TY - JOUR
T1 - Segmental orientations of trains versus loops and tails
T2 - The adsorbed polymethylmethacrylate system when the surface coverage is incomplete
AU - Soga, Iwao
AU - Granick, Steve
N1 - Funding Information:
We thank Dr Peter Frantz for contributions to this study. Financial support was provided through the US National Science Foundation. I.S. also thanks the Mitsubishi Chemical Corporation for financial support and the opportunity to carry out this work.
Copyright:
Copyright 2017 Elsevier B.V., All rights reserved.
PY - 2000/9
Y1 - 2000/9
N2 - We measure, for the first time, the separate surface coverage-dependent orientations of trains and of loops/tails in the structure of an adsorbed polymer, and show that these have different average orientations. The system was PMMA (atactic polymethylmethacrylate) adsorbed onto oxidized silicon from dilute solution in carbon tetrachloride at 25.0°C. The method was FTIR-ATR (infrared spectroscopy in attenuated total reflection). With increasing surface coverage, train segments were observed to maintain constant average anisotropy with respect to the solid surface. Free segments were preferentially flattened when the surface coverage was low, but with increasing surface coverage became progressively more random in orientation. Free and bound segments were separated according to shifts of the vibrational frequencies of carbonyl segments upon hydrogen-bonding to the surface silanol groups. The dependence of segmental orientation on molecular weight of the chain is also discussed. Copyright (C) 2000 Elsevier Science B.V.
AB - We measure, for the first time, the separate surface coverage-dependent orientations of trains and of loops/tails in the structure of an adsorbed polymer, and show that these have different average orientations. The system was PMMA (atactic polymethylmethacrylate) adsorbed onto oxidized silicon from dilute solution in carbon tetrachloride at 25.0°C. The method was FTIR-ATR (infrared spectroscopy in attenuated total reflection). With increasing surface coverage, train segments were observed to maintain constant average anisotropy with respect to the solid surface. Free segments were preferentially flattened when the surface coverage was low, but with increasing surface coverage became progressively more random in orientation. Free and bound segments were separated according to shifts of the vibrational frequencies of carbonyl segments upon hydrogen-bonding to the surface silanol groups. The dependence of segmental orientation on molecular weight of the chain is also discussed. Copyright (C) 2000 Elsevier Science B.V.
KW - Anisotropy
KW - Polymer
KW - Trains
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U2 - 10.1016/S0927-7757(00)00409-X
DO - 10.1016/S0927-7757(00)00409-X
M3 - Article
AN - SCOPUS:0034032872
SN - 0927-7757
VL - 170
SP - 113
EP - 117
JO - Colloids and Surfaces A: Physicochemical and Engineering Aspects
JF - Colloids and Surfaces A: Physicochemical and Engineering Aspects
IS - 2-3
ER -