Download or read book Equilibrium and dynamic phase behavior in thin films of cylinder forming block copolymers written by Armin Knoll and published by . This book was released on 2003 with total page 173 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Mesoscale Modeling of Phase Behavior in Thin Films of Cylinder forming ABA Block Copolymers written by Andriana Horvat and published by . This book was released on 2008 with total page 121 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Nanostructured Soft Matter written by A.V. Zvelindovsky and published by Springer Science & Business Media. This book was released on 2007-11-06 with total page 627 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Block Copolymers written by Ashish Kumar Khandpur and published by . This book was released on 1995 with total page 434 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Polymer Thin Films written by Ophelia Kwan Chui Tsui and published by World Scientific. This book was released on 2008 with total page 312 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book The Effect of Film Thickness and Molecular Structure on Order and Disorder in Thin Films of Compositionally Asymmetric Block Copolymers written by Vindhya Mishra and published by . This book was released on 2011 with total page 258 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Complex Macromolecular Systems I written by Axel H. E. Müller and published by Springer Science & Business Media. This book was released on 2010-05-20 with total page 264 pages. Available in PDF, EPUB and Kindle. Book excerpt: -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
Download or read book Self assembly Behavior of Block Copolymer homopolymer Blends in Thin Films written by Shuaigang Xiao and published by . This book was released on 2004 with total page 208 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Phase Behavior and Kinetics of Cylinder to Sphere Transition in Block Copolymers in Selective Solvents written by Minghai Li and published by . This book was released on 2008 with total page 324 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Manipulating Phase Behavior in Block Copolymers Using Polydispersity written by and published by . This book was released on 2013 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Dynamic Behavior of Block Copolymers written by Sidney Michael Kilbey and published by . This book was released on 1996 with total page 352 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Slow Dynamics in Complex Systems written by American Institute of Physics and published by American Institute of Physics. This book was released on 2004-06-02 with total page 866 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book gives up-to-date information on the liquid-glass transition in various disciplines, such as physics, chemistry, biology, engineering, polymer science, and computer science. The book contains review articles by leading scientists and contributed papers by authors in the forefront of research. The systems studied covered almost all states of matter including solids, liquids, complex solutions, polymers, and suspensions. Significant progress was made on a variety of topics. Among these were experimental and theoretical studies of colloidal systems; experiments on glass to glass transitions in micellar systems; theoretical studies of polyelectrolytes and polymer melts and networks; theoretical and computer studies of hydrodynamics in suspensions and Rayleigh-Taylor and Rayleigh-Couette instabilities; theoretical and experimental studies of the glass transition; computer simulations of the glass transition in thin films; vibrational motions in glass forming liquids and glasses; the effects of shear on supercooled liquids; engineering and experimental studies of metallic glasses; mode-coupling studies of complex glass formation; and Lorentz gas studies of the translational and rotational motion of a rigid rod.
Download or read book Phase Behavior of Block Copolymers in Selective Solvents written by Yongsheng Liu and published by . This book was released on 2008 with total page 290 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: The goal of this research is to study the phase behavior and kinetics of order-order (OOT) and order-disorder (ODT) phase transitions in block copolymers in selective solvents. We focus on examining temperature and pressure dependence of the phase diagram and the kinetics of phase transitions using small angle x-ray scattering (SAXS). The kinetics of ODT and OOT was studied for two block copolymer solutions by time-resolved SAXS using temperature ramp and fast quench methods: (i) Poly(styrene- b -isoprene) (PS-PI) diblock copolymer in tetradecane, selective solvent for PI, which displayed face-centered-cubic (FCC) structure at low temperature, body-centered-cubic (BCC) at intermediate temperature, and was disordered at high temperature. Following a quench from 110 C to 50 C, a long-lived meta-stable BCC phase was detected prior to the formation of FCC. The data agrees very well with Cahn's model for nucleation and growth. (ii) Poly(styrene- b -ethylene- co -butylene- b -styrene) triblock copolymer in dibutyl phthaphate, selective solvent for PS, which displayed hexagonally packed cylinders (HEX) at low temperature and lamellar (LAM) phase at high temperatures. This is unusual because in most block copolymer melts LAM occurs at lower temperature than HEX. A geometric model was developed to understand the mechanism of the transition from LAM to HEX. The calculated scattering intensity agrees very well with the experimental data. A pressure network system for SAXS capable of operating in the range of 1-4000 bars with pressure jump capability was built to study the pressure dependence of phase behavior. The system was used to investigate PS-PI diblock copolymer in diethyl phthaphate. The BCC to disorder transition temperature increased with pressure at 20 C/kbar, and the lattice constant increased with pressure. Brownian Molecular Dynamics simulations were carried out to study the phase behavior of multiblock copolymers in a selective solvent. Disordered, BCC, HEX, and LAM phases were obtained depending on the concentration and number of blocks. This research provides detailed information of the kinetics of structural changes in block copolymers in selective solvents. The results provide a good understanding of the mechanism of order-disorder and order-order transitions, and are directly related to industrial applications of block copolymers.
