SOLID STATE SCIENCES
·
2018
·
IF 1.861
Jianyi Liu,Yan Liu,Dianxin Jin,Minjia Meng,Yinhua Jiang,Liang Ni,Zhanchao Liu
Tannic-acid-templated large pore mesoporous silica nanoparticle (LMSN) was synthesized using one-pot procedure and the external surface was further modified with APTES (LMSN-N) to immobilize trypsin. After modification, trypsin was difficult to be immobilized on the outer surface of the LMSN due to the electrostatic repulsion. Naturally, study of the trypsin immobilized in the interior pores could be implemented solely. Meanwhile, the activity of immobilized trypsin was optimized by response surface method (RSM), and the ANOVA was employed to explore the interaction between independent variables. The maximum enzyme activity (12.28 U/mg) was obtained under a certain condition that the quality of T-LMSN-N-272 was 153 μg, the pH was 7.9, and the temperature was 40.4 °C. Simultaneously, the immobilized enzyme was proved to possess better thermal stability, storage stability and recycling performance than free enzyme.
研究领域:
生物化学
·
材料科学
·
酶工程
✓ 已验证
产品关联
DOI
高影响因子
FUEL PROCESSING TECHNOLOGY
·
2018
·
IF 3.956
Shu-Sen Liu,Yong-Yong Jin,Yahong Han,Jinxian Zhao,Jun Ren
It is a big challenge to improve the stability and anti-coking abilities of catalyst in high temperature CO methanation reaction. To address the issue, SiC was chose as the support, and Ce was used as a promoter to prepare supported Ni catalysts for CO methanation. A long-term high temperature stability evaluation experiment was carried out at 600 °C for 100 h in comparison with Ni/Al 2 O 3 catalyst. The catalysts were characterized by a combination of characterization techniques for understanding the catalytic performance and carbon deposition behaviors in CO methanation. The life test result indicates that, compared to Ni/Al 2 O 3 , Ni/SiC is thermally stable and highly resistant to carbon deposition . Improved cataytic activity and stability was further reached by introduce of Ce promoter into Ni/SiC, which can be attributed to the enhanced interaction between Ni and SiC and improved dispersion of Ni active species.
研究领域:
催化化学
·
能源化学工程
·
材料科学
·
工业催化
·
化学反应工程
✓ 已验证
DOI
高影响因子
CELLULOSE
·
2019
·Vol. 26
·期 3
·1577-1593
·
IF 3.917
Jiang Yan,Liu Xiuyu,Yang Qiang,Song Xueping,Qin Chengrong,Wang Shuangfei,Li Kecheng
Abstract This study investigated effects of residual lignin on composition, structure and properties of cellulose fibrils and cellulose fibril-based films by comparing two groups of cellulose fibrils which contained different amounts of lignin (15% and 2%, respectively) but were similar in cellulose to hemicellulose ratio. The results showed that lignin affected the size and content of nanofibril in cellulose fibrils through initially delaying but ultimately facilitating the mechanical defibrillation. Due to higher thermal stability and strong UV absorption capability, lignin enhanced the thermal stability and UV blocking properties of cellulose fibril-based film. Hydrophobic lignin also improved the dewatering of cellulose fibrils and the hydrophobicity of cellulose fibril-based film. Lignin interfered with the interfibrillar hydrogen bonding and therefore increased the mesopore diameter of cellulose fibril network. Lignin acting as a cement in cellulose fibril-based film made the film with a more densely packed structure, a higher density and a smoother surface. However, lignin decreased the transparency of cellulose fibril-based film due to its chromophore groups and impaired the mechanical strength of cellulose fibril-based film through interfering with the interfibrillar hydrogen bonding. Graphical abstract
研究领域:
材料科学
·
植物学
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2022
·
IF 6.371
Yonghui Xu,Liang Zhang,Shuwen Yin,Xiudi Wu,Hongpeng You
Despite significant progress has been made in the luminescent materials for white light emitting diodes (WLEDs), it is still desirable to develop novel highly efficient phosphors with appropriate excitation and high visible emission for high color rendering WLEDs. In this study, we report a novel phosphor BaGa 2 Si 2 O 7 :Ce 3+ ,Tb 3+ (BGSO:Ce 3+ ,Tb 3+ ) with highly effective green luminescence. BGSO:Ce 3+ ,Tb 3+ phosphor represents a broad excitation band in the range of 300–400 nm and intense emission at approximately 542 nm with a high photoluminescence quantum efficiency of 76.4%. The structure, luminescence, and energy transfer from the Ce 3+ and Tb 3+ ions were investigated in detail. Moreover, the incorporation of Na + or K + ions into BGSO:Ce 3+ ,Tb 3+ for charge compensation can improve the emission intensity and thermal stability. Moreover, a near ultraviolet (n-UV) pumped prototype WLED device was fabricated and it exhibited bright warm-white light with CIE chromaticity coordinates of (0.3561, 0.3344), high color-rendering index (Ra=90.4), and low CCT (3330 K) upon 20 mA driving current. This work provides a new strategy to develop high-quality solid-state LED phosphors.
