FIBERS AND POLYMERS
·
2024
·Vol. 25
·期 4
·1177-1191
·
IF 2.2
Peng Hao,Song Xiaolan,Song Dan,Wang Yi,An Chongwei,Luo Chunwang
The nano-boron powder (n-B) exhibits remarkable efficacy as a combustion catalyst, making it a prime candidate for use in solid propellant metal burners. Nevertheless, throughout the storage phase, the surface of n-B powder is prone to oxidation and substantial agglomeration, resulting in challenges with ignition and incomplete energy dissipation when utilizing boron powder. The synthesis of nano-boron/nitrocellulose/ammonium dinitramide@fluorine rubber (n-B/NC/ADN@F 2602 ) is accomplished via the coaxial electrospinning technique, with n-B uniformly dispersed within the core–shell fiber. The n-B is evenly distributed within the core–shell fiber, and as a result of F 2602 encapsulation, the moisture absorption of n-B/NC/ADN@F 2602 has decreased from 191.6 to 10.1%. In the course of combustion, the fibrous composite of n-B/NC/ADN@F 2602 undergoes an escalation in the rates of energy output and energy release, owing to the constraints imposed by external F 2602 . The n-B/NC/ADN@F 2602 demonstrates a 1.3-fold rise in peak pressure and a 1.15-fold increase in maximum pressure rise rate compared to n-B/NC/ADN. Furthermore, the maximum flame temperature is elevated by 150.5 ℃, and the combustion heat is augmented by approximately 8.7%. The findings of the energy performance assessment reveal that the mean molecular weight (MC) of the combustion byproduct of n-B/NC/ADN@F 2602 stands at 27.6 g·mol −1 , markedly surpassing that of n-B/NC/ADN. The aforementioned findings exemplify that coaxial electrospinning is an exceedingly efficacious technique for enhancing nanostructures, thereby amplifying the reactivity of energetic particles and offering novel insights into their application in energetic materials.
研究领域:
材料科学
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纳米技术
·
燃烧工程
·
高分子科学
·
含能材料
✓ 已验证
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2019
·
IF 7.015
Ziqiang Tong,Xiufeng Liu,Baoquan Zhang
A series of sphere-like polyelectrolyte complexes (PECs) and their homogeneous polyelectrolyte complex membranes (HPECMs) were synthesized by using sodium carboxymethyl cellulose (CMCNa) and poly(diallyldimethylammonium chloride) (PDDA). Different compositions or ionic complexation degrees (ICD) of PECs could be characterized by FT-IR spectra. The circular dichroism spectrum (CD) and field emission scanning electron microscopy (FESEM) were employed to examine the conformation and morphology of PECs, respectively. Zeta (ζ) potential was utilized to investigate the charge density of PEC particles while the surface hydrophilicity of HPECMs was studied by using contact angle (CA) meter. When subjected to ethanol dehydration, HPECMs revealed a satisfactory pervaporation performance and desired anti-trade-off phenomenon. For HPECM 0.31 and HPECM 0.57, the permeation fluxes were 2.25 kg m −2 h −1 and 2.93 kg m −2 h −1 , and the water content in permeate reached up to 99.35 wt% and 99.38 wt%, with respect to 10 wt% water in feed under 70 °C. All the results indicated that small-sized and sphere-like PECs were truly in favor of enhancing the pervaporation performance in ethanol dehydration.
