Advanced Materials Technologies
·
2019
·Vol. 4
·期 10
·1900426
·
IF 5.395
Peng Bi,Xiaowei Liu,Yang Yang,Ziyu Wang,Jing Shi,Gaomin Liu,Fangfang Kong,Benpeng Zhu,Rui Xiong
Wearable devices have become very important for collecting health information and monitoring the condition of seriously ill patients. However, most recently developed wearable devices can only monitor limited signals within a very small range of values. A novel sensor is fabricated by modifying the surface of polyimide nanowires with silver nanoparticles. These nanowire sensors can sense both pressure and temperature changes and have antimicrobial properties. The fabricated sensor can detect a wide range of pressure variation from 5 KPa to 100 KPa. A theoretical model is developed to explain the sensing mechanism of the silver-nanoparticle-modified polyimide nanowires. The experimental and theoretical results for the nanowires are in good agreement. By attaching these sensors to human joints and fingers, real-time information can be detected for human motion, such as walking or holding a hot cup of water. The excellent performance of this device shows that it has great potential for use in artificial skins for detecting temperature and human motion.
研究领域:
生物医学工程
·
纳米医学
·
柔性电子
·
智能材料
·
转化医学
·
可穿戴传感器
✓ 已验证
DOI
高影响因子
POLYMER
·
2023
·
IF 4.6
Peng Wei,Dong Huang,Chen Luo,Yang Sui,Xi Li,Qingkun Liu,Bensheng Zhu,Chuanbo Cong,Qiong Zhou,Xiaoyu Meng
Due to its uncomplicated manufacturing procedure for large-scale industrialization and adaptable conductivity, the competitive proton exchange membrane (PEM) matrix employed is sulfonated poly (ether ether ketone). However, the conflict between the strong proton conductivity and high stability of SPEEK-based PEM constantly upsets the equilibrium; the primary chain of SPEEK will conduct more protons if additional sulfonic acid is introduced, but it also causes a high swelling ratio and lowers stability. To tackle this challenging issue, we coupled the high intrinsic proton conductivity of phosphotungstic acid (HPW) and the excellent stability of polyimide (PI) nanofibers in a single PEM. In particular, sandwich-structure hybrid membranes (PI/SPEEK + HPW) were created to reduce HPW loss under operational conditions, further improving stability. Consequently, the swelling ratio and conductivity of the premium sandwich-structure PI/SPEEK + HPW-20 were 29% and 223.4 mS cm −1 under 60 °C and 100% RH, their respective values were 8% larger than those of SPEEK. Its proton conductivity reached 170.9 mS cm −1 during 13 days of exposure under 60 °C and 100% RH, which would be 30% better than that of SPEEK over the same treatment. Protons in these membranes were transported through Grotthus and vehicle mechanism, and the establishment of an acid-rich layer at the surface among PI nanofiber with HPW/SPEEK, which was confirmed by FTIR, XPS , and TEM , is responsible for these superior performances. From our point of view, our findings might encourage more studies into the creation of high-performance PEM.
研究领域:
材料科学
·
高分子化学
·
能源材料
·
电化学
·
膜科学与技术
✓ 已验证
DOI
高影响因子
COMPOSITES PART B-ENGINEERING
·
2019
·
IF 6.864
Chao Liu,Yufei Dong,Yang Lin,Hongxia Yan,Wenbo Zhang,Yan Bao,Jianzhong Ma
In order to simultaneously improve the dispersibility of graphene in the bismaleimide (BMI) resin and the interfacial interaction between them, the polytriazine@RGO nanocomposite (PTZ@RGO) with terminal amine was obtained by the method of one-step precipitation polymerization. The PTZ@RGO hybrid nanocomposite was then chosen as filler to improve the mechanical and tribological properties of BMI resin. Through effective surface modification, the compatibility and interface strength between graphene and BMI matrix were significantly improved, leading to the flexural strength , impact strength , anti-friction, wear resistance and thermal stability of PTZ@RGO/BMI composites were significantly improved as compared to those of neat BMI resin and RGO/BMI composites. The other properties including hardness and thermal properties of composites were all improved with increasing amount of PTZ@RGO fillers. These high performance BMI composites have a great potential for application in aerospace, mechanical engineering and other automobile brake devices.