研究领域:
材料科学
·
光学工程
·
固体物理
·
发光材料
·
半导体器件
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2021
·Vol. 47
·期 21
·30039-30042
·
IF 4.527
Leihao Feng,Qiwei Hu,Li Lei,Lei Qi,Leilei Zhang,Meifang Pu,Zili kou,Fang Peng,Duanwei He,Yohei Kojima,Hiroaki Ohfuji,Tetsuo Irifune
High-hardness TaN compacts with a diameter and height of 6 mm were synthesized through the phase transformation of CoSn-type into WC-type TaN under experimental conditions of high temperature and high pressure . The Vickers hardness of WC-type TaN compacts obtained at the pressure of 5 GPa and the temperature of 1873 K is found to be ~21.5 ± 1.5 GPa with a load of 3 Kg, which is comparable to that of the pure tungsten carbide compact (~20 GPa) and higher than those of ultrahigh temperature ceramics ZrB 2 and HfB 2 under the same load. The high hardness of WC-type TaN compacts presented in this work is attributed to the deviatoric strain and well-bonded nanograins . The synthesized WC-type TaN compacts also possess a high oxidation temperature (1072 K). These results suggest that the WC-type TaN with high hardness and high thermal stability holds great promise for industrial applications.
研究领域:
材料科学
·
无机非金属材料
·
超硬材料
·
高温材料
·
固态化学
✓ 已验证
DOI
高影响因子
RSC Advances
·
2016
·Vol. 6
·期 99
·97036-97047
·
IF 3.289
Mei Wang,Jianling Xia,Jianchun Jiang,Shouhai Li,Mei Li
Dipentene-maleic anhydride (DPMA) was prepared by the Diels–Alder addition of dipentene with maleic anhydride. DPMA was converted via ammonolysis with para-aminobenzoic acid (PABA) to form N-(3-amino-benzoic acid)terpene-maleamic acid (ABDPMA), which was then converted to zinc soap (ABDPMA-Zn) or calcium soap (ABDPMA-Ca). Their chemical structures were confirmed by FT-IR and ICP-AES. Thermal stabilizing effects of ABDPMA-Ca/ABDPMA-Zn were compared with ABTMA-Ca/ABTMA-Zn (ABTMA: N-(3-amino-benzoic acid)tung-maleamic acid), C36DA-Ca/C36DA-Zn (C36DA: dimer fatty acid), ZnMA/ZnO (MA: maleic acid), EFC/ZnSt2/ESBO (EFC: calcium salt of epoxidised fatty acid; ESBO: epoxidised soybean oil, and CaSt2/ZnSt2 (St: stearic acid). Thermal stabilities of poly(vinyl chloride) (PVC) compounds were determined using Congo Red test, discoloration test, ultraviolet-visible spectroscopy analysis and thermogravimetric analysis. Dynamic mechanical and tensile properties of the PVC compounds were also studied. Besides better plasticization performance, ABDPMA-Ca/ABDPMA-Zn improved the long thermal stability of PVC compared with ABTMA-Ca/ABTMA-Zn, C36DA-Ca/C36DA-Zn, and CaSt2/ZnSt2.
