REACTIVE & FUNCTIONAL POLYMERS
·
2022
·
IF 4.966
Yi Ning,Dian-sen Li,Lei Jiang
This work proposes a facile and solvent-free synthesis of a renewable toughening agent (EGFD) from eugenol , formaldehyde and polyetheramine through the Mannich reaction . EGFD was used to modify bismaleimide (BMI) monomer to synthesize toughened EGFD/BMI resin. Cured EGFD/BMI resin exhibited great toughness evidenced by its tensile elongation at break above 8%. Meanwhile, the cured EGFD/BMI resin showed unique deformation reversibility performance: the compressed resin samples could be quickly restored to its original state when heated at 100 °C for 10 min. In addition, cured EGFD/BMI resin displayed good thermostability with their highest 5% weight loss temperatures (T 5 ) and glass transition temperatures (T g ) of 333 and 122 °C. All the EGFD/BMI resin showed great film uniformity and good dielectric properties : their dielectric constants were from 3.20 to 3.78, and dielectric loss were from 0.0093 to 0.022.
研究领域:
材料科学
·
化学工程
·
高分子科学
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DOI
高影响因子
FIRE SAFETY JOURNAL
·
2025
·
IF 3.3
Haoran Jiang,Yong Hu,Yong Jiang,Rong Qiu,Hui Huang
Due to the increased risk of phosphate depletion, there is an increasing demand for low-phosphorus or bio-based phosphorus flame inhibitors. Therefore, two novel composites with biologically-based phosphorus sources that chelate transition metal ions were synthesized via assembly method, i.e., Mn-PMC and Ni-PMC, the structure and binding states of the composites were examined by SEM, TEM, FTIR, XRD, XPS, BET and TGA. The results indicated that Mn-PMC and Ni-PMC (ⅰ) are nanoscale materials with well dispersed, (ⅱ) have an amorphous structure and have sites that bind to other substances, (ⅲ) contain no halogen elements. Then the combustion inhibition experiments of downward flame spread and TG-IR-MS analysis revealed (ⅰ) that the inhibition efficiency of the two prepared inhibitors was higher than that of commercial phosphate-containing inhibitor ADP. Among them, Ni-PMC had the best suppression effect, and the flame of cellulose sample containing it would automatically extinguish after igniting with a smallest dosage, (ⅱ) two inhibitors reduced the laminar flame velocity and flame temperature. (ⅲ) their flame suppression mechanism was indicated as that the pyrolysis releases inert gas to dilute the free radical concentration. This work is helpful for the development of efficient transition metal fire extinguishing agents to replace traditional phosphorus resources.
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产品关联
DOI
高影响因子
POLYMER DEGRADATION AND STABILITY
·
2022
·
IF 5.204
Xinming Ye,Yu Feng,Panpan Tian,Zhimao Li,Yingchun Li,Wensheng Wang,Jie Li,Liang Qiao,Kun Wang,Wenchao Zhang,Ye-Tang Pan,Rongjie Yang
Despite remarkable advances in developing flame retardants and smoke suppressants for epoxy resin (EP), engineering nitrogen-containing polyhedral oligomeric silsesquioxane (N-POSS) to impart superior fire safety properties to EP has remained an intractable challenge. In this work, two nitrogen-containing polyhedral oligomeric silsesquioxanes (N-POSSs), namely, aminoethyl-aminopropyl-hepta-phenyl polyhedral oligomeric silsesquioxane (AEAP-POSS) and aminopropyl-hepta-phenyl polyhedral oligomeric silsesquioxane (AP-POSS), were synthesized through the “corner-capping” reaction. The molecular structures of N-POSSs were fully characterized by FTIR, 1 H NMR, 29 Si NMR and MALDI-TOF MS, and the synthesized AEAP-POSS and AP-POSS were introduced into EP to solve the shortcomings of flammability. TGA results showed that the incorporation of 4 wt% N-POSS nanoparticles distinctly improved the char residue at 800 °C, which significantly enhanced the thermal stability of the EP composites. When 4 wt% of AP-POSS was introduced into EP, reductions in the peak of heat release rate (p-HRR), fire growth index (FGI), peak of smoke production rate (p-SPR), and the peak of CO production rate (p-COP) reached to 60.6%, 70.2%, 52.3% and 60.4%, respectively. Subsequently, TG-FTIR and XPS were utilized to investigate the flame retardancy and smoke suppression mechanism. Our work presented a considerable advancement for the facile fabrication of flame retardants based on nitrogen-containing polyhedral oligomeric silsesquioxane compounds.
