(78i) 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 f_IN.  We found that in unconfined systems (H >> P), the dependence of f_IN on P follows Onsager theory predictions. Enhanced segmental alignment
is also observed near walls. For strongly confined polymer solutions, f_IN
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 f_IN also affects
the confined polymer solution dynamics.