How Structure-Related Collapse Mechanisms Determine Nanoscale Inhomogeneities in Thermoresponsive Polymers

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• 作者：Dennis Kurzbach ; Martina Sch枚mer ; Valerie S. Wilms ; Holger Frey ; Dariush Hinderberger
• 刊名：Macromolecules
• 出版年：2012
• 出版时间：September 25, 2012
• 年：2012
• 卷：45
• 期：18
• 页码：7535-7548
• 全文大小：548K
• 年卷期：v.45,no.18(September 25, 2012)
• ISSN：1520-5835

文摘

Continuous wave electron paramagnetic resonance (CW EPR) spectroscopy on the amphiphilic spin probe TEMPO in solutions of selectively chosen functional, thermoresponsive poly(propylene oxide) (PPO)- and poly(ethylene oxide) (PEO)-based copolymers of both linear and branched structure is used to elucidate their host鈥揼uest interactions and inverse phase transitions. Three different fundamental types of host鈥揼uest interactions between probes and polymers could be correlated to the phase transition mechanisms (supported by MD simulations), evidencing that these proceed via nanoscale inhomogeneities of the polymers. Because of their ability to host small amphiphilic guest molecules, thermoresponsive copolymers are promising candidates for molecular transport applications. The host鈥揼uest interaction principles derived from our small amphiphilic spin probes may also aid in finding the 鈥渁ppropriate鈥?design for the desired release property of a specific thermoresponsive polymer-based host鈥揼uest systems.