研究领域:
材料科学
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化学工程
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高分子科学
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消防安全工程
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DOI
高影响因子
Advanced Science
·
2020
·Vol. 7
·期 20
·2001681
·
IF 15.84
Daping Qiu,Jingyu Guan,Min Li,Cuihua Kang,Jinying Wei,Feng Wang,Ru Yang
Potassium-ion hybrid capacitors (PIHCs) have attracted tremendous attention because their energy density is comparable to that of lithium-ion batteries, whose power density and cyclability are similar to those of supercapacitors. Herein, a pomegranate-like graphene-confined cucurbit[6]uril-derived nitrogen-doped carbon (CBC@G) with ultra-high nitrogen-doping level (15.5 at%) and unique supermesopore-macropores interconnected graphene network is synthesized. The carbonization mechanism of cucurbit[6]uril is verified by an in situ TG-IR technology. In a K half-cell configuration, CBC@G anode demonstrates a superior reversible capacity (349.1 mA h g −1 at 0.1 C) as well as outstanding rate capability and cyclability. Moreover, systematic in situ/ex situ characterizations, and theory calculations are carried out to reveal the origin of the superior electrochemical performances of CBC@G. Consequently, PIHCs constructed with CBC@G anode and KOH-activated cucurbit[6]uril-derived nitrogen-doped carbon cathode demonstrate ultra-high energy/power density (172 Wh kg −1 /22 kW kg −1 ) and extraordinary cyclability (81.5% capacity retention for 5000 cycles at 5 A g −1 ). This work opens up a new application field for cucurbit[6]uril and provides an alternative avenue for the exploitation of high-performance PIHCs.
研究领域:
材料科学
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电化学
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能源存储
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纳米技术
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DOI
PubMed
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2022
·Vol. 47
·期 3
·1216-1225
·
IF 3.925
Anqi Niu,Hang Xu,Qinlin Yuan,Fengmin Wu,Xuefeng Wei
Lewis acidic ionic liquid-loaded Fe3O4@SiO2 magnetic catalytic microspheres were prepared. When coupled with persulfate, the microspheres catalytically oxidized and removed dibenzothiophene (DBT) from octane. The microspheres used for catalytic desulfurization were characterized and analyzed by SEM, TEM, FT-IR, VSM, and TG-DTA. The results indicated that the prepared catalytic desulfurization microspheres had a uniform particle size distribution, an overall diameter of 200 nm, and a core diameter of Fe3O4 of about 180 nm. The saturation magnetization of the catalytic desulfurization microspheres was 39.8 emug−1, which allowed them to be rapidly magnetically separated. The optimal experimental conditions were 1.5 g catalyst, 1.2 g PMS (20%) oxidant, 30 °C, an initial sulfur content of 500 ppm, 6.0 g octane, and 3.0 g acetonitrile. Under these conditions, the desulfurization rate reached 98.5% after 25 min, which decreased by about 10% after five recycles. GC-MS analysis indicated the oxidation product was dibenzothiophene sulfone (DBTO2). In the desulfurization mechanism, DBT was first extracted by acetonitrile. Then, in the acetonitrile phase, Co2+ catalyzed hydrogen persulfate to form active oxygen atoms that oxidized DBT and eventually formed DBTO2.
研究领域:
化学工程
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环境科学
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材料科学
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分析化学
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DOI
高影响因子
Science of Advanced Materials
·
2022
·Vol. 14
·期 10
·1589-1598
·
IF 1.067
Jin Hong,Wu Yali,Li Yanzhong
Adsorption method has attracted extensive attention in heavy metal wastewater treatment due to its low cost, abundant sources, and simple operation. Kaolin is utilized as raw material, waterborne polyurethane is utilized as dispersion medium, and dimethyl sulfoxide (DMSO) is utilized
as intercalation agent, to prepare intercalation polymerization modified kaolin material (KBEP). It is then characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), thermogravimetry (TG), and other methods. The polymer is utilized
for static adsorption of Cu2+ and Pb2+, and the kinetic analysis of the adsorption process is carried out. The results show that the layer spacing of kaolin increases substantially (from 0.69 nm to 0.81 nm) after modification. When the content of kaolin is less than 1.7%,
kaolin exists in intercalation or stripping state in waterborne polyurethane matrix. When the content of kaolin is higher than 1.7%, kaolin can exist in the form of agglomeration with waterborne polyurethane matrix. Compared with pure polyurethane, the composite’s thermal stability is
improved, and the maximum thermal weight loss of the hard section is increased by 50 °C. When kaolin content is 2.5%, the temperature of the hardness and the fastest thermal decomposition rate of the soft section increases by 30 °C and 26 °C, respectively. The adsorption test reveals
that the Cu2+ elimination rate reaches 93.7% when the addition amount of the prepared material reaches 1.5 g/L. When the addition amount of the prepared material reaches 0.6 g/L, the Pb2+ elimination rate reaches 95.8%. With the increase of the dosage of kaolin composite,
the adsorbability of the polymer to the two metal ions decreases gradually. Kinetic experiments show that the adsorption of Cu2+ and Pb2+ is in line with the pseudo-second-order kinetic (PSOK) equation. The adsorbability of Cu2+ and Pb2+ is 75.3
mg/g and 268.6 mg/g, respectively. The adsorption way is mainly chemical adsorption.
