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Hydration and conformation of temperature-dependent micellization of PEO-PPO-PEO block copolymers in aqueous solutions by FT-Raman | |
Alternative Title | Langmuir |
Guo, C; Wang, J; Liu, HZ; Chen, JY | |
1999-04-13 | |
Source Publication | LANGMUIR
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ISSN | 0743-7463 |
Volume | 15Issue:8Pages:2703-2708 |
Abstract | he micellization of four triblock copolymers of the poly(ethylene oxide)(x)-poly(propylene oxide)(y)-poly(ethylene oxide)(x) type (Pluronic P103, P104, P105, and F88) in aqueous solutions versus temperature is followed by Fouler transform-(FT-) Raman spectroscopy. The frequencies and relative intensities of C-H stretching bands in FT-Raman spectra are sensitive to the local polarity and conformation of block copolymer chains, and their variations with temperature are indicators of micellization. Therefore, the critical micellization temperatures of these copolymers of 10% concentration in aqueous solutions are determined. The deconvolution method is used to resolve the overlapping bands in the C-H stretching region, and the deconvoluted spectra provide information about the structural and microenvironmental changes of ethylene oxide (EO) and propylene oxide (PO) blocks, respectively. The hydration of the EO chains in the corona is found to diminish with increasing temperature, and the conformation changes to a more disordered structure. The structure of PO chains changes from a more polar, gauche conformation at low temperatures to a less polar, stretching conformation at high temperatures. The micellization is explained by the change in structure and microenvironment of the EO and PO units. The results confirm the leading role of the hydrophobic PO units in micellization, and reveal a favorable contribution of the hydrophilic EO units.; he micellization of four triblock copolymers of the poly(ethylene oxide)(x)-poly(propylene oxide)(y)-poly(ethylene oxide)(x) type (Pluronic P103, P104, P105, and F88) in aqueous solutions versus temperature is followed by Fouler transform-(FT-) Raman spectroscopy. The frequencies and relative intensities of C-H stretching bands in FT-Raman spectra are sensitive to the local polarity and conformation of block copolymer chains, and their variations with temperature are indicators of micellization. Therefore, the critical micellization temperatures of these copolymers of 10% concentration in aqueous solutions are determined. The deconvolution method is used to resolve the overlapping bands in the C-H stretching region, and the deconvoluted spectra provide information about the structural and microenvironmental changes of ethylene oxide (EO) and propylene oxide (PO) blocks, respectively. The hydration of the EO chains in the corona is found to diminish with increasing temperature, and the conformation changes to a more disordered structure. The structure of PO chains changes from a more polar, gauche conformation at low temperatures to a less polar, stretching conformation at high temperatures. The micellization is explained by the change in structure and microenvironment of the EO and PO units. The results confirm the leading role of the hydrophobic PO units in micellization, and reveal a favorable contribution of the hydrophilic EO units. |
Keyword | Oxide)-b-poly(Ethylene Oxide) Copolymers Micelle Formation Phase-behavior Potassium Fluoride Triblock Copolymer Lattice Theory Association Probe Water Thermodynamics |
Subtype | Article |
WOS Headings | Science & Technology ; Physical Sciences ; Technology |
URL | 查看原文 |
Indexed By | SCI |
Language | 英语 |
WOS Keyword | OXIDE)-B-POLY(ETHYLENE OXIDE) COPOLYMERS ; MICELLE FORMATION ; PHASE-BEHAVIOR ; POTASSIUM FLUORIDE ; TRIBLOCK COPOLYMER ; LATTICE THEORY ; ASSOCIATION ; PROBE ; WATER ; THERMODYNAMICS |
WOS Research Area | Chemistry ; Materials Science |
WOS Subject | Chemistry, Multidisciplinary ; Chemistry, Physical ; Materials Science, Multidisciplinary |
WOS ID | WOS:000079775700015 |
Citation statistics | |
Document Type | 期刊论文 |
Version | 出版稿 |
Identifier | http://ir.ipe.ac.cn/handle/122111/5957 |
Collection | 研究所(批量导入) |
Affiliation | Chinese Acad Sci, Inst Chem Met, Young Scientist Lab Separat Sci & Engn, Beijing 100080, Peoples R China |
Recommended Citation GB/T 7714 | Guo, C,Wang, J,Liu, HZ,et al. Hydration and conformation of temperature-dependent micellization of PEO-PPO-PEO block copolymers in aqueous solutions by FT-Raman[J]. LANGMUIR,1999,15(8):2703-2708. |
APA | Guo, C,Wang, J,Liu, HZ,&Chen, JY.(1999).Hydration and conformation of temperature-dependent micellization of PEO-PPO-PEO block copolymers in aqueous solutions by FT-Raman.LANGMUIR,15(8),2703-2708. |
MLA | Guo, C,et al."Hydration and conformation of temperature-dependent micellization of PEO-PPO-PEO block copolymers in aqueous solutions by FT-Raman".LANGMUIR 15.8(1999):2703-2708. |
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