研究领域:
高分子科学
·
膜分离技术
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化学工程
·
材料科学
·
物理化学
✓ 已验证
DOI
高影响因子
INTERNATIONAL JOURNAL OF POLYMER ANALYSIS AND CHARACTERIZATION
·
2017
·
IF 0
Zhiquan Chen,Mengwei Jiang,Qingwu Zhang,Yuan Yu,Guangping Sun,Juncheng Jiang
A series of flame-retardant unsaturated polyester resin (UPR) were prepared by the addition of dimethyl methylphosphonate (DMMP) with various amounts of aluminum hydroxide (ATH) or ammonium polyphosphate (APP) as the flame retardants. The combustion resistance effects of ATH/DMMP and APP/DMMP systems were evaluated by limiting oxygen index test and vertical burning test (UL-94). The thermal properties of UPR were investigated by thermogravimetric analysis. The structure of char was observed by scanning electron microscopy. DMMP incorporated with ATH or APP improved the flame retardancy and thermal properties of UPR. However, the fire-retardant mechanism of these two systems were different: The ATH/DMMP system provided synergistic effect in charring property of the UPR, produced great amount of residual char, and thus revealed the excellent flame retardancy. The APP/DMMP system further improved the flame retardancy of the UPR due to the change in the residual char structure rather than the increase in the production of char.
研究领域:
高分子科学
·
材料工程
·
消防安全工程
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化学工程
✓ 已验证
DOI
JOURNAL OF ALLOYS AND COMPOUNDS
·
2022
·
IF 6.371
Jianling Huang,ChengWei Liao,Hui Wang,YuJun Zhao,Liuzhang Ouyang,Jiangwen Liu,Min Zhu
Mg-based alloy anodes suffer from severe corrosion in conventional electrolytes (KOH solution) and this substantially obstructs the cycle life, which is a great challenge for using them in the Ni-MH battery. Herein, a high concentration tetramethylammonium hydroxide (TMAH) aqueous electrolyte with a special hydrate structure is explored and enables excellent cycle stability and high capacity for Mg-based alloy anodes. In this electrolyte, the Mg 0.4 Ti 0.1 Ni 0.5 alloy anode delivers a maximum discharge capacity of 466 mAh g −1 , and maintains 210 mAh g −1 after 100 cycles owing to the reduced corrosion rate , which are much better than that in 6 M KOH electrolyte, being 425 mAh g −1 and 69 mAh g −1 , respectively. Furthermore, by in-situ forming Cu coating on the Mg 0.4 Ti 0.1 Ni 0.5 electrode surface during charging process with the adding 0.01 M of Cu(OH) 2 in TMAH electrolyte, the corrosion of the electrode is further suppressed and the reversible capacity can reach 313 mAh g −1 after 100 cycles. The high conducting Cu coating can also increase the rate capability of the electrode by promoting the charge transfer. Thus, using TMAH electrolytes provides a new approach to promote the electrochemical performances of Ni-MH batteries with Mg-based alloy anodes.
研究领域:
材料科学
·
电化学
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能源存储
·
金属腐蚀与防护
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功能材料
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电池技术
✓ 已验证
DOI
高影响因子
POLYMERS FOR ADVANCED TECHNOLOGIES
·
2011
·Vol. 22
·期 12
·2237-2243
·
IF 1.776
Chenhao Ke,Juan Li,Keyi Fang,Qiliang Zhu,Jin Zhu,Qing Yan
A hyperbranched polyamine was prepared using an A 2 + B 3 approach. It acted as a hyperbranched charring and foaming agent (HCFA) in combination with ammonium polyphosphate (APP) to form a new intumescent flame retardant (IFR) system for polyamide 6 (PA6). Effect of HCFA on flame retardant and thermal degradation properties of IFR-PA6 was investigated by limiting oxygen index (LOI), UL-94 vertical burning, cone calorimeter, and thermogravimetric analysis (TGA) tests. The IFR system presented the most effective flame retardancy in PA6 when the weight ratio of APP to HCFA was 2:1. The LOI value of IFR-PA6 could reach 36.5 with V-0 rating when the IFR loading was 30 wt%. Even if the loading decreased to 25 wt%, IFR-PA6 could still maintain V-0 rating with an LOI value of 31. TGA curves indicated that APP would interact with both PA6 and HCFA in PA6/APP/HCFA composite under heating. The interaction between APP and HCFA improved the char formation ability of IFR system and then much more char was formed for PA6/APP/HCFA composite than for PA6/APP. Therefore, better flame retardancy was achieved. Moreover, the structure and morphology of char residue were studied by Fourier transform infrared (FTIR), X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM). The results indicated that compact and foaming char layer containing P-O-C structure was formed for PA6/APP/HCFA system during combustion. Copyright © 2010 John Wiley & Sons, Ltd.
