Download or read book Morphology Development of Block Copolymer and Homopolymer Blend Films written by Yuxuan Chen and published by . This book was released on 2015 with total page 37 pages. Available in PDF, EPUB and Kindle. Book excerpt: Block copolymers (BCPs) have received considerable attention, as they can self-assemble into different nanoscale structures with different properties under certain conditions for a variety of applications. For example, cylinder forming block copolymers can be applied as effective nano-filtration membranes for oil-water separation. The main objective of this work is to investigate the morphological development of block polymer and homopolymer blend systems that can be ultimately useful in applications. Poly (styrene-block-2vinyl pyridine) (PS-b-P2VP) was blended with varying concentrations from 0-40 wt% homopolymer poly2-vinylpyridine (P2VP) to examine its effect on morphology, domain size and orientation in thin films. We observed morphologies ranging from parallel cylinders to quasi-micellar cylinders. The effect of different annealing methods (oven annealing, CZA-S and direct immersion annealing) was studied. In uniform thermal annealing, the orientation of P2VP cylinders, changes from parallel to perpendicular and back to parallel again as the homopolymer mass fraction increases in blend and then ultimately results in formation of micelles. Similar results were obtained with zone annealing, however the degree of ordering was higher and faster. For direct immersion annealing, the morphology changes from perpendicular to the mixed morphology composing of parallel and perpendicular orientations, which reflects the degree of isotropy provided by the solvent mixture that reduces the bias provided by the substrate interactions to orient cylinders horizontally to substrate. The opportunity to introduce homopolymer into ordered block copolymer domains in selective manner is useful since this allows us to tune the film morphology without synthesizing new block copolymers for varying molecular weights to obtain similar effects. Extraction of the homopolymer by selective solvent after ordering allows us to make nanoporous channels for membrane applications.