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DOI | 10.1007/s10971-012-2739-1 |
Photoluminescent lamellar bilayer mono-alkyl-urethanesils | |
Fernandes, Mariana1,2,3; Ferreira, Rute A. S.4,5; Cattoen, Xavier3; Carlos, Luis D.4,5; Man, Michel Wong Chi3; Bermudez, Veronica de Zea1,2 | |
通讯作者 | Bermudez, Veronica de Zea |
会议名称 | 16th International Sol-Gel Conference |
会议日期 | AUG 28-SEP 02, 2011 |
会议地点 | Hangzhou, PEOPLES R CHINA |
英文摘要 | A new family of lamellar bilayer hierarchically structured mono-urethane cross-linked alkyl/siloxanes designated as mono-alkyl-urethanesils and represented by the notation m-Ut(CY)-ac, with Y = 14, 16 and 22 (where Y is the number of carbon atoms of the pendant polymer chains and ac is acid catalyzed) was prepared by the sol-gel process and self-assembly routes. The compounds were obtained as solid powders and are thermally stable up to 250 A degrees C. The alkyl chains adopt essentially all-trans conformations and are interdigitated. The degree of interpenetration depends non-linearly on the chain length. The intrincate morphology of the samples mimicks cabbage leaves or the desert rose. The present system allowed us to conclude that the nature of the cross-link exerts a key role on the properties of this sort of silsesquioxanes. The hydrogen bonded array in the mono-alkyl-urethanesils is considerably weaker than that formed in the analogue mono-amidosil m-A(14) incorporating alkyl chains with 15 carbon atoms. The order/disorder phase transition temperatures of the mono-alkyl-urethanesils with Y = 14 and 16 are lower than that of m-A(14), making the former samples mechanically more resistant to consecutive heating/cooling cycles. The frequency of conformational-sensitive infrared modes of m-Ut(C16)-ac exhibit hysteresis behaviour during cooling after undergoing the order/disorder phase transition, but, unlike m-A(14), the latter transition, although reversible, is apparently time-independent. The hybrids display an efficient emission at room temperature in the blue-green spectral region with a maximum emission quantum yield value of 0.11 +/- A 0.01 (excited at 350-380 nm), which is of the same order of magnitude of that reported for m-A(14). |
英文关键词 | Alkyl/siloxane hybrid materials Sol-gel Self-directed assembly Structure Morphology Order/disorder phase transition |
来源出版物 | JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY |
ISSN | 0928-0707 |
EISSN | 1573-4846 |
出版年 | 2013 |
卷号 | 65 |
期号 | 1 |
页码 | 61-73 |
出版者 | SPRINGER |
类型 | Article;Proceedings Paper |
语种 | 英语 |
国家 | Portugal;France |
收录类别 | SCI-E ; CPCI-S |
WOS记录号 | WOS:000315037400010 |
WOS关键词 | FUNCTIONALIZED ORGANIC/INORGANIC HYBRIDS ; H STRETCHING MODES ; SOLID-STATE NMR ; BRIDGED SILSESQUIOXANES ; HYDROPHOBIC-INTERACTIONS ; EU3+ IONS ; SILICA ; CHAINS ; LONG ; GEL |
WOS类目 | Materials Science, Ceramics |
WOS研究方向 | Materials Science |
资源类型 | 会议论文 |
条目标识符 | http://119.78.100.177/qdio/handle/2XILL650/301382 |
作者单位 | 1.Univ Tras Os Montes & Alto Douro, Dept Chem, P-5001801 Vila Real, Portugal; 2.Univ Tras Os Montes & Alto Douro, CQ VR, P-5001801 Vila Real, Portugal; 3.CNRS UM2 ENSCM UM1, Inst Charles Gerhardt Montpellier, UMR 5253, F-34296 Montpellier 5, France; 4.Univ Aveiro, Dept Phys, P-3810193 Aveiro, Portugal; 5.Univ Aveiro, CICECO, P-3810193 Aveiro, Portugal |
推荐引用方式 GB/T 7714 | Fernandes, Mariana,Ferreira, Rute A. S.,Cattoen, Xavier,et al. Photoluminescent lamellar bilayer mono-alkyl-urethanesils[C]:SPRINGER,2013:61-73. |
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