研究领域:
环境科学
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材料科学
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化学工程
·
废水处理
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DOI
高影响因子
Journal of Energetic Materials
·
2024
·
IF 1.7
Ying Wu,Yong Liu,Shuai Hou,Qizhi Zhao,Han Gao,Xiao Yan
4,4’-Azo-1,2,4-triazole (atrz) is a new high nitrogen energetic material with high energy density, high gas yield and wide application prospects, but the low synthesis temperature and long time are the main reasons limiting its application. To achieve efficient synthesis of atrz, the double drop synthesis method was designed to solve the problem of unstable concentration of oxidant (HClO) due to batch feeding. The reaction temperature, reaction time, and molar ratio of reactants of n(4-amino-1,2,4-triazole):n(ClO−) were studied and optimized using the single factor variable method; Characterization and analysis of atrz using theoretical calculations with elemental analysis, infrared spectroscopy, crystal morphology, and nuclear magnetic resonance; The thermal properties and stability of atrz were tested and analyzed using TG-DTA. The results showed that the reaction time of the double drop synthesis method was shortened from 5 hours to 1.5 hours under the conditions of similar yield, and the efficiency was increased by 2.3 times. The optimized process was a reaction temperature of 5°C-10°C, reaction time of 1.5 hours, n(4-amino-1,2,4-triazole):n(ClO−) of 1:2, and the yield reached 73%. The product was white, needle-like crystals, which were determined to be atrz by means of characterization and theoretical calculations. Atrz’s decomposition peak temperature is 309.0°C, and when the temperature is below 271.7°C, atrz is thermally stable. The activation energies of atrz calculated by Kissinger and Flynn-Wall-Ozawa methods were 195.0 kJ·mol−1 and 194.6 kJ·mol−1.
研究领域:
化学
·
材料科学
·
能材料
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理论计算
·
热分析
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DOI
高影响因子
CERAMICS INTERNATIONAL
·
2022
·
IF 5.532
Zeshuai Li,Feifei Zhou,Baosheng Xu,Donghui Guo
We present a simple way to fabricate high-entropy (La 0.2 Nd 0.2 Sm 0.2 Dy 0.2 Yb 0.2 ) 2 Zr 2 O 7 (HE-RE 2 Zr 2 O 7 ) ceramic nanofibers using the electrospinning and annealing processing in this work. The microstructure of nanofibers was characterized by thermal gravity-differential scanning calorimetry (TG-DSC), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM), respectively. Meanwhile, the diameter and grain growth of HE-RE 2 Zr 2 O 7 nanofibers under 1000 °C was analyzed. Results indicate that HE-RE 2 Zr 2 O 7 nanofibers can be prepared at temperatures above 400 °C and the crystallite size can be controlled by annealing temperature. Both diameter and the grain growth of HE-RE 2 Zr 2 O 7 nanofibers are lower than that of La 2 Zr 2 O 7 nanofibers, attributed to the sluggish diffusion effect. The advantages of HE-RE 2 Zr 2 O 7 nanofibers can further enlarge the application of nanofibers in the aspect of high-temperature thermal insulation materials.
研究领域:
材料科学
·
陶瓷
·
纳米技术
·
隔热材料
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DOI
高影响因子
JOURNAL OF DRUG DELIVERY SCIENCE AND TECHNOLOGY
·
2024
·
IF 4.5
Yuman Zhang,Yao Yu,Qi Wang,Wenjun Shi,Hanying Hu,Danqing Hou,Zhi Li
Non-alcoholic fatty liver disease (NAFLD) was a pathological syndrome characterized by excessive lipid deposition in the liver. Excessive lipid in the liver produced reactive oxygen species (ROS), the occurrence of oxidative stress and lipid peroxidation was accelerated, which aggravated liver function damage. Based on these, resveratrol, a natural antioxidan, was encapsulated in liposoluble interior by amphiphilic phosphatidylserine, and then self-assembled with chitosan oligosaccharide complexed with zinc ions to form Zn-Cos/Res@Ps nanoparticles. The size of the Zn-Cos/Res@Ps was about 168.57 ± 4.35 nm, and the zeta potential was about 17.45 ± 1.79 mV. Furthermore, Zn-Cos/Res@Ps could significantly inhibition of lipid deposition, decreased the contents of reactive oxygen species (ROS) and synergistically decreased the levels of malondialdehyde (MDA) in HepG2 cells. Zn-Cos/Res@Ps could also reduce the content of serum total cholesterol (TC), triglyceride (TG), aspartate aminotransferase (AST) and alanine aminotransferase (ALT), improved the liver injury and reduced the degree of liver fibrosis in mice. The Zn-Cos/Res@Ps group showed better results than the single-drug nanoparticle group. In conclusion, Zn-Cos/Res@Ps nanoparticles could effectively alleviate the disease progression by inhibiting oxidative stress and lipid peroxidation, promoted fatty acid catabolism, and effectively reverse and prevent the progress of nonalcoholic steatohepatitis.
