Phase diagram for microphase separation transition in poor solvent polymer solutions

1994 ◽  
Vol 272 (11) ◽  
pp. 1486-1497 ◽  
Author(s):  
E. E. Dormidontova ◽  
I. Ya. Erukhimovich ◽  
A. R. Khokhlov
Keyword(s):  
Phase Diagram ◽  
Polymer Solutions ◽  
Microphase Separation ◽  
Poor Solvent

Microphase separation in poor-solvent polyelectrolyte solutions: Phase diagram

1994 ◽  
Vol 3 (4) ◽  
pp. 661-675 ◽  
Author(s):  
Elena E. Dormidontova ◽  
Igor Ya. Erukhimovich ◽  
Alexei R. Khokhlov
Keyword(s):  
Phase Diagram ◽  
Microphase Separation ◽  
Polyelectrolyte Solutions ◽  
Poor Solvent

scholarly journals Phase Behavior of Melts of Diblock-Copolymers with One Charged Block

Polymers ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 1027 ◽  
Author(s):  
Alexey A. Gavrilov ◽  
Alexander V. Chertovich ◽  
Igor I. Potemkin
Keyword(s):  
Phase Diagram ◽  
Phase Behavior ◽  
Electrostatic Interactions ◽  
Diblock Copolymers ◽  
Volume Fraction ◽  
Microphase Separation ◽  
Dissipative Particle Dynamics ◽  
Homogeneous Structure ◽  
Electrostatic Energy ◽  
Ordered Structures

In this work, we investigated the phase behavior of melts of block-copolymers with one charged block by means of dissipative particle dynamics with explicit electrostatic interactions. We assumed that all the Flory–Huggins χ parameters were equal to 0. We showed that the charge- correlation attraction solely can cause microphase separation with a long-range order; a phase diagram was constructed by varying the volume fraction of the uncharged block and the electrostatic interaction parameter λ (dimensionless Bjerrum length). The obtained phase diagram was compared to the phase diagram of “equivalent” neutral diblock-copolymers with the non-zero χ-parameter between the beads of different blocks. The neutral copolymers were constructed by grafting the counterions to the corresponding co-ions of the charged block with further switching off the electrostatic interactions. Surprisingly, the differences between these phase diagrams are rather subtle; the same phases in the same order are observed, and the positions of the order-disorder transition ODT points are similar if the λ-parameter is considered as an “effective” χ-parameter. Next, we studied the position of the ODT for lamellar structure depending on the chain length N. It turned out that while for the uncharged diblock copolymer the product χcrN was almost independent of N, for the diblock copolymers with one charged block we observed a significant increase in λcrN upon increasing N. This can be attributed to the fact that the counterion entropy prevents the formation of ordered structures, and its influence is more pronounced for longer chains since they undergo the transition to ordered structures at smaller values of λ, when the electrostatic energy becomes comparable to kbT. This was supported by studying the ODT in diblock-copolymers with charged blocks and counterions cross-linked to the charged monomer units. The ODT for such systems was observed at significantly lower values of λ, with the difference being more pronounced at longer chain lengths N. The fact that the microphase separation is observed even at zero Flory–Huggins parameter can be used for the creation of “high-χ” copolymers: The incorporation of charged groups (for example, ionic liquids) can significantly increase the segregation strength. The diffusion of counterions in the obtained ordered structures was studied and compared to the case of a system with the same number of charged groups but a homogeneous structure; the diffusion coefficient along the lamellar plane was found to be higher than in any direction in the homogeneous structure.

Microphase Separation in Two-Dimensional Athermal Polymer Solutions on a Triangular Lattice

Langmuir ◽  
2007 ◽  
Vol 23 (17) ◽  
pp. 8678-8680 ◽  
Author(s):  
Piotr Polanowski ◽  
Jeremiasz K. Jeszka
Keyword(s):  
Triangular Lattice ◽  
Polymer Solutions ◽  
Microphase Separation ◽  
Two Dimensional

Patterning in rapidly evaporated polymer solutions: Formation of annular structures under evaporation of the poor solvent

2006 ◽  
Vol 300 (1) ◽  
pp. 293-297 ◽  
Author(s):  
Edward Bormashenko ◽  
Roman Pogreb ◽  
Albina Musin ◽  
Oleg Stanevsky ◽  
Yelena Bormashenko ◽  
...  
Keyword(s):  
Polymer Solutions ◽  
The Poor ◽  
Poor Solvent

Microphase separation in bottlebrush polymers under poor-solvent conditions

2009 ◽  
Vol 88 (6) ◽  
pp. 63002 ◽  
Author(s):  
P. E. Theodorakis ◽  
W. Paul ◽  
K. Binder
Keyword(s):  
Microphase Separation ◽  
Poor Solvent

scholarly journals Two regions of microphase separation in ion-containing polymer solutions

Soft Matter ◽  
2017 ◽  
Vol 13 (38) ◽  
pp. 6831-6844 ◽  
Author(s):  
Artem M. Rumyantsev ◽  
Elena Yu. Kramarenko
Keyword(s):  
Polymer Solutions ◽  
Microphase Separation ◽  
Ion Association ◽  
New Type ◽  
Polyelectrolyte Solutions

A new type of microphase separation driven by ion association is theoretically predicted in concentrated polyelectrolyte solutions.

Predicting flow induced change in phase diagram of polymer solutions in simple shear flow

e-Polymers ◽  
2009 ◽  
Vol 9 (1) ◽  
Author(s):  
Saeedeh Mazinani ◽  
Farhad Sharif ◽  
Naser Mohammadi
Keyword(s):  
Phase Diagram ◽  
Constitutive Equations ◽  
Polymer Solutions ◽  
Polymer Chains ◽  
Polymer Mixture ◽  
Simple Shear Flow ◽  
Polymer Mixtures ◽  
New Approach ◽  
Stress And Deformation ◽  
Constant Shear Rate

AbstractThe change in the phase diagram of polymer mixtures under flow is an important issue since flow may promote mixing or demixing of the phases in a polymer mixture. This work, compared to previous studies, presents a different approach with special attention to the rheology of polymer solutions and flow conditions. Different approaches including Marrucci's approach in calculating stored elastic free energy (ΔGE) have been reviewed. Marrucci’s equation is obtained based on a fundamental analysis of polymer chains microstructure. The new approach introduces the proper viscoelastic constitutive equations to estimate ΔGE. Selecting the appropriate rheological model is essential to correctly estimate the state of stress and deformation rates due to the flow. Moreover, the parameters of viscoelastic constitutive equations were defined, from the microstructural viewpoint, as functions of composition and temperature in semi-concentrated regions. Finally, flow induced change in the phase diagram of polymer solutions is predicted for a well-defined flow condition (constant shear rate and stress), and the results are compared with the previously reported experimental observations of mixing and demixing.

Sign in / Sign up

Export Citation Format

Share Document