BEH.462/3. 962J Molecular Principles of Biomaterials Spring 2003 UQUID POLYMER CONCENTRATION .100000.100,100.000.100100000.10 FIG 20 Temperature-concentration phase diagram showing the characteristics of EasPanEzs fully dissolved in D O. In the low-concentration, low temperature range. the /temperature, a liquid of micelles is formed with micellar volume f10m时钟是 shear plane of 25% solution Ens PaoE25. The three columns 25C, T-27 C, and T=68C, (Source: from (391. with permission.) Transition range: micelles in equlibrium with unimers Experiments by Hatton group at MIT PEO-PPO-PEO micellization at 3 different temperatures measured a by adding a hydrophobic dye that absorbs UV light when bound in a hydrophobic environment(e.g micelle core) but not free in solution logC %o w/v) Figure 3. Effect of concentration, with temperature eter, on the absorption intensity of DPh at 356 nm in solutions of pluronic p104. The critical micellization trations can be estimated from the first break in the Block length determines gel structure H-+OCH2 CH2 .C P 122 FIG 14 Phase diagrams of the systems of (EO)( PO)(EO) block copolymers with y 69 and x increasing from 5 to 106. (Source: from [13], with permis Lecture 8 sical gels 9of12BEH.462/3.962J Molecular Principles of Biomaterials Spring 2003 Lecture 8 – Physical gels 9 of 12 Experiments by Hatton group at MIT: PEO-PPO-PEO micellization at different temperatures measured by adding a hydrophobic dye that absorbs UV light when bound in a hydrphobic environment (e.g. micelle core) but not free in solution Transition range: micelles in equilibrium with unimers o Block length determines gel structure (Chu 1996)