Materials Chemistry Frontiers
·
2019
·Vol. 3
·期 4
·606-614
·
IF 0
Ya Zhao,Weijing Fan,Hanying Zhao
Self-assembly of asymmetric structures has been attractive for applications in the fabrication of hierarchical structures. However, the role of the electrostatic interaction in the self-assembly of charged asymmetric particles in organic solvents has not been fully understood. In this research, self-assembly of positively charged patchy micelles in organic solutions and the reversible ultrasound responsivity of the assemblies are studied. Surface micelles (s-micelles) with cross-linked/quaternized poly(2-(dimethylamino)ethyl methacrylate) (q-PDMAEMA) cores and poly(oligo(ethylene glycol) monomethyl ether methacrylate) (POEGMA) coronae were prepared on the surfaces of silica particles. Positively charged patchy micelles were synthesized upon cleavage of the s-micelles. In THF, the patchy micelles self-assemble into vesicles with positively charged q-PDMAEMA in the walls and POEGMA in the coronae. The average size of the vesicles is dependent on POEGMA chain length. The repelling electrostatic interaction between the positively charged q-PDMAEMA patches in the walls is unfavorable for the achievement of low free energy of the assemblies, but it is energetically favorable for the vesicles to overcome energy barriers in the dissociation of the structures under ultrasound irradiation. The vesicle structures present reversible ultrasound responsivity. Under sonication the vesicles formed by patchy micelles dissociate into transient nanostructures, including aggregates and isolated patchy micelles. When the ultrasound is switched off, the transient nanostructures self-assemble into vesicles. By contrast, crosslinked vesicles do not show ultrasound responsivity. This research provides a new approach to the fabrication of responsive assemblies based on asymmetric structures, and the assemblies could find potential applications in medicine and bioengineering.
研究领域:
高分子化学
·
纳米材料科学
·
生物医学工程
·
软物质物理
·
药物递送系统
✓ 已验证
DOI
SEPARATION AND PURIFICATION TECHNOLOGY
·
2025
·
IF 9
Wei Zhang,Weicheng Fu,Zihao Wang,Shuang Wu,Zhipeng Wang,Yaoming Wang
In this study, organic solutions (30–120 mg/L HA, BSA or SA) and composite solutions (5.93–10.15 wt% inorganic salts with 75 mg/L HA, BSA or SA) were used to investigate the membrane fouling behavior in the vacuum membrane distillation (VMD) system. The different permeate flux attenuation and fouled membrane morphology implied distinct membrane fouling mechanisms during VMD process. Furthermore, we employed the extended Derjaguin-Landau-Verwey-Overbeek (XDLVO) theory as an effective approach to analyze membrane fouling mechanisms. The results showed that the total interaction energy was negative (attraction) within the separation distance of 1–2 nm by applying the XDLVO approach, indicating that a pristine membrane was more prone to fouling. Finally, we elucidated distinct membrane fouling mechanisms in the VMD system. The inorganic feed solution readily induced inorganic fouling on the membrane surface and pore wetting, while organic feed solution and combined feed solution did not cause membrane wetting, conversely, only organic fouling and combined fouling were identified on the membrane surface. This study was expected to facilitate understanding of membrane fouling mechanisms in the VMD process.
研究领域:
环境科学
·
化学工程
·
材料科学
✓ 已验证
DOI
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
·
2016
·
IF 4.758
Huayun Chen,Yuangen Wu,Wenping Yang,Shenshan Zhan,Shuyi Qiu,Pei Zhou
This paper reports a new assay platform that performed in polar organic solutions for ultrasensitive and highly selective detection of isocarbophos pesticide. The sensing system just contains hemin molecules and random ssDNAs. Free hemin molecules have a strong absorption peak at Soret band in polar organic solvents, and they can assemble into few small particles with random ssDNAs via their special π–π stacking interaction. However, the subsequent addition of isocarbophos into above sensing system can aggregate hemin molecules to form many larger particles, which result in a great decrease in absorbance value of sensing solution. UV/Vis absorption spectra and scanning probe microscope (SPM) were used to characterize hemin aggregation. Additionally, the effects of some parameters like type of solvents, hemin amount and random ssDNAs on the sensing platform were also investigated. The present assay platform has a detection limit as low as 0.2 μg/L, a dynamic range of 0.5–500 μg/L, and high selectivity over other competitive pesticides. Moreover, the assay platform also displays excellent stability and accuracy in the detection of spiked real samples, suggesting that such sensing platform will play an important role in biological and environmental detection.
