COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
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2024
·
IF 4.9
Lin Zhou,Yangcheng Lu
Polystyrene-based magnetic composite nanoparticles with well-defined core-shell morphology, customizable surface functionalization , and adjustable magnetic properties are promising catalyst support materials. In this work, chloromethylated magnetic polystyrene composite nanoparticles are successfully prepared through RAFT-mediated surfactant-free emulsion polymerization . A comprehensive investigation is carried out to explore the influence of copolymer monomer ratios and polymerization degrees on emulsion polymerization conversion and encapsulation efficiency. The results unveil the critical importance of moderately adjusting the hydrophobic/hydrophilic properties of the macroRAFT agents in achieving an effective encapsulation process. Excessive monomer addition is found to disrupt the conditions necessary for emulsion polymerization by causing the detachment of macroRAFT agents from the surface of the modified Fe 3 O 4 nanoclusters . These results are instructive for the future rational design and synthesis of high-performance catalysts.
研究领域:
材料科学
·
化学工程
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产品关联
DOI
高影响因子
ACS Applied Polymer Materials
·
2025
·
IF 4.7
Jiani Peng,Yong Gao
Core–shell structure diblock copolymer nanoparticles carrying phenolic groups in the core domain were prepared through the combination of RAFT-mediated dispersion polymerization and the hydrolysis of postpolymerization in this study. Poly(2-(dimethylamino)ethyl methacrylate)23 (PDMAEMA23) was first synthesized through RAFT-mediated solution polymerization, which was then utilized as macro-CTA to mediate the dispersion polymerization of 4-tert-butoxystyrene (tBOS) in isopropanol/water (8:2, v/v) mixtures. PDMAEMA23-PtBOSx diblock copolymer nanoparticles with different morphologies, including spheres, worms, and vesicles, were produced. Subsequently, the selected PDMAEMA23-PtBOS490 vesicles underwent hydrolysis in an acidic environment. During the hydrolysis, tBOS repeat units were partially converted into 4-vinylphenols (VPl), affording polymer nanoparticles bearing phenolic groups in the core domain, accompanied with a gradual morphological transition from vesicles to spheres. The content of VPl units in the core domain could be flexibly adjusted by varying the hydrolysis time. The as-prepared diblock copolymer spheres demonstrated a unique combination of stimuli-responsive emulsifying performances and intrinsic antioxidant activity, as well as antibacterial effectiveness.
研究领域:
聚合物化学
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材料科学
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纳米技术
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胶体科学
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产品关联
DOI
高影响因子
Polymer Chemistry
·
2020
·Vol. 11
·期 35
·5619-5629
·
IF 5.342
Yechun Zhou,Zhe Wang,Yuqing Wang,Lishan Li,Nianchen Zhou,Yuanli Cai,Zhengbiao Zhang,Xiulin Zhu
Azobenzene-based polymeric nanoparticles have emerged as promising candidate for biological detection and controlled drug release in an anaerobic environment for colon disease treatment. Herein, we report a novel and efficient polymerization-induced self-assembly (PISA) strategy for fabricating polymeric nanovehicles to load drugs for triggered release and fluorescence detection based on a TPE (tetraphenylethylene)-azobenzene fluorescence probe sensitive to hypoxic microenvironments. In this study, a series of PISA-nanoparticles, including micelles and vesicles, were synthesized by reversible addition–fragmentation transfer (RAFT) dispersion copolymerization of monomers butyl methacrylate (BMA) and reductive-responsive TPE-AZO-MA (TPE-azobenzene derived methacrylate) in a 1,4-dioxane/water mixture. Subsequently, polymeric micelles loaded with doxorubicin (DOX) in situ were successfully obtained by PISA. Furthermore, the release and fluorescence change of PISA-formed micelles loaded with DOX were studied in a simulated colon environment under the action of azoreductase. As expected, the drug-loaded micelles showed an effective DOX release during enzyme hydrolysis within 24 h owing to azo bond cleavage. Meanwhile, significant fluorescence enhancement was observed, accompanied by the release process. This was due to the aggregation-induced emission (AIE) performance of TPE being efficiently activated by elimination of the fluorescence resonance energy transfer (FRET) process, also owing to azo bond cleavage. Finally, the cytotoxicity and cellular uptake of the blank micelles and DOX-loaded micelles in vitro were evaluated.
