JOURNAL OF APPLIED POLYMER SCIENCE
·
2016
·Vol. 133
·期 35
·
IF 1.866
Yuanzhu Long,Fuhua Sun,Chao Liu,Dong Huang,Xingyi Xie
To explore a new blowing agent for polyurethanes (PUs), palmitic acid was grafted onto a branched polyethyleneimine (bPEI; weight-average molecular weight = 25,000 Da) via N,N ′-carbonyldiimidazole condensation to form a hydrophobically modified bPEI [palmitic acid grafted branched polyethyleneimine (C 16 –bPEI)] with a grafting rate of 12%. A CO 2 adduct of C 16 –bPEI, which trapped 16.8% CO 2 in it, was synthesized from C 16 –bPEI. The long alkyl chain grafting improved the dispersibility of the CO 2 adduct in the PU raw materials and favored a homogeneous release of CO 2 to blow PUs during the exothermic foaming process. The preliminary results show that the foams possessed a density of 72.0 kg/m 3 and a compressive strength of 246 kPa; this matched the required values of foams for the thermal insulation of underground steel pipes. This new blowing agent emitted nothing but CO 2 to the atmosphere, so it will not promote ozone depletion and will avoid global warming problems that are associated with traditional blowing agents such as chlorofluorocarbons and hydrochloroflourocarbons. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133 , 43874.
研究领域:
高分子化学
·
材料科学
·
绿色化学
·
能源与环境材料
·
工业催化
✓ 已验证
DOI
高影响因子
FOOD CHEMISTRY
·
2019
·
IF 5.399
Hui Shen,Mouming Zhao,Weizheng Sun
The influence of pH-induced structural modifications of myofibrillar proteins (MPs) on their interaction mechanisms with pyrazine compounds was investigated. At a lower pH (4.9, 5.5), MPs aggregated to larger particle sizes due to enhanced the protein–protein interactions. The binding with pyrazine compounds was strongly affected by pH and the nature of flavor compounds. MPs exhibited flavor releasing behavior, probably due to protein–protein interactions and surface tension. Fluorescence analysis revealed that the interaction of pyrazine compounds with MPs followed a combination of static and dynamic quenching. The changes in quenching constant ( K sv ) might be attributed to a dynamic quenching, probably due to protein aggregation. The percentages of free 2,5-Dimethylpyrazine (2,5-DMP) were similar to K sv . Thermodynamic parameters indicated that electrostatic interactions and hydrophobic interactions were the major acting forces in the binding of MPs to 2,5-DMP. The binding of 2,5-DMP increased the α-helix content of MPs.
研究领域:
食品科学
·
蛋白质化学
·
风味化学
·
分子互作
·
生物物理化学
✓ 已验证
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2018
·Vol. 43
·期 7
·3741-3749
·
IF 4.229
Xingcheng Hu,Ravi Muchakayala,Shenhua Song,Jingwei Wang,Jianjun Chen,Manlin Tan
Polymeric ionic liquid-based gel electrolyte films are a new generation of electrolyte materials for flexible energy storage device applications. In this work, Li-ion conducting gel electrolyte films are prepared with the polymeric ionic liquid poly(diallydimethylammonium) bis(trifluoromethane sulfonyl)imide (poly(DADMATFSI)) as the host polymer and the lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) salt as the dopant . The crystalline nature, thermal stability, ionic conductivity and electrochemical stability window of the polymeric electrolyte films are analyzed by various characterization techniques. It is found that the polymeric electrolyte films exhibit high flexibility and excellent thermal stability. Their room-temperature electrical conductivity increases with increasing LiTFSI concentration and reaches a high value of 1.00 × 10 −3 S cm −1 at 20 wt% LiTFSI. The ionic transference numbers of the polymeric electrolyte films are in the range of 0.98–0.99, indicating that they are perfect ion conductors. Finally, the electrochemical stability window of the 20 wt% LiTFSI-doped polymeric electrolyte film is determined as approximately 6 V, which is a promising value for flexible energy storage device applications.
研究领域:
材料科学
·
电化学
·
高分子化学
·
能源存储
·
功能材料
✓ 已验证
DOI
高影响因子
Journal of Nanomaterials
·
2019
·Vol. 2019
·期 1
·5290496
·
IF 2.233
Zhenzhu Yu,Fei Nan,Lu Su,Shaofei Zhang,Yan He
Intercalation and exfoliation are key steps in the preparation of graphene by thermal exfoliation, and they determine the quality of the final product. Therefore, it is important to explore the influence of intercalation agents on the intercalation and exfoliation of graphite. In this article, ammonium bicarbonate is intercalated into graphite with different degrees of oxidation to form a graphite intercalation compound (GIC) by means of ultrasound and stirring. Then, they are exfoliated by being heated at high temperatures. After ammonium bicarbonate intercalation and heating treatment, XRD, TG, and BET show that the intercalation and exfoliation effect of graphite oxide (GO) is better than that of graphite (G) and expanded graphite (EG). The intercalation mechanism is that the ammonia molecule in ammonium bicarbonate solution contains a wedge-shaped structure and active point, which provides empty orbits for graphite electrons and forms edge intercalation through physical interaction at the same time.