研究领域:
分析化学
·
环境科学
·
生物化学
✓ 已验证
产品关联
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2021
·
IF 6.901
Bo Zhang,Zhijie Guo,Yingming Zhao,Birong Luo,Dejun Li,Teng Zhao,Jagadeesh Sure,Sri Maha Vishnu,Amr Abdelkader,Chris Harris,Kai Xi
Lithium-sulfur batteries have shown increasing promise for high energy densities and reduced costs. Facile sulfur loading techniques demonstrate a critical way to achieving high dispersions of sulfur in the host's matrix, improving conductivity and simultaneously decreasing the active mass loss from the cathode. Here we investigate the effect of sulfur loading methods on the electrochemical performance of porous carbon/sulfur composites containing approximately 70 wt% sulfur. Three different loading techniques are tested, including one-step molten sulfur impregnation (155°C), two-step molten sulfur impregnation (155°C + 300°C) and a sulfur organic solution impregnation, in which the entire microporous volume of carbon is filled by sulfur. It is found that the simple sulfur organic solution impregnation method is the most effective in enhancing the electrochemical performance of the hierarchical porous carbon/sulfur composite cathode in the lithium-sulfur battery system, due to the weaker interaction occurring between the sulfur and microporous carbon. Our work demonstrates the impact of sulfur loading method on the electrochemical performance of lithium-sulfur batteries, which offers new insights into the preparation technology of electrodes.
研究领域:
材料科学
·
能源技术
✓ 已验证
产品关联
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2017
·
IF 4.798
Weibin Guo,Yuanzhi Chen,Laisen Wang,Jin Xu,Deqian Zeng,Dong-Liang Peng
MoSe 2 represents an important layered transition metal dichalcogenides (LTMDs) that have high electrocatalytic activity in hydrogen evolution reaction (HER). A key issue to achieve excellent electrochemical properties of MoSe 2 is to synthesize nanostructures that are composed of few-layer MoSe 2 with maximized exposure of active edge sites. In this study, we report the synthesis of MoSe 2 nanostructures with network-like and flower-like morphologies via an organic solution approach that utilizes molybdenum hexacarbonyl as Mo precursor and Se powders as Se source. The prepared MoSe 2 nanostructures consist of few-layer ultrathin nanosheets which can have different orientations. Depending on the volume ratio of oleylamine to oleic acid , the arrangement of ultrathin MoSe 2 nanosheets is adjustable and can form porous network-like or discrete flower-like nanostructure which has large specific surface area and a wealth of exposed edge sites. Excellent HER activities with low overpotentials, small Tafel slopes and long-term durability are observed on the as-synthesized MoSe 2 nanostructures. The acetic acid-washing step that may effectively remove the organic molecules capped on MoSe 2 surfaces is also found to be efficient in improving the HER activity of the synthesized MoSe 2 nanostructures.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
Advanced Materials Interfaces
·
2020
·Vol. 7
·期 7
·1902075
·
IF 4.948
Zhenyu Xu,Liang Hu,Jun Yuan,Yiyue Zhang,Yujie Guo,Zhengyuan Jin,Fangchao Long,Yaojia Long,Huawei Liang,Shuangchen Ruan,Yu-Jia Zeng
Fluorescence method for detecting metal ions has advantages of fast detection speed, simple operation, and low price over the conventional methods. Black phosphorus quantum dots (BP QDs) have high photoluminescence quantum yield and modifiable surface, which have great potential in the field of fluorescent probes. In this study, high quality BP QDs are prepared by pyrolysis method and are first time used as trace metal ion probes in both organic solutions and aqueous solutions. The detection limits of Hg 2+ and Cu 2+ in the aqueous solution are 5.3 × 10 −9 m and 1.6 × 10 −6 m , respectively. In addition, the detection limits of Cu 2+ in the organic solution are 16 × 10 −6 m . The fluorescence quenching mechanism based on the calculation of the electronic structure and adsorption energy of BP QDs after adsorption of metal ions is further explained. The results provide a new promising fluorescence probe for trace metal ions without the help of organic molecules.
研究领域:
分析化学
·
纳米生物技术
·
环境监测
·
分子探针
·
光子学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）