研究领域:
药学
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材料科学
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纳米技术
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生物医学工程
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DOI
高影响因子
Polymer Chemistry
·
2022
·Vol. 13
·期 24
·3696-3704
·
IF 5.364
Cheng-Lin Yang,Feng Zhong,Cai-Yuan Pan,Wen-Jian Zhang,Chun-Yan Hong
Polymerization-induced self-assembly (PISA) has been demonstrated to be a powerful strategy to produce polymeric nano-objects of various morphologies. Dependent on the solubility of monomers, PISA is usually classified into two formulations as dispersion polymerization or emulsion polymerization, which may undergo quite different processes of polymerization and morphology transition. Generally, chain propagation of the solvophobic blocks will induce the morphology transition of the nano-objects from spherical micelles to higher order morphologies. However, the limitation of morphology evolution is often observed during PISA, and how to overcome the trapped spherical micelles obviously depends on case-by-case analysis. Herein, RAFT-mediated PISA of benzyl methacrylate (BzMA) in different formulations is investigated by varying the solvent composition (the mass ratio of ethanol/water). The polymerization kinetics, nucleation, and morphology transitions are quite different between these different PISA formulations. The morphology transition of spherical micelles, to worm-like micelles, and finally to vesicles is only observed at a moderate ratio of ethanol/water (5/5, w/w). At either a higher ratio of ethanol/water (7/3, w/w) or lower ratio of ethanol/water (3/7, w/w), morphology transitions of spherical micelles to the higher order ones are both limited, but the limited morphology transitions are caused by a different mechanism. The entrapped spherical micelles at ethanol/water = 7/3 (w/w) are determined by thermodynamic factors, and morphology transition can be achieved by using a shorter solvophilic polymer as the macro-RAFT agent, while the spherical micelles obtained at ethanol/water = 3/7 (w/w) are kinetically trapped, which can be overcome by copolymerization of some other monomers to improve the flexibility of solvophobic blocks. This work is promising as it provides a principle to overcome the limitations of morphology evolution in different cases and develops the design for formulations of PISA.
研究领域:
高分子化学
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材料科学
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纳米技术
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DOI
高影响因子
CHINESE JOURNAL OF POLYMER SCIENCE
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2016
·Vol. 35
·期 1
·54-65
·
IF 1.811
Chen Qi-jing,An Ze-sheng
A series of well-defined core cross-linked star (CCS) polymeric ionic liquids (PILs) were synthesized via a three-step approach. First, the styrenic imidazole-based CCS polymer (S-PVBnIm) was prepared by the RAFT-mediated heterogeneous polymerization in a water/ethanol solution, followed by the quaternization of S-PVBnIm with bromoalkanes and anion exchange. The CCS polymers were characterized by gel permeation chromatography (GPC), nuclear magnetic resonance (NMR) spectroscopy, Fourier transform infrared spectroscopy (FTIR), thermal gravimetric analysis (TGA), and differential scanning calorimetry (DSC). The obtained CCS polymers were used as the effective emulsifiers for oil-in-water high internal phase emulsions (HIPEs). Multiple oils with different polarity including n -dodecane, undecanol, toluene and octanol were emulsified using 0.5 wt% S-PVBnIm aqueous solution under the acidic condition to form HIPEs with long-term stabilities. The excellent emulsification properties of CCS PILs were demonstrated by HIPE formation for a variety of oils. The properties of HIPEs in terms of emulsion type and oil droplet size were characterized by the confocal laser scanning microscopy (CLSM). The intriguing capability of CCS PILs to stabilize HIPEs of various oils holds great potentials for the practical applications.
研究领域:
聚合物化学
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材料科学
·
胶体与表面化学
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）