研究领域:
高分子化学
·
材料科学
·
阻燃材料
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热稳定性
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聚合物复合材料
✓ 已验证
DOI
高影响因子
CELLULOSE
·
2024
·Vol. 31
·期 3
·1519-1532
·
IF 4.9
Zhu Yuan,Zhang Liyi,Qi Benkun,Luo Jianquan,Wan Yinhua
Acidified aqueous solutions of different quaternary ammonium salts were tested for pretreating corn stover compared to control solutions, including single acidic solution and acidified NaCl and NH 4 Cl solutions. The results revealed that quaternary ammonium salt solutions were more effective in delignification and cellulose saccharification than the control solutions. The chemical structure of these salts significantly influenced the pretreatment efficacy. Notably, benzyltrimethylammonium chloride (BTMAC), a cost-effective option, exhibited remarkable capabilities. It achieved approximately 90% xylan removal, 86% lignin removal, and a 48-h enzymatic glucose yield of up to 93%. The BTMAC solution proved to be recycled for at least four runs while maintaining satisfactory performance. This work contributes valuable insights into the promising potential of standalone QAS solutions, offering a viable and cost-effective option for biomass pretreatment.
研究领域:
生物化学
·
生物技术
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化学工程
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可再生能源
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环境科学
✓ 已验证
DOI
高影响因子
Nanoscale
·
2019
·Vol. 11
·期 36
·16907-16918
·
IF 6.97
Hong Lin,Jian Mao,Minchao Qin,Zhilong Song,Wanjian Yin,Xinhui Lu,Wallace C. H. Choy
While red is one of the primary colors for display applications, the investigation of visible red emitting perovskites, particularly 2D perovskites, is relatively limited. In this work, we demonstrate a single-phase Ruddlesden–Popper quasi-2D (C3H7NH3)2CsPb2I7 perovskite for red color LEDs. Through increasing the annealing temperature of (C3H7NH3)2CsPb2I7 perovskite thin films, we have successfully achieved tunable emission wavelengths from 654 to 691 nm. Equally important, for all the quasi-2D perovskite LEDs, once the annealing temperature is fixed, the emission spectrum is independent of bias voltages, which is very important for their use in lighting and displays. With the analysis of the crystallinity, morphology, and thermodynamic stability of the quasi-2D perovskite, we find that the obtained (C3H7NH3)2CsPb2I7 perovskite is a single-phase quasi-2D perovskite with only n = 2 phase. Besides, we found that the red shifting of emission wavelength is caused by the increase of perovskite crystal size while increasing the annealing temperature. Our results also show that the temperature-induced color tunability can be applied to a series of quasi-2D perovskites with different alkylammonium cations. Importantly, we find that short alkylammonium spacers offer better electrical properties for efficient current transport and high performance in LED applications. This work contributes to controlling the optoelectronic properties of quasi-2D perovskites via controlling their crystal growth as well as paves the way to realize practical lighting and display applications of perovskite LEDs.