研究领域:
高分子化学
·
材料科学
·
塑料加工
·
热稳定化
·
功能添加剂
✓ 已验证
DOI
高影响因子
MICROPOROUS AND MESOPOROUS MATERIALS
·
2012
·
IF 3.285
Yi Liu,Hai-Xiao He
Mesoporous alumina with a narrow pore size distribution is synthesized by direct thermolysis of Al-based coordination polymer. By applying the appropriate thermolysis temperature, both high surface area and large pore volume are obtained with the collapses and elimination of the 1,4-benzenedicarboxylate linkers of Al-based coordination polymer. This new class of mesoporous alumina display better adsorption properties and higher thermal stability, which retain mesoporous properties and high surface area after calcination in 900 °C. This thermolysis method provides a new approach to synthesize mesoporous alumina with high thermal stability by using coordination polymers.
研究领域:
材料科学
·
无机化学
·
纳米材料
·
多孔材料
·
热分析
✓ 已验证
DOI
高影响因子
THERMOCHIMICA ACTA
·
2018
·
IF 2.189
Feng Bao,Lishuai Zong,Nan Li,Yuanyuan Song,Yunxing Pan,Jinyan Wang,Xigao Jian
In this study, a series of poly(phthalazinone fluorenyl ether ketone ketone) (PPFEKK) copolymers were designed and synthesized via nucleophilic aromatic substitution polymerization of 1,4-bis(4-fluorobenzoyl)benzene (BFBB), 4-(4-hydroxyphenyl)(2 H)-phthalazin-1-one (DHPZ) and 9,9-bis(4-hydroxyphenyl)fluorene (BHPF) to investigate the effects of bulky fluorene units on the processability and thermal degradation behavior of the polymers. The structures of the PPFEKKs were investigated and confirmed by FTIR, 1 H NMR, wide-angle X-ray diffraction (WAXD) and gel permeation chromatography (GPC) techniques. Traditional thermal measurements showed that the T d 5% and T d 10% values of the copolymers increased as the content of BHPF units increased from 0 to 100 mol%, while their glass transition temperatures gradually decreased. The rheological measurements showed that the processability of the copolymers significantly improved upon incorporation of BHPF units; the poly(aryl ether)s were less viscous and thus more processable. The thermal degradation kinetics were clarified using TGA with Kissinger’s method. The copolymer undergoes two thermal degradation processes: as the content of BHPF units in the copolymers increased from 0 to 100 mol%, the activation energy of the first degradation reaction increased from 228 to 254 kJ mol −1 , and the activation energy of the second degradation reaction increased from 271 to 298 kJ mol −1 . The resulting films displayed excellent tensile strength (higher than 76 MPa), and their Young’s modulus values were inversely proportional to their BHPF contents. Dynamic mechanical analysis showed storage modulus values at 30 °C of approximately 2662, 2826, 2698, 2791 and 2830 MPa for the prepared polymers. Furthermore, the PPFEKKs were soluble in a variety of organic solvents, making them suitable for film casting.
研究领域:
高分子化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING
·
2023
·
IF 4.1
Kang Cheng,Xinyue Liu,Weichao Huang,Xinyong Gong,Chaoyong Deng
Cr 3+ is an ideal activator for near-infrared phosphor. Cr 3+ ions have an electronic structure in which the outermost shell is not fully filled, which makes the emission of Cr 3+ susceptible to the crystal field environment and the change of local structural. Therefore, when Zn 2+ -Ti 4+ ion pairs are replaced with Al 3+ -Al 3+ /Ga 3+ -Ga 3+ ion pairs , changes in the crystal structure and the crystal field are strengthened, which improves the luminescence performances of Zn 2 TiO 4 :Cr 3+ phosphors. The thermal stability and the intensity of the luminescence can be clearly seen to have increased.
