylate (PSi/PA) core/shell latexes are fabricated, and the particle morphology, the film structure, as well as the properties of the latex films are investigated by comparing with blend latexes, and the relationship between structure and property is proposed. Results indicate that the structure and property of the latex films heavily depend on the particle morphology. The sea–island latex films with uniform distribution of PSi phases can be formed from the PSi/PA core/shell latexes, and with the mass ratio from 1:1 to 1:4, their tensile strength and elongation at break are close to the pure PA latex film, while the elastic recovery and water vapor permeability improve notably. It is found that the phase segregation occurs in the blend latex films, and although the blend latex films provide better water vapor breathability, their mechanical properties sacrifice obviously. Therefore, the various properties must be balanced for practical applications and the core/shell latexes are competitive for meeting the balanced requirements. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134 , 45258.
研究领域:
高分子科学
·
材料化学
·
功能材料
·
胶体与界面化学
·
薄膜材料
✓ 已验证
DOI
高影响因子
Green Energy & Environment
·
2021
·Vol. 8
·期 2
·589-600
·
IF 8.207
Liuting Zhang,Farai Michael Nyahuma,Haoyu Zhang,Changshan Cheng,Jiaguang Zheng,Fuying Wu,Lixin Chen
Nb 2 O 5 nanoparticles with an average particle size of 10 nm supported on a rhombic dodecahedral metal organic framework (MOF) were successfully synthesized by a facile one-pot hydrothermal reaction and subsequent calcination process. Experimental results demonstrated that the prepared catalyst drastically improved the hydrogen storage behavior of MgH 2 . 7 wt% Nb 2 O 5 @MOF doped MgH 2 started to desorb hydrogen at 181.9 °C and 6.2 wt% hydrogen could be released within 2.6 min and 6.3 min at 275 °C and 250 °C, respectively. The fully dehydrogenated composite also displayed excellent hydrogenation by decreasing the onset absorption temperature to 25 °C and taking up 4.9 wt% and 6.5 wt% hydrogen within 6 min at 175 °C and 150 °C, respectively. Moreover, the corresponding activation energy was calculated to be 75.57 ± 4.16 kJ mol −1 for desorption reaction and 51.38 ± 1.09 kJ mol −1 for absorption reaction. After 20 cycles, 0.5 wt% hydrogen capacity was lost for the MgH 2 +7 wt% Nb 2 O 5 @MOF composite, much lower than 1.5 wt% of the MgH 2 +7 wt% Nb 2 O 5 composite. However, the addition of Nb 2 O 5 @MOF had limited effect on reducing the dehydrogenation enthalpy of MgH 2 . Microstructure analysis revealed that Nb 2 O 5 particles were uniformly distributed on surface of the MgH 2 matrix and synergistically improved the hydrogen storage property of MgH 2 with MOF.
研究领域:
材料科学
·
无机化学
·
纳米催化
·
能源存储
·
氢能源
·
固态储氢
✓ 已验证
DOI
高影响因子
DALTON TRANSACTIONS
·
2022
·Vol. 52
·期 2
·376-383
·
IF 4.569
Enming Ping,Lingyun Kong,Mengyao Liu,Yunshan Zhou,Lijuan Zhang,Nan Chen
The reaction of porous γ-Al2O3 particles acting as both a sacrificial template and an aluminum source with 1,4-naphthalene diacid (H2NDC) resulted in the formation of γ-AlOOH@Al(OH)(1,4-NDC) composites, in which ZIF-67 was then loaded by the in situ crystallization method, leading to the formation of γ-AlOOH@Al(OH)(1,4-NDC)@ZIF-67 composites. The deliberately designed composite was used to separate H2/D2 at 77 K in a 1 m chromatographic column. The results demonstrated that the optimized composite can achieve the effective separation of H2/D2 in gas chromatography due to the additive effects of kinetic sieving and chemical affinity quantum sieving of Al(OH)(1,4-NDC) and ZIF-67. By optimizing chromatographic separation conditions, the resolution R reached 2.02 with the separation time t = 7.72 min. The composite also showed satisfactory repeatability and reproducibility.