研究领域:
纳米技术
·
药理学
·
肝病学
·
分子生物学
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DOI
高影响因子
CERAMICS INTERNATIONAL
·
2022
·
IF 5.532
Hongju Qiu,Weiwei Huang,Yanqiong Zhang,Jin Chen,Lei Gao,Mamdouh Omran,Li Nan,Guo Chen
In the family of inorganic nanomaterials , zirconia is a highly promising functional ceramic with a high refractive index , hardness, and dielectric constant, as well as excellent chemical inertness and thermal stability. These properties are enhanced in nano-zirconia ceramics, because nanopowders have a small particle size, good morphology, and uniform and dispersive distribution. In this study, a co-precipitation process was proposed to synthesise highly dispersed MgO–Y 2 O 3 co-stabilized ZrO 2 nanopowders. The effects of different calcination temperatures on the crystallisation degree and particle dispersion of zirconia nanopowders were characterised by X-ray diffraction (XRD), thermogravimetry-differential scanning calorimetry (TG-DSC), Raman spectroscopy , Fourier transform infrared spectroscopy (FTIR), nitrogen adsorption using the Brunauer–Emmett–Teller (BET) theory, transmission electron microscopy (TEM), and field emission scanning electron microscopy (FESEM). The optimum synthesis conditions were obtained as follows: 6 h of high-energy planetary grinding and calcination at 800 °C in an electric furnace. Under these optimum conditions, the average particle size of the prepared powder was 28.7 nm. This process enriches the literature on the controllable preparation of Mg–Y/ZrO 2 nanopowders obtained by the co-precipitation method.
研究领域:
材料科学
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纳米技术
·
陶瓷工程
·
化学工程
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DOI
高影响因子
Materials
·
2018
·Vol. 11
·期 1
·111
·
IF 2.467
Hongda Chen,Jihui Wang,Aiqing Ni,Anxin Ding,Xia Han,Ziheng Sun
In order to improve the efficiency of intumescent flame retardants (IFRs), a novel macromolecular charring agent named poly(ethanediamine-1,3,5-triazine-p-4-amino-2,2,6,6-tetramethylpiperidine) (PETAT) with gas phase and condense phase synergistic flame-retardant capability was synthesized and subsequently dispersed into polypropylene (PP) in combination with ammonium polyphosphate (APP) via a melt blending method. The chemical structure of PETAT was investigated by Fourier transform infrared spectroscopy (FTIR), and1H nuclear magnetic resonance (NMR) spectroscopy. Thermal properties of the PETAT and IFR systems were tested by thermogravimetric-derivative thermogravimetric analysis (TGA-DTG) and thermogravimetry–Fourier transform infrared spectroscopy (TG-FTIR). The mechanical properties, thermal stability, flame-retardant properties, water resistance, and structures of char residue in flame-retardant composites were characterized using tensile and flexural strength property tests, TGA, limiting oxygen index (LOI) values before and after soaking, underwritten laboratory-94 (UL-94) vertical burning test, cone calorimetric test (CCT), scanning electron microscopy with energy dispersive X-ray spectrometry (SEM-EDXS), and FTIR. The results indicated that PETAT was successfully synthesized, and when the ratio of APP to PETAT was 2:1 with 25 wt % loading, the novel IFR system could reduce the deterioration of tensile strength and enhance the flexural strength of composites. Meanwhile, the flame-retardant composite was able to pass the UL-94 V-0 rating with an LOI value of 30.3%, and the peak of heat release rate (PHRR), total heat release (THR), and material fire hazard values were considerably decreased compared with others. In addition, composites also exhibited excellent water resistance properties compared with traditional IFR composites. SEM-EDXS and FTIR analyses of the char residues, as well as TG-FTIR analyses of IFR were used to investigate the flame-retardant mechanism of the APP/PETAT IFR system. The results indicated that the efficient flame retardancy of PP/IFR composites could be attributed to the synergism of the free radical-quenching and char layer-protecting mechanisms in the gas phase and condense phase, respectively.
研究领域:
材料科学
·
高分子化学
·
消防安全工程
·
分析化学
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DOI
高影响因子
危险品化学品经营许可证（带存储）