INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
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2024
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IF 7.7
Congcong Wang,Jingjing Zhang,Qian Fu,Chenxi Niu,Yvtao Xu,Youhui Chen,Zaowen Zhao,Lingbin Lu
Due to marvelous sensitivity and flexibility, conductive hydrogels are popularly used as strain sensors in intelligent skin and wearable electronic devices fields. However, hydrogel tends to be destroyed after long-term use or in accident, leading to performance degradation. Herein, we developed an environmental-friendly Ti-containing conductive hydrogel. The hydrogel network was constructed via a simple two-step method with coordination reaction and amidation reaction based on a metal ion precursor from transitional coordination. The synergies of reversible metal coordination bonds and dynamic hydrogen bonds endowed the hydrogel with excellent self-healing properties (3 h, 93.66 %), tensile properties (136.46 kPa), compression properties (1.122 MPa), and anti-fatigue performance. At the same time, the hydrogel showed excellent self-adhesion, even underwater. Due to Ti 4+ , electrical conductivity of the hydrogel was visibly enhanced (σ = 25.64 mS·cm −1 ), which resulted in fast response (TS [time sensitivity] = 24.78 s −1 ) and short recovery time (153 ms). As a flexible strain sensor, the hydrogel with stable conductivity and high sensitivity could precisely detect and distinguish a series of human motions, even different letter pronunciations. These remarkable features make it a promising application in the fields of intelligent skin and wearable electronic devices.
研究领域:
材料科学
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生物医学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Applied Materials & Interfaces
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2022
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IF 10.383
Jianping Yang,Zhonghao Liu,Haoran Zhou,Lei Jia,Anhua Wu,Linwen Jiang
Efficient and stable electromagnetic-wave (EMW) absorption materials have attracted great attention in the field of reducing microwave pollution. Herein, FeCoNiCuTix high-entropy alloys (HEAs) as electromagnetic-wave absorbing materials were prepared by a high-energy ball-milling method. The as-milled HEA powders presented a flaky shape with a high aspect ratio. Impedance matching was efficiently optimized by severe lattice distortion, which was caused by Ti incorporation. The introduced plentiful defects in FeCoNiCuTix HEAs provided abundant polarization sites for dielectric loss. By tuning Ti contents, FeCoNiCuTi0.2 HEAs delivered excellent EMW absorption performances. The maximal reflection loss (RLmax) values reached −47.8 dB at 10.86 GHz as thin as 2.16 mm, and the widest bandwidth was 4.76 GHz (5.97–10.73 GHz). Furthermore, the introduction of Ti enhanced corrosion resistance via increasing the charge transfer resistance of a passivated film. Those characteristics of FeCoNiCuTix HEAs made these materials a practical gigahertz-range EMW absorber. Additionally, our findings provided a facile and tunable strategy for designing EMW absorbing materials, which was aimed at lightweight, highly efficient absorption, and resistance to harsh environments.
研究领域:
材料科学
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电磁学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CANADIAN JOURNAL OF CHEMICAL ENGINEERING
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2020
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IF 1.687
Jiang Gao,Lin Gao,Baoqiang Zhang,Haoyu Wang,Weihua Ma
Titanium silicalite-1 (TS-1) has unique catalytic properties for oxidation reactions due to the titanium atom in the framework. To increase the Ti content in the framework, polyvinylpyrrolidone (PVP) was added as a surfactant to modify TS-1 (PTS-1). The titanium content in PTS-1 as the active site in the catalytic reaction increased to 0.87 wt%, compared with the traditional TS-1 which has a titanium content of 0.64 wt%. Simultaneously, the average particle size of PTS-1 is reduced to 180 nm, compared with TS-1 (230 nm). The increase in Ti content makes the Au loading increase; thus, Au/PTS-1 shows higher catalytic performance for propylene epoxidation, and the propylene oxide (PO) formation rate increases from 95 g PO h −1 kg Cat −1 with Au/TS-1 to 190 g PO h −1 kg Cat −1 with Au/PTS-1. In addition, the mechanism for the modification of Ti content by PVP is proposed.
研究领域:
材料科学
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催化化学
✓ 已验证
产品关联
DOI
高影响因子
Molecular Catalysis
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2020
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IF 3.687
Wei Peng,Jianmei Xie,Junying Zhang,Xia Yang,Aihua He
The isoprene polymerization kinetics by using TiCl 4 /MgCl 2 type Ziegler-Natta catalysts (TMC) with different titanium contents were studied for better understanding the possible active-specie structures of heterogeneous Ziegler-Natta (Z-N) catalysts for conjugated diene polymerizations. The catalytic features including the catalytic activity (CA), number of active centers ([C*]/[Ti]), rate constant for polymerization (k p ), stereoregularity of these TMC catalysts were studied. The low titanium content catalyst TMC-1 (Ti = 0.09 wt.%) with more isolated mononuclear titanium species showed higher CA and yielded cis-1,4-/trans-1,4- mixed microstructure polyisoprene with low molecular weight ( M w ) in the initial polymerization stage. The medium high titanium content catalyst TMC-2 (Ti = 2.38 wt.%) with more clustered mononuclear titanium species showed lower CA and yielded cis-1,4-/trans-1,4- mixed microstructure polyisoprene with high M w in the early stage of polymerization. The high titanium content catalyst TMC-3 (Ti = 3.76 wt.%) presented lowest CA and yielded high trans-1,4- polyisoprene with higher M w .
研究领域:
高分子化学
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催化化学
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聚合物合成
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材料科学
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配位聚合
✓ 已验证
DOI
高影响因子
POLYMER
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2024
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IF 4.1
Qingtao Niu,Aihua He,Chongdian Si,Guodong Liu,Mingxuan Xiao,Guifan Chen,Manman Jin
Four TiCl 4 /MgCl 2 Ziegler-Natta catalysts (Cat-1∼Cat-4) with titanium contents in the range of 0.038–0.578 wt% were synthesized by the chemical rout and used for isoprene polymerizations. Four catalysts had similar possessed rod-like morphologies and their surface areas gradually increased as Ti contents increased. Cat-1 with the lowest Ti content (0.038 wt%) had the highest catalytic activity (28039.6 g∙P/(g∙Ti∙h)). To our knowledge, this was the highest activity achieved for isoprene polymerization using the heterogeneous TiCl 4 /MgCl 2 Ziegler-Natta catalyst. With the increasing Ti content, the catalyst activity gradually decreased in the order of Cat-1 < Cat-2 < Cat-3 < Cat-4, whereas the trans -1,4 stereoselectivity increased. Cat-4 with the highest Ti content (0.578 wt %) gave highest trans -1,4 units (97.7 mol%). The polymers were mainly composed of fraction C, D and G. C and D had high trans -1,4 structure while G fraction had low trans -1,4 structure. The plausible stereospecific transformation models of MgCl 2 -supported Ziegler-Natta catalyst with different Ti contents were discussed.
研究领域:
催化
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高分子化学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
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