Download or read book Phase Behavior of Model ABC Triblock Copolymers written by Joon Chatterjee and published by . This book was released on 2007 with total page 554 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Phase Behavior of Diblock Copolymer in Thin Films and Membranes written by Giang Thi Vu and published by . This book was released on 2018 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Studies of Block Copolymer Thin Films and Mixtures with an Ionic Liquid written by Justin Virgili and published by . This book was released on 2009 with total page 240 pages. Available in PDF, EPUB and Kindle. Book excerpt: Block copolymers are capable of self-assembling into structures on the 10-100 nm length scale. Structures of this size are attractive for applications such as nanopatterning and electrochemical membrane materials. However, block copolymer self-assembly in these examples is complicated by the presence of surfaces in the case of thin films and the presence of an additive, such as an ionic liquid, in the case of electrochemical membrane materials. Improved understanding of the structure and thermodynamics of such systems is necessary for the development of structure-property relationships in applications for block copolymers, such as nanopatterning and electrochemical devices. To address the challenge of block copolymer thin film characterization over large areas, resonant soft X-ray scattering (RSoXS) has been applied to characterize order formation in copolymer thin films. Using theory and experiment, the dramatic chemical sensitivity of RSoXS to subtle differences in the bonding energies of different blocks of a copolymer is demonstrated. The unambiguous identification of structure and domain size in block copolymer thin films using RSoXS enables a quantitative comparison of the bulk block copolymer structure and domain size, leading to improved understanding of the impact of surfaces on block copolymer self-assembly. The self-assembly of block copolymer/ionic liquid mixtures has been characterized as a function of block copolymer composition and molecular weight, mixture composition, and temperature using small-angle X-ray scattering (SAXS), optical transmission characterization, wide-angle X-ray scattering (WAXS), and differential scanning calorimetry (DSC). The resulting phase behavior is reminiscent to that of block copolymer mixtures with a selective molecular solvent and lamellar, cylindrical, ordered spherical micelles, and disordered phases are observed. Analysis of order-disorder transitions and molecular weight scaling analysis qualitatively indicates that the segregation strength between block copolymer phases increases with ionic liquid loading. DSC characterization of the thermal properties of the block copolymer/ionic liquid mixtures reveals two composition dependent regimes. At high block copolymer concentrations, a "salt-like" regime corresponding to an increase in the block copolymer glass transition temperature is observed, while at intermediate block copolymer concentrations, a "solvent-like" regime corresponding to a decrease in the block copolymer glass transition temperature is observed. The distribution of ionic liquid within microphase-separated domains of a block copolymer has been characterized using contrast matched small-angle neutron scattering (SANS) and DSC. The ionic liquid is shown to partition selectively into domains formed by one block of a block copolymer in agreement with studies of the phase behavior of ionic liquid/block copolymer mixtures. Unexpected differences in ionic liquid partitioning are observed in mixtures containing a deuterated versus hydrogenated ionic liquid.
Download or read book Self assembly of Functional Amphiphilic Triblock Copolymer Thin Films written by Namrata Salunke and published by . This book was released on 2018 with total page 155 pages. Available in PDF, EPUB and Kindle. Book excerpt: "The concept of liquid wetting on solids is one of the most fundamental and fascinating phenomena understood in terms of physical chemistry, statistical physics, short and long-range forces, and fluid dynamics" - P. G. de Gennes. Monte Carlo simulations have shown that interfacial free energy between co-existing phases is strongly impacted by reducing system dimensionality, d, in thin films, the interfacial area ~L[superscript d-1]and linear dimension L[subscript z] cause logarithmic finite-size effects of order ln(L)/L[superscript d-1]and ln(L[subscript z])/L[superscript d-1]respectively. The unexplored coupling between these two phenomena in amphiphilic triblock copolymer systems forms the basis of this dissertation, with a view towards stimuli responsive properties of physico-chemical surfaces. This dissertation explores in detail the hypotheses conjoining these two phenomena in an amphiphilic triblock copolymer - FDF consisting of hydrophobic domain, F: poly(2-(N-ethylperfluorooctanesulfonamido) ethyl methylacrylate), and hydrophilic domain, D: poly(N,N'-dimethyl acrylamide) in thin film format. The effect of chemistry-based block copolymer phase separation and thin film confinement physics lead to a controlled wetting/non-wetting spatio-temporal transition in thin FDF films. Further, the effect of FDF film casting conditions, particularly the rate of solvent evaporation as well as annealing temperature and time were explored on surface phase-domain structure that allowed for control of the film wettability. A third aspect of the study examined the external stimuli response behavior of such systems via changes in film swelling, morphology and optical properties induced by humidity changes to which the block copolymer was strongly responsive. In situ grazing incidence small angle X-ray scattering (GISAXS) and specular reflectance experiments with controlled relative humidity (RH) were used to determine film and domain swelling in these amphiphilic copolymers. These results also indicated strong optical "artificial color" variation arising from the coupling of film finite-size interference. Confinement effects were observed to influence dynamic properties in FDF films including domain swelling and "active" structural color.
