Gelation Originated from Growth of Wormlike "Living Polymer" of Symmetrically Dendronized Large-Ring Crown Ether in Dilute Solutions

doi:10.1021/ma901494z

CORC > 化学研究所 > 中国科学院化学研究所

	Gelation Originated from Growth of Wormlike "Living Polymer" of Symmetrically Dendronized Large-Ring Crown Ether in Dilute Solutions
	Yan, Jing-Jing 1,2; Tang, Ru-Pei 3; Zhang, Ben 1,2; Zhu, Xing-Qi 1,2; Xi, Fu 3; Li, Zi-Chen 1,2; Chen, Er-Qiang 1,2
刊名	MACROMOLECULES
	2009-11-10
卷号	42 期号:21 页码:8451-8459
ISSN号	0024-9297
DOI	10.1021/ma901494z
英文摘要	The hierarchical pathway From homogeneous solution to gel of a large-ring: crown ether symmetrically substituted With four first-generation Percec-type dendrons (1) in n-dodecane has been followed by differential scanning calorimetry (DSC), small-angle X-ray scattering (SAXS), and fluorescence anisotropy methods. The 1/n-dodecane mixture requires it rather low gelation concentration of similar to 0.1% (w/v) at room temperature Mainly on the basis of m situ thermal SAXS measurements, we have found that upon Cooling from the homogeneous solutions of 1/n-dodecane the I molecule first undergoes,I solution self assembly to form wormlike micelle with the core of crown ether and the shelf of alkyl tails, which is "living polymers" containing only one disklike molecule of 1 percross-sectional repeating unit. The driving force of the assembly can be mainly attributed to the reduction of free energy during microphase separation among the different regions of molecules with distinct chemical properties and the lipophilic-lipophobic interaction in the solvent that is selective for the alkyl tails. Growth of the "living polymer" proceeds continuously With lowering temperature and eventually brings the wormlike chains to entangle and to enter the miscibility gap of 1/n-dodeciine We propose that phase separation of the "living polymer" solution is the main mechanism of the gelation, which gives a three-dimensional network of the slow-component of the "living polymer". The 1/n-dodecane gel is "wet" with the solvent molecules participating in the "polymer"-rich phase. The Iyotropic orderings of rectangular and nematic-like packing of the wormlike micelles can be obtained using slow and fast cooling Protocol! respectively, which are very different from the hexagonal columnar phase found in the bulk and xei ogel samples We have also tested whether the channel Formed by dibenzo-30-crown-10 moiety at the cylindrical micelle center of 1 can accommodate guest molecules. Using rhodamine B as an example. we have demonstrated that 1 can solubilize the cationic dye in n-dodecane at high temperature. After the micellization and gelation, the rhodamine B Molecules are successfully Introduced into the crown ether cavities.
语种	英语
出版者	AMER CHEMICAL SOC
WOS记录号	WOS:000271233600059
内容类型	期刊论文
源URL	[http://ir.iccas.ac.cn/handle/121111/65897]
专题	中国科学院化学研究所
通讯作者	Chen, Er-Qiang
作者单位	1.Peking Univ, Beijing Natl Lab Mol Sci, Dept Polymer Sci & Engn, Minist Educ,Coll Chem, Beijing 100871, Peoples R China 2.Peking Univ, Key Lab Polymer Chem & Phys, Minist Educ, Coll Chem, Beijing 100871, Peoples R China 3.Chinese Acad Sci, State Key Lab Polymer Phys & Chem, Joint Lab Polymer Sci & Mat, Inst Chem, Beijing 100190, Peoples R China
推荐引用方式 GB/T 7714	Yan, Jing-Jing,Tang, Ru-Pei,Zhang, Ben,et al. Gelation Originated from Growth of Wormlike "Living Polymer" of Symmetrically Dendronized Large-Ring Crown Ether in Dilute Solutions[J]. MACROMOLECULES,2009,42(21):8451-8459.
APA	Yan, Jing-Jing.,Tang, Ru-Pei.,Zhang, Ben.,Zhu, Xing-Qi.,Xi, Fu.,...&Chen, Er-Qiang.(2009).Gelation Originated from Growth of Wormlike "Living Polymer" of Symmetrically Dendronized Large-Ring Crown Ether in Dilute Solutions.MACROMOLECULES,42(21),8451-8459.
MLA	Yan, Jing-Jing,et al."Gelation Originated from Growth of Wormlike "Living Polymer" of Symmetrically Dendronized Large-Ring Crown Ether in Dilute Solutions".MACROMOLECULES 42.21(2009):8451-8459.