Effects of local order parameter dependent transport coefficient in diblock copolymers under applied electric fields

Area of Science:

• Materials Science
• Polymer Physics
• Chemical Engineering

Background:

• Diblock copolymers are crucial in nanotechnology.
• Understanding their behavior in electric fields is key for device applications.
• Existing models lack thermodynamic consistency for time-dependent phenomena.

Purpose of the Study:

• To develop a thermodynamically consistent time-dependent model for diblock copolymer thin films under electric fields.
• To investigate the impact of electric fields on the dynamics and structure of these films.
• To provide a framework for simulating more complex systems, including electrolytes.

Main Methods:

• Application of linear irreversible thermodynamics principles.
• Incorporation of a local order parameter-dependent transport coefficient.
• Numerical simulations of thin films of incompressible diblock copolymers.
• Comparison with experimental results and ad hoc models.

Main Results:

• The model shows sensitivity to initial conditions due to the transport coefficient's dependence on the order parameter.
• Transient behavior differs significantly from models with constant transport coefficients.
• Electric field-induced alignment of lamellae domains was observed, matching experimental findings qualitatively.

Conclusions:

• The developed approach provides a systematic method for creating kinetic models for diblock copolymer thin films.
• The model's accuracy in predicting electric field effects enhances its utility for designing nanostructured materials.
• This work paves the way for simulating advanced systems with electrolytes and electric fields.