研究领域:
材料科学
·
分离科学
·
物理化学
·
纳米材料
·
能源化学
✓ 已验证
DOI
高影响因子
POLYMERS FOR ADVANCED TECHNOLOGIES
·
2017
·Vol. 28
·期 11
·1438-1447
·
IF 1.907
Xin Liu,Xuewen Guo,Yunfei Zhi,Shaoyun Shan,Yonghao Ni,Qingming Jia
The recent development of sulfur dioxide (SO 2 ) polymerization has seen a renaissance in its chemistry, especially poly(olefin sulfone)s from the copolymerization of SO 2 , and unsaturated hydrocarbons can be found to have many applications, including transient electronic packaging, drug delivery, and electron beam-resistant materials. In this work, a type of functional poly(norbornene sulfone) was synthesized via two different polymerization methods. Aiming to understanding the effects of different polymerization methods on poly(olefin sulfone)s and gain further understanding on the kinetics of poly(olefin sulfone)s's thermal instability, we investigated their detailed thermal degradation behaviors using thermogravimetry and analyzed the resultant kinetics in accordance with three kinetic models. The results supported the conclusion that although the poly(norbornene sulfone)s obtained have different activation energy, the thermal degradation kinetics are the same and also obey the D n type. Copyright © 2017 John Wiley & Sons, Ltd.
研究领域:
高分子化学
·
材料科学
·
热分析
·
功能高分子
·
可控降解材料
✓ 已验证
DOI
高影响因子
MATERIALS & DESIGN
·
2015
·
IF 3.501
Heng Zhang,Libo Wang,Qiang Chen,Ping Li,Aiguo Zhou,Xinxin Cao,Qianku Hu
In this study, a Ti 3 C 2 nanomaterial and Ti 3 C 2 /UHMWPE (ultrahigh molecular weight polyethylene) nanocomposites were prepared. The morphology, structure and properties of the Ti 3 C 2 /UHMWPE nanocomposites were investigated. The results indicate that Ti 3 C 2 nanoparticle can improve the thermal and mechanical properties of UHMWPE . The crystallinity and hardness of the Ti 3 C 2 /UHMWPE nanocomposite increase with the content of Ti 3 C 2 . The tensile and breaking strengths of the nanocomposites are enhanced with increasing Ti 3 C 2 content and reach maximum values at a mass fraction of 0.75 wt.%. The creep performance is enhanced after the addition of Ti 3 C 2 to the matrix. The frictional properties of the Ti 3 C 2 /UHMWPE composites were investigated using a pin-on-disc tester. The Ti 3 C 2 /UHMWPE composites exhibited a better friction-reducing performance compared with pure UHMWPE . The addition of Ti 3 C 2 can reduce the adhesive wear and plow friction, which results in the worn surfaces of the Ti 3 C 2 /UHMWPE composite being smoother than those of pure UHMWPE.
研究领域:
材料科学
·
高分子材料
·
摩擦学
·
纳米复合材料
·
机械工程
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry A
·
2013
·Vol. 1
·期 35
·10184-10192
·
IF 0
Jie Shao,Xuezhang Xiao,Lixin Chen,Xiulin Fan,Leyuan Han,Shouquan Li,Hongwei Ge,Qidong Wang
A system of 2LiH–MgB2 and its hydrogenated 2LiBH4–MgH2 is an attractive candidate for hydrogen storage. However, its hydriding–dehydriding kinetics have to be further improved for practical application. In the present work, three kinds of Ni–B nanoparticles with different crystalline states and particle sizes were prepared by wet-chemical reduction and mechanochemical methods, and then introduced into a 2LiH–MgB2 composite for catalytic enhancement. The catalytic roles of Ni–B nanoparticles on the hydriding–dehydriding properties were investigated systematically. The results show that all of the Ni–B nanoparticles can significantly enhance the hydriding–dehydriding kinetics of the 2LiH–MgB2 composite, resulting in no incubation period for the formation of MgB2 during dehydrogenation. The more disordered the amorphous structure and the smaller sized the Ni–B particles are, the better the catalytic effect that is obtained. Microstructure analyses clearly reveal the formation of the MgNi3B2 phase in the dehydriding process, which acts as the nucleation agent for MgB2 formation determined by an edge-to-edge model. Directly doping with Ni–B nanoparticles in the 2LiH–MgB2 system shows a higher hydrogen desorption capacity of 9.4 wt% and obtains a better catalytic efficiency than doping with NiCl2.
研究领域:
材料科学
·
储能材料
·
无机化学
·
纳米催化
·
氢储存
✓ 已验证
DOI
危险品化学品经营许可证（带存储）