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Water‐proton relaxivity of hyperbranched polymers carrying TEMPO radicals
Author(s) -
Hayashi Hiroyuki,
Karasawa Satoru,
Tanaka Akihiro,
Odoi Keisuke,
Chikama Katsumi,
Kuribayashi Hideto,
Koga Noboru
Publication year - 2009
Publication title -
magnetic resonance in chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.483
H-Index - 72
eISSN - 1097-458X
pISSN - 0749-1581
DOI - 10.1002/mrc.2384
Subject(s) - chemistry , polymer , proton , radical , transmission electron microscopy , styrene , yield (engineering) , relaxation (psychology) , polymer chemistry , copolymer , nuclear magnetic resonance , nanotechnology , organic chemistry , composite material , materials science , nuclear physics , psychology , social psychology , physics
Abstract High water‐soluble hyperbranched poly(styrene) (HPS) polymers carrying stable 2, 2, 6, 6‐tetramethylpiperidine‐1‐oxyl (TEMPO) radicals, HPS‐N‐TEMPO, HPS‐Im‐TEMPO, and HPS‐Im‐(TEMPO) 2 , were prepared in ca. 60% introducing yield. HPS‐N‐TEMPO and HPS‐Im‐TEMPO were determined to be nearly spherical shapes of the diameter of 2.4 ± 0.6 and 2.2 ± 0.6 nm, respectively, by transmission electron microscope (TEM) images. The values of water‐proton relaxivity, r 1 , at 25 MHz, 0.59 T, and 25 °C were 6.0, 5.2, and 14 mM −1 sec −1 for HPS‐N‐TEMPO, HPS‐Im‐TEMPO, and HPS‐Im‐(TEMPO) 2 , respectively. The spin‐lattice relaxation time ( T 1 )‐weighted images in phantom were also observed. Copyright © 2009 John Wiley & Sons, Ltd.