In this study, porous micron‐sized fibers of polylactic acid (PLA) are fabricated via electrospinning of PLA‐dichloromethane (DCM)‐hexane systems with no post treatment involved. Several compositions from the liquid‐liquid phase separated region of the phase diagram of this ternary system are selected and their electrospinnability are investigated throughout their phase separation process before gelation. We show that under constant processing and ambient parameters, there is a phase separation shelf time for each composition wherein the viscoelasticity of the systems is optimum to produce long, uniform porous fibers. For the first time, we investigate the effect of aging time during phase separation on the morphology of the electrospun fibers using scanning electron microscopy (SEM). Based on our results, certain phase separated systems provide a range of viscosity allowing for the production of porous spherical micro beads or fibers via electrospraying and electrospinning, respectively. It is also shown that obtaining long, uniform fibers from electrospinning of highly phase separated systems, e.g., a gel, is not feasible due to the high degree of crystallinity of their polymer‐rich domains and the solid‐like yielding behavior. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44862.

This paper focuses on shear modulus and shear deformation behavior of Graphene Nano Ribbons (GNR) post wrinkling initiation taking into account size effect. Atomistic modeling of armchair and zigzag GNR were performed at 300 o K for GNR with a constant 10 nm width and lengths ranging from 2.5 nm to 25 nm. Results show that ridge formation is oriented at 45 degrees for GNR with an aspect ratio less than one and that the number of ridges is equal to the reciprocal of the aspect ratio, while for aspect ratios higher than one, the ridge formation direction coincides with the diagonal direction of the GNR and only one ridge is formed. Once the diagonal tension reached its ultimate elastic level, three major stress-relaxing phenomena are reported. Results show that the average slope of the stress-strain curve beyond the ultimate elastic stress decreases with increasing GNR length. Moreover, the slope of the shear stress-strain curve in that region is always greater in armchair GNR than in Zigzag GNR. GNR can sustain very high plastic shear strains beyond 400% before failure for wide GNR. It is observed that the shear modulus is inversely proportional to the aspect ratio of the GNR.