Author: Armin KnollPublisher:
ISBN:
Category :
Languages : en
Pages : 173
Book Description
Equilibrium and dynamic phase behavior in thin films of cylinder forming block copolymers
Mesoscale Modeling of Phase Behavior in Thin Films of Cylinder-forming ABA Block Copolymers
Author: Andriana HorvatNanostructured Soft Matter
Author: A.V. ZvelindovskyPublisher: Springer Science & Business Media
ISBN: 140206330X
Category : Science
Languages : en
Pages : 627
Book Description
This book provides an interdisciplinary overview of a new and broad class of materials under the unifying name Nanostructured Soft Matter. It covers materials ranging from short amphiphilic molecules to block copolymers, proteins, colloids and their composites, microemulsions and bio-inspired systems such as vesicles.
Polymer Thin Films
Author: Ophelia Kwan Chui TsuiPublisher: World Scientific
ISBN: 9812818820
Category : Science
Languages : en
Pages : 312
Book Description
Ch. 1. Block copolymer thin films / J.-Y. Wang, S. Park and T. P. Russell -- ch. 2. Equilibration of block copolymer films on chemically patterned surfaces / G. S. W. Craig, H. Kang and P. F. Nealey -- ch. 3. Structure formation and evolution in confined cylinder-forming block copolymers / G. J. A. Sevink and J. G. E. M. Fraaije -- ch. 4. Block copolymer lithography for magnetic device fabrication / J. Y. Cheng and C. A. Ross -- ch. 5. Hierarchical structuring of polymer nanoparticles by self-organization / M. Shimomura ... [et al.] -- ch. 6. Wrinkling polymers for surface structure control and functionality / E. P. Chan and A. J. Crosby -- ch. 7. Crystallization in polymer thin films: morphology and growth / R. M. Van Horn and S. Z. D. Cheng -- ch. 8. Friction at soft polymer surface / M. K. Chaudhury, K. Vorvolakos and D. Malotky -- ch. 9. Relationship between molecular architecture, large-strain mechanical response and adhesive performance of model, block copolymer-based pressure sensitive adhesives / C. Creton and K. R. Shull -- ch. 10. Stability and dewetting of thin liquid films / K. Jacobs, R. Seemann and S. Herminghaus -- ch. 11. Anomalous dynamics of polymer Films / O. K. C. Tsui.
Complex Macromolecular Systems I
Author: Axel H. E. MüllerPublisher: Springer Science & Business Media
ISBN: 3642128750
Category : Science
Languages : en
Pages : 264
Book Description
-Effects of Electric Fields on Block Copolymer Nanostructures By H. G. Schoberth, V. Olszowka, K. Schmidt, and A. Böker -Nanopattern Evolution in Block Copolymer Films: Experiment, Simulations and Challenges By L. Tsarkova, G.J. Agur Sevink, and G. Krausch -Controlled Wrinkling as a Novel Method for the Fabrication of Patterned Surfaces By A. Schweikart, A. Horn, A. Böker, and A. Fery -Layered Systems Under Shear Flow By D. Svenšek and H. R. Brand -Thermal Diffusion in Polymer Blends: Criticality and Pattern Formation By W. Köhler, A. Krekhov, and W. Zimmermann -Foaming of Microstructured and Nanostructured Polymer Blends By H. Ruckdäschel, P. Gutmann, V. Altstädt, H. Schmalz, and A.H.E. Müller
Block Copolymers
Author: Ashish Kumar KhandpurPublisher:
ISBN:
Category :
Languages : en
Pages : 434
Book Description
The Effect of Film Thickness and Molecular Structure on Order and Disorder in Thin Films of Compositionally Asymmetric Block Copolymers
Author: Vindhya MishraPublisher:
ISBN: 9781267020277
Category :
Languages : en
Pages : 258
Book Description
Through studies on block copolymers which exhibit an order-order transition in bulk, we found that that subtle differences in the packing frustration of the spherical and cylindrical phases as well as the higher configurational entropy of free chain ends at the surface can drive the equilibrium configuration in thin films away from the stable bulk structure. These studies have revealed unexpected consequences of confining block copolymers to thin films on their equilibrium behavior, identified some limitations of block copolymer assisted lithography and as well as elucidated ways to overcome them.
