JOURNAL OF DISPERSION SCIENCE AND TECHNOLOGY
·
2020
·
IF 1.701
Kai Zheng,Yilin Deng,Hui Cao
To improve the properties of xanthan gum (XG), 3-chloro-2-hydroxypropyltrimethylammonium chloride and propylene oxide were used as modifiers to etherify XG and to obtain cationic hydroxypropyl xanthan gum (HCXG), and cationic hydroxypropyl xanthan gum (CHCXG), further optimized by super-gravity reaction. The structure of the product was characterized by infrared spectroscopy and nuclear magnetic resonance. The rheological properties of XG, HCXG, and CHCXG solutions and their performance as fracturing fluids were studied. Infrared and nuclear magnetic test results showed that the cationic etherification agent and hydroxypropyl group were successfully connected to XG, and the degree of substitution of CHCXG was higher. The rheological properties of the CHCXG solution and the performance of the fracturing fluid base fluid were superior to those of the XG and HCXG solutions. The viscosity of the solution after the super-gravity modification was further increased, and the apparent viscosity of the 0.4% CHCXG solution was 28.96% higher than that of the HCXG solution. After XG modification, the solution strength, yield stress, viscoelasticity, temperature resistance, and shear resistance were all significantly improved. The rheological properties of the HCXG solution and the performance of the fracturing fluid base fluid are good and can be used for fracturing fluid thickener.
研究领域:
生物化学
·
材料科学
·
石油工程
✓ 已验证
DOI
高影响因子
ADVANCED MATERIALS
·
2024
·Vol. 36
·期 24
·2400075
·
IF 27.4
Guang-Chang Xu,Yihan Nie,Hao-Nan Li,Wan-Long Li,Wan-Ting Lin,Yu-Ren Xue,Kai Li,Yu Fang,Hong-Qing Liang,Hao-Cheng Yang,Haifei Zhan,Chao Zhang,Chaofeng Lü,Zhi-Kang Xu
Designing nanocomposite hydrogels with oriented nanosheets has emerged as a promising toolkit to achieve preferential performances that go beyond their disordered counterparts. Although current fabrication strategies via electric/magnetic force fields have made remarkable achievements, they necessitate special properties of nanosheets and suffer from an inferior orientation degree of nanosheets. Herein, a facile and universal approach is discovered to elaborate MXene-based nanocomposite hydrogels with highly oriented, heterogeneous architecture by virtue of supergravity to replace conventional force fields. The key to such architecture is to leverage bidirectional, force-tunable attributes of supergravity containing coupled orthogonal shear and centrifugal force field for steering high-efficient movement, pre-orientation, and stacking of MXene nanosheets in the bottom. Such a synergetic effect allows for yielding heterogeneous nanocomposite hydrogels with a high-orientation MXene-rich layer (orientation degree, f = 0.83) and a polymer-rich layer. The authors demonstrate that MXene-based nanocomposite hydrogels leverage their high-orientation, heterogeneous architecture to deliver an extraordinary electromagnetic interference shielding effectiveness of 55.2 dB at 12.4 GHz yet using a super-low MXene of 0.3 wt%, surpassing most hydrogels-based electromagnetic shielding materials. This versatile supergravity-steered strategy can be further extended to arbitrary nanosheets including MoS 2 , GO, and C 3 N 4 , offering a paradigm in the development of oriented nanocomposites.
研究领域:
材料科学
·
纳米技术
·
电磁学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Polymers
·
2021
·Vol. 13
·期 3
·459
·
IF 4.329
Kangkang Yu,Tao Yuan,Songdi Zhang,Chenlu Bao
Thermal conductive polymer composites (filled type) consisting of thermal conductive fillers and a polymer matrix have been widely used in a range of areas. More than 10 strategies have been developed to improve the thermal conductivity of polymer composites. Here we report a new “hypergravity accumulation” strategy. Raw material mixtures of boron nitride/silicone rubber composites were treated in hypergravity fields (800–20,000 g, relative gravity acceleration) before heat-curing. A series of comparison studies were made. It was found that hypergravity treatments could efficiently improve the microstructures and thermal conductivity of the composites. When the hypergravity was about 20,000 g (relative gravity acceleration), the obtained spherical boron nitride/silicone rubber composites had highly compacted microstructures and high and isotropic thermal conductivity. The highest thermal conductivity reached 4.0 W/mK. Thermal interface application study showed that the composites could help to decrease the temperature on a light-emitting diode (LED) chip by 5 °C. The mechanism of the improved microstructure increased thermal conductivity, and the high viscosity problem in the preparation of boron nitride/silicone rubber composites, and the advantages and disadvantages of the hypergravity accumulation strategy, were discussed. Overall, this work has provided a new, efficient, and simple strategy to improve the thermal conductivity of boron nitride/silicone rubber and other polymer composites (filled type).Keywords:boron nitride;silicone rubber;hypergravity;thermal conductivity;microstructure;high viscosity problem;MPPT theory;thermal conductive polymer composites;fillers
