High Pressure Phase Diagram of an Aqueous PEO-PPO-PEO Triblock Copolymer System via Probe Diffusion Measurements

Abstract

Phase diagrams of soft fragile materials are typically determined via static structural methods, such as small angle neutron scattering (SANS;

Microrheology of biomaterial hydrogelators

“…Microrheology not only permits the characterization of scarce and rare materials, but it also enables researchers to screen the material rheology over a large parameter space, including composition, 65,66,[84][85][86][87] changes in environmental stimuli [88][89][90] and even with respect to variations in thermodynamic control variables, such as pressure and temperature. 91,92 Active microrheology has been used to screen the mechanical properties of cells 93,94 and tissues that mimic blood vessels. 95 In the latter case, microrheology techniques enable the measurement of a population of cells experiencing the same deformation, providing statistical significance to the measurements.…”

Stabilization of Supramolecular Polymer Phase at High Pressures

“…Clearly, pressure affects the miscibility in polymer mixtures, promoting miscibility in LCST polymer solutions and in UCST polymer blends due to volume changes on mixing. More complicated is the effect of pressure on triblock copolymer micelles, where it is found to promote crystal to liquid transition, but often the micellar liquid is interacting topologically . Furthermore, pressure is found to affect the glass transition and associated alpha relaxation (typically increasing the glass temperature) in supercooled liquids and a wide range of shape-persistent polymeric materials with intrinsic orientational order, for which the lack of thermal energy rather than free volume is proposed to be responsible for vitrification .…”

“…More complicated is the effect of pressure on triblock copolymer micelles, where it is found to promote crystal to liquid transition, but often the micellar liquid is interacting topologically. 5 Furthermore, pressure is found to affect the glass transition and associated alpha relaxation (typically increasing the glass temperature) in supercooled liquids 6 and a wide range of shape-persistent polymeric materials with intrinsic orientational order, for which the lack of thermal energy rather than free volume is proposed to be responsible for vitrification. 7 In general, soft materials experience high pressures in a variety of applications or during their transformation, which renders relevant studies necessary.…”

Mesoscopic simulation on phase behavior of star-like block polyether solution in the absence and presence of shear

“…All the simulations are carried using MesoDyn module in a commercial software package Cerius 2, version 4.6, from Accelrys, Inc. Comparing with linear polymers studied by Lam, 42 Altevogt, 43 Zhang, 10 and Kloxin, 44 both the cmc and the aggregate structure transition concentration are reduced. These simulations show that both the ratio of PPO and PEO and the structure of the polyether can affect the concentrations at which aggregates are formed.…”

“…Poly(ethylene oxide)-poly(propylene oxide) block copolymers are an important class of amphiphilic molecules, which exhibit a rich phase behavior as a function of solvent, temperature and pressure. [1][2][3][4][5][6][7][8][9] Many reports have been published on the aqueous solution properties and applications of this kind of copolymer, [10][11][12][13][14] and most of the published works deal with linear polymers such as Pluronic (BASF). [15][16][17][18] It is well known that the physicochemical properties and practical applications of amphiphilic molecules depend greatly upon their molecular structures.…”