Materials Today Communications
·
2022
·
IF 3.662
Zhouyao Yue,Huashan Wang,Xiurong Hou,Yuting Shi,Xin Zhang
Positive temperature coefficient (PTC) materials usually have NTC effect, and the effect is poor. In this paper, conductive carbon black (CB) and amorphous elastomer (TPO) were introduced into high-density polyethylene (HDPE) by melting mixing and hot pressing methods and treated with peroxide crosslinking to improve the PTC properties of conductive composites. The results show that the percolation threshold reduces from 24 wt% to 22 wt% for crosslinked elastic networks. At the same time, the room temperature resistance of the composite material does not show monotonicity after three cycles, which has good reproducibility and eliminates the NTC effect of the composite material. This work provides both a simple way to produce high-performance PTC materials and a new idea to improve the stability of PTC materials.
研究领域:
材料科学
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高分子科学
·
电气工程
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DOI
高影响因子
Catalysts
·
2023
·Vol. 14
·期 1
·18
·
IF 3.9
Kaixuan Chen,Linsheng Xu,Yuanfeng Li,Jing Xiong,Dawei Han,Yaxiao Ma,Peng Zhang,Haoqi Guo,Yuechang Wei
Herein, we present an in-depth investigation into the enhancement of catalytic soot oxidation through cerium-doped three-dimensional ordered macroporous (3DOM) La-Co-Ni-based perovskites synthesized with the colloidal crystal template (CCT) method. The 3DOM structure significantly contributes to the accessibility and interaction efficiency between soot and catalyst. Based on the results of powder X-ray diffraction (XRD), N2adsorption-desorption measurements, scanning electron microscopy (SEM), temperature-programmed oxidation of NO (NO-TPO), temperature-programmed reduction of H2(H2-TPR), in situ infrared Fourier transform spectroscopy (In-situ DRIFTS), and temperature-programmed oxidation (TPO) reactions, the role of cerium doping in modifying the structural and catalytic properties of 3DOM perovskite-type La2−xCexCoNiO6catalysts was investigated systematically. The optimized cerium doping ratio in La2−xCexCoNiO6catalysts can improve the microenvironment for efficient soot-catalyst contact, enhancing the catalytic activity of soot oxidation. Among the catalysts, the 3DOM La0.8Ce1.2CoNiO6catalyst shows the highest catalytic activity for soot oxidation, whose T10, T50, and T90values are 306 °C, 356 °C, and 402 °C, respectively. The mechanism of the cerium doping effect for boosting soot oxidation is proposed: The doping of Ce ions can increase the surface oxygen species, which is the main active species for promoting the key step of NO oxidation to NO2in catalyzing soot oxidation. This research provides a new strategy to develop high-efficient non-noble metal catalysts for soot oxidation in pollution control and sustainable environmental practices.
研究领域:
催化
·
环境科学
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材料科学
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产品关联
DOI
高影响因子
COLLOID AND POLYMER SCIENCE
·
2020
·Vol. 298
·期 10
·1285-1291
·
IF 1.536
Xie Chuanbao,Leng Kangwei,Sheng Jie,Wang Xuemei,Li Qianmin,Song Liang,Liu Lei,Sun Hejing,Huang Xiaowen,Wang Zhongwei,Yu Qing
Poly(methyl methacrylate) (PMMA) microspheres were synthesized through visible light–induced photopolymerization of methyl methacrylate (MMA). 2,4,6-Trimethylbenzoyldipenylphosphine oxide (TPO), polyvinylpyrrolidone (PVP), and light-emitting diodes (LEDs) were used as the photoinitiator, stabilizer, and light source, respectively. No other additive was involved. The effect of LEDs, TPO, and PVP was discussed. Results showed that PMMA microspheres with the size of 0.5–0.8 μm could be obtained when LED@385 nm was the light source, and the content of TPO and PVP was 2 wt% and 30 wt% of MMA. Moreover, the possible formation pathway of PMMA microspheres was proposed based on the investigation of reaction time and addition method of PVP.
Graphical abstract
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
PROGRESS IN ORGANIC COATINGS
·
2023
·
IF 6.6
Zhenya Wang,Haihang Luo,Li Wang,Heng Li,Yi Chen,Jun Xiang,Haojun Fan
Thermoplastic polyolefin (TPO) is widely used in automotive interior materials, but it has long been faced with the challenge of weak adhesion between water-based polyurethane (WPU) coating and substrate. Herein, chlorinated polypropylene (CPP) was grafted by styrene (St) firstly, then a water-based CPP adhesives with polar recognition both for non-polar TPO substrate and polar WPU coating were prepared via phase conversion methods, and the adhesives properties as well as the adhesive mechanism for different polar substrates were investigated. The introduction of polystyrene side-chain has improved the recognition ability of CPP adhesive to non-polar TPO substrate and the interaction force between interfaces. Compared with unmodified CPP adhesive, T-peeling strength of modified one has increased by 35 % and reached 24.2 N/cm, meeting the adhesive requirements of TPO as an automobile interior material. Adhesive mechanism study reveals that polar mutual recognition CPP adhesive plays a bridging role, one end recognizes the non-polar TPO substrate and another end recognizes the polar WPU surface coating , and forms a strong bond between the guest and the host through their respective interfacial force.