研究领域:
材料科学
·
无机化学
·
发光材料
·
固体物理
·
功能材料
✓ 已验证
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2019
·Vol. 43
·期 16
·6136-6145
·
IF 3.069
Tianlu Xu,Jinrui Zhang,Lijie Qu,Xueyan Dai,Peihong Li,Yanlong Sui,Chunling Zhang
A phenyl group was introduced into the polymeric network of polysiloxane foam for the improvement of its thermal insulation capacity and thermal stability. Phenyl-containing polysiloxane was prepared via ring-opening polymerization, and phenyl-containing polysiloxane foam was fabricated through simultaneous foaming and crosslinking reactions. With increasing phenyl content, the thermal conductivity of the polysiloxane foam decreased from 0.093 W m−1 K−1 to 0.079 W m−1 K−1. When the phenyl content was 6.15 mol%, the average cell diameter decreased from 384 μm to 165 μm and the cell density increased from 0.58 × 108 cells per cm3 to 4.67 × 108 cells per cm3. When the phenyl content was 8.5 mol%, the cell morphology became imperfect and the average cell diameter and cell density reached 259 μm and 1.29 × 108 cells per cm3, respectively. TGA results revealed the improved thermal stability of the polysiloxane foam. The TGA curves under nitrogen and air conditions could be divided into three stages. Under nitrogen conditions, the mass loss of the maximum decomposition stage decreased and the residue at 800 °C slightly increased. Under air conditions, the maximum decomposition temperatures of the three stages increased. The compressive strength and specific compressive strength were measured and showed a downward trend.
研究领域:
高分子材料科学
·
热功能材料
·
复合泡沫材料
·
材料化学
·
绝缘材料工程
✓ 已验证
DOI
高影响因子
Journal of Energy Storage
·
2021
·
IF 6.583
Tiantian Zhang,Shi Juan,Wang Yi,Zhenqian Chen
Halloysite nanotube (HNT), a natural and environmentally friendly low-cost material with significant reserves, has become one of promising candidates for preparation of form-stable composite PCM with satisfactory thermal properties owing to their hollow tubule structure and high surface area. The present work prepared the form-stable composite with HNTs and acid etching HNTs (A-HNTs) and compares the properties closely related to thermal energy storage application. Specifically, the micromorphology, thermal properties, shape-stabilized properties, as well as thermal conductivities of the composite materials were characterized by utilizing SEM, TEM, FTIR, DSC, BET, and Hot-disk wire methods, respectively. The results showed that the n-octadecane can both adhere on the inner lumen and the outer wall of HNTs and A-HNTs, while the A-HNTs possess significantly improved absorption thanks to the fact that the pore volume of A-HNTs was enlarged by 19.2% in comparison with HNT, which empowers the extra 5.8% phase transition enthalpy of n-octadecane@A-HNT. In addition, the composite PCMs have a good long-term thermal stability based on multi-cycle heat absorption and release further highlights the potentials in thermal storage application.
研究领域:
材料科学
·
纳米科技
·
能源材料
·
热力学
·
环境友好材料
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2022
·Vol. 49
·期 7
·10273-10279
·
IF 5.532
Daiyuan Liu,Ting Wang,Yichun Liu,Chao Wang,Zhichao Liu,Xiaodie Zhu,Ya Liu,Jian Zhang,Zhaowei Teng,Yang Zhong,Yakovlev Alexey Nikolaevich,Xuhui Xu
The photoluminescence behavior of inorganic phosphors is generally influenced by thermal stability, which determines the luminescence efficiency of the corresponding devices. Here, a series of Eu 2+ , Mn 2+ co-doped LiAl 5 O 8 blue-green-emitting phosphors with thermal robust are successfully fabricated. The concentration-dependent emission spectra and the decay curves of the as-obtained LiAl 5 O 8 : Eu 2+ , Mn 2+ samples manifest the occurrence of the energy transfer from Eu 2+ to Mn 2+ ions via dipole-dipole interaction, and the corresponding emitted colors are gradually modulated from blue to green under the excitation of 310 nm. Moreover, the zero-thermal-quenching luminescence is observed when the operation temperature is up to 423 K, which is attributed to the energy release from the trapping centers to emitting centers (Eu 2+ and Mn 2+ ) at high temperature. Furthermore, a warm white light-emitting diodes (WLEDs) device with correlated color temperature of 5061 K, a color rendering index of 80.6 and long-term stability is fabricated by combining UV LED chip (λ ex = 310 nm), as-obtained LiAl 5 O 8 : Eu 2+ , Mn 2+ phosphor, commercially available red phosphor and green phosphor. These results prove the potential application of the as-obtained LiAl 5 O 8 : Eu 2+ , Mn 2+ phosphor for UV-pumped WLEDs devices.
研究领域:
材料科学
·
发光材料
·
固态化学
·
光电子学
·
无机化学
·
器件物理
·
纳米材料
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）