研究领域:
材料科学
·
热传导工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ADVANCED POWDER TECHNOLOGY
·
2021
·
IF 4.833
Zhonghua Bao,Ke Li,Shuo Wang,Kai Gao,Dongliang Zhang,Mei Li
Submicron-cerium oxide particles were synthesized by applying hypergravity using ammonium bicarbonate (precipitant) and cerium nitrate hexahydrate (precursor). The influence of the concentration, pH, dispersant loading, flow rate, rotation speed of the hypergravity rotating bed, calcination temperature, and time on the cerium oxide particle size were examined by zeta potential, solid–liquid contact angle, thermo-gravimetry–differential scanning calorimetry, scanning electron microscopy, X-ray diffraction, and transmission electron microscopy. The cerium oxide particles were highly dispersed, with an average particle size of 200 nm. Calcining at 650 °C for 1.5 h afforded the smallest particles. The crystallite size and fraction crystallinity increased with prolonged calcination. Crystalline cerium dioxide grew along three crystal planes, forming a complete face-centered cube, affording high hardness and activity of the polishing powder. The optimal conditions were: cerium nitrate concentration: 0.7 mol/L, cerium nitrate/ammonium bicarbonate molar ratio: 1:3, dispersant mass fraction: 3%, cerium nitrate initial pH: 4–5; the precursor solution was adjusted to pH 9 with ammonia water. Hypergravity coprecipitation with 1.5 h calcination afforded submicron-sized cerium oxide with a uniform size distribution using ammonium bicarbonate in an industrially viable process. The simple and low-cost manufacturing process may enable the development of hypergravity-assisted chemical synthesis technology.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
ADVANCED FUNCTIONAL MATERIALS
·
2024
·
IF 18.5
Xiuyu Nie,Mingzhang Xiong,Jing Zeng,Chenggang Li,Yue Chen,Zushun Xu,Wen Fan
Nanoscale structuring of gallium-based liquid metals has emerged as a promising approach for generating unique properties and functionalities in advanced materials and devices. However, their exceptionally high surface tension presents significant challenges for achieving surface nanostructuring using conventional fabrication techniques. Here, a hypergravity nanoimprinting method is introduced, which harnesses horizontal centrifugation to generate hypergravity fields that drive liquid gallium into nanoscale cavities on an elastic polymer stamp surface at subzero temperatures, where it solidifies and preserves imprinted features down to 100 nm lateral resolution. This surpasses previous limits of gallium patterning, enabling phenomena such as iridescent structural colors with a wide range of hues and high saturation. Numerical simulations reveal the intricate fluid dynamic behaviors and interfacial interactions during the imprinting process, providing valuable insights for process optimization and control. By synergistically combining advanced soft lithography techniques with the reversible solid-liquid phase transition properties of liquid metals, hypergravity nanoimprinting offers a practical nanofabrication approach, facilitating the development of next-generation nanoscale gallium devices with finely structured nanofeatures across diverse application domains, such as nanoelectronics and photonic metamaterials.
研究领域:
材料科学
·
纳米技术
·
光学工程
✓ 已验证
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2019
·
IF 3.375
Jiahui Wu,Dong Zhang,Xiaomin He,Yang Wang,Shengwei Xiao,Feng Chen,Ping Fan,Mingqiang Zhong,Jun Tan,Jintao Yang
“Janus-featured” hydrogels with different structure and function for each layer can be particularly important in diverse application. However, very few studies have been conducted on multifunctional Janus-featured hydrogel, and significant challenge for simple, rapid, and efficient fabrication of such hydrogels remains. Herein, Janus-featured poly(N-hydroxyethyl acrylamide) (polyHEAA) hydrogel loaded with modified silica nanoparticle was fabricated by the supergravity method. Silica nanoparticles grafted with poly(3-(dimethyl(4-vinylbenzyl) ammonio) propyl sulfonate) (polyDVBAPS) were first prepared and then introduced into progel of polyHEAA hydrogel. During the formation of the hydrogel, a supergravity resulting from centrifugation was applied, from which silica nanoparticles moved to one side of the hydrogel, forming Janus-featured hydrogels, i.e., a pristine polyHEAA layer and a composite layer. These two layers showed different properties, where the prinstine polyHEAA layer showed excellent antifouling property by resisting the bacteria adsorption (<106 cells/cm2) for up to 5 days, and the nanoparticle-loaded hydrogel layer showed excellent bacteria-releasing properties by releasing >94% adherent bacteria upon a simple treatment with 2.0 M NaCl solution for 10 min. Based on its superb biocompatibility and low biotoxicity, we expect that our interesting strategy may provide a new assumption for the fabrication of “Janus featured” hydrogel and hopefully offer reference significance for the design of hydrogel-based wound dressing in the near future.
研究领域:
生物材料
·
高分子科学
·
组织工程
·
感染控制
·
再生医学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）