研究领域:
材料科学
·
高分子化学
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产品关联
DOI
高影响因子
QUIMICA NOVA
·
2021
·Vol. 44
·期 1
·58-63
·
IF 0.961
Tang Shiyun,Yang Song,Tan Sheng,Guo Junjiang,Tang Anjiang
Qualitative and quantitative assessment of total sulfur and sulfur species in solid phase is necessarily important for development of effective desulfurization methods, reduction of environmental pollution, and prevention of catalyst poisoned. In this work, TPO-IR (Temperature Programmed Oxidation- Infrared) method was used for rapid determination of sulfur species in solid minerals. The high purity of Ag2S was used as the calibration materials at the fixed temperature of 1100 °C, and the TPO experimental runs were performed on the solid minerals of phosphorite and coal. The results show that pyrite sulfur with Tmax of 426 °C, and two thiophene sulfurs with Tmax of 450 °C and 481 °C were found in Kaiyang phosphorite by fitting the TPO-IR curves; while pyrite sulfur with Tmax of 432 °C, complex sulfide with Tmax of 679 °C and sulfate sulfur with Tmax of 939 °C were found in Weng’an phosphorite. For Gas coal, the TPO-IR curves of sulfur release can be deconvoluted into seven individual curves, while that of Anthracite deconvoluted into four individual curves. In conclusion, the TPO-IR method has many advantages for determination of sulfur species in solid phase systems, such as less sample consumption, simple pretreatment, convenient operation and low cost, etc.
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DOI
高影响因子
CELL BIOCHEMISTRY AND BIOPHYSICS
·
2014
·Vol. 71
·期 2
·945-950
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IF 2.38
Chen Qing-quan,Han Xuesong,Wang Wan-ming,Zhao Liangyu,Chen Aimin
Danggui Sini decoction (DSD), a famous Chinese medicine, has been used therapeutically in various diseases. In this study, we tried to investigate whether and how DSD could ameliorate myelosuppression in an animal model, in which myelosuppression is induced by cyclophosphamide treatment. The myelosuppression model was established by intraperitoneal injection of 100 mg/kg cyclophosphamide in mice. Flow cytometry was used to assess cell numbers and evaluate the bone marrow cell cycle distribution. Spleen samples were collected, and the mRNA expression levels of thrombopoietin (TPO) and c - Mpl were analyzed by RT-PCR. Our results demonstrated that DSD could significantly elevate the level of bone marrow hematopoietic stem progenitor cells in myelosuppression mice model. DSD also accelerated cell proliferation by switching cell cycles from G0/G1 phase to S and G2/M phase. Moreover, DSD significantly elevated the mRNA expression level of TPO , but not c - Mpl in spleen. Overall, the present results indicated that DSD is a promising Chinese medicine that is highly potent to ameliorate myelosuppression induced by chemotherapy by upregulating TPO expression.
研究领域:
药理学
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血液学
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肿瘤学
·
分子生物学
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2022
·
IF 10.53
Yaqi Wang,Tanlong Xue,Zhihao Si,Chang Liu,Shuai Yang,Guozhen Li,Yan Zhuang,Peiyong Qin
Recently, the preparation of polymeric membranes by UV-induced polymerization is encouraged due to the ultrafast curing and controllable operation. However, the long-period exposure under UV light has a great threat to both the environment and operators. Herein, we developed the visible-light-induced polymerized PDMS membrane for the pervaporative separation of furfural . The differences among photoinitiator ethyl(2,4,6-trimethylbenzoyl)phenylphosphinate (TPO-L), diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide (TPO) and 2-hydroxy-2-methylpropiophenone (1173) in the polymerization kinetics , membrane structure and separation performance are compared. Results show that the absorbance of TPO-L matches 405 nm of the visible light region; and it can be well dispersed and compatible with PDMS and obtain high initiation efficiency. Furthermore, the conditions including TPO-L concentration and PDMS viscosity are optimized, and the prepared membrane has an outstanding pervaporation performance containing 1299.5 g m −2 h −1 of total flux and 40.2 of furfural separation factor. Importantly, the ultrafast and continuous preparation process of membrane is operated by a home-made machine, indicating the wonderful potential for its large-scale application.
研究领域:
材料科学
·
化学工程
·
高分子化学
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DOI
高影响因子
Additive Manufacturing
·
2023
·
IF 11
Zhengqiang Guo,Hongrui Zhang,Weigui Xie,Aimin Tang,Wangyu Liu
Due to the constraints of photoinitiators and mechanical properties, vat photopolymerization 3D printable hydrogels are still the focus of current research. Drawing inspiration from the water-soluble modification of the photoinitiator diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide (TPO), a rapid and expedient UV-curable hydrogel with remarkable strength and toughness has been developed using polymerizable micelles . The incorporation of polymerizable micelles not only significantly enhances the solubility of TPO, an efficient commercial photoinitiator, thereby eliminating the need for specific organic solvents , but also serves as physical crosslinking points for polymer chains. Moreover, by harnessing the abundant hydrogen bonding present in glycerol and plant cellulose, the precursor hydrogel exhibits a rapid layer-by-layer printing capability of 6 s per layer, accompanied by an enhanced mechanical toughness reaching 4.55 MJ/m³. The hydrogel-based resistance sensor demonstrates wide-ranging detection capabilities and high sensitivity. It has the gauge factor (GF) of 2.28 within low strains (<100 %) and can maintain a high linear GF of 5.84 even under large strains (200–500 %). This allows the hydrogel-based sensor to have a significant change in relative resistance when detecting human limb movements. The lattice structure design imparts a notable pressure sensitivity of 1.13 KPa −1 . Additionally, the utilization of a glycerol/water binary solvent ensures excellent water retention properties. Furthermore, the hydrogel exhibits significant advantages in capacitive sensors owing to its printed surface gradient bulge structure. Consequently, the hydrogel developed in this study possesses exceptional printing abilities, high strength, and impressive toughness, making it a valuable option for the design and fabrication of flexible electronic devices.
研究领域:
材料科学
·
3D打印
·
传感器
·
机械工程
·
高分子科学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）