449922 Shifting Isotropic-Nematic Transition in Strongly Confined Semi-Flexible Polymer Solutions
We investigated the phase behavior of semi-flexible polymer solutions under sub-persistence length slit confinement of height H. Strong confinement leads to increased intra-polymer segmental correlation length (l//) in the unconfined dimensions that could reach up to twice the polymer persistence length P. The increased l// results in better alignment of segments and shifts the isotropic-nematic transition density fIN. We found that in unconfined systems (H >> P), the dependence of fIN on P follows Onsager theory predictions. Enhanced segmental alignment is also observed near walls. For strongly confined polymer solutions, fIN decreases as H decreases due to the increased segmental correlation length, and enhanced segmental alignment is found throughout the solution. Qualitative agreements with mean-field theory are found. The shift in fIN also affects the confined polymer solution dynamics.