Insight into the origin of the thermosensitivity of poly[2-(dimethylamino)ethyl methacrylate]

	Insight into the origin of the thermosensitivity of poly[2-(dimethylamino)ethyl methacrylate]
	Liu, Guangming ; Wu, Dan ; Ma, Chengcheng ; Zhang, Guangzhao ; Wang, Hongfei ; Yang, Shihe
刊名	chemphyschem
	2007-10-22
卷号	8 期号:15 页码:2254-2259
关键词	conformation analysis hydration/dehydration interfaces phase transitions thermosensitivity
英文摘要	we investigate the effects of ph and temperature on the conformotional changes of poly[2-(dimethylamino)ethyl methacrylate] (pdem) chains at the air/water interface by using longmuir balance and sum frequency generation vibrational spectroscopy. at ph 4, the tertiary amine groups are fully charged and the pdem chains are so hydrophilic that they completely enter into the water phase and do not exhibit thermosensitivity. at ph 7, these groups are only partially charged, and the accompanying hydration/dehydrotion-followed by repartitioning into the water and air phases-gives rise to a marked thermosensitivty. finally, at ph 10, the tertiary amine groups become uncharged and thus preferentially stay in the hydrophobic air phase, devoid of associated water molecules, which results in the surface-pressure change (delta pi) being nearly independent of the temperature. our longmuir-balance experiments, coupled with surface-sensitive spectroscopy, demonstrate that: 1) the thermosensitivity of the pdem chains relates to the hydration/dehydration of the tertiary amine groups, 2) the phase transition of thermosensitive polymers is most likely initiated by the dehydration of the chains, and 3) the phase transition of thermosensitive polymers at the air/water interface is markedly different from that in aqueous solution because of the redistribution of the macromolecular segments induced by the asymmetric forces at the air/water interface.
WOS标题词	science & technology ; physical sciences
类目[WOS]	chemistry, physical ; physics, atomic, molecular & chemical
研究领域[WOS]	chemistry ; physics
关键词[WOS]	water-soluble block ; sum-frequency generation ; diblock copolymer monolayers ; air/water interface ; neutron reflectivity ; vibrational spectroscopy ; reversible activation ; ph modulation ; chain ; methacrylate
收录类别	SCI
语种	英语
WOS记录号	WOS:000250493600014
公开日期	2015-11-17
内容类型	期刊论文
源URL	[http://159.226.238.44/handle/321008/140611]
专题	大连化学物理研究所_中国科学院大连化学物理研究所
作者单位	1.Hong Kong Univ Sci & Technol, Dept Chem, Kowloon, Hong Kong, Peoples R China 2.Univ Sci & Technol China, Hefei Natl Lab Phys Sci Microscale, Dept Chem Phys, Hefei 230026, Peoples R China 3.Chinese Acad Sci, Inst Chem, State Key Lab Mol React Dynam, Beijing 100080, Peoples R China
推荐引用方式 GB/T 7714	Liu, Guangming,Wu, Dan,Ma, Chengcheng,et al. Insight into the origin of the thermosensitivity of poly[2-(dimethylamino)ethyl methacrylate][J]. chemphyschem,2007,8(15):2254-2259.
APA	Liu, Guangming,Wu, Dan,Ma, Chengcheng,Zhang, Guangzhao,Wang, Hongfei,&Yang, Shihe.(2007).Insight into the origin of the thermosensitivity of poly[2-(dimethylamino)ethyl methacrylate].chemphyschem,8(15),2254-2259.
MLA	Liu, Guangming,et al."Insight into the origin of the thermosensitivity of poly[2-(dimethylamino)ethyl methacrylate]".chemphyschem 8.15(2007):2254-2259.