Globule-to-Coil Transition of a Single Homopolymer Chain in Solution
نویسندگان
چکیده
Using a nearly monodisperse high molar mass poly(N-isopropylacrylamide) (PNIPAM) sample, we successfully made the conformation change of individual PNIPAM chains from a coil to a fully collapsed stable single chain globule in an extremely dilute aqueous solution, which enabled us to study for the first time the globule-to-coil transition of a single homopolymer chain in solution. A comparison to the coil-to-globule and the globule-to-coil transitions revealed a hysteresis in the globuleto-coil transition. Our results also confirmed the existence of two additional thermodynamically stable states between the coil and the globule states, namely, the crumpled coil and the molten globule. [S0031-9007(98)05965-1]
منابع مشابه
First Observation of the Molten Globule State of a Single Homopolymer Chain.
In a recent laser light-scattering study on the “globule-to-coil” transition (melting) of a single poly(Nisopropylacrylamide) (PNIPAM) linear chain in water (the solution is in the stable one-phase region at all temperatures), we observed that at the initial melting stage the ratio of the hydrodynamic radius to the radius of gyration underwent an unexpected maximum s,1.61d which is even higher ...
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Using a newly prepared nearly monodisperse (Mw/Mn < 1.05) high molar mass (Mw ) 1.3 × 107 g/mol) poly(N-isopropylacrylamide) (PNIPAM) sample, we successfully, for the first time, made the conformation of individual PNIPAM chains change from a coil to a fully collapsed thermodynamically stable single chain globule and then back to a coil in an extremely dilute aqueous solution (∼6.7 × 10-7 g/mL)...
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