研究领域:
材料科学
·
光电功能材料
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半导体器件
·
纳米结构材料
·
固态照明
✓ 已验证
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2018
·
IF 2.829
Ming Li,Xiaohong Liu,Ning Liu,Zihe Guo,Puneet Kumar Singh,Shiyu Fu
Cellulose nanocrystals (CNCs) is a kind of natural, renewable, and biocompatible materials that can be functional via the surface modification. A covalently bonded CNCs-g-PDMAEMA was prepared by grafting 2-(dimethyl-amino) ethyl methacrylate (DMAEMA) on the CNCs’ surface via atom transfer radical polymerization (ATRP). Subsequently, the tertiary amino groups of the CNCs-g-PDMAEMA were transferred to quaternary ammonium groups by adding alkyl bromides with different carbon chain lengths (C10-C18). It was found that the antibacterial activity of the prepared materials is related to the quaternary group structure. The material containing C10 alkyl in quaternary group exhibited the best antibacterial efficiency, which was closely associated with the wettability of the quaternary CNCs-based polymers. The lower wettability of materials with higher hydrophobicity may impose a restriction on the polymeric antibacterial groups’ accessibility to the cytoplasmic membrane of bacteria. The antimicrobial CNCs-based composites may be potential to apply as coating agents for aseptic packaging.
研究领域:
高分子科学
·
生物材料
·
表面化学
·
抗菌材料
·
包装材料
✓ 已验证
DOI
高影响因子
Pigment & Resin Technology
·
2022
·Vol. 53
·期 1
·114-121
·
IF 1.126
Jianqing Hu,Hongjun He,Feiliang Dai,Xingyu Gong,Haowei Huang
PurposeThe purpose of this paper is to develop the efficiency of styrene-acrylate (SA) emulsions for polymer cement waterproof coatings with improved bacteria resistance and mechanical properties.Design/methodology/approachFor effective bacteria resistance and excellent mechanical properties, various concentrations of methacryloxyethylhexadecyl dimethylammonium bromide (MHDB) were synthesised and incorporated into SA emulsions. The properties of SA emulsions modified with MHDB were characterised and compared with those of unmodified ones according to the formulations of polymer cement waterproof coatings.FindingsThe SA emulsions modified with MHDB exhibited significant enhancement of bacteria resistance and mechanical properties over the unmodified ones. The positive quaternary nitrogen and long-chain alkyl groups of MHDB in SA emulsions could attract phospholipid head groups of bacterial and insert them into the cell wall, which results in biomass leak and bactericidal effect. Moreover, MHDB as a softened monomer was beneficial to the synthesis of SA copolymer with low glass-transition temperature (Tg), then the copolymer and cement would form a more compact film which was the main reason for the enhancement of mechanical properties.Research limitations/implicationsThe modifier MHDB was synthesised from diethylaminoethyl methacrylate (DEAM) and 1-bromohexadecane. Besides, the congeners of MHDB could be synthesised from DEAM and 1-bromododecane, 1-tetradecyl dromide, 1-octadecyl bromide, etc. In addition, the efficiency of other modifications into SA emulsions for antibacterial polymer cement waterproof coatings could be studied as well.Practical implicationsThe method provided a practical solution for the improvement of water-based antibacterial acrylate polymer cement waterproof coatings.Originality/valueThe method for enhancing bacteria resistance and mechanical properties of the waterproof coating was novel and valuable.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2024
·
IF 4.9
Zhenghua Sun,Yahui Ji,Haicheng Wang,Jingyi Zhang,Cheng Yuan,Mingjie Kang,Yujun Feng,Hongyao Yin
The incorporation of hydroxy groups into long-chain quaternary ammonium surfactants can enhance their solubility and confer other desirable properties; however, the systematic investigation on the solution properties and the influence of molecular structures was less documented. In this work, two saturated C 18 -tailed quaternary ammonium surfactants with dual hydroxyethyl moieties, namely N , N -bis(2-hydroxyethyl)- N -methyloctadecan-1-aminium iodide (HEOAI) and N , N -bis(2-hydroxypropyl)- N -methyloctadecan-1-aminium iodide (HPOAI), were designed and synthesized. We investigated and compared their Krafft temperature ( T k ), surface activities, self-assembly behaviors, and rheological properties. Our findings demonstrate that the introduction of hydroxyethyl groups dramatically improves the solubility and surface activities. The T k of HEOAI and HPOAI is approximately 50 °C lower than that of the corresponding surfactant octadecyl trimethylammonium iodide. Both surfactants exhibit lower critical micelle concentration and equilibrium surface tension compared to those of corresponding conventional quaternary ammonium surfactant. This should be ascribed to the formation of hydrogen bonds between hydroxyl groups and water molecules. Moreover, HPOAI shows even better solubility and surface activities than HEOAI does. Additionally, the presence of two more methyl groups for HPOAI enhances its ability to form worm-like micelles in pure water. However, HEOAI shows better salt and temperature resistance for maintaining stability of worm-like micelles. A solution containing 50 mM HEOAI with 10 % NaCl exhibits temperature tolerance up to around 80 °C, indicating potential application as fracturing fluid for shallow and medium oil/gas reservoirs. These findings contribute to designing surfactants with improved solubility and diverse properties.