研究领域:
材料科学
·
纳米材料
·
物理化学
·
碳材料
·
功能材料
✓ 已验证
DOI
高影响因子
Journal of Materials Research and Technology-JMR&T
·
2023
·
IF 6.4
Jinhui Wang,Ruisong Wang,Xiaoxiao Ji,Chunde Jin,Yutao Yan
Phenol formaldehyde (PF) resin adhesives are widely used in the production of bamboo-based composites owing to their excellent bonding strength and durability. However, the inherent brittleness of cured PF resin may result in notable stress concentration at the interface between PF resin and bamboo bonding, leading to the generation of cracks. In this study, a hyperbranched compound polyethyleneimine (PEI) with high reaction activity was incorporated into a PF resin adhesive to toughen the adhesive and the bonding interface. And the effects of PEI incorporation on the properties of the adhesive and the bonding performance between PF resin and bamboo were comprehensively investigated. The results showed that introduction of flexible PEI chains could effectively facilitated stress transfer, avoiding stress concentration, thus enabling efficient energy release and play a toughening effect. In addition, PEI could react with PF resin and bamboo components during hot pressing, forming a three-dimensional network structure and enhancing the bonding interface, which was proved by FT-IR and XPS analysis. When 1 wt% PEI was incorporated, the bending strength and Charpy impact toughness of the modified PF resin was significantly increased by 38.88% and 76.02%, respectively, compared with the pure PF resin. While the dry and wet shear strength of the bamboo composite bonded by the PEI modified PF resin were also obviously increased. This study is expected to address the problem of cracking in the bonding interface of bamboo composite, and endow the composites with high strength and durability, which can prolong its service life and contribute to the healthy and sustainable development of the bamboo industry.
研究领域:
材料科学
·
木材科学与技术
·
高分子化学
·
复合材料工程
·
胶接与界面科学
✓ 已验证
DOI
高影响因子
DALTON TRANSACTIONS
·
2022
·Vol. 51
·期 12
·4728-4733
·
IF 4.569
Chunlan Tang,Wenhao Xing,Naizheng Wang,Jian Tang,Zheshuai Lin,Jieyun Wu,Wenlong Yin,Bin Kang
Inorganic metal chalcohalides are significant semiconductive materials for photovoltaics, photodetetion and infrared optics. Thus it is considerably rewarding to develop a new synthetic strategy to provide more degrees of freedom for atomic coordination to tune the optical and electronic properties of metal chalcohalides. In this work, the mixed-anion strategy is performed to synthesize two new metal chalcohalides Cs2InPS4X2 (X = Cl, Br) with mixed-anion structure by the reaction of InPS4 and CsX. Single-crystal X-ray diffraction analysis shows that they are isostructural and crystallize in the centrosymmetric space group P21/n, consisting of zero-dimensional structure [In2P2S8X4]4− (X = Cl, Br) built from tetrahedral [PS4]3− and octahedral [InS4X2]7− (X = Cl, Br) through edge-sharing, with Cs cations filling in intervening voids. The UV-vis-NIR diffuse reflectance spectroscopy measurement reveals that Cs2InPS4Cl2 and Cs2InPS4Br2 exhibit large optical bandgaps of 3.21 eV and 3.12 eV, respectively. The electronic structure calculations show that the bandgap mainly originates from the [InS4X2]7− (X = Cl, Br) mixed-anion groups. First-principles calculations indicate that the birefringence of Cs2InPS4Cl2 and Cs2InPS4Br2 is ∼0.08 and ∼0.05 at 2090 nm, respectively. Furthermore, thermal analysis reveals that the Cs2InPS4X2 (X = Cl, Br) are thermostable up to 400 °C. This discovery enriches the structural diversity of inorganic chalcohalides and provides an insight for the exploration of new semiconductive materials.
