Materials Chemistry Frontiers
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2019
·Vol. 3
·期 4
·606-614
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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
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纳米材料科学
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生物医学工程
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软物质物理
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药物递送系统
✓ 已验证
DOI
Innovative Food Science & Emerging Technologies
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2012
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IF 3.03
Wei Liu,Zhao-Qin Zhang,Cheng-Mei Liu,Ming-Yong Xie,Rui-Hong Liang,Jun-Ping Liu,Li-Qiang Zou,Jie Wan
Previous research indicated that the unfolding of trypsin induced by dynamic high–pressure microfluidization (DHPM) treatment had enhanced its hydrolytic stability. However, the unfolding trypsin is in a metastable state and will subsequently aggregate to be in the lowest energy state. In this study, monomethoxy polyethylene glycol-succinimidyl carbonates (mPEG–SC) was chosen to modify trypsin acted as a molecular patch. The results indicated mPEG–SC showed a significant effect on storage stability and thermal stability of unfolded trypsin. Compared to trypsin DHPM–treated under pressure of 100 MPa, further mPEG–SC modification increased the activity from 50% to 74% and from 70% to 87% after 4 °C for 8 days and 55 °C for 10 min, respectively. Fluorescence quenching demonstrated the conjugation of mPEG–SC and trypsin, and indicated molecular patch modification could inhibit the refolding of unfolded trypsin. Industrial relevance Dynamic high–pressure microfluidization (DHPM) is a promising technology that has been widely applied for innovative foods with modified functional properties or structure. Trypsin has been widely used in modern food industry and biological field. Either DHPM treatment or mPEG–SC modification enhanced the thermal stability of trypsin, while, the combination of the two enhanced the thermal and storage stability of trypsin more significantly. It is expected that this study can provide a new viewpoint and technical scheme for basic research on theory and application of enzyme modification .
研究领域:
食品科学
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生物化学
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酶工程
✓ 已验证
产品关联
DOI
高影响因子
COMPOSITES PART B-ENGINEERING
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2024
·
IF 12.7
Cong Liu,Hefeng Li,Jiabao Zhu,Xianhua Huan,Ke Xu,Hongbo Geng,Xiaodong Guo,Lei Ge,Xiaolong Jia,Xiaoping Yang,Hao Wang
The emerging graphene oxide membranes (GOm) showcase superiority in molecule barrier applications, yet their hydrogen (H 2 ) barrier performance is still less than ideal due to the insufficient control of GOm assembly architecture. Here, molecular patch engineering, in which amino rich polyethyleneimine (PEI) is controllably introduced into the GO system, is proposed to construct a highly aligned self-supporting PGO membrane (PGOm) for exceptional H 2 barrier performance. Based on the non-covalent and covalent interactions between GO nanosheets and PEI, the assembly behavior of GO nanosheets from the liquid phase to the solid phase is efficiently optimized in both extension and alignment synergistically, resulting in the superior alignments of PGOm with a Herman's orientation factor as high as 0.86. Owing to the excellent alignments, the hydrogen permeability (P H2 ) of PGOm is substantially reduced to a mere 2.28 cm 3 cm/(cm 2 ·s·Pa)·10 −15 even at a high temperature of 80 °C, representing a remarkable three-order-of-magnitude decrease compared to GOm. Additionally, at 25 °C, the P H2 of PGOm-enhanced epoxy sandwich composites is minimized to 1.2 cm 3 cm/(cm 2 ·s·Pa)·10 −15 , approximately 50 times lower than that of pure EP. This highlights the significant potential of PGOm in enhancing the gas tightness of composite pressure vessels.
研究领域:
材料科学
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
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2022
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IF 10.383
Zhiqi Zhao,Qiujin Li,Yu Dong,Jixian Gong,Zheng Li,Jianfei Zhang
Textile-based flexible electronic devices have attracted tremendous attention in wearable sensors due to their excellent skin affinity and conformability. However, the washing process of such devices may damage the electronic components. Here, a textile-based piezoresistive sensor with ultrahigh sensitivity was fabricated through the layered integration of gold nanowire (AuNW)-impregnated cotton fabric and silver ink screen-printed nylon fabric electrodes, sealing with Parafilm. The prepared piezoresistive sensing patch exhibits outstanding performance, including high sensitivity (914.970 kPa–1, <100 Pa), a fast response time (load: 38 ms, recovery: 34 ms), and a low detection limit (0.49 Pa). More importantly, it can maintain a stable signal output even after 30 000 s of loading–unloading cycles. Furthermore, this sensing patch can efficiently detect breathing, pulse, heart rate, and joint movements during the activities. After five cycles of mechanical washing, the piezoresistive performance keeps 90.3%, demonstrating the high feasibility of this sensor in practical applications. This sensor has a simple fabrication, with good fatigue resistance and durability due to its all-fabric core element. It provides a strategy to address the machine-washing issues in textile electronics. This washable textile sensor is expected to show significant potential in future applications of health monitoring, human–machine interfaces, and artificial skin.
研究领域:
材料科学
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纳米技术
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可穿戴技术
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生物医学工程
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传感器技术
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产品关联
DOI
PubMed
高影响因子
CARBOHYDRATE POLYMERS
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2021
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IF 9.381
Yuyang Wu,Xincheng Jiang,Jiangya Ma,Jingbo Wen,Shuang Liu,Hongxia Liu,Huaili Zheng
A kind of starch-based flocculant (starch- graft -poly[(2-methacryloyloxyethyl) trimethyl ammonium chloride], denoted St-g-PDMC-LPUV) has been synthesized by low-pressure ultraviolet initiation and was employed to remove humic acid (HA) for water purification . The physicochemical characteristics of starch and St-g-PDMC-LPUV were characterized by FT-IR, 1 H NMR, XRD, TGA , SEM and BET to confirmed the successful grafting DMC onto starch. Effects of flocculant dosage, pH, the adding amount of Fe 3 O 4 , initial HA concentration and stirring speed were investigated systematically. The prepared St-g-PDMC-LPUV flocculant with non-toxic, biodegradability and environmental friendliness exhibited effective performance for removing HA from water in a wide pH range (5–10). The flocculation mechanism was attributed to the effective collision between function groups of the St-g-PDMC-LPUV flocculant and HA by charge neutralization, adsorption, bridging and patching.
研究领域:
环境科学
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化学工程
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材料科学
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水处理
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）