کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
612184 880692 2007 8 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Room temperature sphere-to-rod growth and gelation of PEO–PPO–PEO triblock copolymers in aqueous salt solutions
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی شیمی کلوئیدی و سطحی
پیش نمایش صفحه اول مقاله
Room temperature sphere-to-rod growth and gelation of PEO–PPO–PEO triblock copolymers in aqueous salt solutions
چکیده انگلیسی

The effects of NaCl and KF on the sphere-to-rod micellar growth behavior of triblock copolymers having two different compositions, (EO)20(PO)70(EO)20 (P123) and (EO)26(PO)40(EO)26 (P85), have been studied by dynamic light scattering (DLS), small angle neutron scattering (SANS) and dilute solution viscometry. NaCl can effectively tune the sphere-to-rod growth temperature of the micelles of both these copolymers and induce micellar growth down to the room temperature and below. The growth behavior is found to be dependent on the composition of the copolymer as P123 being more hydrophobic shows the room temperature growth in the presence of ethanol at significantly lesser NaCl concentration than the less hydrophobic copolymer P85. DLS studies depict for the first time the growth driven transition of the copolymer solutions from dilute to semi-dilute regime as a function of copolymer and salt concentrations. KF can also induce room temperature growth of the P123 micelles at lesser salt concentration than NaCl but it fails to induce any such growth of the P85 micelles. A pseudo-binary temperature-concentration phase diagram on 15% copolymer solutions shows the variation of the sphere-to-rod transition temperature and the cloud point of the copolymer solutions as a function of salt concentration.

Room temperature sphere-to-rod growth of PEO–PPO–PEO based copolymer micelles.Figure optionsDownload as PowerPoint slide

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Colloid and Interface Science - Volume 315, Issue 2, 15 November 2007, Pages 693–700
نویسندگان
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