研究领域:
无机化学
·
材料科学
·
半导体物理
·
晶体工程
·
红外光学
✓ 已验证
DOI
高影响因子
Small
·
2024
·Vol. 21
·期 1
·2403051
·
IF 13
Yandi Luo,Hongli Ma,Nafees Ahmad,Usman Ali Shah,Zhuanghao Zheng,Shuo Chen,Zhenghua Su,Jun Zhao,Xianghua Zhang,Guangxing Liang
Antimony selenide (Sb 2 Se 3 ) has demonstrated considerable potential and advancement as a light-absorbing material for thin-film solar cells owing to its exceptional optoelectronic characteristics. However, challenges persist in the crystal growth, particularly regarding the nucleation mechanism during pre-selenization process for Sb 2 Se 3 . The defects originating from this process significantly impact the quality of the absorber layer, leading to the degradation in the power conversion efficiency (PCE) of the device. Herein, the evolution of pre-selenization using rapid thermal processing (RTP) on the crystallization quality of Sb 2 Se 3 film is systematically investigated. By optimizing the initial nucleation process during pre-selenization, resulting in a reduction of grain boundaries and nucleation centers, the Sb 2 Se 3 thin films demonstrate enhanced crystallinity and pinholes-free morphology. It is found that the improved quality of the grain interior and interfaces of the Sb 2 Se 3 absorber can mitigate intrinsic defects within the bulk layer, and passivate interfacial defect recombination. As a result, the short circuit current density ( J SC ) is elevated to 28.97 mA cm −2 , and a competitive efficiency of 9.03% is achieved in Sb 2 Se 3 device. This study provides comprehensive insight into the process of crystal growth and the mechanism for defect suppression, which holds guiding significance for advancing photovoltaic performance.
研究领域:
材料科学
·
光伏技术
·
半导体物理
·
薄膜制备
·
凝聚态物理
·
能源材料
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2024
·Vol. 50
·期 15
·26493-26502
·
IF 5.1
Lan Zhang,Meihui Xiao,Jiali Li,Lin Chen,Jun Sun,Jianjun Ding,Xiaoxiao Li,Yi Gong,Kang Zheng,Xian Zhang,Xingyou Tian
The Bi 2 O 3 –B 2 O 3 –SiO 2 –ZnO–Al 2 O 3 (BBSZA) glass/Al 2 O 3 composites are prepared by quenching and quenching-free methods and conducted a comparative analysis of their microstructures and properties. The results reveal that the BBSZA/Al 2 O 3 composite obtained by quenching free method has smaller pores and superior performance. Specifically, at a BBSZA content of 50 wt%, the composite exhibits a thermal conductivity of 5.352 W/m·K and a flexural strength of 193.54 MPa, which are 1.38 times and 2.08 times those obtained using the quenching method, respectively. XRD and TEM analyses , along with parallel experiments using other glasses, suggest that presintering crystallization may be the prerequisite for achieving denser composites via the quenching-free method. BBSZA glass reacts with Al 2 O 3 at the presintering process to generate a great amount of ZnAl 2 O 4 crystals, which enhances grain boundary energy and increases sintering density. This work provides insights into the low-cost and high-performance development of low temperature co-fired ceramics (LTCC).
研究领域:
材料科学
·
无机非金属材料
·
陶瓷学
·
复合材料工程
·
电子封装材料
✓ 已验证
DOI
高影响因子
Nano Energy
·
2020
·
IF 16.602
Hongtao Zhao,Run Hu,Pan Li,Anzhu Gao,Xuantong Sun,Xiaohui Zhang,Xiangjun Qi,Qiang Fan,Yida Liu,Xuqing Liu,Mingwei Tian,Guangming Tao,Lijun Qu
Soft actuators with accurate and real-time motion perception are of great importance for flexible machines and artificial intelligence robotics to enable an autonomic response to surroundings. To enhance the sensing-signal reliability and calibration, synchronous motion perception with multiplex feedback signals is desired but has not been sufficiently explored. Herein, we present a soft bimorph actuator that has electrical and visual dual channel signal feedback functions for real-time multiplex motion perception. Cellulose paper and polyimide tape were assembled together as bimorph actuation layers on which an MXene/graphene bilayer was coated for electrothermal function and electrical signal feedback and a thermochromic interlayer was used for real-time visual signal feedback. Based on the proposed actuators, three kinds of bionic robotics and an electro-puppetry robot, “ Wu Song Fights the Tiger ”, with motion-programmable features are demonstrated, revealing the broad application prospects of the present soft actuators in bionic soft robotics with real-time multiplexing motion perception.