Self-assembly Behavior of Block Copolymer/homopolymer Blends in Thin Films
Author: Shuaigang XiaoPhase Behavior and Kinetics of Cylinder to Sphere Transition in Block Copolymers in Selective Solvents
Author: Minghai LiPublisher:
ISBN:
Category :
Languages : en
Pages : 324
Book Description
Abstract: The main goal of this dissertation is to study the phase behavior and kinetics of cylinder to sphere phase transition in block copolymers in selective solvents using time- resolved small angle x-ray scattering (SAXS), rheology, Atomic Force Microscopy (AFM), modeling and simulation. Block copolymers consist of two or more chemically distinct polymer blocks connected by a covalent bond. The incompatibility of the constituent blocks leads to phase separation on length scales of 10-1000 nm instead of bulk phase separation. The addition of a selective solvent which preferentially solubilizes one of the components further enriches the phase behavior and provides easier control over the morphology of micellar domains. Although many studies have been made on the phase diagrams of block copolymer solutions the kinetics of phase transitions between two different crystalline symmetries are less understood. The experiments were conducted on a triblock copolymer of poly(styrene- b -ethylene- co -butylene- b -styrene) (SEBS), in mineral oil, a solvent selective to middle EB block. AFM measurements clearly showed the cylindrical micelles arranged hexagonally (HEX) at 110°C. Synchrotron based time-resolved SAXS measurements showed that the transition from HEX to spherical micelles arranged on body-centered cubic (BCC) lattice occurs via a nucleation and growth mechanism for shallow temperature jumps and via spinodal decomposition for deep temperature jumps. We developed a geometrical model of coupled anisotropic fluctuations to calculate the scattering and found very good agreement with the SAXS data. Brownian Molecular Dynamics simulations were carried out to provide microscopic insights on the HEX to cubic transition. HEX, face-centered cubic (FCC), lamellar, and hexagonally perforated lamellar ordered phases were obtained depending on the concentration, temperature and solvent selectivity. Kinetics of HEX to FCC was examined by quenching the temperature or rapidly changing the well-depth of the Lennard-Jones potential used in the simulation. The observations from snapshots, density profiles and calculated scattering intensity all agree well with the nucleation and growth mechanism. This work provides a detailed understanding of the mechanism and kinetics of phase transition of cylinders to spheres in block copolymer solution system. The results have relevance to block copolymer processing and other applications.
Manipulating Phase Behavior in Block Copolymers Using Polydispersity
Author: Publisher:
ISBN:
Category :
Languages : en
Pages : 231
Book Description
The effects of polydispersity, or broad molecular weight distributions, on the phase behavior of block copolymer melts and thin films are systematically explored. Linear AB diblock, ABA triblock, and BAB triblock copolymers are synthesized with continuous polydispersity in the B block (Mw/Mn 8́ơ 1.70́32.0) and relatively monodisperse A blocks (Mw/Mn 8́ơ 1.10́31.3) to understand how the self0́3assembly of polydisperse block copolymers can be altered with chain architecture and block connectivity. Broad dispersity in the M block of poly(styrene0́3b0́3methyl methacrylate) (SM) diblock copolymer melts induces domain dilation and morphological transitions to higher M block volume compositions with respect to predictions for monodisperse SM diblock copolymers. A comparison between poly(styrene0́3b0́31,40́3butadiene0́3b0́3styrene) triblock copolymers (SBS) with mid0́3block (B) polydispersity and poly(methyl methacrylate0́3b0́3styrene0́3b0́3methyl methacrylate) triblock copolymers (MSM) with outer0́3block (M) polydispersity reveals that the location of the polydisperse block and how it is connected to the other blocks is critical. Center block polydispersity in SBS, where one block is constrained at two block junctions, leads to a lamellar phase window shift to higher volume fractions of B, increases in domain periodicity, and the stabilization of a new, disordered bicontinuous morphology. The domain periodicity in the MSM triblocks with outer M block polydispersity is at least twice that predicted for monodisperse MSM triblock copolymers. However, in contrast to the SBS triblocks, the polydisperse MSM triblocks exhibit a lamellar phase window shift to lower M block compositions. The behavior of the SBS and MSM triblock copolymers is clarified in the context of the chain architectures present in the melts resulting from the block polydispersity. Preliminary studies of the thin film behavior of the SM diblock and MSM triblock copolymers revealed that despite the polydispersity of the M block, perpendicular microdomain orientation can be achieved. The MSM triblock copolymer thin films exhibit film thickness0́3dependent morphological behavior arising from a confluence of M outer0́3block polydispersity and the presence of a random brush0́3modified substrate. In summation, this dissertation demonstrates that polydispersity can be used to manipulate the phase behavior of block copolymer melts and thin films and may facilitate access to new materials with potentially useful properties.