研究领域:
物理化学
·
胶体与界面科学
·
材料化学
·
石油工程
·
表面活性剂化学
✓ 已验证
DOI
高影响因子
Journal of Environmental Sciences
·
2018
·
IF 3.12
Fan Bu,Baoyu Gao,Qinyan Yue,Xue Shen,Wenyu Wang
Coagulation–ultrafiltration (C–UF) is widely used for surface water treatment. With the removal of pollutants, the characteristics of organic matter change and affect the final treatment efficiency and the development of membrane fouling . In this study, we built a dynamic C–UF set-up to carry out the treatment of micro-polluted surface water, to investigate the characteristics of dissolved organic matter from different units. The influences of poly aluminum chloride and poly dimethyldiallylammonium chloride (PDMDAAC) on removal efficiency and membrane fouling were also investigated. Results showed that the dosage of PDMDAAC evidently increased the UV 254 and dissolved organic carbon removal efficiencies, and thereby alleviated membrane fouling in the C–UF process. Most hydrophobic bases (HoB) and hydrophobic neutral fractions could be removed by coagulation. Similarly, UF was good at removing HoB compared to hydrophilic substances (HiS) and hydrophobic acid (HoA) fractions. HiS and HoA fractions with low molecule weight accumulated on the surface of the membrane, causing the increase of transmembrane pressure (TMP). Membrane fouling was mainly caused by a removable cake layer, and mechanical cleaning was an efficient way to decrease the TMP.
研究领域:
环境工程
·
水处理技术
·
膜分离
·
有机地球化学
·
给水处理
✓ 已验证
DOI
高影响因子
Journal of Physical Chemistry Letters
·
2020
·
IF 6.71
Ziren Zhou,Shuang Yang,Kaixuan Xu,Hong Wei Qiao,Jin Xie,Zeqing Lin,Bing Ge,Jingjing He,Mengjiong Chen,Jun Zhang,Yu Hou,Hua Gui Yang
The insertion of organic spacers into halide perovskite slabs has offered a trade-off between the efficiency and stability of perovskite solar cells (PSCs). The layered structure of diammonium-intercalated cesium lead halide perovskites is virtually unexplored, in contrast to several works on the monoammonium system. In this report, we find that perovskite with 1,4-butanediammonium (BDA) and cesium cations can only form n = 1 and n = 2 layered isologues defined by the chemical formula of (BDA)Csn–1Pbn(I0.7Br0.3)3n+1, while the n = 3–4 ones will self-construct into unique heterostructures comprising separated quantum wells (QWs; n = 1–2) and 3D (n = ∞) perovskites. We highlight that the 2D/3D heterostructures show a structural resemblance to that of bulk heterojunction in organics, thus improving the charge separation and transport more than surface passivation. Solar cells based on the (BDA)Cs3Pb4I9.1Br3.9 (n = 4) absorbing layer delivered a power conversion efficiency (PCE) reaching 9.49% with ideal light and thermal stability.
研究领域:
材料科学
·
光伏技术
·
纳米技术
·
固体物理
·
化学合成
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）