研究领域:
生物医学工程
·
智能材料
·
柔性电子
·
仿生学
·
软体机器人
✓ 已验证
DOI
高影响因子
Materials Today Communications
·
2021
·
IF 3.383
Daifeng Wu,Rui Li,Tai Sun,Renheng Tang,Fangming Xiao
Mg/MgH 2 as a thermochemical energy storage (TCES) material suffers from a slow hydrogenation-dehydrogenation kinetic and poor reversibility. Addition of metal oxide is an effective way to improve the kinetic properties of Mg/MgH 2 . However, there is little study on the effects of complex oxides . Thus, the catalytic effects of complex metal oxides and its catalytic mechanism were investigated in this paper. Results show that the dehydrogenation peak temperature and apparent activation energy of MgH 2 -Ta 2 O 5 are 320.8 °C and 128.54 kJ/mol. Combined with complex metal oxide, MgH 2 -Ta 2 O 5 -Nd 2 O 3 could further reduce the dehydrogenation peak temperature (307.2 °C) and apparent activation energy (95.33 kJ/mol). MgO and NdH 2.61 are found in the dehydrogenated MgH 2 -Ta 2 O 5 -Nd 2 O 3 , indicating that n-typed oxide Ta 2 O 5 and p-typed oxide Nd 2 O 3 are formed and improved the kinetics properties of MgH 2 . Furthermore, Nd 2 O 3 /Ta 2 O 5 interface is formed and acted as “p-n junction”. When heating, the “p-n junction” is exposed to thermal radiation and produce electrons and holes, and then the kinetics properties of MgH 2 are further enhanced.
研究领域:
材料科学
·
能源化学
·
物理化学
·
无机功能材料
·
热能存储
✓ 已验证
DOI
高影响因子
BIOCHEMICAL ENGINEERING JOURNAL
·
2019
·
IF 3.371
Liya Zhou,Xucong Luo,Jiaojiao Li,Li Ma,Ying He,Yanjun Jiang,Luyan Yin,Liya Gao
The meso-molding three-dimensionally ordered macroporous alumina (3DOM/m-Al) was synthesized via a dual-templating approach (polystyrene (PS) colloidal crystals as hard template and triblock copolymer P123 as soft template) with hydrous aluminum isopropoxide as precursor. The obtained 3DOM/m-Al was characterized, and the results showed that 3DOM/m-Al had ordered macropores ( ca. 300 nm in diameter) with wormhole-like mesopores, relatively high surface areas (338.1 m 2 /g), large pore volumes (0.4030 cm 3 /g) and tunable pore sizes. The amino functionalized 3DOM/m-Al by aminopropyltriethoxysilane (APTES) was activated by glutaraldehyde and used as support for the immobilization of three different commercial enzymes (Lipase B from Candida antarctica (CALB), penicillin G acylase (PGA) and nitrile hydratase (NHase)). The result of confocal laser scanning microscopy (CLSM) indicated that the enzyme was successfully immobilized onto glutaraldehyde-activated NH 2 -3DOM/m-Al. The effect of the immobilized conditions on the specific activity of enzymes was investigated. Compared with free enzymes, the immobilized enzymes exhibited enhanced thermal stability. The three immobilized enzymes (CALB@NH 2 -3DOM/m-Al, PGA@NH 2 -3DOM/m-Al and NHase@NH 2 -3DOM/m-Al) were applied for the synthesis of palmitic acid, 6-aminopenicillanic acid (6-APA) and acrylamide, respectively. After recycling 10 times, CALB@NH 2 -3DOM/m-Al, PGA@NH 2 -3DOM/m-Al and NHase@NH 2 -3DOM/m-Al retained approximately 76%, 87% and 52% of their initial activities, respectively, indicating that the immobilized enzymes had good operational stability. Therefore, this work documented herein provides a versatile platform for enzyme immobilization with several inherent advantages.
研究领域:
材料科学
·
生物催化
·
纳米材料
·
酶工程
·
多孔材料
✓ 已验证
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2017
·
IF 2.714
Zhilin Xi,Zhenya Feng,Ang Li
For the control of pulverized coal, we propose a dust suppressant by applying a blend of mixed polyethylene oxide (g-PEO) and sodium dodecyl sulfate ( SDS ). In our experimental study, the thermal characteristics, critical micelle concentration ( CMC ), wettability and adhesion of the dust suppressant are investigated. It was found that g-PEO had a low fusing temperature and its combustion temperature was close to that of coal, thus, the solution containing g-PEO applied coal dust control did not affect the use of the coal. Based on steady-state fluorescence using pyrene as a fluorescent label, quantitative analysis revealed that the CMC s of g-PEO and SDS were 1 and 20 g/L in g-PEO& SDS solution, respectively. The solution containing SDS had the best wettability, but it only had a short-term effect. The solution containing g-PEO showed negligible wetting ability to wet coal dust. The solution containing g-PEO& SDS had better wetting ability and adhesion. Scanning electron microscopy showed that the coal dust covered by g-PEO& SDS on its surface could form a thin layer of armor by holding the particles together after air-drying. It was concluded that the g-PEO& SDS solution containing g-PEO for 1 g/L and SDS for 20 g/L could suppress coal dust and maintain a long-term effect.
研究领域:
环境工程
·
矿业安全
·
颗粒物控制
·
表面化学
·
燃烧科学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）