Small-Angle X-ray Scattering of Concentration Dependent Structures in Block Copolymer Solutions

다국어 초록 (Multilingual Abstract)

<P>The concentration and temperature dependence of the structure of a poly(styrene-<I>b</I>-ethylene-<I>alt</I>-propylene) (PS–PEP) diblock copolymer in squalane, a highly selective solvent for the PEP block, was investigated using small-angle X-ray scattering (SAXS). With decreasing concentration, between 100% and 10% by weight, a nearly monodisperse PS–PEP (block molecular weights of 42 000 g/mol and 62 000 g/mol for PS and PEP, respectively) exhibited lamellae (LAM), hexagonally packed cylinders (HEX), body-centered cubic spheres (BCC) and disordered spherical micelles. The results show that squalane (C<SUB>30</SUB>H<SUB>62</SUB>) is essentially completely segregated into the PEP domains, and thus it behaves like a short PEP homopolymer. With increasing amounts of squalane the conformation of the PS block changes from stretched to nearly fully relaxed at the lowest polymer concentrations.</P><P><B>Graphic Abstract</B>
<IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/mamobx/2014/mamobx.2014.47.issue-22/ma5016819/production/images/medium/ma-2014-016819_0008.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/ma5016819'>ACS Electronic Supporting Info</A></P>