研究领域:
材料科学
·
高分子复合材料
·
表面工程
·
摩擦学
·
航空航天材料
✓ 已验证
DOI
高影响因子
TETRAHEDRON-ASYMMETRY
·
2010
·
IF 2.625
Zhen-Wei Zhang,Gui Lu,Miao-Miao Chen,Ning Lin,Yong-Bo Li,Tamio Hayashi,Albert S.C. Chan
The first asymmetric Mannich-type reaction of methyl isocyanoacetate with N -sulfonylimines catalyzed by cinchona alkaloid derivatives yielded 2-imidazolines with high diastereoselectivities and good enantioselectivities (up to >99:1 dr and 70% ee). This reaction provided a convenient route to access various substituted 2-imidazoline-4-carboxylates and related α,β-diamino acids in high enantiomeric purities.
研究领域:
有机化学
·
药物化学
·
不对称合成
·
催化化学
·
生物有机化学
✓ 已验证
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2022
·
IF 7.392
Ruihan Wang,Nanxi Dong,Guofeng Tian,Gang Liu,Bo Zhou,Shengli Qi,Dezhen Wu
In order to allow polyimide (PI) to resist the erosion of atomic oxygen (AO) in Low Earth Orbit to extend the life of the aircraft, an in-situ precursor network approach was proposed to manufacture the inorganic gradient microstructure across the organic/inorganic transition interface and simplify the process, which create a three-tier microstructure film and lead the dense SiO 2 protective layer firmly grasps the PI film. Benefiting from the integrated structure, SiO 2 -coated PI film shows remarkable surface and interface state after 3000 times mechanical bending, which able to delay the initial AO corrosion caused by the defect of the protective layer, resistance to AO reported as AO erosion yield of 2.39 × 10 −26 cm 3 O atom −1 under 7 × 10 21 O atoms cm −2 AO fluence. This work proposes a novel approach for the fabrication of high-performance and AO resistant PI to enable the aircraft to complete more efficient and highly integrated flight missions and shows great potential in the general preparation of organic-inorganic interface.
研究领域:
高分子材料科学
·
航天材料工程
·
表面与界面化学
·
空间环境效应
·
功能涂层技术
✓ 已验证
DOI
高影响因子
POLYMER TESTING
·
2022
·
IF 4.931
Yang-he Mo,Hui Wang,Shao-hua Jin,Ke-lin Peng,Zi-ming Yang,Pu-wang Li,Yu Chen
Fast curing hydrogels are highly valuable in the skin care industry. Multi-arm polyethylene glycol (PEG) is a commonly used crosslinking agent for the preparation of fast curing hydrogels. However, the hydrogel preparation using multi-arm PEG crosslinking agents usually requires the end group modifications of reactants, which makes the preparation process complicated and produces hydrogels with low curing rates. In the present study, a fast in situ curing hydrogel, 4-arm-PEG-succinimidyl carbonate/carboxymethyl chitosan (PEG-SC/CMCS), was prepared using 4-arm-PEG-SC as the crosslinking agent and carboxymethyl chitosan (CMCS), a derivative of natural polysaccharide with excellent comprehensive properties, as the framework without any end groups modified. The structure and properties of the prepared hydrogel were characterized by FTIR, XRD, SEM, rheology and swelling kinetics. The effects of reaction conditions on the structure and properties of hydrogel were investigated. The PEG-SC/CMCS hydrogel exhibited pH-sensitive swelling behaviors. Its application potential in skin care products is demonstrated with its excellent sustained-release performance of Vitamin C, a model drug for skin treatment, and high adsorption capacity of heavy metal ions that are easily deposited on skin surface. Our work has provided a new strategy for building multifunctional gel materials for skin care and offered a PEG-SC/CMCS hydrogel with great application potentials.
研究领域:
生物材料
·
高分子化学
·
药剂学
·
皮肤科学
·
组织工程
·
药物递送系统
·
环境毒理学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）